ASHS 2025 Conference: Full Schedule

7:59am CDT

HSMP 2 - Oral Session

Tuesday July 29, 2025 7:59am - 8:00am CDT

Strand 11B

Presiding/Moderator

Abishkar Regmi

Graduate Research Assistant, Texas Tech University

Tuesday July 29, 2025 7:59am - 8:00am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants

8:29am CDT

GG 1 - Oral Session

Tuesday July 29, 2025 8:29am - 8:30am CDT

Foster 2

Speakers

Mujahid Hussain

Graduate Research Assistant, University of Florida

I am pursuing my PhD in the Horticultural Sciences Department, University of Florida in Dr. Kevin Folta's lab. My PhD project is related to exploring molecular basis of low chill apple cultivars with a focus on how genetic and regulatory mechanisms of low chill apple cultivars influence... Read More →

Tuesday July 29, 2025 8:29am - 8:30am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

8:30am CDT

GG 1 - Genetic diversity in low chill apple germplasm

Tuesday July 29, 2025 8:30am - 8:45am CDT

Foster 2

There is an urgent need to diversify high-value fruit crops in low-chill areas, especially as climate change decreases the number of chill hours in cropping areas. Apple is largely considered a temperate crop, yet a subset of germplasm exhibits strong flowering responses even after minimal chill. These genotypes originate from Israeli breeding programs, as well as heritage commercial varieties and backyard discoveries. Future breeding efforts will benefit from characterization of the genetic mechanisms that govern flowering in response to limited chill. In this study we hypothesized that examination of sequence polymorphisms and flowering associated gene sequence differences may permit grouping of low chill materials based on common mechanisms. Relatedness was examined using a series of simple sequence repeat markers (SSRs). In addition, genomic sequence from a number of low chill accessions, including Dorsett Golden, Shell of Alabama, and an early-flowering accession from Mississippi, was compared to publicly available reads from ‘Anna’ (low chill), moderate chill (‘Fuji’, ‘Gala’) and high chill (‘Honeycrisp’; ‘Antonovka’) varieties. Genomes were aligned to Golden delicious reference genome, and shared and unique variants were identified. The data show that all low and moderately low chill cultivars share common sequence polymorphisms not found in high-chill germplasm. Examination of flowering and dormancy-related genes shows common sequence polymorphisms shared within low chill materials that contrast against high chill genotypes. These include members of MADS-boxes family, Frigida family, Early bud break (AP2/ERF) family, auxin responsive factors, transcription factors DELLA family, FRIGIDA INTERACTING PROTEIN, and others. This study illuminates potential mechanisms of low-chill responses, opening opportunities for marker-assisted breeding and increased genetic diversity in development of low chill apple cultivars.

Speakers

Mujahid Hussain

Graduate Research Assistant, University of Florida

Co-authors

Jugpreet Singh

University of Florida, Tropical Research and Education Center

Kevin Folta

University of florida

Tuesday July 29, 2025 8:30am - 8:45am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Funding Source University of Florida Experiment Station

8:44am CDT

LOCSY 1 - Oral Session

Tuesday July 29, 2025 8:44am - 8:45am CDT

Foster 1

Speakers

Armando Villa-Ignacio

Colorado State University

Armando Villa-Ignacio is a Ph.D. student under Jennifer Bousselot Ph.D. in the Department of Horticulture and Landscape Architecture at Colorado State University. He received his B.S. in Conservation from SUNY-ESF and his M.S. in Horticulture at CSU. He is currently researching raspberry... Read More →

Tuesday July 29, 2025 8:44am - 8:45am CDT
Foster 1

Oral presentation, Local Food Systems 1

8:44am CDT

PNM 1 - Oral Session

Tuesday July 29, 2025 8:44am - 8:45am CDT

Strand 11B

Presiding/Moderator

Ester Cristina Ricken

University of Florida

Tuesday July 29, 2025 8:44am - 8:45am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

8:45am CDT

GG 1 - The Origin Story of Dorsett Golden apple; New Evidence from Horticultural Forensics

Tuesday July 29, 2025 8:45am - 9:00am CDT

Foster 2

Prior to the formal breeding programsof the 19th century, farmers contributed to apple (Malus× domestica Borkh.) breeding by selecting trees based on the desirable characteristics. The transcontinental seed spread was common, and modern breeding programs identified elite commercial trees and high quality fruits. There is a rekindling interest in low-chill apples, both as a high value crop in the USA Southeast, as well as development of new varieties to confront climate change. But the genetic record is poor. Dorsett Golden (DG) is low chill apple cultivar believed to have been discovered in The Bahamas by a Mrs. Dorsett in 1950. As legend has it, she was a jet-setting traveler that loved apples, and planted a set of trees when she relocated to the Bahamas. This allegedly led to the identification of ‘Dorsett Golden’. While this quickly became the accepted story, some questioned the claim. Observations of phenological data in DG trees next to other Israeli germplasm (e.g. ‘Anna’, ‘Ein Shemer’) led Dr. Wayne Sherman to posit in 1980 that DG’s origin was likely from the Israeli breeding program. To test this hypothesis, whole genome sequence from DG was compared to ‘Anna’ and other reference sequences in public databases. Consistent with Dr. Sherman’s 45 year old predictions, DG shares it’s most significant sequence similarity to ‘Anna’, and less with other low-chill varieties. The majority (~92%) of the total variants are in intergenic, upstream, downstream, or intronic regions suggesting recent divergence of ‘Anna’ and DG. The results are consistent with Dr. Sherman’s phenological data that suggest that DG possessed genetics more similar to Israeli genotypes than a chance seedling from Golden Delicious as legend describes. Most importantly, the study illustrates the power of genomic sequencing in selection of parents for low-chill apple crosses as well as debunking horticulutral methology.

Speakers

Mujahid Hussain

Graduate Research Assistant, University of Florida

Co-authors

Jugpreet Singh

University of Florida, Tropical Research and Education Center

Kevin Folta

University of florida

Tuesday July 29, 2025 8:45am - 9:00am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Funding Source University of Florida Experiment Station

8:45am CDT

LOCSY 1 - Evaluating Leafy Green Production Under Opaque and Bifacial Silicon Modules in a Rooftop Agrivoltaics System

Tuesday July 29, 2025 8:45am - 9:00am CDT

Foster 1

With populations rising and cities expanding, it is necessary to consider new ways to supplement current energy and food systems. Urban agriculture has the potential to enhance food systems, energy production and stormwater management within urban areas. This can be achieved by implementing rooftop agrivoltaics (RAV), a combination of rooftops, agriculture, and photovoltaics. This study evaluates the growth and yield of leafy greens in RAV by examining how shade from photovoltaic arrays influences leafy green production. An RAV system was built at the CSU Spur Campus in Denver, Colorado, featuring a 45 cm deep substrate and three treatments: full sun, opaque silicon PV modules, and bifacial silicon PV modules. Leafy greens—arugula, kale, lettuce, spinach, and Swiss chard—were germinated and transplanted in randomized rows, with environmental conditions monitored continuously using HOBO sensors. Fresh weight, dry weight, stomatal conductance, and plant size at harvest were collected, and statistical analysis was conducted using two-way ANOVA to assess the effects of the treatments on each crop type. Leafy greens grown under the PV treatments had reduced stomatal conductance compared to the full sun treatment. The plant size at harvest was also higher in lettuce and spinach grown under the PV module treatments compared to the full sun. Fresh and dry weight of plants grown under the opaque and bifacial PV module treatments, however, were reduced compared to the full sun treatment. By understanding these interactions, the research aims to determine the feasibility of RAV systems for urban agriculture.

Speakers

Armando Villa-Ignacio

Colorado State University

Co-authors

Jennifer Bousselot

Colorado State University

Maria Chavez

New Mexico State University

Tuesday July 29, 2025 8:45am - 9:00am CDT
Foster 1

Oral presentation, Local Food Systems 1

Subject Local Food Systems

8:45am CDT

PNM 1 - Potato biomass P uptake and tuber yield response to P-fertilizer in northeast Florida

Tuesday July 29, 2025 8:45am - 9:00am CDT

Strand 11B

Compared to other crops, potatoes have a low phosphorus (P) use efficiency (PUE). This characteristic, combined with low soil P availability, can impact the yield. The common method to verify the availability of a nutrient to the crops is through soil testing. In 2012, Florida transitioned from Mehlich-1 (M1) to Mehlich-3 (M3) for soil P recommendations; however, the updated M3 guidelines indicate that no additional P should be applied. Many other studies have confirmed that yield responses to P fertilizer continue to be observed. The objective of this study was to identify a P fertilization strategy involving multiple applications and using two different sources of P-fertilizer to increase potato yield and PUE. A field experiment with nine treatments and four replications was established in Hastings Agricultural Extension Center-HAEC/IFAS/UF in three areas with different soil P levels, 118, 179, and 219 mg/kg P (M3). These areas were cultivated with the potato cultivar Atlantic during the 2024 and 2025 growing seasons. A single rate of 120 lb/ac of P2O5 of granular phosphate was applied at 30 and 15 days before planting, at planting, and at 25 and 50 days after planting (DAP). The same P-rate was also split into 40 and 60 lb/ac of P2O5 applied at 0, 25, 50 DAP, and 0 and 25 DAP, respectively. In addition, a liquid P-source was applied using this same split application and times. At the harvest, tubers were graded according to USDA size standards, and specific gravity, total, and marketable yields were measured. To calculate PUE, the total yield was divided by the initial soil P content plus the applied P fertilizer. There were no significant differences in total yield as a function of the application timing within each area, as well as for specific gravity. The PUE significantly decreased with the increase in soil initial P level. In 2024, the area with the lowest initial soil P concentration had the highest yield, producing 332 cwt/ac, while the area with the highest initial P concentration produced 268 cwt/ac of potatoes, and the medium initial soil P area produced 324 cwt/ac. In 2025, the area with the highest initial soil P concentration produced 332 cwt/ac, while the lowest area produced 327 cwt/ac, and the medium initial soil P area had the lowest yield, producing 308 cwt/ac. The results of this study may support updating Florida’s recommendation guidelines to enhance P-fertilizer use efficiency and crop yield.

Speakers

Ester Cristina Ricken

University of Florida

Co-authors

Judyson de Matos Oliveira

University of Florida

Lincoln Zotarelli

University of Florida

Tuesday July 29, 2025 8:45am - 9:00am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv

8:59am CDT

CHEX 1 - Oral Session

Tuesday July 29, 2025 8:59am - 9:00am CDT

Strand 12A

Presiding/Moderator

Karen Stauderman

Commercial Horticulture Agent III, UF/IFAS Extension Volusia County

Tuesday July 29, 2025 8:59am - 9:00am CDT
Strand 12A

Oral presentation, Commercial Horticulture 1

8:59am CDT

HSMP 1 - Oral Session

Tuesday July 29, 2025 8:59am - 9:00am CDT

Strand 10

Presiding/Moderator

Clinton Shock

Scientific Ecological Services

Tuesday July 29, 2025 8:59am - 9:00am CDT
Strand 10

Oral presentation, Herbs; Spices and Medicinal Plants 1

8:59am CDT

WCPM 1 - Oral Session

Tuesday July 29, 2025 8:59am - 9:00am CDT

Strand 12B

Presiding/Moderator

Muneeb Elahi Malik

University of Georgia

Tuesday July 29, 2025 8:59am - 9:00am CDT
Strand 12B

Oral presentation, Weed Control and Pest Management 1

9:00am CDT

CHEX 1 - Profiting from Cultural Diversity: Exploring Cut Marigold Flowers as a New Crop for Florida

Tuesday July 29, 2025 9:00am - 9:15am CDT

Strand 12A

Introduction and Background: Florida, experiencing rapid population growth with an influx of 1,218 new residents daily, presents abundant opportunities for agricultural diversification, particularly in niche markets. The ceremonial flower industry, catering to cultural and traditional practices, offers a unique avenue for innovation. Marigold flowers (Tagetes erecta), widely celebrated in Asian, Hispanic, and Hindu cultures, hold significant potential as a profitable crop within Florida's burgeoning cut flower sector. The demand for marigolds spans diverse occasions, including festivals, weddings, and religious ceremonies, making them an ideal candidate for market expansion. This study investigates the economic viability of six marigold cultivars by assessing their performance in terms of market potential, yield, and profitability, aiming to provide growers with actionable insights for Florida's agricultural industry. Objectives: (a) Evaluate six marigold cultivars during a spring field trial to identify the top two cultivars suitable for cut flower production in Florida. (b) Assess marketability by analyzing critical factors such as flower size, yield, and profitability. Methods: Six marigold cultivars—Garuda Yellow, Chedi Orange, Garuda Deep Gold, Oriental Deep Gold, Sumati Orange, and Mayan Orange—sourced from Ameriseed®, were evaluated in a spring trial conducted in Lake County, FL. Seeds were sown on 21 February 2023 in 72-cell packs containing a custom growing mix. Transplants were moved to field plots on 28 March 2023. Fertilization strategies combined Miracle-Gro liquid fertilizer with time-release granular fertilizers to ensure optimal plant growth. Flowers were harvested bi-weekly between 18 April and 27 June 2023. Key metrics, including flower size and yield, were subjected to statistical analysis to identify top-performing cultivars. Results: Garuda Yellow, Garuda Deep Gold, and Oriental Deep Gold produced the largest flowers, measuring 7.73 mm, 7.75 mm, and 7.18 mm in diameter, respectively. However, Garuda Deep Gold's yield was the lowest among the cultivars, limiting its profitability. Conversely, Garuda Yellow, Oriental Deep Gold, and Sumati Orange demonstrated robust yields, making them ideal candidates for large-scale production. Implications: This study underscores the viability of marigolds as a profitable crop for Florida's cut flower industry, particularly in niche cultural markets. Cultivating multiple cultivars not only diversifies production but also extends the blooming season, enhancing profitability. By leveraging the cultural significance of marigolds, Florida growers can explore new markets while fostering economic growth and cultural preservation. This research equips farmers with practical recommendations to strengthen Florida's agricultural landscape.

Speakers

Karen Stauderman

Commercial Horticulture Agent III, UF/IFAS Extension Volusia County

Co-authors

David Norman

UF/IFAS Mid Florida Research

Edzard van Santen

University of Florida

Tuesday July 29, 2025 9:00am - 9:15am CDT
Strand 12A

Oral presentation, Commercial Horticulture 1

Subject Commercial Horticulture
Poster # csv

9:00am CDT

GG 1 - Genome-wide study of Salt Tolerance in USDA Tomato Germplasm at Seedling Stage

Tuesday July 29, 2025 9:00am - 9:15am CDT

Foster 2

Salinity is a major constraint on tomato crop production and is increasingly intensified by changing climate conditions. This study aimed to develop superior salt-tolerant tomato cultivars by evaluating genetic variation in salt tolerance, identifying associated single-nucleotide polymorphism (SNP) markers through genome-wide association studies (GWAS), and performing genomic prediction (GP). A total of 265 tomato accessions from the USDA germplasm collection were evaluated at the seedling stage under controlled greenhouse conditions with saline stress (200 mM NaCl). Nineteen accessions were identified as salt-tolerant, exhibiting leaf injury scores ≤3.0 (on a 1–5 scale) and chlorophyll reduction of

Speakers

Ainong Shi

Associate Professor, University of Arkasnas

Dr. Ainong Shi is a faculty member in the Department of Horticulture at the University of Arkansas. His research laboratory specializes in plant breeding and genetics, particularly focusing on vegetable crops such as arugula, cowpea, and spinach for cultivar and germplasm development... Read More →

Co-authors

haizheng xiong

University of Arkansas

Hanan Alkabkabi

university of arkansas

Ibtisam Alatawi

University of Arkansas

Kai-Shu Ling

USDA-ARS

Kenani Chiwina

University of Arkansas

Qun Luo

university of arkansas

Tuesday July 29, 2025 9:00am - 9:15am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Poster # csv

9:00am CDT

HSMP 1 - Fenugreek Cultivation on the Delmarva Peninsula

Tuesday July 29, 2025 9:00am - 9:15am CDT

Strand 10

Fenugreek (Trigonella foenum-graecum) is a multifaceted and ancient herb widely utilized in culinary, medicinal, and industrial sectors. This research investigated Fenugreek cultivation on the Delmarva Peninsula, focusing on climatic requirements, planting methodologies, growth stages, and prevalent diseases. Results indicated that high-density planting was crucial for effective weed management. Conversely, crop failures were associated with rainfed cultivation and flood irrigation practices. The crop demonstrated the capacity for thrice-yearly harvesting and exhibited frost tolerance. Notably, during the initial years (2022-2023), no diseases were observed, and no herbicides, pesticides, or fungicides were applied, ensuring a healthy yield. A community survey among local Asian residents highlighted a strong interest in purchasing locally grown Fenugreek leaves. To promote cultivation, 'Fenugreek Days' were organized at the University of Maryland Eastern Shore, fostering community engagement. Additionally, community members contributed culinary recipes utilizing Fenugreek leaves, and educational YouTube videos were produced for broader dissemination. Fenugreek cultivation presented significant potential for agricultural diversification and sustainable crop production. Enhanced knowledge of its agronomic requirements and challenges could assist farmers in optimizing yields, thereby ensuring the consistent availability of this versatile herb for diverse applications.

Speakers

Naveen Dixit

University of MD Eastern Shore

Tuesday July 29, 2025 9:00am - 9:15am CDT
Strand 10

Oral presentation, Herbs; Spices and Medicinal Plants 1

Subject Herbs Spices and Medicinal Plants
Funding Source NE-SARE

9:00am CDT

LOCSY 1 - Concentrated Organic and Synthetic Fertilizers for Peppers Grown in Extensive Green Roof Environments

Tuesday July 29, 2025 9:00am - 9:15am CDT

Foster 1

Extensive green roof mediums are shallow with low nutrient content and oftentimes susceptible to rapid drainage, which results in the use of concentrated synthetic fertilizers that can have a negative affect on runoff water quality. Therefore, a study was conducted on ‘Sweet Hungarian’ pepper (Capsicum annuum) over three growing seasons to compare organic and conventional synthetic fertilizers at manufacturer recommended rates for their impacts on fruit yield, leaf chlorophyll content (SPAD), and plant vigor on a green roof having an expanded clay medium. The fast release synthetic fertilizer utilized produced the highest yield per unit fertilizer cost while the controlled release synthetic fertilizer had the highest overall yield but at much higher cost compared to other treatments. Bloodmeal had the highest yield among organic treatments and was similar to the fast release synthetic. Although SPAD was correlated with yield differences among treatments, plant vigor rating better explained these variations in yield. Pre and post growing season medium analyses revealed several interesting trends over the three-years of the study regarding pH, soil organic matter and nutrient contents that will be reviewed in detail. Additionally, an analysis of yield tradeoffs with fertilizer product costs among several popular organic and synthetic fertilizers for a nutrient-demanding crop grown in an extensive green roof environment will also be discussed. Green roof agriculture is a promising solution to enhance sustainability, especially where growing space is limited, but nutrient management is an important part of this system that needs to be sufficiently considered.

Speakers

Alan Walters

Southern Illinois University

Co-authors

Amir Sadeghpour

Southern Illinois University-Carbondale

John W. Groninger

Southern Illinois University-Carbondale

Karen S. Midden

Southern Illinois University-Carbondale

Richard Little

Washington State University

Tuesday July 29, 2025 9:00am - 9:15am CDT
Foster 1

Oral presentation, Local Food Systems 1

Subject Local Food Systems
Poster # csv

9:00am CDT

PBIG 1 - Testing RITA® Temporary Immersion Bioreactor System For Germination Of Cornus florida Somatic Embryos

Tuesday July 29, 2025 9:00am - 9:15am CDT

Strand 11A

Powdery mildew, caused by the fungus Erysiphe pulchra, is one of the most serious diseases affecting the popular ornamental tree flowering dogwood (Cornus florida). Employing gene editing techniques such as CRISPR to introduce powdery mildew resistance by inactivating the Mildew Locus O (MLO) gene requires an efficient genetic transformation system. This novel research will fill a critical gap in our knowledge of flowering dogwood biotechnology. Previous research efforts have genetically transformed embryogenic dogwood cultures, now we are aiming to produce transgenic plantlets. Recent research focused on using the RITA® temporary immersion bioreactor system for testing germination of somatic embryos and conversion to plants. The primary test was the impact of the plant growth regulator (PGR) gibberellic acid (GA3). For this experiment, we analyzed the impact of different environmental light exposures on dogwood embryo stress levels by observing anthocyanin production. The starting material was unwashed callus transformed with the GUS reporter gene and subjected to one of three RITA® treatments to examine the influence of varying light levels. Treatments included full darkness, continuous low light, and a combination of both light conditions for different durations of time. Few somatic embryos germinated from the treatment with 60 days of full darkness, but the anthocyanin stress was absent. We observed the same result for constant low light exposure except for exponential growth of the transgenic callus. The treatment in which the somatic embryos were in full darkness for 30 days and switched to low light for another 30 days showed a higher germination rate, but there were increased signs of anthocyanin stress. Implementation of this research will assist in the optimization of the production of plantlets from dogwood cultures transformed with a CRISPR-Cas9 construct that can inactivate the MLO gene to obtain powdery mildew resistance.

Speakers

Heather Gladfelter

University of Georgia

Co-authors

Dayton Wilde

University of Georgia

Julianne Patterson

University of Georgia

Tuesday July 29, 2025 9:00am - 9:15am CDT
Strand 11A

Oral presentation, Plant Biotechnology 1

Subject Plant Biotechnology
Poster # csv
Funding Source University of Georgia Horticulture Department

9:00am CDT

PNM 1 - Cellular distribution of elements in three Macadamia Species from Australia

Tuesday July 29, 2025 9:00am - 9:15am CDT

Strand 11B

Macadamia integrifolia and M. tetraphylla, unlike M. ternifolia, are known for their edible nuts. All three species over-accumulate the trace metal nutrient manganese (Mn) in their shoots. This study seeks to examine tissue- and cellular-level distribution of Mn and other plant nutrients in the three Macadamia species. The distribution of Mn, calcium (Ca), iron (Fe) and potassium (K) were investigated in whole leaves and cross-sections of roots, petioles and lea ves using synchrotron-based X-ray Fluorescence Microscopy (µXRF) in M. integrifolia, M. tetraphylla and M. ternifolia. The results show Mn sequestration primarily in the leaf and midrib palisade mesophyll cells of all three species. Leaf interveinal regions, root cortical cells and phloem cells were also found to be Mn-loaded. The current study confirms earlier findings but further reveals that Mn is concentrated in the vacuoles of mesophyll cells owing to the exceptional resolution of the synchrotron µXRF data, and the fact that fresh hydrated samples were used. New insights gained here into Mn compartmentalisation in these highly Mn-tolerant Mac adamias expand knowledge about potentially toxic overaccumulation of an essential micronutrient, which ultimately stands to inform strategies around farming edible species in particular.

Speakers

Farida Abubakari

The University of Queensland

Tuesday July 29, 2025 9:00am - 9:15am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv

9:00am CDT

WCPM 1 - Precision Targeting of a High-Power Diode Laser Using a Clavel-Based Delta Parallel Robot for Weed Elimination

Tuesday July 29, 2025 9:00am - 9:15am CDT

Strand 12B

Weed overgrowth in high-value crops like onions remains a major challenge due to labor costs, herbicide resistance, and environmental concerns. Robotic laser-based weed control offers a precise, chemical-free alternative capable of targeting individual weeds while protecting crop health and the environment. This research introduces the application of a Clavel-based delta parallel robot for precision weed elimination using a high-power diode blue light laser. The delta robot employed in this study features three degrees of freedom and is capable of achieving maximum accelerations up to 20 m/s². It consists of aluminum proximal arms connected to servo motors and carbon fiber distal arms, reducing weight and enhancing agility. These servo motors are housed within a top base constructed from ABS 3D printed parts. Movement calculations and inverse kinematics are managed by an embedded ARM Cortex-M3 controller integrated with the servo motors. A 450 nm, 10W diode laser serves as the robot's end-effector, actuated using the Transistor-transistor logic (TTL) signals. Both robot movements and laser activation are simultaneously controlled through an external Arduino Mega 2560 microcontroller, leveraging a custom-developed C library to ensure workspace safety and precision. Experiments conducted to assess positional accuracy involved 100 trials, resulting in a mean radial positional error of 0.83 mm. Further experiments measured laser exposure time and stand-off distance. The results showed complete weed destruction in less than 6 seconds at distances of up to 100 mm. These results support the robot's effectiveness in targeted weed management for precision agriculture.

Speakers

Muneeb Elahi Malik

University of Georgia

Co-authors

MD Sulton Mahmud

University of Georgia

Tuesday July 29, 2025 9:00am - 9:15am CDT
Strand 12B

Oral presentation, Weed Control and Pest Management 1

Subject Weed Control and Pest Management
Poster # csv

9:15am CDT

CHEX 1 - Cutting Edge Technologies: Assessing ROI and Safety of Autonomous Mowers

Tuesday July 29, 2025 9:15am - 9:30am CDT

Strand 12A

The landscape industry is facing increasing labor shortages and rising operational costs, leading to a growing interest in automation. Autonomous mowing technology has the potential to address these challenges by reducing labor dependency and increasing efficiency. However, there is limited research evaluating the return on investment (ROI) and performance of these mowers in real-world conditions. One of the primary concerns for landscape professionals is whether autonomous mowers can operate effectively across various terrains and obstacle-heavy environments while maintaining efficiency and safety standards. This study assessed the performance of autonomous and manual mowers by measuring mowing time, energy consumption, and adaptability across different landscapes. Two mower types were tested: a manual battery-powered mower and an autonomous gas-powered mower. Testing was conducted on two landscape designs—a simple square plot and a complex plot with obstacles—to analyze variations in efficiency, along with two turf types. There was no significant difference in either mower’s performance on bermuda or ryegrass. Preliminary results indicate that manual mowers perform significantly faster than autonomous mowers, and the autonomous mowing time increases significantly in complex landscapes. The energy consumption of the gas autonomous mower is higher than that of manual battery-powered mowers. Factors such as sensor reliability and obstacle detection remain areas of concern. The collected data provides insight into the operational efficiency of autonomous mowers and their potential impact on the landscape industry. Future research will focus on calculating ROI values by incorporating cost analysis and industry data, as well as investigating safety protocols related to obstacle detection and avoidance to enhance autonomous mowing technology for commercial use.

Speakers

Landon Erbrick

Auburn University

Co-authors

Mark Hoffman

Auburn University

Paul Bartley

Auburn University

Tanzeel Rehman

AUBURN UNIVERSITY

Tuesday July 29, 2025 9:15am - 9:30am CDT
Strand 12A

Oral presentation, Commercial Horticulture 1

Subject Commercial Horticulture
Funding Source USDA-AMS

9:15am CDT

GG 1 - Genome-wide Association Study of Salt Tolerance at the Seedling Stage in Lettuce

Tuesday July 29, 2025 9:15am - 9:30am CDT

Foster 2

Lettuce (Lactuca sativa L.) is one of the most important leafy vegetable crops worldwide. Soil salinity adversely affects lettuce production leading to considerable yield losses. Identification of genetic loci controlling salt tolerance will facilitate molecular marker development and thereby assist breeders in developing lettuce cultivars with salt tolerance. Accordingly, we conducted a genome-wide association study (GWAS) to identify marker-trait association for salt tolerance at the seedling stage using 409 diverse lettuce accessions and 56,820 high-quality single nucleotide polymorphism (SNP) markers obtained through genotype-by-sequencing technology. Several statistical models, including GLM, MLM, FarmCPU, and BLINK were employed using the GAPIT version 3 software tool for GWAS. Based on three important seedling stage traits affected by salinity, i.e., shoot fresh weight (FW), shoot dry weight (DW) and chlorophyl index (SPAD), 13 significant salt tolerance related SNPs representing 10 QTLs were identified on lettuce chromosomes 1, 3, 4, 6, 7, 8 and 9. Notably, a major QTL on chromosome 4, encompassing four significant SNPs within a 116 bp region of the lettuce reference genome (v8), explained 49% of the phenotypic variation for FW. The identified salt tolerance-related QTLs provide a valuable resource for developing assays for marker-assisted selection to breed lettuce cultivars with improved salt tolerance.

Speakers

Modan Das

USDA-ARS

Co-authors

Beiquan Mou

USDA-ARS

Ivan Simko

USDA-ARS

Tuesday July 29, 2025 9:15am - 9:30am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Poster # csv

9:15am CDT

HSMP 1 - Purple Roof Majesties: Evaluation of Crocus sativus L. on Green Roofs in the Rocky Mountains

Tuesday July 29, 2025 9:15am - 9:30am CDT

Strand 10

Green roof and rooftop agrivoltaics systems have been gaining popularity in urban areas over the past decade for their ability to improve food security in populous cities. Saffron (Crocus sativus L.), a high value perennial herb historically cultivated in arid mountainous regions of the Middle East, thrives under similar abiotic stressors experienced on green roofs such as limited precipitation, nutrient poor, fast draining soils, and high solar radiation. Little research currently exists on saffron cultivation in green roof systems or under shade. This study tests the hypothesis that light availability limits C. sativus performance in rooftop agrivoltaics systems by quantifying the effects of shade on saffron yield (dried stigmas) and vegetative growth. Two-hundred saffron corms were studied across ten solar treatments in nine rooftop agrivoltaics plots and one at grade control plot- five at CSU Spur Campus in Denver, Colorado, and five at the CSU Foothills Campus in Fort Collins, Colorado. Corms were planted 15 cm deep with 10 cm spacing and received supplemental hand watering weekly. Environmental data collected included substrate volumetric water content, substrate surface and subsurface temperatures, and solar radiation. Bi-Weekly observations and harvest measured floral timing, abundance, along with fresh and dry stigma weights (g). Vegetative measurements on leaf length were taken after the flowering period. Overall, shade had a significant impact on the floral yield (p

Speakers

Reece Bailey

Colorado State University

Tuesday July 29, 2025 9:15am - 9:30am CDT
Strand 10

Oral presentation, Herbs; Spices and Medicinal Plants 1

Subject Herbs Spices and Medicinal Plants
Poster # csv

9:15am CDT

LOCSY 1 - Water Management is Crucial for Culinary Herbs in an Extensive Green Roof Environment

Tuesday July 29, 2025 9:15am - 9:30am CDT

Foster 1

Urban agriculture is important to provide sources of local food for urban residents. Extensive green roofs can be used to provide spaces for local agriculture in these urban environments, although extreme conditions in these environments can be challenging for edible crop production. Moisture in these environments are often the most limiting factor influencing growth and often create problems for urban agriculture activities. Therefore, two culinary herb experiments were conducted on the Southern Illinois University – Carbondale extensive green roof located on top of the agriculture building to evaluate the influences of various water management strategies on resulting plant growth and overwintering. Results indicated weekly irrigation was critical to increase both annual (basil) and perennial (sage and thyme) plant vigor compared to biweekly watering. Although the use of pine bark mulch improved basil growth, sage and thyme growth was not affected by its use. The addition of hydrogels in the medium for water retention did not influence resulting plant growth for either the annual or perennial herbs evaluated. Our results highlight the importance of consistent water supply for growth and overwintering success for both annual and perennial culinary herbs grown in an extensive green roof environment. Although many culinary herbs thrive in dry, well-drained conditions, mimicking their native Mediterranean climate, water management strategies are still important considerations for sustaining culinary herb production on extensive green roofs.

Speakers

Alan Walters

Southern Illinois University

Co-authors

Hunter M. Christenson

Southern Illinois University-Carbondale

Kaitlyn Lamaster

Southern Illinois University

Steven M. Still

Southern Illinois University-Carbondale

Tuesday July 29, 2025 9:15am - 9:30am CDT
Foster 1

Oral presentation, Local Food Systems 1

Subject Local Food Systems
Poster # csv

9:15am CDT

PBIG 1 - FreshID: Machine Learning for Fruits and Vegetables Quality Evaluation

Tuesday July 29, 2025 9:15am - 9:30am CDT

Strand 11A

Fresh fruits and vegetables are invaluable for human health, but their quality deteriorates before reaching consumers during distribution due to ongoing biochemical processes and compositional changes. The current lack of any objective indices for defining “freshness” of fruits or vegetables limits our capacity to control product quality and leads to food loss and waste. In this work, we undertook interdisciplinary research to address plant science challenges related to food security and human health. This work has leveraged machine learning technologies and multi-omics tools to understand post-harvest senescence and microbial spoilage of fresh produce for the purpose of developing a simple imaging “FreshID” device to evaluate fruit and vegetable quality. In essence, we are proposing a comprehensive research program to identify proteins and compounds as “freshness-indicators” and to aid development of an innovative and easy-to-use accessibility tool to accurately estimate the freshness and/or contamination of produce. The goal of the proposed research will be advances in both basic research and applied science. Such a tool would allow a new level of post-harvest logistics, supporting availability of high-quality, nutritious, fresh produce.

Speakers

Tie Liu

University of Florida

Tuesday July 29, 2025 9:15am - 9:30am CDT
Strand 11A

Oral presentation, Plant Biotechnology 1

Subject Plant Biotechnology
Poster # csv
Funding Source NIFA

9:15am CDT

PNM 1 - Comparative Analysis of Alternative Iron Sources and Rates for Iron Biofortification in Pea and Radish Microgreens

Tuesday July 29, 2025 9:15am - 9:30am CDT

Strand 11B

Iron (Fe) is an essential micronutrient involved in numerous metabolic processes and is vital for proper growth and development in plants and humans. However, in humans, dietary Fe deficiency is one of the leading micronutrient deficiencies affecting approximately 10 million people in the U.S., and over 1 billion people worldwide. Fe deficiency can lead to many health complications, including Fe deficiency anemia. Pregnant women and young children are particularly at risk for developing Fe deficiency and severe consequences can result in maternal and neonatal deaths during pregnancy. Improving dietary Fe intake is critical and utilizing agronomic approaches to enhance Fe levels in plants could be a viable, sustainable solution. Microgreens are a noteworthy nutritional source and are a convenient candidate crop for agronomic Fe biofortification as they can be grown quickly, have low anti-nutrient levels, require fewer inputs for cultivation, and can be consumed raw. Conventional Fe fertilizers like ferrous sulfate (FeSO4) have been widely used in agriculture and research for Fe biofortification, however in oxidizing and alkaline conditions, plant Fe uptake is reduced, even with sufficient levels present in the environment. Various studies have reported the use of Fe chelate and Fe nanofertilizers as an alternative, more efficient option for improving Fe availability, than conventional Fe fertilizers. However, there is limited information comparing multiple Fe fertilizer sources and their effectiveness in Fe biofortification in microgreens. Herein, we investigate, in a soilless system, the effect of different Fe sources (Ferrous sulfate, Ferric sulfate, Fe-EDTA, Fe-EDDHA, Fe-NP) applied via fertigation at different concentrations (0, 15, 30, 45 mg/L of Fe) on the Fe content in radish and pea microgreens. We found that Fe-EDTA was the most effective fertilizer source and increased Fe content by 2-3-fold in pea microgreens and 3-5-fold in radish microgreens, compared to the untreated control. Additionally, Fe-EDTA treatments increased Zn concentration by 5-20% in pea microgreens. In radish microgreens, however, we found that the same treatments showed slight phytotoxicity symptoms and reduced fresh and dry biomass. Further evaluation of Fe sources and concentrations is needed to avoid compromising yield and nutritional quality. However, these results suggest that using alternative Fe fertilizers through fertigation can improve Fe concentration in pea and radish microgreens more effectively than standard sources. Fe-enriched microgreens may be used as functional foods to combat Fe malnutrition at both individual household and larger community scales.

Speakers

Rishi Ravichandran

Student, Pennsylvania State University

Co-authors

Francesco Di Gioia

Pennsylvania State University

Tuesday July 29, 2025 9:15am - 9:30am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv
Funding Source Open Philanthropy through the grant Food Resilience in the Face of Catastrophic Global Events with the support of the PDA SCBG award # C940001096 and the USDA NIFA and Hatch Appropriations under Project #PEN04723 and Accession #1020664.

9:15am CDT

WCPM 1 - Enhancing Pre-Emergence Herbicide Tolerance in Tomato Transplants via Novel Seed and Root-Targeted Safening Strategies

Tuesday July 29, 2025 9:15am - 9:30am CDT

Strand 12B

The use of pre-emergence herbicides under plastic mulch is an effective strategy for weed control in plasticulture beds in vegetable production systems. S-metolachlor is a pre-emergence herbicide labeled for application in soil prior to laying plastic mulch in tomato production in Florida. However, the risk of crop injury has limited its adoption in plasticulture systems, highlighting the need for crop-safe herbicide application approaches. This study aimed to evaluate the potential of herbicide safeners including chemical seed treatments and activated charcoal in mitigating tomato transplant injury from herbicides such as S-metolachlor. A greenhouse experiment was conducted at the Southwest Florida Research and Education Center (SWFREC) in Immokalee, FL, across two trials: March–June (Trial I) and August–November (Trial II) of 2024. Field soil was collected and used in pots for both trials. Treatments included tomato seed pre-treatments with benoxacor or fenclorim, and transplant root treatments with activated charcoal applied either as a root dip or poured into planting holes. All treated transplants and non-treated controls were grown in S-metolachlor-treated soil. Seed pre-treatment with benoxacor or fenclorim reduced crop injury by over 63% compared to non-treated controls. Activated charcoal applied to transplant roots reduced injury by 40–70% in Trial I and by over 70% in Trial II. Chlorophyll content was consistently higher in safener-treated plants, with activated charcoal increasing levels by more than 16% at 2 weeks after transplanting (WAT) and by 11–20% at 6-WAT. Similarly, benoxacor and fenclorim treatments improved chlorophyll content by 12–19% at 6-WAT. Root biomass in non-treated transplants was reduced by 56–70% due to S-metolachlor exposure. In contrast, both activated charcoal and seed-applied safeners helped preserve root biomass, with benoxacor and fenclorim reducing root weight loss by 65–70% compared to untreated controls. Overall, the results demonstrate that both seed-applied (benoxacor, fenclorim) and root-applied (activated charcoal) safeners are effective in mitigating S-metolachlor injury in tomato transplants and may offer viable strategies for enhancing crop safety in plasticulture-based vegetable production.

Speakers

Ramdas Kanissery

University of Florida

Co-authors

Ruby Tiwari

University of Florida

Tuesday July 29, 2025 9:15am - 9:30am CDT
Strand 12B

Oral presentation, Weed Control and Pest Management 1

Subject Weed Control and Pest Management
Funding Source Florida Department of Agriculture and Consumer Services/Florida Specialty Crop Block Grant

9:30am CDT

CHEX 1 - Strengths of Tested Almond Varieties and Selections in Three California Trials

Tuesday July 29, 2025 9:30am - 9:45am CDT

Strand 12A

Evaluating cultivars is of such importance that the California almond industry has funded four generations of variety trials over the last several decades. These multi-site field trials have evaluated all the varieties that are now the most widely planted in California. Field evaluation trials are helpful for revealing which varieties are promising. Thirty named cultivars and numbered breeder selections were planted in three replicated commercial orchards across California’s Central Valley in 2014 (third generation trial). Of these 30, thirteen varieties continue to be evaluated through 2025. The thirteen varieties being evaluated through the 12th season show at least moderate yield and do not possess a fatal flaw such as low yield, lack of breeder interest, extremely early bloom timing, or poor harvestability. Additional evaluation measures have included intercepted canopy photosynthetically active radiation, hull split timing, and disease susceptibility. From these thirteen varieties and selections one numbered selection ‘Y116-161-99’ from the USDA has been commercially released as ‘Yorizane’. This self-fertile variety has been gaining industry interest and is beginning to be planted more widely. A second self-fertile USDA numbered selection ‘Y117-91-03’ with high yield, few kernel defects, and no major flaws documented after eleven years of evaluation is slated to be named and released to nurseries for propagation in late 2025. Two of the eleven remaining varieties, are industry standards, including the top yielding, and nearly 150-year-old variety ‘Nonpareil’. Potential for adoption remains for some of the remaining nine varieties under evaluation, particularly as pollinizers for ‘Nonpareil’.

Speakers

Luke Milliron

University of California Agriculture Natural Resources

Co-authors

Phoebe Gordon

University of California Cooperative Extension

Roger Duncan

UCCE Stanislaus

Tuesday July 29, 2025 9:30am - 9:45am CDT
Strand 12A

Oral presentation, Commercial Horticulture 1

Subject Commercial Horticulture
Funding Source Almond Board of California

9:30am CDT

GG 1 - Transcriptomics reveals candidate genes associated with high temperature stress tolerance in chile pepper (Capsicum annum)

Tuesday July 29, 2025 9:30am - 9:45am CDT

Foster 2

Chile pepper (Capsicum annuum) is widely produced and consumed, but farmers face significant challenges associated with high temperature stress. Tolerance to high temperatures is a phenotype comprised of numerous component traits each of which contribute to the overall performance of the plant. Our aim was to identify the key mechanisms associated with heat stress response in the leaves and in the floral organs of chile pepper. One-month-old plants of heat-sensitive (AVPP1609-038) and -tolerant (AVPP1609-015) recombinant inbred line (RIL) of chile pepper were subjected to heat stress (38 and 28°C day and night temperatures) and control conditions (32 and 24°C day and night temperatures) in growth chambers with a 14-hour photoperiod. Leaf and floral bud samples were collected for RNA extraction at 11 and 18 days after treatment, respectively, with four biological replicates per tissue. Differentially expressed genes (DEGs) were identified by comparing tolerant and sensitive RILs across treatments and tissues. For the heat-tolerant AVPP1609-015 under heat stress, 1,118 DEGs were identified, with 649 specific to floral buds, 381 in leaves, and 88 shared between the two tissues. Biological processes such as RNA splicing and heat acclimation were predominantly upregulated in floral buds, while lipid catabolism was enhanced in leaves. Developmental processes were consistently suppressed in both tissues for the RILs under heat stress conditions. For the heat-tolerant AVPP1609-015 nuclease activity was strongly suppressed, likely to preserve nucleic acid integrity under heat stress. Hormonal regulation showed tissue specificity, with salicylic acid playing a pivotal role in leaves and ethylene in floral buds, potentially associated with flower abscission. Additionally, key transcription factors associated with heat tolerance were identified. While some mechanisms of heat tolerance were shared between tissues, distinct responses were observed as well, suggesting the need for different breeding approaches to enhance heat tolerance in vegetative and reproductive tissues of chile pepper. These findings provide valuable insights for developing heat-resilient chile pepper and a foundation for future research.

Speakers

Derek Barchenger

World Vegetable Center

Co-authors

Fang-Min Chang

National Chung Hsing University

Jesish Ojha

World Vegetable Center

Lourena Arone Maxwell

World Vegetable Center

Ming-Ren Yen

National Chung Hsing University

Swaroop KO

University of Agricultural Sciences, Dharwad

Yu-Ming Hsu

Université Paris-Saclay

Yu-Shin Nai

National Chung Hsing University

Tuesday July 29, 2025 9:30am - 9:45am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Funding Source This work was funded by APSA-WorldVeg Consortium Members and the long-term strategic donors to the World Vegetable Center: Taiwan, US Agency for International Development (USAID), Australian Centre for International Agricultural Research (ACIAR), Germany, Thailand, Philippines, Korea and Japan.

9:30am CDT

HSMP 1 - Quantification of Total Soluble Phenolics, Antioxidant Activity, and Anti-Hyperglycemic Potential in Onion (Allium cepa L.)

Tuesday July 29, 2025 9:30am - 9:45am CDT

Strand 10

Research into the health-promoting properties of dietary phenolics has highlighted phenolic-rich foods as a promising strategy for the preventive management of health and wellness. Building on this rationale, the present study focused on alliums, which have held a prominent place in traditional medicine for their therapeutic benefits since ancient times. Specifically, this research evaluated onion cultivars (Red Bull, Hamilton, Gunnison, and White Cap) for their total soluble phenolics and associated antioxidant and anti-hyperglycemic activity in-vitro. Two types of extracts were prepared: one from fresh samples to simulate raw consumption, and another from cooked samples. The total soluble phenolics (TSP) content was quantified using the Folin-Ciocalteu reducing assay. Antioxidant capacity was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays. The anti-hyperglycemic potential was assessed by measuring the percentage inhibition of α-amylase and α-glucosidase enzyme. A significant difference (p

Speakers

Sidra Saleem

North Dakota State University

Co-authors

Harlene HattermanValenti

NDSU

Tuesday July 29, 2025 9:30am - 9:45am CDT
Strand 10

Oral presentation, Herbs; Spices and Medicinal Plants 1

Subject Herbs Spices and Medicinal Plants
Poster # csv

9:30am CDT

LOCSY 1 - Optimizing Pepper Productivity in an Extensive Green Roof Environment: Comparison of Variety and Mulch Use

Tuesday July 29, 2025 9:30am - 9:45am CDT

Foster 1

Fresh local produce is often limiting in densely populated cities, resulting in unhealthy food option for urban residents. Roof tops are underutilized spaces that can be used to help supplement production of fresh edibles for urban consumers. Peppers are used in a variety of cuisines and desired by many consumers in urban areas. Therefore, three pepper (Capisum annuum) varieties (San Joaquin, Red Impact, and Pot-a-Peno) having different growth habits and fruit types were compared with the application of a pine bark mulch or no mulch for resulting growth and yields in the extensive green roof environment located atop the Southern Illinois University-Carbondale Agriculture Building. Growth characters were collected during early-, mid-, and late-season, while fruit were harvested at 4-week intervals six times through the growing season. Pepper variety and mulch use did not generally influence (P > 0.05) leaf chlorophyll content or plant vigor at any timing. Marketable fruit yields differed (P < 0.05) among varieties, with ‘San Joaquin’ having higher fruit numbers than ‘Red Impact’ and weights greater than ‘Red Impact’, and ‘Pot-a-Peno’. Pepper plant vigor, leaf chlorophyll content and yield results indicate that this crop can be effectively grown in an extensive green roof environment with proper variety selection although mulch use was not beneficial. These results will be further discussed regarding the use of pepper as an edible crop in extensive greenroof environments.

Speakers

Gracie Carmon

Graduate Assistant, Southern Illinois University Carbondale

Co-authors

Alan Walters

Southern Illinois University

Kaitlyn Lamaster

Southern Illinois University

Steven Still

Southern Illinois University

Tuesday July 29, 2025 9:30am - 9:45am CDT
Foster 1

Oral presentation, Local Food Systems 1

Subject Local Food Systems
Poster # csv

9:30am CDT

PBIG 1 - Bioinformatics-Assisted Identification of Novel Plant Promoter Motifs

Tuesday July 29, 2025 9:30am - 9:45am CDT

Strand 11A

Plant natural promoters are always very long and contain many different promoter motifs, providing complex expression patterns, while synthetic promoters can be constructed to be very short in sequence and very strong in promoter strength. Bioinformatics-assisted de novo promoter motif discovery searches for statistically overrepresented motifs without the inclusion of biological information, leading to limited prediction efficiency. To overcome this limitation, we have developed a novel ensemble approach by mapping the motifs detected by a set of selected bioinformatics tools back to the promoter sequences and looking for overlapping motif regions among the detected motifs. Using this approach, we searched and identified novel constitutive promoter motifs from the soybean genome. Seven user-friendly bioinformatics tools, including BioProspector, CisGenome, HOMER, MEME, MotifSuite, RSAT Plants, and Weeder were employed for the de novo discovery of constitutive motifs among 11 published soybean constitutive promoters. A total of 62 promoter motifs were detected among the 11 soybean constitutive promoters by at least four of the seven bioinformatics tools. A tetramer (4×) of each promoter motif was cloned in front of the minimal 35S promoter driving GUS reporter gene expression, and used for tobacco leaf agroinfiltration and stable Arabidopsis transformation. Quantitative GUS activity assays following transient tobacco leaf agroinfiltration identified 26 of the 62 promoter motifs that drove GUS expression significantly higher than the basal level conferred by the minimal 35S promoter. Histochemical GUS analysis of stable transgenic Arabidopsis seedlings found that 16 of the 26 promoter motifs were 19 ~ 60 bp in length and exhibited constitutive expression with variable promoter strength, and 7 of the 26 promoter motifs showed strong constitutive expression which was comparable to (slightly weaker than) the 35S promoter. Thus, these novel constitutive motifs can be used to drive constitutive gene expression in dicot species.

Speakers

Wusheng Liu

North Carolina State University

Co-authors

debao huang

NCSU

Emily Brooks

North Carolina State University

Tuesday July 29, 2025 9:30am - 9:45am CDT
Strand 11A

Oral presentation, Plant Biotechnology 1

Subject Plant Biotechnology
Poster # csv
Funding Source BASF

9:30am CDT

PNM 1 - The biofortification of spinach (Spinacia oleracea) with zinc and its interaction with nitrogen dynamics.

Tuesday July 29, 2025 9:30am - 9:45am CDT

Strand 11B

Zinc (Zn) is essential for human cell growth and development, metabolism, cognitive function, reproduction, and the immune system. Biofortification aimed at enhancing the bioavailability and its interaction with nitrogen metabolism in spinach (Spinacia oleracea L.) remains poorly understood. Spinach, known for its high nutritional value and rapid growth cycle, is emerging as a promising candidate for biofortification. As leafy green, spinach has significant nitrogen requirements, underscoring the need for further research into how varying nitrogen levels affect Zn uptake and accumulation in edible leaves. This study investigated the effects of different zinc application rates (2.3 µM, 9.2 µM, 18.4 µM, and 27.6 µM) on yield, mineral content, phytochemical profiles, and gene expression under low (50 ppm) and high (100 ppm) nitrogen conditions. The results showed that increasing the amount of Zn significantly boosted its concentration in the leaves across both nitrogen regimes. Applying 18.4 µM of zinc led to a twofold increase in both fresh and dry biomass at high nitrogen and significantly greater Zn content in the leaves under both nitrogen conditions. The initial findings from enzyme activities and RNA-Seq profiling could improve our understanding of Zn uptake and other bivalent cations in the context of rising nitrogen availability. Comprehending these interactions is crucial for optimizing nutrient management and enhancing the nutritional value of spinach.

Speakers

Sandeep Sran

Graduate Research Assistant, Texas A & M University, College Station

Co-authors

Dalton Thompson

Texas A

Vijay Joshi

Texas A

Tuesday July 29, 2025 9:30am - 9:45am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv

9:30am CDT

WCPM 1 - Evaluating Newer Herbicide Combinations for Weed Control Efficacy and Phytotoxicity in Christmas Tree Production

Tuesday July 29, 2025 9:30am - 9:45am CDT

Strand 12B

A successful Christmas tree production requires a good and effective weed management program. Most common weed control practices in Christmas tree production involve mechanical mowing and the application of chemical herbicides. Repeated applications of the existing herbicide options have resulted in the development of herbicide-resistant weed species. It is also important to test newer herbicides to expand the list of herbicide options. Hence the objectives of this research were to evaluate labeled (1X) and double (2X) rates of newer herbicides for weed control efficacy and for phytotoxicity in Fraser fir variety of Christmas tree. Field experiments were conducted in summer and fall 2024 at a commercial Christmas tree farm located at Gobles, MI. Christmas tree variety chosen for the experiment was four-year-old Fraser fir (Abies fraseri). The herbicide treatments included glyphosate trifloxysulfuron-sodium, glyphosate flumetsulam, glyphosate flumetsulam clopyralid, glyphosate chlorimuron, glyphosate cloransulam, glyphosate topramezone, glyphosate flumioxazin. Out of these treatments, the last two were considered as industry commercial standards. The control treatment included only glyphosate. All herbicides were tested for their labeled (1X) rates and double (2X) rates. Treatments were applied before bud break as directed application towards the lower 18 inches of the trees with a carbon dioxide backpack sprayer calibrated at 27 gallons per acre output. The experiments were complete randomized block design with four replications of each treatment. Data were collected at 1, 2, 3, and 4 months after treatment (MAT) which included visual estimation of weed control based on a scale of 0% to 100% (0% meaning no weed control and 100% meaning complete weed control) and phytotoxicity based on a scale of 0% to 100% (0% meaning no plant injury and 100% meaning complete death of a branch). Dominant weed species were recorded as well. Data were analyzed by ANOVA in SAS 9.4 and means were separated out by Tukey’s HSD test. Results showed that 1X rates of glyphosate chlorimuron and glyphosate trifloxysulfuron-sodium provided 70%-90% weed control till 4 MAT and their 2X rates showed no significant injuries to the Fraser fir variety till 4 months. Hence, glyphosate chlorimuron and glyphosate trifloxysulfuron-sodium can be additional options for Christmas tree growers for weed control in future. However, long-term multiple year studies are still required based on different herbicidal rates and on different varieties of Christmas trees for expansion of these herbicide labels.

Speakers

Debalina Saha

Michigan State University

Tuesday July 29, 2025 9:30am - 9:45am CDT
Strand 12B

Oral presentation, Weed Control and Pest Management 1

Subject Weed Control and Pest Management
Poster # csv

9:45am CDT

CHEX 1 - Evaluation of Magnesium Fertilization Effects on Phenolic Compounds Accumulation in Watercress.

Tuesday July 29, 2025 9:45am - 10:00am CDT

Strand 12A

Watercress (Nasturtium officinale) is a nutrient-dense leafy green from Brassicaceae family, rich in secondary metabolites, including phenolics that contribute to its antioxidant and disease-preventing and/or health-promoting properties. Magnesium was identified as a nutrient that stimulates secondary metabolic pathways including synthesis of phenolic compounds in leafy greens from Brassicaceae family. This study aimed to evaluate the effect of different supplemental magnesium fertilization rates on phenolic accumulation in watercress grown hydroponically under a controlled environment condition. A split-plot design with four treatments: magnesium concentrations (100 mg/L, 150 mg/L, 200 mg/L, and 250 mg/L) was applied using a Nutrient Film Technique (NFT) hydroponic system with constant monitoring of environmental parameters such as temperature, light y, pH, and electrical conductivity to ensure optimal watercress growth. light, temperature, pH, and electrical conductivity. Different extracts of harvested watercress tissues (roots, stem and leaves) were analyzed and quantified including total phenolic content (TPC) using spectrophotometer and High-Performance Liquid chromatography (HPLC). Additionally, fresh and dry biomass yield was recorded. The preliminary results revealed a positive correlation between magnesium application and phenolics, with the increase in concentration rate significantly enhancing total phenolic content and biomass production. These results have practical implications for hydroponic growers aiming to improve leafy greens nutritional quality and productivity through nutrient optimization in hydroponic systems. In summary, watercress exhibits strong antioxidant properties and contains phenolic compounds that may hold potential biological interests. Keywords: Watercress, Phenolics, Antioxidant, Magnesium, Controlled environment.

Speakers

Germaine Akeza

Kentucky State University

Ms. Germaine N. Akeza is a graduate Research Assistant at Kentucky State University, pursuing a master’s in environmental studies. Born and raised in a densely populated Country from a family of subsistence farmers whose farming experience instilled in her the principles of hard... Read More →

Co-authors

Richard Kabanda

Kentucky State University

THEONESTE NZARAMYIMANA

Kentucky State University

Tuesday July 29, 2025 9:45am - 10:00am CDT
Strand 12A

Oral presentation, Commercial Horticulture 1

Subject Commercial Horticulture
Poster # csv

9:45am CDT

GG 1 - Chemical and CRISPR-Induced Mutagenesis for Herbicide Tolerance in Plants: From Agronomic to Horticultural Crops

Tuesday July 29, 2025 9:45am - 10:00am CDT

Foster 2

Herbicide tolerance in plants is an increasingly valuable trait due to the high labor and costs associated with weed control in agriculture. Herbicide application remains the most effective and widely used weed management strategy, making the development of tolerant plants essential. First discovered in the 1970s and commercially grown since 1984, herbicide resistant crops have become a key tool in agriculture, with increasing demand for new tolerant varieties. Chemical mutagenesis and CRISPR-mediated gene editing have been used to induce mutations and develop herbicide tolerant plants. Chemical mutagenesis involves treating plant tissue with mutagens such as ethyl methanesulfonate (EMS) to induce random mutations, followed by screening to identify tolerant mutants. This conventional approach has played a significant role in breeding programs and remains widely used for developing herbicide tolerant crops. EMS mutagenesis has successfully generated ALS-resistant varieties in several agronomic crops, including Clearfield® maize, rice, and wheat, which are resistant to imidazolinone (IMI) herbicides without being classified as genetically modified (GM). It is particularly effective for developing crops resistant to ALS- and ACCase-inhibiting herbicides, as these mutations typically require only minor changes in the target genes. CRISPR-mediated gene editing, using tools such as CRISPR-Cas9, base editing (CBE, ABE), and prime editing, enables precise modifications in plant genomes to confer herbicide tolerance. These advancements have revolutionized crop development through their efficiency, precision, and cost-effectiveness. By targeting herbicide receptor genes such as ALS, ACCase, and EPSPS, CRISPR-based systems have produced herbicide tolerant varieties in several agronomic crops. CRISPR is particularly valuable for engineering tolerance to non-selective herbicides, such as glyphosate, due to the complex genomic architecture of the EPSPS gene. Chemical mutagenesis facilitates the discovery of novel mutations and is particularly useful in understudied species lacking the genomic information required for CRISPR-based modification. In contrast, CRISPR-based genome editing provides a highly precise and efficient method for developing herbicide tolerant crops, especially when targeting complex genes. Integrating chemical mutagenesis with CRISPR-mediated gene editing expands the range of available herbicide tolerance traits and offers new opportunities for sustainable weed management. These advances in agronomic crops provide a strong foundation for extending herbicide tolerance studies to horticultural and specialty crops, where research has been more limited despite similar weed management issues.

Speakers

Mase Merkel

University of Florida

Co-authors

Zhanao Deng

University of Florida

Tuesday July 29, 2025 9:45am - 10:00am CDT
Foster 2

Oral presentation, Genetics and Germplasm 1

Subject Genetics and Germplasm
Funding Source USDA Hatch Project FLA-GCC-006190; USDA AMS Specialty Crop Block Grant through the Florida Department of Agriculture and Consumer Services (FDACS) Specialty Crop Block Grant Program

9:45am CDT

HSMP 1 - Cultivation of California yerba santa as a source of potentially important flavonoids

Tuesday July 29, 2025 9:45am - 10:00am CDT

Strand 10

California yerba santa (Eriodictyon californicum) is a chaparral shrub of western California and SW Oregon. Its leaves contain flavonoids of potential medical importance including sterubin, hesperetin, homoeriodictyol, eriodictyol and others. Seed from natural populations of California yerba santa were collected in the wild from plants relatively rich in the flavonoid sterubin and alternatively relatively rich in eriolic acid C. Seedlings from these two sources were transplanted to the field in replicated trials. Plants were harvested after three months and the plants were divided vertically into four equal parts to determine their relative dry weight yield, essential oils, and flavonoids. Total leaf dry weight yield averaged 2.8 Mg/ha and total stem dry weight averaged 1.8 Mg/ha. Leaf dry weight was least and the stem dry weight was greatest in the lower quarter of the plants. The leaves in the top quarter of the plants had consistently higher concentration of most of the flavonoids than the lower leaves. Leaves in the top quarter of the higher sterubin plant line contained 50 mg of sterubin per g of dry weight and a total of 116 mg/g of total flavonoids while the other line had negligible sterubin. Conversely, eriolic acid C was substantial in the tops grown from seed from plants with considerable eriolic acid C in nature. Considering all the leaves, those from the higher sterubin plant line yielded a total of 101 kg/ha of sterubin, 22 kg/ha of hesperetin, 60 kg/ha of homoeriodictyol, 16 kg/ha of eriodictyol and a total of 237 kg/ha of flavonoids. Plants can be selected for the horticultural production of specific flavonoids or leaves with specific herbal properties.

Speakers

Clinton Shock

Scientific Ecological Services

Co-authors

Jianping Zhao

University of Mississippi

Joseph Lee

University of Mississippi

Mei Wang

USDA, ARS, NPURU

Tuesday July 29, 2025 9:45am - 10:00am CDT
Strand 10

Oral presentation, Herbs; Spices and Medicinal Plants 1

Subject Herbs Spices and Medicinal Plants
Poster # csv

9:45am CDT

LOCSY 1 - Integration of Cover Crops and Compost Applications: Evidence-Based Approaches for Enhancing Soil Health in Indiana Urban Agricultural Systems

Tuesday July 29, 2025 9:45am - 10:00am CDT

Foster 1

Urban farmers across Indiana are facing the effects of rising fertilizer, chemical, and energy prices. In this climate, soil health has emerged as a top priority. In a 2023 statewide survey of Indiana urban farmers, 91.6% expressed interest in learning more about improving soil health (n=81), underscoring a strong desire for practical, sustainable strategies that reduce costs and boost productivity. Cover crops and compost application represent two fundamental approaches to improving soil health and fertility. Implementing cover crops and incorporating compost are essential practices for regenerating and maintaining healthy soil ecosystems. Farmers seeking to enhance soil vitality often rely on two primary methods: planting cover crops and applying compost. Soil health can be significantly improved through the integration of cover cropping systems and regular compost applications. hairy vetch, sunn hemp, rye, and mustard, are gaining traction as an alternative or complement to compost. These crops can trap nitrogen, build organic matter, and improve water retention, which are relevant benefits in compacted, nutrient-depleted, and low-organic-matter soils common in urban spaces. However, barriers like limited space, short-term leases, and concerns about short-term yield reduction can make adoption difficult for small-scale growers. When managed properly, composting transforms organic waste like food scraps, straw, and manure into a slow-release soil amendment that boosts organic matter, microbial life, and nutrient retention. However, not all compost is created equal. Overapplication, especially of manure-based compost, can lead to nutrient imbalances, phosphorus buildup, nitrate leaching, and elevated pH, which may reduce yields. Urban farmers are encouraged to test compost for nutrient content and monitor soil health regularly to guide application timing and rates. The Soil to Market project, an ongoing Purdue-led study launched in 2021, is evaluating cover crop and compost combinations at multiple Indiana locations. At the Meigs Purdue Agriculture Center in Lafayette, IN, cover crops alone, particularly sorghum and sunn hemp, did not significantly increase total available phosphorus (P). In contrast, compost treatments, especially high volume (2 yd³), manure-based applications, resulted in statistically significant increases in soil P, with mean values ranging from 280 to 365 mg/kg. These treatments highlight potential effectiveness in improving P availability in nutrient-depleted, urban soils. However, high phosphorus levels in compost treatments highlight the need for careful, adaptive management in sensitive environments, such as near waterways due to the increased risk of P runoff or leaching. Management of application timing, placement, and rates is crucial to maximize benefits while minimizing environmental impacts on urban farms.

Speakers

Nathan Shoaf

Purdue University

Nathan Shoaf earned his M.S. in Horticulture and Landscape Architecture from Purdue University, specializing in horticulture and soil microbial ecology. With over two decades of experience, he has expertise in urban farms and specialty crop production, fostering impactful collaborations... Read More →

Co-authors

Petrus Langenhoven

Purdue University

Tuesday July 29, 2025 9:45am - 10:00am CDT
Foster 1

Oral presentation, Local Food Systems 1

Subject Local Food Systems
Funding Source USDA-NIFA

9:45am CDT

PBIG 1 - Declining Nitrogen Availability Increases Sink Strength and Storage Root Formation in Sweetpotato cv. ‘Beauregard’

Tuesday July 29, 2025 9:45am - 10:00am CDT

Strand 11A

In sweetpotato (Ipomoea batatas L.), the sink strength of developing adventitious roots limits storage root formation. Sucrose synthase (SuSy) has been identified as a marker for sink strength in developing storage roots. In model systems, declining nitrogen (N) availability has been associated with increased carbohydrate allocation to root systems. To test the hypothesis that N limitation triggers increased SuSy activity that leads to storage root formation, we subjected sweetpotato cv. ‘Beauregard’ to progressively declining N treatments in a split-root system. SuSy expression and root system architecture were evaluated over 15 days, and storage root formation was assessed at 50 days. Declining N availability enhanced SuSy activity in the root base tissue across all time points and was associated with increased lateral root count at 15 days. Previous work has shown that the anatomical cue of the onset of storage root formation, the appearance of anomalous cambia, is initially limited to the root base tissue. The omission of N was associated with decreased root base SuSy activity and an overall reduction in root architectural attributes. These data support the hypothesis that declining N could be a critical switch for storage root formation in sweetpotato. Our findings have profound implications for increasing N fertilizer efficiency and enhancing our understanding of the intrinsic and environmental variables that mediate storage root formation and productivity in this globally important crop.

Speakers

Marissa Barbosa

Lousiana State University

Co-authors

Arthur Villordon

LSU Agcenter

Don La Bonte

Louisiana State Univ

Lisa Arce

Louisiana State University

Mae Ann Bravo

Louisiana State University

Tuesday July 29, 2025 9:45am - 10:00am CDT
Strand 11A

Oral presentation, Plant Biotechnology 1

Subject Plant Biotechnology
Poster # csv
Funding Source US-Israel Agricultural Research Development Fund

9:45am CDT

PNM 1 - Evaluating Biostimulants for Enhancing Nutrient Efficiency in Lettuce under Differential Fertilizer Regimes

Tuesday July 29, 2025 9:45am - 10:00am CDT

Strand 11B

In the arid and semi-arid regions of the southwestern United States, particularly Arizona, lettuce production is challenged by high input costs, water scarcity, and nutrient leaching due to coarse-textured soils. These constraints underscore the need for sustainable solutions that maintain productivity while reducing fertilizer dependency. Biostimulants—products that stimulate natural plant processes—are emerging as promising tools to improve nutrient use efficiency and stress tolerance in vegetable crops grown under desert conditions. This study evaluated the efficacy of three commercial biostimulants—silica-based, plant and animal peptide-based, and insect larvae and frass-based—on head lettuce (Lactuca sativa cv. ‘Iceberg’) grown under two fertilizer regimes: 100% and 50% of the recommended inorganic fertilizer rates. The field experiment followed a partial split-plot design with three replications at the Maricopa Agricultural Center, University of Arizona. Biostimulants were applied during the rosette and head formation growth stages. Morphological and physiological traits (plant diameter, height, leaf thickness, SPAD chlorophyll index, stomatal conductance, and mesophyll quantum absorption) were measured at multiple growth stages. Two-way ANOVA revealed significant effects of both fertilizer rate and biostimulant treatment, with 50% fertilizer often matching or outperforming 100%, particularly in SPAD. The peptide-based biostimulant showed the most consistent enhancement in plant diameter after the second application. These findings demonstrate that targeted use of biostimulants may allow fertilizer reductions without yield penalties, offering a viable strategy for resource-efficient lettuce production in arid environments.

Speakers

Subhankar Mandal

Arizona State University

Co-authors

Eleanore Kelleher

Arizona State University

Sharanya Venkatesan

Arizona State University

Tuesday July 29, 2025 9:45am - 10:00am CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv

9:45am CDT

WCPM 1 - A Water Soluble β-triketone Enriched Extract of Manuka Oil has Effective Pre-and-Post Emergence Efficacy Against Lolium multiflorum, Amaranthus retroflexus, and Abutilon theophrasti

Tuesday July 29, 2025 9:45am - 10:00am CDT

Strand 12B

Specialty and organic crop weed management strategies are challenging due to limited chemical control products with good efficacy that are cost effective. The need for new bioherbicide modes of action has become increasingly urgent in modern agriculture as most bioherbicides have nonspecific modes of action with no systemic activity. Introducing new bioherbicides that are also registered as organic is essential to diversify weed control strategies. By fostering innovations in bioherbicide development agricultural systems can be more environmentally friendly by preserving ecosystems while maintaining the ability to feed a growing global population. Manuka oil is derived from the leaves and branches of the Manuka tree (Leptospermum scoparium) and contains β-triketones. The β-triketone rich fraction contains leptospermone that inhibits a key enzyme, p-hydroxyphenylpyruvate dioxygenase (HPPD). This process directly inhibits carotenoid biosynthesis, upstream in the biochemical pathway, which causes damage to the photosynthetic apparatus and leads to bleaching of the leaf tissue which eventually kills the plant. There were three studies that examined the efficacy of β-triketone extract against Lolium multiflorum, Amaranthus retroflexus, and Abutilon theophrasti. The studies were 1) pre-emergence β-triketone extract ranging from 0 to 2.5 mg ml-1, 2) post-emergence β-triketone extract ranging from 0 to 6%, and 3) post-emergence β-triketone extract at 0.5 and 2.0% with five different organic adjuvants. In the pre-emergence study, there were significant differences between the β-triketone extract treatments and 100% weed control down to 0.625 mg ml-1. In the post-emergence study, there was significant decreases in weed height and fresh and dry mass when compared to the control treatment. However, the adjuvants did not have any effect on weed height and fresh and dry mass. Thus, there is significant evidence that commercializing a water soluble β-triketones enriched extract of Manuka oil can be an effective weed control, especially as a pre-emergent bioherbicide for specialty and organic crop production.

Speakers

T. Casey Barickman

Research Plant Physiologist, USDA-ARS

I am a Research Plant Physiologist with USDA-ARS in the Natural Product Utilization Research Unit in Oxford, MS. We are housed on the beautiful campus of the University of Mississippi. My research encompasses bioherbicide discovery from natural products and elucidating their modes... Read More →

Co-authors

Amber Reichley

USDA-ARS

Charles L. Cantrell

USDA-ARS-NPURU

Sherif Sharfadine

USDA-ARS

Tuesday July 29, 2025 9:45am - 10:00am CDT
Strand 12B

Oral presentation, Weed Control and Pest Management 1

Subject Weed Control and Pest Management
Poster # csv

1:29pm CDT

O/LT - Oral Session

Tuesday July 29, 2025 1:29pm - 1:30pm CDT

Strand 11A

Speakers

Alexis Suero

North Carolina State University

Tuesday July 29, 2025 1:29pm - 1:30pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

1:30pm CDT

O/LT - Integrating Polarization Imaging into Turfgrass Phenotyping for Enhanced Drought Stress Assessment

Tuesday July 29, 2025 1:30pm - 1:45pm CDT

Strand 11A

Investigating novel sensing solutions is important for improving the existing phenotyping pipeline. Polarization is strongly correlated with the geometric properties of an object, such as surface roughness and its orientation relative to the sensor or light source. It has the potential to detect leaf wilting and quantify leaf angles in turfgrass, which are both crucial in precision turfgrass irrigation and crop coefficient determination. This study explores the integration of polarization imaging into RGB imaging pipelines for evaluating turfgrass responses to drought. A controlled dry-down was conducted on two zoysiagrass cultivars and two bermudagrass cultivars grown in pots. Polarization images, RGB images, and visual wilting ratings were collected daily during the four-day dry-down period. Leaf angles, both azimuth and zenith, were derived from top- and side-view RGB images, respectively. We analyzed polarization metrics, including the degree of linear polarization (DoLP) and the angle of polarization (AoP), to assess their relationship with drought stress indicators, such as wilting scores, low Excess Green Index (EGI) values, and changes in leaf angles. EGI and the standard deviation of AoP strongly correlated with wilting scores. Furthermore, DoLP values correlated with leaf zenith angle when the incident light angle was known.

Speakers

Alexis Suero

North Carolina State University

Co-authors

Jerome Maleski

North Carolina State University

Jing Zhang

North Carolina State University

Michael Kudenov

North Carolina State University

Tuesday July 29, 2025 1:30pm - 1:45pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf

1:44pm CDT

CE 1 - Oral Session

Tuesday July 29, 2025 1:44pm - 1:45pm CDT

Strand 12B

Presiding/Moderator

Ava Forystek

Cornell University

Tuesday July 29, 2025 1:44pm - 1:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

1:44pm CDT

PNM 2 - Oral Session

Tuesday July 29, 2025 1:44pm - 1:45pm CDT

Strand 11B

Presiding/Moderator

Gerardo Nunez

University of Florida

Tuesday July 29, 2025 1:44pm - 1:45pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

1:44pm CDT

POM 1 - Oral Session

Tuesday July 29, 2025 1:44pm - 1:45pm CDT

Foster 1

Presiding/Moderator

Edgar Vinson

Auburn University

Tuesday July 29, 2025 1:44pm - 1:45pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

1:44pm CDT

PROP - Oral Session

Tuesday July 29, 2025 1:44pm - 1:45pm CDT

Strand 12A

Presiding/Moderator

Benjamin Hoover

Associate Professor of Sustainable Nursery Production, California Polytechnic State University

Associate Professor of Sustainable Nursery Production | Horticulturist and Plant Nerd | Eternally Curious | Book Lover | Educator | Research Interests: Nursery and Propagation Substrates, Plant Growth and Establishment, Plant Health, Plant Selection, and Teaching Methods

Tuesday July 29, 2025 1:44pm - 1:45pm CDT
Strand 12A

Oral presentation, Propagation

1:45pm CDT

CE 1 - From ultraviolet-B to red photons: Effects of end-of-production supplemental light on anthocyanins, phenolics, ascorbic acid, and biomass production in red leaf lettuce

Tuesday July 29, 2025 1:45pm - 2:00pm CDT

Strand 12B

Advances in crop lighting using light-emitting diodes (LEDs) have enabled the application of targeted light spectra to elicit specific plant responses during cultivation. However, there is a lack of comparative studies evaluating the effects of different spectral regions within the same crop. We comprehensively quantified how various light spectra, ranging from ultraviolet-B to red, affect plant growth and the accumulation of beneficial phytochemicals, including anthocyanins, phenolics, and ascorbic acid, in red leaf lettuce (Lactuca sativa) cultivars ‘Red Salad Bowl’ and ‘Rouxai’. Plants were grown under a background white LED light of 200 µmol m-2 s-1 for 16 hours per day (control), and supplemented with red (peak at 659 nm), blue (444 nm), violet (404 nm), ultraviolet-A (UVA; 368 nm) radiation at 60 µmol m-2 s-1, or ultraviolet-B (UVB; 309 nm) radiation at 3 µmol m-2 s-1 during the last 7 days of a 28-day production period (end-of-production stage, EOP). For both lettuce cultivars, red, blue and UVB treatments significantly enhanced leaf anthocyanin content compared to the control, with UVB being the most effective despite its low application dosage, followed by the blue and red light treatments. UVB radiation significantly increased total phenolic content in both cultivars (by 80%–99.1% compared to the control), while blue light treatment increased total phenolics by 31.4% in ‘Red Salad Bowl’ only. However, supplemental UVB radiation did not affect total ascorbic acid in either cultivar; the other EOP treatments (red to UVA) increased total ascorbic acid by 19%–35% in ‘Red Salad Bowl’ but had no significant effects in ‘Rouxai’. Notably, crop yield under the UVB treatment was the lowest in both cultivars, with 8.9%–49% lower shoot fresh weight compared to other treatments. In contrast, the violet light treatment resulted in the highest leaf area and shoot biomass in both lettuce cultivars, although it was not effective in enhancing anthocyanins and total phenolics. Our result indicated that there is often a tradeoff between nutritional quality and crop yield, and specific light spectra can be strategically used to enhance nutritional quality or biomass. Low-intensity UVB was the most effective at maximizing anthocyanins and total phenolics, followed by blue light, while supplemental violet light most significantly enhanced lettuce leaf expansion and biomass compared to other light spectra.

Speakers

Yilin Zhu

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Shuyang Zhen

Texas A

Tuesday July 29, 2025 1:45pm - 2:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Funding Source USDA-NIFA, Hatch project 1026236

1:45pm CDT

O/LT - Responses of Landscape Plants under Deficit Irrigation

Tuesday July 29, 2025 1:45pm - 2:00pm CDT

Strand 11A

Ornamental plants are essential components of both rural and urban landscapes, with the horticultural industry generating $2.01 billion in bedding and garden plant sales in 2019. However, increasing drought stress, affecting 99.3% of Utah in 2023, highlights the need for water-efficient landscaping. Water-wise landscaping offers a promising solution by conserving water while maintaining visual appeal, making it increasingly popular in arid and semi-arid regions. This study was to investigate the effects of deficit irrigation frequency on the morphological and physiological of 13 landscape plant taxa: Caryopteris ×clandonensis ‘Blauer Splatz’ (Sapphire SurfTM bluebeard), Cercis canadensis (eastern redbud), Cercis occidentalis (western redbud), Cotoneaster ×suesicusn ‘OSUCOT2’ (Emerald BeautyTM cotoneaster), Hesperaloe parviflora ‘Straight Up Red’ (‘Straight Up Red’ Texas red yucca), Miscanthus sinensis ‘NCMS2B’ (bandwidth maiden grass), Penstemon barbatus ‘Novapenblu’ (Rock CandyTM blue penstemon), Penstemon pinifolius (pineleaf beardtongue), Penstemon strictus (rocky mountain beardtongue), Physocarpus opulifolius ‘Diabolo’ (‘Diabolo’ ninebark), Physocarpus opulifolius ‘Little Devil’ (Little DevilTM ninebark), Rosa ×hybrida ‘Meifranjin’ (Blushing Drift® rose), and Vitex agnus-castus ×rotundifolia ‘Helen Froehlich’ (Summertime BluesTM vitex). The experiment was conducted at the Utah Agricultural Experiment Station’s Greenville Research Farm in North Logan, UT, from 1 Jun to 31 Oct 2024. Eight plants per species were randomly assigned to one of three irrigation frequencies based on reference evapotranspiration (ETo): high (80% ETo), moderate (50% ETo), and low (20% ETo). Overall plant appearance was evaluated biweekly using a visual rating scale from 0 (dead) to 5 (excellent). Plant growth, stomatal conductance, and canopy temperature were recorded monthly. Net photosynthetic rate, transpiration rate, and vapor pressure deficit were measured in August and September. Results indicate species-specific responses to deficit irrigation. Some species, such as P. barbatus and P. strictus, exhibited improved visual quality, lower canopy temperatures, and higher photosynthetic rates under more frequent irrigation. In contrast, other species were not affected by reduced irrigation frequency.

Speakers

Zirui Wang

Utah State University

Co-authors

Darren Haver

University Of California Cooperative Extension

Jared Sisneroz

UC Davis

Lloyd Nackley

oregon state university

Lloyd Nackley is a plant ecologist who applies a systems approach to improve nursery and greenhouse management. Nackley's research program at Oregon State University focuses on addressing four challenges facing nursery and greenhouse production in Oregon: irrigation application, pest... Read More →

Lorence Oki

University Of California, Davis

Natalie Levy

University Of California Cooperative Extension

Ryan Contreras

Oregon State University

Soohyung Kim

University of Washington

Ursula Schuch

University of Arizona

Youping Sun

Utah State University

Tuesday July 29, 2025 1:45pm - 2:00pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf

1:45pm CDT

PNM 2 - Nitrogen Fertilizer Rate Effect on Growth and Yield of ‘Ouachita’ Blackberry in Arkansas

Tuesday July 29, 2025 1:45pm - 2:00pm CDT

Strand 11B

Current literature on blackberries indicates that inadequate nitrogen (N) fertilizer application negatively impacts plant growth and profitability for blackberry growers. Overapplication of fertilizer can decrease fruit marketability and increase labor costs, while insufficient fertilization stunts plant growth and decreases yield. The current N fertilizer rate recommendation for southeastern blackberry (67–101 kg N/ha) was developed outside the Southeast. The objectives of this study were to verify the current blackberry N fertilizer rate recommendation for the Southeast by investigating the effect of N fertilizer rate on ‘Ouachita’ blackberry yield and plant growth. Tissue culture plug plants of ‘Ouachita’ were planted in 2021, and fertilized with ammonium-nitrate from 2022 to 2024 at six different rates (0, 34, 67, 101, 134, 168 kg N/ha) at the University of Arkansas Fruit Research Station in Clarksville, AR. Fertilizer was applied via drip irrigation over fifteen weeks starting at primocane emergence. The experiment was laid out in a randomized complete block design with five plants in each replicate (n=4). Each year marketable and non-marketable blackberry yield was recorded. Subsamples from plots were also collected to assess fruit firmness at the day of harvest and fruit quality after seven days (decay, leakage, and red drupelet reversion). In the spring (2023-2025) plants were pruned to a grower standard and pruning weights (kg) were collected. In this study, marketable yield ranged from 2.64–2.82 kg/plant per year. No significant differences in yield were observed across fertilizer rate or fertilizer rate by year interaction. Total yield and percent non-marketable fruit were not observed to be significantly different across N treatment. Percent fruit decay after seven days was highest at the 168 kg N/ha rate, which was significantly higher than the 0, 34, and 67 kg N/ha rates. Firmness at day of harvest, percent leakage and red drupelet reversion after seven days were not impacted by N rate. Higher rates of N fertilizer resulted in higher pruning weights (p

Speakers

Amanda Lay-Walters

University of Arkansas

Co-authors

Amanda Mcwhirt

University of Arkansas

Renee Threlfall

University of Arkansas

Ryan Dickson

University of Arkansas

Trenton Roberts

University of Arkansas

Tuesday July 29, 2025 1:45pm - 2:00pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv
Funding Source Southern Region Small Fruit Consortium and Arkansas Soil Test Review Board

1:45pm CDT

POM 1 - Application Timing and Efficacy of Bacteriophage Treatment for Managing Xanthomonas-Induced Bacterial Spot in Peach

Tuesday July 29, 2025 1:45pm - 2:00pm CDT

Foster 1

Bacterial spot, caused by Xanthomonas arbicola pv. pruni, is considered an economically important disease of peach and other stone fruit. In peaches, bacterial spot can affect leaves, twigs, and fruit. The disease can cause slight to nearly complete defoliation of infected trees. When significant defoliation occurs early in the season, fruit size can be reduced. In more severe cases, fruit may become infected. Small water-soaked spots can develop on the fruit at any time during fruit development. Early infection is the most concerning because unsightly cratering or pitting on the fruit can occur. Copper based fungicides are the main product used to manage bacterial spot in peaches and are associated with the potential for elevated phytotoxicity. This damage to the leaves resembles the actual disease and can cause defoliation in severe cases. Bacteriophage technology employs viruses that specifically infect bacteria offering a targeted approach to managing bacterial spot without the risk of phytotoxicity. The efficacy of these products have not been widely tested in the southeastern United States. The objective of this study was to determine the optimal timing during the growing season for applying a bacteriophage product in Central Alabama to achieve control of bacterial spot that is comparable to or better than a traditional copper-based spray program. A study was conducted at the Chilton Research and Extension Center in Clanton, AL. Treatments were applied to single tree replications and each treatment was replicated four times. The study followed a randomized complete block design. The control treatment (standard protocol) consisted of a copper-based product applied at each phenological stage. Bacteriophage treatments consisted of applications of the bacteriophage at select phenological stages in place of the copper-based product. Treatments were applied weekly. The entire canopy of each treatment tree was rated for incidence of bacterial spot every two weeks. At harvest, fruit were separated by degree of bacterial spot infection, counted, and weighed. Applications of bacteriophage during specific phenological stages—such as from pink to open bloom, delayed dormant to early bud swell, and from petal fall to early shuck split—were associated with the lowest incidence of foliar bacterial spot. Across all bacteriophage treatments, most fruit exhibited only mild symptoms and remained marketable. These findings suggest that targeted application timing may improve bacteriophage efficacy, though additional studies are needed to validate and optimize these strategies.

Speakers

Edgar Vinson

Auburn University

Co-authors

Elina Coneva

Auburn University

Kassie Conner

Auburn University

Tanzeel Rehman

AUBURN UNIVERSITY

Wendiam Sawadgo

Auburn University

Tuesday July 29, 2025 1:45pm - 2:00pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

1:45pm CDT

PROP - The Effects of Gibberellic Acid, Smoke Water, and Cold Stratification on the Germination of Native Perennial Seed

Tuesday July 29, 2025 1:45pm - 2:00pm CDT

Strand 12A

In this study, we evaluated the germination rates of twenty native plant species and their response to cold stratification as well as four chemical solution treatments—water (control), gibberellic acid, smoke water, and gibberellic acid with smoke water. Seeds were evaluated and counted twice a week. Of the twenty evaluated species, sixteen had germination rates over 3%, or 1 seed out of 30. Stratification increased germination by 54% when compared to the control. For chemical treatments, gibberellic acid and gibberellic acid with smoke water were significantly different from the control and increased germination by an average of 47% and 48%, respectively. Six species showed a response to chemical treatment and stratification. Four species showed a response to chemical treatments only, and four species showed a response to stratification only. No growth defects were discovered upon further evaluation after sowing the seed. This study suggested that the combination of stratification with smoke water and/or gibberellic acid has a significant effect on seed germination yield of some native perennials.

Speakers

Jared Barnes

SFASU

Co-authors

Michael Maurer

Stephen F Austin State University

Zyreasha Tippins

Stephen F Austin State University

Tuesday July 29, 2025 1:45pm - 2:00pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv

2:00pm CDT

CE 1 - Increasing the Far-Red Fraction or Decreasing Blue Light Increases Indoor Hydroponic Lettuce Growth and Nitrogen Demand

Tuesday July 29, 2025 2:00pm - 2:15pm CDT

Strand 12B

Because indoor vertical farms require sole-source lighting, light spectra that maximize desired crop attributes are pivotal. Although previous research has revealed growth responses of leafy greens to blue (B), red (R), and far-red (FR) light, the combined effects of the FR fraction [FR:(R FR)] and the B photon flux density (PFD) on biomass accumulation and nutrient uptake in lettuce (Lactuca sativa) remain unclear. We conducted an indoor hydroponic experiment on red-leaf lettuce ‘Rouxai’ using a randomized complete block design (with four blocks) to investigate how the FR fraction and the B PFD influenced growth, morphology, coloration, and nutrient uptake. The first two blocks and the second two blocks were performed over time. From day 0 to 11, we grew plants from seed in rockwool indoors under continuous warm-white light-emitting diodes (LEDs), with a mean photosynthetic PFD of 180 μmol∙m−2∙s−1. From day 11 to 28, we grew plants in hydroponic units under nine continuous LED lighting treatments, which were combinations of three FR fractions (0%, 25%, and 40%) and three B PFDs (30, 60, and 90 μmol∙m−2∙s−1). The mean air temperature and humidity were 23.6 °C and 62.5%, respectively, in the first two blocks, and 25.0 °C and 20.0%, respectively, for the second two blocks. Foliage coloration was measured on day 26, while growth and morphology data were collected on day 28. Increasing the FR fraction from 0% to 40% increased shoot biomass (by 24%–78%), leaf length (by 21%–41%), and plant diameter (by 17%–32%) across the three B PFDs. Decreasing the B PFD from 90 to 30 μmol∙m−2∙s−1 also increased shoot biomass (by 24%–50%) across the three FR fractions and increased plant diameter (by 9%–11%) at FR fractions of 0% and 25%, but not 40%. Despite some interactions, the FR fraction and the B PFD mostly influenced plant growth and morphology independently. Interestingly, chlorophyll index and coloration were largely unaffected by light spectra, indicating that the lowest B PFD might have saturated pigmentation. Increasing the FR fraction or decreasing the B PFD generally increased total nitrogen uptake to support growth promotion, but decreased tissue nutrient concentrations of nitrogen and potassium, possibly due to the dilution effect. We conclude that increasing the FR fraction (from 0% to 40%) or decreasing the B PFD (from 90 to 30 μmol∙m−2∙s−1) generally increased shoot biomass, leaf expansion, and nitrogen demand in indoor hydroponic lettuce ‘Rouxai’, without influencing foliage coloration.

Speakers

David Haule

University of Delaware

Co-authors

Qingwu Meng

University of Delaware

Tuesday July 29, 2025 2:00pm - 2:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Funding Source Foundation for Food and Agriculture Research

2:00pm CDT

O/LT - A Tale of Three City Parks

Tuesday July 29, 2025 2:00pm - 2:15pm CDT

Strand 11A

Horticulturists and landscape managers are often highly skilled professionals with an extensive understanding of plant biology and growth requirements. However, despite this knowledge, the post-construction soil conditions in which new landscapes are often installed can undermine the success of plantings. In the best-case scenario, horticulturists with passion and perseverance provide attentive management to the plants to help establish the landscape, but this process can often require a deep dive into soil science, an area that many horticulturists may not be equipped to handle fully. The issue of urban soil is gaining increased attention from soil scientists, but a greater integration of horticulture and urban soil science is essential. Similarly to how soil science and crop science are often interwoven, a more holistic approach is needed to bridge the gap between plant knowledge and urban soil conditions. This would better equip horticulturists and landscape professionals to manage the complexities of urban environments. A notable example of this challenge can be found in downtown Oklahoma City, where three large public gardens have been developed within a one-mile span. Each garden presents its own set of unique challenges, including varying soil types, management timelines, and irrigation sources. Myriad Gardens, established in 1970’s has soil that has been disturbed and modified since the early 1900’s. With a complete garden renovation in 2012, Myriad has an average soil pH range of 6.7-7.7. Upper Scissortail previously, an industrial neighborhood was established in 2019 and constructed utilizing seven different soil formulas. With 1000 newly planted trees, poor quality well irrigation water, and a soil pH over 8.0, plant establishing has been challenging for the staff. Finally, Lower Scissortail built in 2022 was also developed with five soil formulas and like Myriad is on city water that has shown to be a better source of water. This case study highlights the complexity of managing urban landscapes and underscores the importance of addressing soil issues at the onset. For horticulturists, it is no longer enough to possess plant knowledge alone. They must also understand the intricate soil dynamics that can make or break the success of a landscape.

Speakers

Casey Hentges

Oklahoma State University

Co-authors

Justin Quetone Moss

Oklahoma State University

Tuesday July 29, 2025 2:00pm - 2:15pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf

2:00pm CDT

PNM 2 - Sustainable Wastewater Reuse in Blueberry Cultivation: Evaluating a Novel Integrated Electrodialysis-Forward Osmosis Process

Tuesday July 29, 2025 2:00pm - 2:15pm CDT

Strand 11B

Agriculture accounts for up to 80% of the total U.S consumptive water use. Increasing water scarcity and severity of droughts have accelerated the need for alternate water sources, including the use of reclaimed wastewater for irrigation and other agricultural operations. However, concerns over wastewater-borne pathogens and emerging contaminants necessitate effective treatment methods. In our short-term study, we evaluated a novel integrated electrodialysis-forward osmosis (iEDFO) method for wastewater treatment and its impact on southern highbush blueberry (Vaccinium corymbosum L.) grown in soilless media. Plants were fertigated with untreated municipal or dairy digestate, recovered nutrient water from the digestates treated by iEDFO, or a modified Hoagland solution (control). Leaf area and shoot biomass were similar across all treatments, indicating no adverse effects of the treated and untreated digestates on growth. While salinity levels exceeded threshold for blueberry (> 2 dS·m-1), periodic freshwater flushing mitigated osmotic stress in the plants. Nutrient analysis indicated high potassium levels amongst all treatments, suggesting the need for adjustments to optimize nutrient balance in each solution. Mass spectrometry confirmed significant removal of pharmaceuticals and pesticides (>90%), demonstrating effectiveness of iEDFO in treating reclaimed water for potential pathogens and reducing potential human health risks. A longer-term study is currently underway to assess the viability of the iEDFO system and its enduring impact on crop performance and potential contaminants in the fruit. In this case, 2-year-old ‘Star’ blueberry plants were transplanted to 25-L containers filled with soilless media and irrigated three times a week with untreated municipal digestate, recovered nutrient water from the digestates treated by iEDFO, or a modified Hoagland solution. Initial findings showed that while the control had the overall highest plant growth, treatments did not differ in cane or stem mass or visible root growth. Leaf macro- and micronutrients were also similar amongst the treatments, except for boron, which was highest with municipal wastewater. This summer, we will evaluate the effects of these treatments on production and quality of the fruit.

Speakers

Andrea Retano

Oregon State University

Co-authors

David Bryla

USDA

Quang Tran

Oregon State University

Xue Jin

Oregon State University

Tuesday July 29, 2025 2:00pm - 2:15pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv

2:00pm CDT

POM 1 - Profiling Sweet Cider Apple Cultivars for the U.S. Midwest

Tuesday July 29, 2025 2:00pm - 2:15pm CDT

Foster 1

Sweet cider serves as both a fresh juice product and a precursor for hard cider production and is an important facet of agrotourism within the apple industry in the U.S. In this study, juice characteristics and physiological traits of apple cultivars developed by the Midwest Apple Improvement Association (MAIA) and apple cultivars bred at Iowa State University (ISU) by Spencer Ambrose Beach were compared to an industry-standard cultivar for sweet cider quality from 2022 to 2024. Given the historical and economic significance of apple production in Iowa during the early 1900s and its subsequent decline due to multiple factors, including a devastating winter storm that killed thousands of apple trees, this research examines the potential for regionally bred cultivars to compete with established industry standards. Juice quality parameters were analyzed, including pH, Brix, titratable acidity (TA), sorbitol content, nutritional composition, and oxidation rates. Flowering and harvest dates were assessed to determine the impact of climatic risks like spring and fall freezes, which are typical weather occurrences and concerns for apple growers in the Midwest during bloom and harvest periods, respectively, on production timing and feasibility. Preliminary findings indicate that Secor (ISU) demonstrated comparable juice quality metrics to the industry standard GoldRush and ranked highest in sensory preference evaluations. Sweet Zinger (MAIA) also received high consumer preference scores, suggesting promise as a regionally bred apple that is marketable both as a fresh-eating or cider apple. One cultivar, the Original Delicious (Iowa), scored the lowest consistently in consumer preference. While having relatively high Brix, it lacked acidity, with a pH of 4.0. GoldRush, a preferred cultivar, had a pH value of 3.2, suggesting the need for blending with more acidic cultivars to optimize cider quality. These findings provide insight into the quality and economic viability of regionally bred cultivars and their potential role in strengthening the cider industry in the U.S. Midwest.

Speakers

Olivia Meyer

Iowa State University

Co-authors

Abigail Knight

Iowa State University

Emma Frederick

Iowa State University

Kellie Walters

University of Tennessee-Knoxville

Suzanne Slack

Iowa State University

Tuesday July 29, 2025 2:00pm - 2:15pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

2:00pm CDT

PROP - Seed Priming with Plasma Activated Water Enhances Germination Metrics of Spinach (Spinacia oleracea L.)

Tuesday July 29, 2025 2:00pm - 2:15pm CDT

Strand 12A

Commercial spinach (Spinacia oleracea L.) production is underrepresented in hydroponic production due to inconsistent germination rate, uniformity, and percentage. Seed treatments to enhance germination require tedious decoating of the pericarp or priming with synthetic chemicals. This study was carried out to investigate the effects of plasma activated water (PAW) on spinach seed germination. PAW is generated by applying cold atmospheric plasma to water, resulting in a multitude of direct and indirect chemical reactions at the interface. PAW is rich in reactive nitrogen and oxygen species, and it has been shown to enhance several agricultural processes including seed germination. Seeds of spinach were primed for a set period of time in distilled water (control) or PAW and germinated in petri dishes. After 14 d, seeds that had been primed in PAW for any length of time germinated with greater percentage than control (74.6% and 66.1%, respectively). Optimal priming in PAW was found to be 6 h, yielding a study high germination percentage of 80%. Additionally, seeds primed with PAW improved mean germination time compared to control conditions. This study demonstrates the effectiveness of PAW as a useful tool in seed priming to improve germination.

Speakers

Nathan Eylands

Tuesday July 29, 2025 2:00pm - 2:15pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv
Funding Source California Department of Food and Agriculture

2:15pm CDT

CE 1 - Teen-Leaf Lettuce Cultivar and Lighting Optimization For CEA Cultivation

Tuesday July 29, 2025 2:15pm - 2:30pm CDT

Strand 12B

Determining optimal cultivars and lighting conditions for teen-leaf lettuce in protected cultivation (Controlled Environment Agriculture, CEA) is critical to support the growing leafy greens industry segment. Teen-leaf lettuce is considered to be more mature than baby-leaf and less mature than head lettuce. It is typically harvested at 24-30 days. As teen-leaf lettuce is a relatively new part of the leafy greens industry segment, foundational research into environmental conditions and cultivars is currently lacking. The objective of this experiment is to observe a diverse set of lettuce cultivars growth in response to light intensity. This study provides insight into how different lettuce cultivars respond to varied light intensities and also highlights phenotypic traits to be evaluated to potentially further improve CEA-grown lettuce. Eight cultivars (Azirka, Danstar, Gladius, Ilema, Klee, Muir, Oscarade, Volcana) representing seven lettuce ‘sub-types’ (Crunchleaf, Romaine, Lollo, Salanova, Batavia, Oakleaf, Bibb) were evaluated under two different lighting conditions low DLI (targeting 10 mol m⁻² d⁻¹) and high DLI (targeting 20 mol m⁻² d⁻¹). Fourteen day old seedlings were planted in Deep Water Culture (DWC) systems with three repeated blocks under each lighting treatment. Seedlings were grown in the systems for an additional 21 days. Weekly destructive harvests took place between days 14 and 35 to establish growth curves for several measured parameters: fresh mass, dry weight, leaf count, growth index, and plant diameter for each plant. Cultivars Danstar and Muir had significantly higher fresh weight when grown under the higher light treatment. Higher light also significantly increased dry weight regardless of cultivar, however dry mass responsiveness varied between cultivars. Cultivars Danstar, Gladius, Muir, and Oscarade exhibited significantly higher dry weight when grown under the higher light treatment. Leaf number was not significantly affected by light, except for cultivar Ilema which had significantly more leaves when grown under the higher lighting treatment. The findings of this study provide insight into which cultivars are more shade tolerant and which are better suited for CEA production. Future research will further investigate the phenotypic traits present in these cultivars and identifying anatomical traits (such as stomatal density) that may be associated with higher crop performance, guiding future breeding efforts.

Speakers

Ava Forystek

Cornell University

Co-authors

Neil Mattson

Cornell University

Nick Kaczmar

Cornell University

Tuesday July 29, 2025 2:15pm - 2:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Funding Source Hatch/Smith-Lever, School of Integrative Plant Science Fellowship

2:15pm CDT

O/LT - Thriving in Bloom: Opportunities and Challenges for Flower Growers in the Northeastern United States

Tuesday July 29, 2025 2:15pm - 2:30pm CDT

Strand 11A

Flower production in the Northeastern United States is experiencing a revival as consumer demand for locally grown flowers rises alongside increased interest in sustainable agriculture. However, growers in the region face persistent challenges, including a short and unpredictable growing season, limited land availability, high input and labor costs, and market saturation during peak months. This study draws from field interviews, survey data, and stakeholder engagement with flower growers, floriculture educators, and agricultural service providers across New England. It examines key production and marketing strategies that successful flower farms have adopted, including diversified cropping, succession planting, season extension, direct-to-consumer sales, and floristry integration. Additionally, this work highlights systemic needs in research, infrastructure, and technical assistance tailored to the ornamental crop sector. Findings emphasize the potential for expanded investment in floriculture education, cooperative distribution models, and grower networks to strengthen the viability of flower farming in the region. By elevating grower perspectives and showcasing practical innovations, this presentation contributes to the broader discussion on supporting ornamental crop producers through targeted outreach and research.

Speakers

Ankit Singh

University of Maine

www.aksapsjb.weebly.com

Tuesday July 29, 2025 2:15pm - 2:30pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf

2:15pm CDT

PNM 2 - Can Mild Phosphorus Deficiencies Be Used To Promote Rooting of Southern Highbush Blueberry Transplants?

Tuesday July 29, 2025 2:15pm - 2:30pm CDT

Strand 11B

Phosphorus (P) is an essential nutrient for the growth and development of southern highbush blueberry plants (SHB, Vaccinium corymbosum interspecific hybrids). SHB plants exhibit both morphological and physiological responses to P deficiency. Previous studies have shown that P-deficient SHB plants shift their biomass allocation strategy—favoring root growth while limiting canopy development. Although this response may be detrimental in fruiting fields, it could be advantageous in nursery settings, where young plants must rapidly establish roots in new soils or substrates. Here, we report the results of an experiment evaluating the response of two SHB cultivars, ‘Farthing’ and ‘Sentinel’, to five different P fertilization rates during the nursery stage. Rooted cuttings were transplanted into 1.0-L pots filled with a substrate consisting of 70% coconut coir and 30% horticultural-grade perlite. Plants received weekly applications of 0, 15, 30, 45, or 60 mg P, while all other nutrients were supplied through a P-free commercial fertilizer. The plants were grown in a temperature-controlled greenhouse for 12 weeks. Subsets from all treatments (n = 6) were destructively harvested at weeks 0, 4, 8, and 12 to assess plant growth and nutrient content. P fertilization treatments had profound effects above and belowground. Leaf P concentrations exceeded the deficiency threshold only in plants receiving more than 15 mg P per week. Root biomass responses to P treatments differed between cultivars: low P rates increased root biomass in ‘Farthing’ SHB but decreased it in ‘Sentinel’ SHB. P deficiency symptoms appeared in ‘Farthing’ SHB leaves after 12 weeks, while symptoms appeared in week 8 in ‘Sentinel’ SHB leaves. These findings suggest that a brief period of suboptimal P fertilization could be used to promote rooting in ‘Farthing’ SHB during nursery production. However, this strategy may not be effective for ‘Sentinel’. Future research should explore P deficiency responses across a broader range of SHB cultivars to develop generalizable nursery practices that encourage rapid root development while minimizing P leaching.

Speakers

Gerardo Nunez

University of Florida

Co-authors

Marlon Retana-Cordero

University of Florida

Tuesday July 29, 2025 2:15pm - 2:30pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv
Funding Source Florida Department of Agriculture and Consumer Services - Office of Agricultural Water Policy (Contract #28710)

2:15pm CDT

POM 1 - From GWAS to Glass: Genetic Insights into Cider Apple Quality

Tuesday July 29, 2025 2:15pm - 2:30pm CDT

Foster 1

Traditional cider apples are typically classified by their sugar, acid, and phenolic composition and concentration, which all impact the sensory profile and fermentation characteristics of the final beverage. Despite the practical importance of these traits, the genetic basis underlying cider apple fruit quality remains poorly understood and few functional genetic markers have been successfully adapted for cider apple breeding. Using a genome-wide association study (GWAS) on 253 cider apple accessions from the USDA-Plant Genetic Resources Unit Malus collection held in Geneva, NY, we found 19 significant marker-trait associations for titratable acidity, pH, total polyphenols, and non-structural carbohydrates. Notably, we identified a distinct marker on chromosome 15 strongly associated with total polyphenols, a key determinant of bitterness and astringency. A major association on chromosome 16, near the Ma1 locus, explained a substantial proportion of the phenotypic variance for titratable acidity and pH, confirming the importance of this region. Significant marker-trait associations were detected for sugar concentration on chromosomes 1, 6, 8, and 10. Further analysis confirmed identification of favorable alleles for titratable acidity, total polyphenols, glucose and sucrose concentration. These results provide a foundation for identifying apple cultivars with desirable phenotypic traits for cider production from germplasm collections and for making marker assisted selections within breeding programs.

Speakers

Pierre Bouillon

Cornell University

Co-authors

David Zakalik

Cornell University, Horticulture

Gregory M. Peck

Cornell University, Horticulture

Michael G. Brown

Cornell University, Horticulture

Tuesday July 29, 2025 2:15pm - 2:30pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

2:15pm CDT

PROP - Photoperiods Significantly Affect Rooting Qualities of Kratom Stem Cuttings in an Aeroponic System

Tuesday July 29, 2025 2:15pm - 2:30pm CDT

Strand 12A

Kratom (Mitragyna speciosa), a tropical evergreen tree indigenous to Southeast Asia, has gained attention in recent years due to its potential as a natural medicine for pain management and its ability to alleviate symptoms associated with opioid withdrawal. These properties indicate that kratom could be a promising candidate for drug development aimed at addressing the opioid epidemic. Despite growing interest in kratom’s therapeutic applications, its domestic cultivation remains limited, and investigations on vegetative propagation methods are unavailable. The traditional propagation technique, i.e., rooting stem cuttings in greenhouse settings with misting systems, has resulted in inconsistent success and varying quality. To address these challenges and improve propagation efficiency, this study evaluated the use of an aeroponic system to root kratom cuttings in controlled environments under various conditions. Stem cuttings were cultured in aeroponic devices under three photoperiods provided by light-emitting diode (LED) lights in environmentally controlled rooms. Rooting percentages reached 87, 88, and 90% in six weeks under 10-, 14-, and 24-hr photoperiods, respectively. Cuttings rooted three days earlier under 24-hr compared to those rooted at 10- and 14-hr photoperiods. On the other hand, the 14-hr photoperiod led to the highest root dry mass,109% and 14% greater than the 10- and 24-hr treatments, respectively. Furthermore, propagules rooted under 14-hr photoperiod had the highest total root length, 92% and 33% greater than those rooted under 10- and 24-h photoperiods. Additionally, the 14-hr photoperiod significantly enhanced root projected area, surface area, root volume, and number of root forks by 82, 81, 80, and 124%, respectively compared to those rooted under the 10-hr photoperiod, although these enhanced parameters were not statistically different from those rooted under 24-hr photoperiod. Our results showed that photoperiod generally had little effect on rooting percentages, shoot growth (e.g. new leaf number and new leaf area), average root diameter, and number of root tips and crossings; higher rooting quality was produced under 14-hr photoperiod. These findings provide valuable insights for improving rooting of this novel medicinal plant.

Speakers

Mengzi Zhang

Biological Scientist, University of Florida

Co-authors

Brian Pearson

Oregon State University

Jianjun Chen

University of Florida

Tuesday July 29, 2025 2:15pm - 2:30pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv

2:30pm CDT

CE 1 - Evaluation of Narrowband Supplemental Lighting and Nitrogen Concentrations on Physiology, Growth, and Yield of Hydroponic Lettuce

Tuesday July 29, 2025 2:30pm - 2:45pm CDT

Strand 12B

Maintaining optimal daily light integrals (DLI) and nutrient solution concentrations is essential for enhancing growth traits of leafy greens such as lettuce (Lactuca sativa L.) in greenhouse production systems. Research is needed to better understand the synergistic effect of supplemental lighting and nitrogen (N) concentrations on hydroponic lettuce production during seasons of low natural light. The objective of this study was to determine the effects of narrowband supplemental lighting treatments and nitrogen concentrations on the growth, yield, and physiological traits of lettuce cultivars in a nutrient film technique (NFT) hydroponic system. Three lettuce cultivars (cvs. Nancy, Salvius, and Thurinus) were grown in the fall of 2024 (Nov 13. to Dec 18.) and the winter of 2025 (Jan 29. to March 03.) under three light treatments including supplemental 80% red and 20% blue light (80R/20B); 80R, 10B, and 10% far red light (80R/10B/10FR); non-supplemental natural light (control) and two nitrogen concentrations (100 and 200 ppm N). Both light treatments supplemented a DLI of 6 mol.m-2.d-1. Supplemental lighting treatments had limited effects on the weekly net assimilation rate, averaging 11.124 and 10.130 µmol.m-2.s-1 versus 12.046 and 10.564 µmol.m-2.s-1 in the control treatments in fall and winter cycles, respectively. In fall with 200 ppm N, the 80R/20B and 80R/10B/10FR light treatments significantly increased the fresh yield by 90% and 45% respectively when compared to the control treatment. While in winter with 200 ppm N, these increases were only 10% and 1%, suggesting a relatively limited benefit of supplemental lighting during this season. With 100 ppm N during the winter cycle, compared with the non-supplemented light, 80R/20B and 80R/10B/10FR lights increased the yield by 58% and 30% respectively while contrasting results were observed with the light treatments with 100 ppm N in the fall cycle. Supplemental light in the fall cycle increased the average leaf area index (LAI) by 27% only when combined with 200 ppm N but not with 100 ppm. In contrast, in winter, supplemental light increased LAI by 11% only with 100 ppm N but not with 200 ppm N. Overall, the beneficial effect of supplemental lighting on the growth and yield traits was greater in fall when combined with 200 ppm N but was greater in winter when combined with 100 ppm N.

Speakers

Joshua Osuch

East Texas A

Co-authors

Desire Djidonou

East Texas A

Tuesday July 29, 2025 2:30pm - 2:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Poster # csv

2:30pm CDT

O/LT - Enhanced Detection of Japanese Maple Scale Using Cutting-Edge Artificial Intelligence Technology

Tuesday July 29, 2025 2:30pm - 2:45pm CDT

Strand 11A

The Japanese maple scale (JMS) (Lopholeucaspis japonica) is an armored scale insect that causes significant losses in the ornamental industry through direct injury, plant rejection, unmarketable stock, increased pest control costs, and restricted interstate plant movement. Ornamental growers typically identify JMS by visually inspecting trunks, branches, and twigs for waxy covers or by using sticky tape traps to monitor crawler activity. However, its microscopic size and camouflaged appearance make early detection challenging. This study aims to develop an artificial intelligence (AI)-guided, on-the-go pest scouting system to address the current challenges in early management of JMS in ornamental crop production. To develop the scouting system, a Sony ILX-LR1 professional camera with a 61.0 megapixel full-frame sensor and interchangeable E-mount lenses designed for detailed industrial applications is used to capture high-resolution images. A small amount of data has been collected so far, with plans to gather a larger image dataset during the summer months. In the initial analysis, captured images were sliced into smaller patches to make the microscopic JMS detectable. These sliced images were used to train a transformer-based AI model for detecting JMS. The trained model, tested on the small dataset, showed it could detect JMS with an Intersection over Union (IoU) of over 0.8. While the model shows potential for detecting microscopic JMS, comprehensive training and testing with a larger dataset are needed to validate its performance. Upon completion, the developed scouting technology will serve as an effective tool for early detection and management of JMS in nursery environments, reducing plant injury and rejection while improving profits for ornamental growers.

Speakers

Hasan Jahanifar

University Of Georgia

Co-authors

Karla Addesso

Tennessee State University

Md Sultan Mahmud

University Of Georgia

Tuesday July 29, 2025 2:30pm - 2:45pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf

2:30pm CDT

PNM 2 - Relationship between indexes of soil nutrient availability and foliar analysis in cranberries (Vaccinium macrocarpon Aiton) through the crop phenology in Southern of Chile

Tuesday July 29, 2025 2:30pm - 2:45pm CDT

Strand 11B

Cranberry, a fruit crop native to North America, has found a thriving production hub in Southern Chile. While the USA and Canada lead global production, Chile stands out in the Southern Hemisphere, achieving remarkable yields and demonstrating significant potential for future growth. Crucial to this success is effective nutrient management, as cranberries are cultivated in sandy soils with limited clay content. This research investigates the critical nutritional requirements of cranberry plants in Southern Chilean agroecosystems, correlating soil and plant tissue analyses across different phenological stages. We aim to establish optimal nutrient levels for maximizing yield and quality. Our study, conducted in collaboration with Cran Chile from 2018 to 2020, monitored 'Pilgrim' cranberry plants across three parcels under four different fertilization strategies. We tracked the foliar variation of ten essential nutrients, comparing plants grown in soils with varying fertility levels and aligning these data with growing degree days (GDD) to model nutrient dynamics. Key findings reveal distinct patterns in nutrient concentration over time: Nitrogen, phosphorus, and potassium levels decreased, while magnesium, sulfur, iron, and zinc followed a third-degree polynomial curve. Calcium, boron, and manganese concentrations increased throughout the season. These nutrient dynamics provide a broader window for tissue sampling and are essential for establishing critical nutrient concentration benchmarks for cranberry plants. Furthermore, this study examines the phenology of cranberry in Southern Chile, comparing it to established models from the USA and Canada. We utilized GDD-based functions to model phenological stages, revealing a notable difference: cranberry development in Chile occurs earlier than in the Northern Hemisphere. This advancement is likely attributed to the milder winters in Chile, which result in less pronounced dormancy compared to the colder climates of the USA and Canada. In conclusion, this research provides valuable insights into the nutritional needs and phenological behavior of cranberry plants in Southern Chile. By understanding these dynamics, we can optimize cultivation practices, ensuring sustainable and high-yield cranberry production in the region.

Speakers

Dante Pinochet

Universidad Austral de Chile

I am Profesoor in Soil Science working in horticultural crops nutrition

Co-authors

Danilo Abarca

Cran Chile

Guillermo Ernst

bestfed

Luz Maria Bennett

Cran Chile

Tuesday July 29, 2025 2:30pm - 2:45pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv

2:30pm CDT

POM 1 - The Foraged Fruit Project: Explorations into Foraging Apples for Hard Cider Production

Tuesday July 29, 2025 2:30pm - 2:45pm CDT

Foster 1

The Foraged Fruit Project began in 2021 and involves researchers from Cornell and Rutgers Universities, with support from the New York Cider Association and funding from the David M. Einhorn Center for Community Engagement. The aim of this project was to better understand the practice of foraging in New York through a transdisciplinary lens, which includes ethnographic interviews, genetic identification of apple trees, and fruit quality assessments of the foraged apples. Over 30 commercial cider producers were interviewed for this study and we analyzed fruit samples from nearly 50 different trees. Seventy-eight percent of the submitted samples were unique apple genotypes, meaning there was no match among the thousands of samples in the MyFruitTree reference panel managed by Washington State University. According to the Long Ashton Research Station’s cider apple classification, 45% of the apple samples were bittersharp, 14% were bittersweet, 35% were sharp, and 6% were sweet. Based on these data, New York cider producers are largely foraging for high tannin and high acid apples which are difficult to procure from commercial apple producers in the region. Common themes revealed through the ethnographic interviews related to climate change resiliency, reparation for indigenous groups, intellectual property control, discovering unique genetics, and access to public and private lands. By studying these factors, we sought to better support the practice of foraging, unlock unique apple genetics that can benefit growers in a rapidly changing climate, and increase the profitability and uniqueness of New York cider.

Speakers

Gregory Peck

Cornell University

Co-authors

Andrew James

Cornell University

Maria Kennedy

Rutgers University

Victoria Broughton

Cornell University

Tuesday July 29, 2025 2:30pm - 2:45pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

2:30pm CDT

PROP - Rooting Herbaceous Cuttings in Stratified Substrates

Tuesday July 29, 2025 2:30pm - 2:45pm CDT

Strand 12A

Stratified substrates may offer some advantages in containerized plant production, but their function in the propagation environment has not been extensively studied. We tested unrooted cutting root develop and plug stability with four herbaceous species [Agastache × ‘Sunrise Red Improved’, Cuphea hyssopifolia 'Maria' (Floriglory®), Gaillardia ×grandiflora 'Eclipse' (Lunar®), and Salvia ×jamensis 'Ignition Purple' (VIBE®)] in stratified propagation substrates. We used small, round pots to mimic a liner cell (top diameter 63.2 mm, depth 61.2 mm, volume 140 cm3 ). The control was a commercial propagation mix. We created top and middle-stratified treatments, using amendments of coarse perlite, fine coconut shell biochar, and parboiled rice hulls. The top-stratified treatments had 3 cm of an amendment material on top, with the control substrate underneath. The middle-stratified treatment contained the control on the top and bottom, with a 2-cm layer of amendment in the middle. We tested the species in separate experiments, with 7 replications each, in an approximately 30 day experiment. We repeated the experiments in a second cycle. At harvest, we assigned each cutting a plug integrity rating on a 0 to 5 scale: 0 = no visible roots, unstable, 1 = minimal roots, one or two roots visible, unstable, 2 = moderate roots, more than two roots but large spaces with no roots, partially unstable, 3 = acceptable roots, many roots with only small gaps, stable, 4 = optimum roots, many roots with full coverage, stable. Most of the stratified substrates had lower ratings than the control (P < 0.05). The top stratified rice hull treatment had a lower mean rating than the control for every plant in every cycle. Cuphea and Gaillardia with middle perlite stratification were not significantly different than the control in both cycles, while all top stratified mixes had significantly lower ratings than the control for Cuphea. Root growth in stratified substrates was similar to the control in the majority of cases. Cuphea cuttings had lower total root length (mm) than the control in all top stratification treatments and the middle perlite treatments in both cycles (P < 0.05). Some non-significant trends in the data repeated in both cycles, showing repeating patterns between the stratification treatments. Stratified substrates generally had lower plug integrity than the control, with few significant root growth effects.

Speakers

Benjamin Hoover

Associate Professor of Sustainable Nursery Production, California Polytechnic State University

Co-authors

Annica Wu

California Polytechnic State University

Emma Whitehead

California Polytechnic State University

Martin Joseph De La Cruz

California Polytechnic State University

Tuesday July 29, 2025 2:30pm - 2:45pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv
Funding Source We thank Griffin Greenhouse Supplies, Inc for donating unrooted cuttings.

2:45pm CDT

CE 1 - Optimizing Lettuce Growth in Controlled High-Humidity Environments

Tuesday July 29, 2025 2:45pm - 3:00pm CDT

Strand 12B

Successful cultivation of lettuce in indoor agriculture relies on precise control of environmental factors to optimize crop yields. However, some controlled environment facilities may lose control of humidity due to the net moisture input of transpiration from high-density lettuce overwhelming dehumidification and cooling systems. This study observed the effects of different lighting treatments and air velocities on lettuce at varying levels of humidity as a means of mitigating deleterious effects of elevated humidity. Romaine lettuce (Lactuca sativa, cv. Teton) was cultivated in three growth chambers under three different humidity levels (70%, 80%, and 90%). Each room contained three hydroponic trays setup up for ebb and flow, with one lighting treatment per tray: white light (W), white light supplemented with far red (WFR), and wide amber supplemented with far red (WA). Additionally, each tray contained a low and high velocity zone at 0.5 and 1 m/s respectively, delivered by a polyethylene tube attached to a duct fan. Average velocity ranged from 0.23–3.0 m/s, but no correlation between air velocity and any growth parameter was observed for any treatment. However, tipburn for all treatment combinations was either less severe or eliminated altogether. This can be attributed to the general improvements in plants’ transpiration rates as the air velocity increased. Increasing humidity enhanced growth parameters except for fresh mass, where 70% and 90% RH did not differ significantly but both outperformed 80% RH by 9%. For other metrics—height, head diameter, chlorophyll content, and dry mass—80% RH and 90% RH performed better than 70% RH but did not significantly differ. WA performed the best for all growth parameters, with 7.4% and 14% greater leaf area than W and WFR respectively. Compared to WA, WFR underperformed in most metrics despite also having far-red supplementation, indicating potentially more synergistic interactions of FR with amber wavelengths than blue or red wavelengths. Gas exchange results varied based on the treatments, but it was generally observed that photosynthetic rates were higher at higher air velocities and under WA. The results of this study indicate the effectiveness of air velocity levels up to 3.0 m/s at eliminating tipburn in lettuce up to 90% RH without causing additional stress responses. Further improvements can be achieved with WA supplemented with far-red, improving both morphological development and physiological processes even at higher humidity levels.

Speakers

Wong Jordan

McGill University

Co-authors

Mark Lefsrud

McGill University

Tuesday July 29, 2025 2:45pm - 3:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Poster # csv

2:45pm CDT

O/LT - Effects of Azospirillum Brasiliense on Zoysiagrass

Tuesday July 29, 2025 2:45pm - 3:00pm CDT

Strand 11A

Zoysiagrass is a popular choice for Florida lawns but requires supplemental fertilization and irrigation. Nitrogen-fixing bacteria, such as Azospirillum Brasilense (Azb), may improve nutrient uptake and rooting, potentially reducing fertilizer and irrigation needs. The experiment is taking place from Summer 2024 to Fall 2026 at the University of Florida, evaluates the effects of Azb on Zoysiagrass under varying nitrogen (N) and irrigation rates. The experiment uses ‘CitraZoy’ Zoysiagrass treated with three Azb products (Tazo-B, AzoPro Turf, Azo Root) and a non-inoculated control. Treatments are applied monthly at three N levels (100%, 50%, 0%) and two irrigation levels (100% and 75% recommended irrigation), using a randomized complete block design with four replicates per treatment. Weekly data collection includes normalized difference vegetation index (NDVI), visual quality, soil moisture, and digital image analysis. Statistical analysis is performed using ANOVA, with mean comparisons determined by Fisher’s Protected Least Significant Difference (LSD) at p ≤ 0.05. Results indicate that Azb products mitigate the impact of reduced irrigation on soil moisture. Combining Tazo-B or Azo Root with 50% N achieves an optimal balance of turf quality and sustainability. Additionally, Tazo-B with 100% N and 75% irrigation yields green cover comparable to fully irrigated treatments. These first-year findings suggest Azb enhances Zoysiagrass performance while reducing nitrogen and irrigation requirements. A second year of research will confirm these results, supporting the potential of Azb to improve turfgrass sustainability.

Speakers

VICTOR ABARCA

University of Florida

Co-authors

Alex Lindsey

University of Florida

Tuesday July 29, 2025 2:45pm - 3:00pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf
Poster # csv

2:45pm CDT

PNM 2 - Correlating Spectrographic Data to the Changes in Nitrogen Status of Three Cranberry Cultivars.

Tuesday July 29, 2025 2:45pm - 3:00pm CDT

Strand 11B

The goal of this project is to determine what electromagnetic radiation wavelengths correlate with the changes in the nitrogen status of three cranberry cultivars. For this project, isolated propagation containers or “mini-bogs” were evenly split between three cultivars: Early Black, Stevens, and Mullica Queen. Each “mini-bog” was planted with 98 cranberry plugs. Each cultivar was subsequently split into four even groups with each group assigned one of four fertilizer regimes: 10% optimal, 50% optimal, 100% optimal, and 150% optimal. Over that growing season, physiochemical and spectrographic data was collated from 48 sets of cranberry plants grown separately in “mini-bogs”. Canopy and contact level spectrographic data was collected using the ASD FieldSpec 4 field spectrometer and leaf clip attachment. Clippings from each “mini-bog” were collected after spectrographic data collection and sent for wet digestion total nitrogen laboratory analysis. Using the Automated Radiative Transfer Models Operator (ARTMO) package within MATLABs and ARTMO’s Machine Learning Regression Algorithms (MLRAs) toolbox and Spectral Indices (SI) toolboxes, we were able to examine 298 datasets collected during the 2024 growing season. MLRA results show strong correlation between the changes in the nitrogen concentration and the spectrographic readings. The MLRA produced correlation results for 30 machine learning regression algorithms, including gaussian processes, kernel ridge process, random forest processes, linear regressions, and neural network processes. Early Black had a correlation up to 98.41%, Stevens up to 91.43% correlation, and Mullica Queens had up to 99.98% correlation. Applying the strongest correlation of the MLA functions to the band analysis tool within MLRA, we identified the top 20 bands out of 2151 bands that strongly correlate with the changes in the nitrogen concentration. This study showed that over 20 electromagnetic radiation wavelengths correlated strongly with the changes in the nitrogen status of our cultivars. Combining these wavelengths with reference wavelength in a spectral index is the next step to finding a combination that can accurately and precisely derive the nitrogen status of cranberry vegetation.

Speakers

Jeremy Foote

University of Massachusetts - Amherst

Tuesday July 29, 2025 2:45pm - 3:00pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 1

Subject Plant Nutrient Management
Poster # csv
Funding Source Cranberry Institute

2:45pm CDT

POM 1 - UAV Remote Sensing for Diagnosing Rapid Apple Decline

Tuesday July 29, 2025 2:45pm - 3:00pm CDT

Foster 1

Modern apple production has moved from traditional open orchard formats to that of high-density trellised plantings. As industry has shifted, the number of trees in commercial apple orchards typically reaches 1,500 per acre, making the management of these orchard blocks on a per-tree basis impractical. The use of unmanned aerial vehicles (UAVs) in the form of portable drones offers a method for collecting image data for thousands of trees in a matter of minutes. Combining these UAVs with multispectral cameras, which collect visual data on spectra that the human eye cannot perceive, allows for the calculation of vegetation indices (VIs) such as the normalized difference vegetation index (NDVI) for individual trees. Many VIs correlate with important orchard management considerations such as tree vigor, nutrient status, and disease severity. Multiple challenges hinder the incorporation of VIs into orchard management: parsing data on a per-tree basis is challenging in high-density systems, there is no comprehensive understanding of how VIs vary across a growing season and between cultivars, and at what magnitude deviation from expected norms is indicative of a weak tree is uncertain. This experiment aimed to classify this variation in VIs by examining a large cohort of cultivars at multiple timepoints and sites. A DJI Mavic 3M equipped with a 4-channel (green, red, red edge, and near infrared) multispectral camera was used to perform flights at both commercial and research orchards in upstate New York. Orthomosaics of each site were created using Agisoft Metashape and analyzed in QGIS and R (using the FIELDimageR package). Results showed statistically significant differences in VI values between cultivars and timepoints. These differences increased in intensity later in the growing season- in September, differences in cultivar explained 40% of the observed variance in NDVI at one orchard site, compared to only 19% in July.

Speakers

Kenneth Buck

Cornell University

Co-authors

Jason Londo

Cornell University

Tuesday July 29, 2025 2:45pm - 3:00pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology

2:45pm CDT

PROP - The Effects of Indole-3-Butyric Acid (IBA) and Propagation Duration for Leaf Cuttings on three Achimenes Cultivars

Tuesday July 29, 2025 2:45pm - 3:00pm CDT

Strand 12A

Achimenes are rhizomatous gesneriads that can be used as flowering houseplants or grown in hanging baskets and mixed containers. Achimenes are typically asexually propagated from scaly rhizomes. The potential exists to propagate from leaf cuttings, however, there is limited published information on this propagation method. Thus, a leaf cutting study was initiated to further investigate the effects of indole-3-butyric acid (IBA) and propagation time on root development, plantlet, and rhizome production. We tested three Achimenes cultivars, ‘Charm’, ‘Apricot Glow’, and ‘Pink Cloud’. A total of 96 leaf-cuttings per cultivar were obtained from pre-flowering plants. Leaves were treated with one of four treatments; control (water), 1,000, 3,000, and 8,000 ppm of powder rooting hormone and were propagated under mist for a period of 3, 6, or 9 weeks. Data collection included root fresh and dry weights, plantlet number (stolons that emerged above the media surface), and rhizome development. In addition, root development was qualitatively evaluated on a scale from 1 = no rooting to 5 = prolific rooting. Propagation time significantly impacted each variable for all cultivars (p < 0.0001). Root ratings showed that all cultivars had ratings of 5 at 6 and 9 weeks, significantly higher than at 3 weeks. Generally, root dry weights significantly increased with increased propagation times. The interaction between rooting hormone and propagation time was significant for ‘Charm’ and ‘Apricot Glow’ for plantlet production. Increased plantlets were observed as both hormone concentration and propagation time increased, although not always significantly. ‘Apricot Glow’ leaf cuttings treated with 1,000 ppm and propagated for 9 weeks produced the most plantlets (1.6), however, plantlet number was not significantly different between hormone concentrations. Rhizome development significantly increased as propagation time increased for all cultivars (p < 0.0001). Rhizome number of all three cultivars significantly increased by double or triple for cuttings grown for 9 weeks compared to the 3 weeks. Our findings suggest that rooting hormones are negligible in enhancing propagation of Achimenes leaf cuttings for the cultivars evaluated. Propagation duration has a greater impact on growth and development than treatment concentrations. In this study, minimal differences in growth and development were observed after 6 weeks. This suggests that the ideal propagation period is within 3 and 6 weeks. Additional leaf cutting research is warranted to evaluate subsequent growth and development of Achimenes plants.

Speakers

Liz Malobicky

Colorado State University

Co-authors

Chad T. Miller

Colorado State University

Tuesday July 29, 2025 2:45pm - 3:00pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv
Funding Source The Fred C. Gloeckner Foundation Research Fund

3:00pm CDT

CE 1 - Multi-Season Comparison of Lettuce Growth and Water Use in Three Different Hydroponic System Types, Deep-Water Culture, Nutrient Film Technique, and Vertical System

Tuesday July 29, 2025 3:00pm - 3:15pm CDT

Strand 12B

This study evaluated the growth, yield, and water use of four lettuce cultivars (Lactuca sativa L. cv. ‘Green Forest’ (GF), ‘New Red Fire’ (NRF), ‘Paris Island’ (PI), and ‘Rouxai’ (R)) cultivated in three different hydroponic system types: Deep-Water Culture (DWC), Nutrient Film Technique (NFT), and Vertical System (VS). Trials were conducted across three seasons (S1: Oct–Nov 2023; S2: Mar–Apr 2024; S3: Apr–May 2024) in a high tunnel at the Texas A

Speakers

Seunghyun Choi

Postdoctoral research associate, Texas A&M Agrilife Research

Co-authors

Asmita Nagila

Texas A

Asmita Sharma

Texas A

Chungkeun Lee

Texas A

Daniel Leskovar

Texas A

Joshua Harvey

Texas A

Xuejun Dong

Texas A

Tuesday July 29, 2025 3:00pm - 3:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Poster # csv

3:00pm CDT

O/LT - Improving Turfgrass Vitality and Irrigation Efficiency with Compost Amendments

Tuesday July 29, 2025 3:00pm - 3:15pm CDT

Strand 11A

As climate variability increases and urban water demand rises, the turfgrass industry faces challenges in maintaining high-quality landscapes with limited irrigation. Water restrictions and escalating costs necessitate sustainable solutions to improve water efficiency without compromising turf performance. Research from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has shown that compost incorporation can enhance soil structure, increase plant-available water, and potentially reduce irrigation needs for warm-season turfgrasses in Florida. While initial studies demonstrated benefits for new landscape installations, limited research exists on established lawns. Our study aims to evaluate the influence of compost and fertilizer applications under varying irrigation conditions on turfgrass quality. This study, conducted in 2023 and 2024 at the UF/IFAS Plant Science Research and Education Unit in Citra, Florida, examines the combined effects of compost and fertilizer applications under different irrigation regimes. The experimental design had six distinct management practices: a control with neither compost nor fertilizer; compost topdressing once per growing season; combined compost topdressing and fertilizer application once per season; compost topdressing twice per season; both compost and fertilizer applied twice per season; and fertilizer alone applied twice per season. Irrigation was applied at 50%, 75%, and 100% of UF/IFAS recommendations. Compost was applied at 0.5 yd³/1000 ft², and fertilizer at 1.0 lb N/1000 ft². Results from statistical analysis consistently demonstrated that compost topdressing combined with fertilizer twice per season (CTD

Speakers

Jaspal Singh

University of Florida

Co-authors

Alex Lindsey

University of Florida

Eban Bean

University of Florida

Natasha Restuccia

University of Florida

VICTOR ABARCA

University of Florida

Tuesday July 29, 2025 3:00pm - 3:15pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf
Poster # csv

3:00pm CDT

PNM 2 - Leaf Sap Analysis To Monitor Nutrient Dynamics In Peaches And The Effects Of Foliar Applications During Fruit Growth

Tuesday July 29, 2025 3:00pm - 3:15pm CDT

Strand 11B

Current fertilization recommendations for mature peach orchards rely on spring soil sampling and postharvest leaf analysis. Soil sampling assesses nutrient status at the soil level, while standard leaf analysis is mainly useful for the next crop cycle, limiting major in-season adjustments. The objective of this study was to understand how macro and micro elements change over time using leaf sap nutrient analyses. This study was conducted in a nine-year-old peach orchard using a split-plot randomized complete block design with three replicates, where irrigation systems, drip vs micro-sprinkler, served as whole-plots and foliar treatments as split plots. Foliar treatments included water (control), nanocellulose crystals (CNC 3%), Calcium (Ca 6%), Potassium Silicate (K2SiO3), CNC plus Ca, and CNC plus K2SiO3. Trees did not receive any soil-based fertilization and water was managed based on the Peach Smart Irrigation App recommendations (https://smartirrigationapps.org/peach-app/). Foliar applications were carried out three or four days prior to leaf sampling. Leaf samples, including petioles, were collected between 8 am and 11 am at 40, 72, 86, and 100 days after full bloom (DAFB) for sap analysis. Leaf sap analysis showed that N, primarily as NH₄, and Mg, were within sufficiency ranges. P and K were excessive; and Ca, S, and all micronutrients were deficient. Elevated P likely limited Zn and Fe uptake. B deficiency may have impaired sugar, N, and P loading and transport to sink tissues. Mo (

Speakers

Selvin Carrillo Ramos

University of Georgia

Co-authors

Dario Chavez

University of Georgia

Tuesday July 29, 2025 3:00pm - 3:15pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv

3:00pm CDT

POM 1 - Role of Oxidative Stress in Strawberry (Fragaria x ananassa) Fruit Development

Tuesday July 29, 2025 3:00pm - 3:15pm CDT

Foster 1

Understanding the dynamics of oxidative stress during the growth of strawberry fruits is essential for optimizing fruit yield, quality, and shelf life. By strategically targeting reactive oxygen species (ROS) generation and the antioxidant defense mechanisms across various developmental stages, researchers and producers can refine cultivation practices, resulting in healthier and more flavorful strawberries. Strawberry fruits were categorized into six distinct developmental and ripening stages: small-size green fruits (S1, indicating the early stage of development), medium-size green fruits (S2, characterized by continued growth and elongation), full-size green fruits (S3, where the fruit attains its final size), white fruits (S4), turning-stage pink fruits (S5), and fully matured red fruits (S6). To evaluate the influence of oxidative stress and antioxidant defenses throughout the growth phases, several parameters were analyzed. These included hydrogen peroxide (H2O2), malondialdehyde (MDA), superoxide dismutase (SOD), lipoxygenase (LOX), catalase (CAT), guaiacol peroxidase (GPOD), ascorbate peroxidase (APOD), glutathione reductase (GR), and glutathione-S-transferase (GST). The levels of H2O2 and MDA exhibited variation across the different developmental stages. SOD and POD activities demonstrated an initial increase followed by a decline, while CAT and APOD levels showed a decrease in the later stages of fruit development. Additionally, LOX activity was elevated in the early developmental stages and declined as maturation progressed. The intricate role of oxidative stress in strawberry fruit growth highlights its significance for improving cultivation methods and post-harvest management. This understanding not only contributes to delivering superior-quality strawberries to consumers but also promotes sustainable agricultural practices.

Speakers

Naveen Dixit

University of MD Eastern Shore

Tuesday July 29, 2025 3:00pm - 3:15pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology
Poster # csv
Funding Source USDA Evans-Allen

3:00pm CDT

PROP - Technological Advances in Micropropagation of Northern Berry Crops and Variations in Micropropagated Plants

Tuesday July 29, 2025 3:00pm - 3:15pm CDT

Strand 12A

Northern berry crops including blueberry (Vaccinium spp.), lingonberry (V. vitis-idaea L.), cranberry (V. macrocarpon Ait.), cloudberry (Rubus chamaemorus L.) and huckleberry (V. membranaceum Douglas ex Torr.) are native to the North. Their health promoting role in anti-oxidant, anti-inflammatory, anti-ulcer and anti-tumor activities is due to their high contents of bioactive components. Although conventional methods of berry crop propagation are successful, for producing a large number of disease-free high quality plants, in vitro propagation (micropropagation) is more desirable. With the introduction of in vitro culture techniques, it is widely used to produce the true-to-type plants for year around multiplication. Propagation in vitro, using semi-solid and liquid media in different bioreactor systems, has advanced a multi-billion dollar industry in various crop plants globally. However, stresses during in vitro culture can provoke a range of genetic and epigenetic variabilities in the genome of the micropropagules leading to somaclonal variation. These variations (genetic or epigenetic) in micropropagated berry crops that include increased shoot and rhizome growth, berry production and/or antioxidant properties, might be useful for early establishment and berry production to the northern growers. This review updates the propagation technologies used in northern berry crops along with the evaluation of clonal fidelity and somaclonal variation in micropropagated plants. The existing gap in literature will be covered.

Speakers

Samir Debnath

St. John’s Research and Development Centre

Samir Debnath, Ph.D., P.Ag. Dr. Samir C. Debnath, a Research Scientist of Agriculture and Agri-Food Canada and an Adjunct Professor of Biology, Memorial University of Newfoundland, has authored and co-authored around 140 publications in peer-reviewed journals including review papers... Read More →

Co-authors

Abir Igamberdiev

Memorial University of Newfoundland

Amrita Ghosh

Memorial University of Newfoundland

David McKenzie

St. John's Research and Development Centre

Mehdi Sharifi

Summerland Research and Development Centre

Dr. Mehdi Sharifi is a “soil nutrient management” research scientist at Summerland Research and Development Centre in British Columbia, Canada. Before his current position, he was a professors at Trent and Dalhousie Universities. He completed two postdoctoral fellow positions... Read More →

Rajesh Barua

Memorial University of Newfoundland

Rishi Burlakoti

Agassiz Research and Development Centre

Sayani Kundu

Memorial University of Newfoundland

Sweety Majumder

Memorial University of Newfoundland

Umanath Sharma

Memorial University of Newfoundland

Tuesday July 29, 2025 3:00pm - 3:15pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv

3:15pm CDT

CE1 - Lunar Regolith Supports Lettuce Seedling Growth With Nutrient Supplementation

Tuesday July 29, 2025 3:15pm - 3:30pm CDT

Strand 12B

Better understanding of food production using in situ resources such as lunar regolith is necessary as we advance to establish an ongoing presence on the moon. The potential of lunar regolith to serve as a viable substrate for plant growth has yet to be studied. We investigated the feasibility of using lunar regolith for cultivation of two lettuce cultivars (‘Outredgeous’ and ‘Rex’) in two types of simulants, JSC-1A (lunar mare) and OPRH4W30 (lunar highlands), compared to inert substrates peat and rockwool, with and without a complete nutrient solution. The experiment was conducted under controlled conditions (200 µmol m-2 s-1, 25/22 °C, and 70% relative humidity) in a walk in growth chamber, assessing seed germination, seedling growth, and biomass accumulation over three consecutive plantings. In the first harvest, peat and rockwool with nutrient supplementation yielded the greatest fresh and dry mass, while regolith with deionized water severely stunted growth. Nutrient supplementation enhanced plant growth in regolith, with an 8.4-fold increase in shoot fresh weight and a 7.3-fold increase in leaf area for ‘Rex’ grown in JSC-1A compared to those grown with deionized water. Similar responses were observed in ‘Outredgeous’ and in the OPRH4W30 simulant. However, plant growth in simulants was substantially reduced, up to 13.5 times smaller, compared to rockwool and peat, even when supplemented with the same nutrient solution. However, growth in both regolith types with nutrient supplementation improved with subsequent plantings. Seed germination varied across substrates in initial planting, averaging 67% in OPRH4W30, 77% in the JSC-1A, and 88-93% in peat and rockwool, but increased to over 85% in both regoliths in the second and third plantings. These results highlight regolith’s potential to support crop growth with proper nutrient management strategies and recycling for lunar agriculture, underscoring the possibility for using in situ lunar resources for food production for long-term lunar habitation.

Speakers

Hikari Skabelund

Texas A&M University

Co-authors

Shuyang Zhen

Texas A

Tuesday July 29, 2025 3:15pm - 3:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Poster # csv

3:15pm CDT

O/LT - Assessing the Safety of S-Metolachlor as an Over-the-Top Pre-Emergent Herbicide on 'Denver Daisy' Black-eyed Susan (Rudbeckia hirta 'Denver Daisy')

Tuesday July 29, 2025 3:15pm - 3:30pm CDT

Strand 11A

Preemergence herbicides play a critical role in weed management but can pose challenges for ornamental plant safety during establishment. Black-eyed Susan (Rudbeckia hirta) cv “Denver Daisy” is a popular ornamental cultivar valued for its vibrant blooms and adaptability. An experiment was conducted in 2024 at the Southwest Research and Extension Center in Hope, AR to evaluate transplanted Black-eyed Susan tolerance to topically applied S-metolachlor. S-metolachlor was applied as a broadcast application at 0, 2.8, 5.6, and 11.2 kg ai ha-1 two weeks after Black-eyed Susan plants were transplanted into raised beds. Visual injury, plant heights, and plant widths were collected at 2- and 4-weeks after application. There was no visual injury at any rating, however, some damage from deer feeding on plants was observed so only plant widths are reported. Plant widths ranged from 9 to 10.5 cm at 2-weeks after treatment and 15.7 to 17.3 cm at 4-weeks after treatment, with no differences between treatment at either data collection timing. Data from this study suggests that topically applied S-metolachlor may be a viable residual weed control option for ornamental Black-eyed Susan.

Speakers

Anthony Bowden

University of Arkansas

Co-authors

David Nistler

University of Arkansas

Hannah Wright-Smith

University of Arkansas

Tuesday July 29, 2025 3:15pm - 3:30pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf
Poster # csv
Funding Source The IR-4 Project

3:15pm CDT

PNM 2 - Can foliar boron application to Carolina strongback grafted plants improves watermelon fruit yield?

Tuesday July 29, 2025 3:15pm - 3:30pm CDT

Strand 11B

Grafting is an effective management strategy in watermelon crop against soil borne pathogens. Carolina strongback (SB) rootstock used for grafting, is resistant to both fusarium wilt and root knot nematodes which are devastating soil borne pests of watermelon. However, recent trials have shown that SB grafted plant bear fruits 7-10 days later than regulate plants leading to farmers losing early market which is more profitable. Further, tissue boron content in SB grafted plants were reported to be lower than regular watermelon nursery plants. Boron is a key micro-nutrient that involves in cell wall and cell membrane, pollination, pollen germination, cell division, translocation of carbohydrates and fruit development. We hypothesize that foliar application of boron will cure the boron deficiency in grafted plants and leads to early fruit set similar to regular watermelon nursery. To test this hypothesis, a field experiment was conducted at Edisto Research and Education Centre, SC. Two foliar boron applications at 30 and 50 days after transplanting significantly improved the pollen viability of SB grafted SP6 pollinizer at 60 days than control and non-grafted plants. Similar to pollen viability two foliar boron applications recorded the highest total fruit yield and tissue boron content than all other treatments. Highest gross, and net returns were observed with two foliar boron application treatments and lowest net returns were observed in one foliar boron application treatment. We will be repeating the experiment in 2025 to collect second year of data.

Speakers

Bhupinder Jatana

Assistant Professor -Horticulture, Clemson University

Co-authors

Tom Sanders III

Clemson University

Yefan Nian

Clemson University

Tuesday July 29, 2025 3:15pm - 3:30pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv

3:15pm CDT

POM 1 - Physiological Responses of Flordaguard and MP-29 Peach Rootstocks to Soil Salinity

Tuesday July 29, 2025 3:15pm - 3:30pm CDT

Foster 1

Many low-lying coastal areas worldwide, including Florida, experience soil salinization due to tropical rainstorms, storm surges that cause superficial flooding with saline water, and groundwater salinization from saltwater intrusion. Additionally, excessive fertilizer applications can increase soil salinization, which can reduce the productivity of soil and affect crop growth. This study evaluated the response to salinity stress of two peach rootstocks: 1) Flordaguard, the current recommended rootstock in Florida, and 2) MP-29, a peach-plum hybrid rootstock with the potential to be recommended in the state. A total of 60 plants were distributed in five blocks and exposed to three salinity levels (0, 75, and 150 µM NaCl) for 24 days in a greenhouse. Photosynthetic rate (A), stomatal conductance (gs), and efficiency of photosystem II (ΦPSII) were recorded every other day. Stem water potential (Ψs) and foliar nutrient concentrations were assessed at the end of the experiment. A decline in A level was observed in all plants over time, with a higher reduction under salinity treatments. Starting 16 days after treatment, gs was significantly lower in plantlets exposed to 150 µM NaCl compared to controls. Interestingly, ΦPSII was more stable in Flordaguard plants during the experiment. Moreover, ΦPSII response suggested higher sensitivity to salinity in MP-29 plants. Similarly, Ψs in salinity stressed plants was at least 33% lower compared to the control group. On the other hand, Ψs in ‘MP-29’ was 11% lower compared to ‘Flordaguard’, indicating higher water stress in the hybrid rootstock. Foliar nutrient concentrations were influenced by treatment (N), cultivar (Ca, B, Mn, Zn), or their interaction (Mg, S), while P, K, Fe, and Cu remained unchanged. These results suggest that MP-29 rootstock is more sensitive to salinity stress than Flordaguard, which may have implications for rootstock selection in saline-prone soils.

Speakers

Jonathan Clavijo Herrera

Postdoctoral Associate, University of Florida

Co-authors

Ali Sarkhosh

University of Florida

Jonathan Lainez

University of Florida

Tuesday July 29, 2025 3:15pm - 3:30pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology
Poster # csv

3:15pm CDT

PROP - Prairie Willow (Salix humilis) Micropropagation: Inducing Bud Break With Cytokinin BAP

Tuesday July 29, 2025 3:15pm - 3:30pm CDT

Strand 12A

Prairie willow (Salix humilis) is a compact shrub willow native throughout the eastern United States. Aside from its desirable habit, attractive flowers and foliage, and pervasive ecological associations, prairie willow demonstrates profound adaptability in its native range, offering potential for urban green infrastructure applications. The dwarf variety (S. humilis var. tristis) is particularly favorable for horticultural applications due to its pronounced short stature. However, prairie willow exhibits a unique recalcitrance to traditional asexual propagation techniques commonly employed with willows. Tissue culture, a highly effective means for propagating recalcitrant woody plants, has not been explored for prairie willow. Given its potential horticultural value, tissue culture serves as a promising alternative for commercializing this taxon. This study explored the impact of four concentrations (0mg/L, 0.1mg/L, 1mg/L, and 10mg/L) of the common shoot-inducing hormone BAP (6-benzylaminopurine, a cytokinin) on initial growth in culture. Plant material was harvested from actively growing softwood tissue on a greenhouse-grown stock plant of the dwarf variety (USDA-GRIN accession AMES35806) and was trimmed to 1-2cm single-node explants (N=80, n=20). Sterilization involved an initial rinse in tap water with Tween-20, followed by a 30-second soak in 70% ethanol, a 5-minute soak in 0.9% sodium hypochlorite, and intermittent 5-minute rinses in sterile distilled water. Explants were stuck in 15mL falcon tubes with 4mL of media (2.41g/L woody plant media 30g/L sucrose 7g/L agar BAP). Culture tubes were placed on a light rack (18.3°C) with continuous light (40 watt fluorescent) and monitored weekly. The number of expanded buds and contamination rates were recorded. Contamination rates were low (12.5%), indicating successful sterilization. Development was slow across all treatment groups, suggesting the need for stock plant rejuvenation before propagule harvest. However, days to bud break indicated that 0.1mg/L BAP may result in the quickest shoot proliferation. Percentages of explants with expanded buds by week 5 were 13% (0mg/L), 68% (0.1mg/L), 41% (1mg/L) and 6% (10mg/L). All explants in 10mg/L exhibited browning and necrosis by week 5, while all but 5% of explants in 0mg/L remained green despite limited bud expansion. Future trials will investigate rejuvenation and alternative cytokinins to generate a complete protocol for introducing prairie willow into tissue culture. This research supports the integration of this versatile plant into commercial production, enhancing the ornamental plant palette for challenging urban landscapes.

Speakers

Hazel Schrader

Graduate Research Assistant, University of Minnesota Twin Cities

Co-authors

Brandon Miller

University of Minnesota

Tuesday July 29, 2025 3:15pm - 3:30pm CDT
Strand 12A

Oral presentation, Propagation

Subject Propagation
Poster # csv

3:30pm CDT

CE 1 - Life Cycle Assessment and Operational Scenario Analysis for Hydroponic Lettuce Cultivation in Controlled Environment Agriculture

Tuesday July 29, 2025 3:30pm - 3:45pm CDT

Strand 12B

Controlled Environment Agriculture (CEA) is gaining momentum as a viable strategy for addressing food security in urban areas while mitigating the environmental pressures associated with conventional agriculture. However, the environmental sustainability of these systems remains under scrutiny due to their high energy and resource demands. This study presents a comprehensive Life Cycle Assessment (LCA) and operational scenario analysis of hydroponic lettuce production within a growth chamber using a nutrient film technique (NFT) system. By integrating experimental measurements, plant growth modeling, and LCA methodologies compliant with ISO 14040–14044 standards, the study evaluates environmental trade-offs under five different lighting scenarios ranging from 200 to 1000 µmol m⁻² s⁻¹ photosynthetic photon flux density (PPFD), while keeping temperature and CO₂ constant. A mechanistic plant growth model was utilized to simulate fresh biomass yield under varying PPFD conditions. Model predictions closely aligned with experimental data, yielding R² values of 0.95–0.98 for both fresh weight and leaf area across light scenarios. Water consumption was estimated by establishing linear relationships between plant biomass and evapotranspiration rates, while electricity usage for lighting and HVAC was continuously monitored using a Fluke 1735 Power Logger. Results indicated substantial increases in yield, water use, and energy consumption with increasing light intensity. For example, yields ranged from 1.69 kg at 200 PPFD to 14.06 kg at 1000 PPFD, while electricity usage increased from 257 to 361 kWh per growth cycle. The LCA adopted a cradle-to-gate system boundary and a functional unit of 1 kg fresh lettuce, covering inputs including lighting, climate control, water, nutrients, system materials, post-harvest processing, and transportation. Impact categories were assessed using ReCiPe 2016 midpoint (H) indicators: global warming potential (GWP100), terrestrial acidification potential (TAP), fossil fuel potential (FFP), freshwater and marine eutrophication potential (FEP, MEP), and water consumption potential (WCP). Environmental impacts showed strong inverse relationships with light intensity up to 600 PPFD, beyond which impacts plateaued. GWP100 decreased from 69.09 kg CO₂-eq at 200 PPFD to 12.87 kg CO₂-eq at 1000 PPFD, primarily due to increased yield efficiency. Across all scenarios, the lettuce production stage was the dominant contributor to environmental impacts, followed by system manufacturing, with minor contributions from post-harvest processes and waste management. Optimal light intensity for balancing yield and sustainability was identified between 400–600 PPFD. Notably, the integration of dynamic plant modeling enabled scenario-specific inventory estimation, enhancing the robustness of the LCA compared to conventional top-down methods.

Speakers

Sujit Dahal

University of Wyoming

Co-authors

Lichen Wu

University of Wyoming

Liping Wang

University of Wyoming

Tuesday July 29, 2025 3:30pm - 3:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 1

Subject Growth Chambers and Controlled Environments
Poster # csv

3:30pm CDT

O/LT - Performance Assessment of Commercial Leaf Blowers Across Power Sources

Tuesday July 29, 2025 3:30pm - 3:45pm CDT

Strand 11A

The landscape maintenance industry is under growing legislative scrutiny for its environmental and noise impacts. Among professional tools, the leaf blower is most frequently targeted due to its high decibel output and widespread use. In response, advancements in battery technology have introduced commercial-grade battery-powered alternatives. Despite this progress, many landscape professionals remain concerned about the work capacity and efficiency of battery-powered blowers compared to traditional gas-powered models. This study evaluated commercial gas and battery leaf blowers through controlled laboratory tests measuring runtime, task efficiency, output force, and sound levels. Results showed that some battery-powered models operated longer on a single charge than gas-powered blowers on a single tank of fuel. However, gas-powered blowers were 24% to 200% more effective in completing standardized tasks when operated by experienced users. This advantage stemmed from their ability to maintain high, consistent output throughout operation. In contrast, most battery-powered blowers sustained peak performance only briefly before throttling output to conserve energy, reducing their effective work capacity. Additionally, several battery models failed to meet manufacturer claims regarding output force. While battery blowers offered quieter operation—producing 20% to 26% lower decibel pressures than gas units—the performance tradeoffs remain a concern for high-demand applications. These results highlight the disparity between power sources in leaf blowers, one of the most frequently used tools in landscape maintenance, and emphasize the current limitations and tradeoffs involved in transitioning to battery-powered equipment under regulatory pressure.

Speakers

Paul Bartley

Auburn University

Co-authors

Allison Link

Auburn University

Landon Erbrick

Auburn University

Mark Hoffman

Auburn University

Tuesday July 29, 2025 3:30pm - 3:45pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf
Poster # csv

3:30pm CDT

PNM 2 - Evaluating Coupled Organic Fertilizer and Biostimulant Effects on Iceberg Lettuce Growth, Development, and Yield under Subsurface Drip Irrigation in the Southwest Desert

Tuesday July 29, 2025 3:30pm - 3:45pm CDT

Strand 11B

Arizona ranks as the second-largest lettuce producer in the United States, with leafy greens contributing approximately $2 billion annually to the state’s economy. As interest in sustainable production systems grows, organic lettuce production is becoming increasingly important due to its potential to reduce synthetic input use, enhance soil quality, and support agroecosystem services. However, managing the high nitrogen demand of lettuce, particularly during its rapid vegetative and heading stages, presents a major challenge in organic systems, especially under arid conditions. Despite these benefits, limited research in local conditions has made it difficult for farmers to effectively incorporate biostimulant into organic cropping systems. The research objectives were to: (1) assess the combined impacts of biostimulant and organic fertilizeron lettuce growth development and yield production: (2) evaluate the efficiency of biostimulant in improving soil health quality (soil water retention, mitigate salt stress): and (3) evaluate the adoption of best management practices, such as site-specific, sensor-based monitoring of soil nitrate levels, to enhance nutrient use efficiency while minimizing environmental risks. This research is conducted at Yuma Agricultural Center, Yuma, Arizona, a region characterized by an arid climate with less than 3 inches of annual precipitation. The field was planted with the iceberg lettuce variety SVLD0023 on October 29th, 2024, under the subsurface drip irrigation method with two irrigation scheduling strategies (sensor-based irrigation (SI) and traditional irrigation (TI) based on growers' standard decision basis that is common in the Yuma area. Two fertilizer treatments were imposed: (1) organic fertilizer, and (2) a combination of biostimulant and organic fertilizer. The experimental site consists of clay loam soil, with a field capacity of 31.9% volumetric water content, a permanent wilting point of 15.5%, and a particle size distribution of 21% sand, 48% silt, and 31% clay. The topsoil contains 1.5% organic matter. Two types of organic fertilizers were applied: 2,000 lbs/acre of chicken pellets (4-4-2) and 1,800 lbs/acre of a high-nitrogen organic fertilizer (9-6-1). Preliminary results revealed the highest plant height of 20.3 cm under the organic fertilizer treatment with TI. Similar findings were observed for yield. The data strongly support the conclusion that the greatest yield and highest plant height were found under the organic fertilizer treatment with TI.

Speakers

Ali Mohammed

University of Arizona/Yuma Ag Center

Dr. Ali Mohammed is an Assistant Professor and Extension Specialist in the School of Plant Sciences at the University of Arizona, based at the Yuma Agricultural Center. His work focuses on advancing sustainable organic agricultural practices in arid desert regions and holds statewide... Read More →

Tuesday July 29, 2025 3:30pm - 3:45pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 2

Subject Plant Nutrient Management
Poster # csv

3:30pm CDT

POM 1 - Evaluation of Effects of ACC and Tree Architecture on Mechanical Trunk Shaking Harvest Efficiency in Table Olives in California

Tuesday July 29, 2025 3:30pm - 3:45pm CDT

Foster 1

Table olives in California have historically been hand-harvested. Hand labor crews are increasingly difficult to attract to small acreage orchards and are often prohibitively expensive when available. Mechanical harvesting equipment is available; however, harvest efficiencies typically range from 55-65%, leaving 35-45% of the crop on the tree. While much less expensive than hand-harvesting, the harvest efficiency is not adequate and leaves growers to decide whether to glean the remaining crop or forfeit the income from that portion of the crop. This low efficiency is partially due to the inherent architecture and physiology of olive trees. Additionally, the force required to remove an olive fruit from the tree is relatively high because table olives are harvested before their physiological maturity. In 2024 we conducted a study to evaluate the effects of altering tree architecture by skirting trees in May, removing lower limbs up to 4 feet from the ground to avoid any contact with the harvest machinery. This led to a 15.5% increase in harvest efficiency over trees where lower limbs were left, without affecting total yield. In addition, we examined the effect of a foliar application of 1-aminocyclopropane-1-carboxylic acid (ACC, commercially available as Accede®), an ethylene precursor, at 100 gallons per acre of 1500ppm solution a week before harvest. ACC applications reduced the amount of force required to remove fruit from the tree by 26% and increased harvest efficiency by up to 10.7%. The combination of both removing the skirts of the trees and applying ACC improved harvest efficiency by 23%. These strategies provide clear pathways to improving the economic sustainability of the table olive industry in California.

Speakers

Becky Wheeler-Dykes

UCCE Glenn

Co-authors

Georgia Drakakaki

University of California Davis

Louise Ferguson

University of California Davis

Minmin Wang

University of California Davis

Tuesday July 29, 2025 3:30pm - 3:45pm CDT
Foster 1

Oral presentation, Pomology 1

Subject Pomology
Poster # csv
Funding Source California Olive Committee

3:44pm CDT

NUTS - Oral Session

Tuesday July 29, 2025 3:44pm - 3:45pm CDT

Strand 12A

Presiding/Moderator

Amandeep Kaur

Oklahoma State University

Tuesday July 29, 2025 3:44pm - 3:45pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops

3:45pm CDT

NUTS - Isolation and Identification of Mycorrhizal Fungi with Enhanced Nitrogen Absorption Capacity in Pecan Roots

Tuesday July 29, 2025 3:45pm - 4:00pm CDT

Strand 12A

Pecans [Carya illinoinensis (Wangenh.) K. Koch] are an economically important nut crop, with nitrogen nutrition critically influencing their productivity. Sustainable nutrient management strategies, including enhancing microbial associations in the rhizosphere, offer potential to optimize nutrient use efficiency and reduce fertilizer dependency. This study aimed to isolate and identify mycorrhizal fungi (beneficial) from pecan roots capable of improving nitrogen uptake efficiency, thereby reducing fertilizer inputs for pecan producers. We hypothesized that mycorrhizal fungi exhibiting stable growth across varied nitrogen sources and concentrations would be good candidates for effective inoculation of pecans. For this experiment, fine root samples of pecans were collected from six improved orchards (with cultivars Pawnee and Kanza) and two native groves across Oklahoma. Samples were collected at two sampling events (February and May 2023), obtaining composite samples by combining three subsamples per tree at 15-20 cm soil depth. Fine roots were surface cleaned, sterilized, and cultured on potato dextrose and malt agar to isolate fungi. After isolation and purification, fungi were visually screened, excluding known pathogens based on morphological traits (color, spores, etc.). Twenty selected fungi were evaluated for growth on mineral salt medium (MSM) agar supplemented with glucose, under varying nitrogen conditions (0.1, 0.05, 0.01 g/L urea and ammonium chloride), and a nitrogen-free control. Fungal growth was quantified by measuring hyphal extension daily. Four isolates demonstrating minimal growth variation across nitrogen treatments were selected for further identification. Subsequently, DNA extraction was performed on these selected four fungi using FastDNA SPIN Kit (MP Biomedicals, USA), and fungal identities were confirmed by sanger sequencing (ITS region). From the sequencing results, two fungal isolates will be selected as promising candidates for the next phase of the study, where they will be inoculated into pecan seedlings to confirm symbiosis formation and evaluate their potential to enhance nitrogen uptake efficiency under different nitrogen fertilization scenarios. Findings from this study will provide a scientific foundation for sustainable pecan rootstock nursery and orchard management, helping producers optimize fertilizer use, and reduce costs.

Speakers

Amandeep Kaur

Oklahoma State University

Co-authors

Lu Zhang

Oklahoma State University

Niels Maness

Oklahoma State University

Tingying Xu

Oklahoma State University

Wei Ren

Oklahoma State University

Tuesday July 29, 2025 3:45pm - 4:00pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops

3:45pm CDT

O/LT - Assessing Landscape Bed Temperature Dynamics and Light Transmission under Five Frost Protection Fabrics

Tuesday July 29, 2025 3:45pm - 4:00pm CDT

Strand 11A

Providing protection from winter elements and seasonal temperature shifts are important considerations for nursery growers and landscape contractors. Frost protection fabrics can provide additional insulation to sensitive plants by maintaining temperatures at more moderate thresholds; however, with a wide range of weights and materials on the market, it is necessary to understand the extent to which various frost fabrics can serve this purpose. Five frost cloth materials were evaluated over a three-month period (January through March 2025) at the LSU AgCenter Hammond Research Station, with individual landscape bed replicates covered with one of four different weights of a non-woven frost fabric, one woven frost fabric, or left uncovered. Landscape bed replicates were comprised of typical landscape bed media (i.e. aged pine bark and sand) with a steel edging frame and support hoops. Each replicate was provided with a temperature sensor below the bed surface and a temperature and light sensor at the bed surface. Sensors recorded temperature and light conditions every 30 minutes, providing insights towards ambient environmental conditions beneath the frost fabrics (or in open air) as well as within the landscape bed media. Uncovered plots received the most amount of light and were subject to the highest degree of variability in temperature; however, the frost protection fabrics provided varying degrees of light transmission and temperature moderation. The woven frost protection fabric allowed the greatest amount of light transmission for all frost protection fabrics investigated, where it also yielded higher surface and subsurface temperatures relative to non-woven materials and uncovered replicates. Non-woven frost fabrics of varying weights generally provided similar levels of insulation to each other; however, it was observed that heavier frost fabrics were capable of minimizing temperature fluctuations. All investigated frost fabrics were effective in raising the minimum surface and subsurface temperatures relative to the uncovered replicates. As the study (and spring season) progressed, peak temperatures under frost cloths were at times elevated above uncovered plots. The results indicate that frost cloths of various materials and weights provide different levels of insulation, and that careful attention to environmental conditions is necessary for deciding when to place and remove frost cloths in the field.

Speakers

Damon Abdi

Louisiana State University Agricultural Center

Tuesday July 29, 2025 3:45pm - 4:00pm CDT
Strand 11A

Oral presentation, Ornamentals/Landscape and Turf

Subject Ornamentals Landscape and Turf
Poster # csv
Funding Source Louisiana Nursery and Landscape Association

3:59pm CDT

CE 2 - Oral Session

Tuesday July 29, 2025 3:59pm - 4:00pm CDT

Strand 12B

Presiding/Moderator

Chieri Kubota

The Ohio State University

Tuesday July 29, 2025 3:59pm - 4:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments

3:59pm CDT

CITR 1 - Oral Session

Tuesday July 29, 2025 3:59pm - 4:00pm CDT

Foster 2

Presiding/Moderator

Caroline de Favari Tardivo

PhD Candidate, University of Florida

Tuesday July 29, 2025 3:59pm - 4:00pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops

3:59pm CDT

PH 1 - Oral Session

Tuesday July 29, 2025 3:59pm - 4:00pm CDT

Foster 1

Presiding/Moderator

Chris Watkins

Cornell University

Tuesday July 29, 2025 3:59pm - 4:00pm CDT
Foster 1

Oral presentation, Postharvest 1

3:59pm CDT

VCM 1- Oral Session

Tuesday July 29, 2025 3:59pm - 4:00pm CDT

Strand 11B

Presiding/Moderator

Guodong Liu

University of Florida

Tuesday July 29, 2025 3:59pm - 4:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management

4:00pm CDT

CE 2 - Supplemental far-red light prevents semi-dormancy and enhances yield and fruit quality of short-day strawberry in indoor production

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Strand 12B

Optimizing the light environment for indoor strawberry production is critical for ensuring high productivity and fruit quality. Short-day (SD) strawberries require SD conditions for flower induction. However, SD can also cause semi-dormancy symptoms that inhibit strawberry plant growth and production. Current strategies to address this challenge in SD strawberry production is extension of photoperiod to prevent semi-dormancy. This preliminary study investigated the effect of photoperiod adjustment and light quality modification by analyzing two SD strawberry cultivars ‘Earliglow’ and ‘Nyohou’ under three photoperiod treatments (SD, LD, or alternating SD/LD) with or without supplemental far-red (FR) treatments (56 % FR over total photon flux density, 400-750 nm). Plants under continuous SD conditions exhibited a typical semi-dormancy like morphology with shorter petioles and peduncles. Supplemental FR treatment significantly extended petiole and peduncle length, regardless of daylength. Strawberry total yield, percent marketable yield, and total number of fruit were improved in plants with supplemental FR treatment. Supplemental FR light treatment also increased soluble solid concentration (SSC, brix %) and SSC-to-TA ratio regardless of cultivar. No significant differences in leaf net photosynthetic rates were observed among photoperiod or FR treatments. The increase in productivity and fruit SSC was partly attributed to improved plant morphology under supplemental FR light, which enhanced photoassimilates allocation to fruit. Addition of FR light seems to be beneficial in indoor production of SD-type strawberry cultivars for preventing semi-dormancy and enhancing yield and fruit quality.

Speakers

Chieri Kubota

The Ohio State University

Co-authors

Yiyun Lin

The Ohio State University

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Funding Source Foundation for Food and Agriculture Research (FFAR) grant number 21-000051

4:00pm CDT

CITR 1 - Delaying Candidatus Liberibacter asiaticus Infection of Citrus Trees Through Use of Individual Protective Covers and Systemic Delivery of Oxytetracycline

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Foster 2

Huanglongbing (HLB), associated with Candidatus Liberibacter asiaticus (CLas), continues to devastate citrus production worldwide. Individual protective covers (IPCs) offer a physical barrier against the Asian citrus psyllid, delaying CLas infection in young trees. However, once removed, trees become vulnerable to rapid infection. This study evaluates an integrated approach utilizing IPCs followed by systemic oxytetracycline (OTC) trunk injections to mitigate disease progression and sustain tree health. A field trial was established with ‘Valencia’ sweet orange (Citrus sinensis) grafted onto US-812 or US-942 rootstocks. Trees were either protected with IPCs for 18 months after planting (“late infected”) or had “open” IPCs (“early infected”). All trees received annual OTC injections in 2023 and 2024, beginning 10 months after IPC removal. CLas titers, OTC residues, tree growth, fruit yield and quality, leaf nutrient content, and root endorhizosphere microbial dynamics were assessed. Results indicate that IPCs successfully delayed infection, as late-infected trees maintained lower CLas titers for the first five months after IPC removal and exhibited denser canopies and larger scion and rootstock trunk diameters than early-infected trees. OTC injections significantly reduced CLas titers in leaves, with effects persisting for up to six months. However, no significant reductions in CLas titers were detected in fibrous roots, suggesting limited OTC translocation to the root system. Injected trees exhibited a greener canopy color, greater leaf size, higher chlorophyll content, higher yield, larger fruit size, and better juice quality compared to non-injected trees. No significant changes in leaf nutrient content were observed, and the root endorhizosphere microbial diversity remained unchanged across treatments, indicating minimal disruption to the microbial community due to the antibiotic. These findings provide evidence supporting the combination of IPCs and systemic delivery of OTC as an integrated strategy to manage HLB in new citrus plantings. IPCs delay the onset of infection, allowing trees to establish a healthy canopy and robust root system, while OTC injections aid in sustaining tree health post-infection. The integration of these practices provides a promising framework for establishing productive citrus orchards under HLB-endemic conditions.

Speakers

Caroline de Favari Tardivo

PhD Candidate, University of Florida

Co-authors

Brittney Monus

University of Florida

Fernando Alferez

University of Florida

Gabriel de Castro Marconi Pugina

University of Florida

Leigh Archer

University of Florida

Sarah Strauss

University of Florida/IFAS, Southwest Florida Research and Education Center

Ute Albrecht

University of Florida/IFAS, Southwest Florida Research and Education Center

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source USDA NIFA ECDRE 2022-70029-38481 / 2020-70029-33202
Funding Option SCRI funded all or part of the research associated with this abstract

4:00pm CDT

NUTS - Comparing the Efficiency of Different Foliar-Applied Zinc Formulations in Pistachio

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Strand 12A

Comparing the Efficiency of Different Foliar-Applied Zinc Formulations in Pistachio Zinc (Zn) deficiency is a major concern in California pistachio production. Foliar fertilization is a rapid and efficient way to improve Zn in pistachio trees during periods of high demand. However, the absorption and translocation of different foliar-applied Zn in pistachio trees vary significantly. Thus, it is necessary to optimize foliar Zn applications. The goals of the research were to evaluate different sources of Zn (Zn sulfate - ZnS, Zn sulfate potassium (K) 1% - ZnS K, and chelated Zn - CHZn) on leaf uptake, yield, and nut quality (fresh and dry weight, nut split in-shell, and nut non-split). The Zn dose of 807 g ha-1 was applied to 4 replications (5 trees per replicate) per treatment (including an untreated control) in a randomized complete block in a commercial ‘Golden Hills’ pistachio orchard in California. Trees were sprayed in April, a period of highest absorption efficiency (1/2- to 2/3-leaf expansion). Leaf samples were taken 2, 8, 24 hours, and 7 days after spray to measure Zn absorption efficiency. Leaf (August) and fruit samples (harvest) were taken for quality and nutrient analysis. Yield was determined for every replicate at harvest. After verifying the significance of the variance analysis (p < 0.05), the means were compared by the Duncan test (p < 0.05). Trees treated with Zn during leaf expansion exhibited significantly higher leaf Zn content than those in the control treatment. The first-year results indicated that adding K may increase the average Zn content in leaves compared to trees sprayed with Zn alone, suggesting that K at 1% may enhance Zn uptake at this stage of leaf development. Foliar application of CHZn significantly increased Zn content in leaves compared to all other treatments. Spraying Zn when leaves were between half and two-thirds expanded allowed sufficient absorption to maintain significantly higher leaf Zn contents until August, compared to control trees. As expected, no significant differences were observed in yield and nut quality in the first year of the experiment. Future research should address the cumulative effect of different Zn sources on the retention of floral buds, bud break, and flowering.

Speakers

Francielle Lima

Associate Specialist, UC ANR

Dr. Lima has been working with emphasis on soil fertility and plant nutrition to increase nutrient use efficiency, food quality, and sustainable production in the agroecosystems.

Co-authors

Arnon Dag

Volcani Institute

Donald Williams III

UC ANR

Douglas Amaral

UC ANR

Giulia Marino

UC Davis

Jonathan Rodriguez-Alvarado

UC ANR

Louise Ferguson

UC Davis

Luiz Roberto G Guilherme

Universidade Federal de Lavras

Paula Guzman-Delgado

University of California Davis

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops

4:00pm CDT

PH 1 - 1-Methylcyclopropene (1-MCP) Effects on Fruit and Vine Quality of Cluster Tomatoes

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Foster 1

Effects of 1-MCP on tomato fruit ripening have been well studied, but much less attention has been given to its effects on vine quality. In a series of experiments, 0.5 or 1 µL L-1 1-MCP was applied to tomato clusters when the least mature fruit on the vine was mature green (MG), breaker (BR) or light red (LR). The clusters were stored at 12oC for 18 days. Overall fruit quality remained high in the MG, BR and LR fruit clusters for 18, 9, and 6 days, respectively. Quality of the 1-MCP-treated BR stage fruit did not decline until after 12 days, while little effect of 1-MCP was found for the LR fruit. Cluster weight was not affected by 1-MCP treatment. However, visual appearance of the vine tissues was greatly affected by 1-MCP. Loss of vine quality was lowest in the MG vines without 1-MCP treatment. However, the highest quality ratings were found in 1-MCP treated vines, regardless of fruit maturity. Retention of vine quality by 1-MCP was closely associated with reduced water loss from the vine tissues. These results confirm that 1-MCP can delay ripening of tomato fruit, but also highlight that the benefits of 1-MCP may be through better visual appearance of the cluster vines.

Speakers

Chris Watkins

Cornell University

Co-authors

Cheon Soon Jeong

Kangwon National University

Jennifer DeEll

Ontario Ministry of Agriculture, Food and Agribusiness

Seok-Kyu Jung

Daegu Catholic University

Youngjae Shin

Dankook Univiversity

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source Ontario Greenhouse Vegetable Growers, AgroFresh, Inc., NIFA Multistate NE2336

4:00pm CDT

VCM 1 - Enhancing Phosphorus Utilization in Vegetable Production: Exploring the Benefits of Split-Applications

Tuesday July 29, 2025 4:00pm - 4:15pm CDT

Strand 11B

Phosphorus (P) is an essential nutrient for snap bean growth, directly influencing root development, plant health, and overall yield. However, P bioavailability is often limited by soil fixation, particularly in highly acidic and alkaline environments. In the Hastings region, soil pH can drop to 4.7 during the growing season, leading to substantial P immobilization due to high concentrations of extractable aluminum (1,300–2,000 lbs/acre) and iron (250–600 lbs/acre). These metals readily react with P, forming insoluble complexes that restrict plant uptake. Chemically, one pound of aluminum can fix up to 2.6 pounds of phosphorus pentoxide, significantly reducing P availability for crop growth. Conversely, in the Homestead region, where soil pH reaches 8.4, P fixation occurs primarily through reactions with calcium, with one pound of calcium binding approximately 1.2 pounds of phosphorus pentoxide, further limiting P solubility. Conventional P fertilization typically relies on a single pre-plant application, which does not align with the plant’s continuous nutrient demands throughout the growing season. Moreover, prolonged soil-P interaction exacerbates fixation losses, further reducing bioavailable P. This study investigates the effectiveness of split P applications as a strategy to mitigate fixation and improve nutrient uptake efficiency. By minimizing phosphorus’s contact time with reactive metals, split applications—through multiple dry granular P applications or fertigation—help sustain adequate P concentrations in plant tissue. Preliminary results indicate that split applications significantly enhance P uptake and use efficiency, leading to higher snap bean yields compared to conventional single-dose treatments. These findings suggest that split P applications offer a more effective and sustainable approach to optimizing phosphorus management in snap bean and other vegetable production.

Speakers

Guodong Liu

University of Florida

Tuesday July 29, 2025 4:00pm - 4:15pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management

4:14pm CDT

WUM 1 - Oral Session

Tuesday July 29, 2025 4:14pm - 4:15pm CDT

Strand 11A

Presiding/Moderator

Carlene Chase

University of Florida

Tuesday July 29, 2025 4:14pm - 4:15pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management

4:15pm CDT

CE 2 - Strawberry Yield and Flavor is Influenced by Day and Night Temperature in CEA Production

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Strand 12B

In the United States (U.S.), strawberries (Fragaria ×ananassa) are the most popular berry fruit with a value of $2.8B. To meet consumer demand for flavorful, fresh, local, and year-round strawberries, the industry is expanding into controlled environment (CE) production of day-neutral (everbearing) cultivars in greenhouses and indoor farms. Within CEs, growers can potentially improve flavor through the manipulation of environmental parameters such as temperature, light, vapor pressure deficit, and carbon dioxide concentration. The objectives of this study were to 1) quantify flavor related compounds of day-neutral cultivars in greenhouses; 2) determine how day and night temperatures influence fruit quality; and 3) develop a model to predict the cardinal temperatures of yield and flavor for each cultivar. Four cultivars, ‘Albion’, ‘Mara Des Bois’, ‘San Andreas’, and ‘Seascape’ were grown at day/night temperatures (12 h/12 h) of 15/7, 18/10, 21/13, 24/16, or 27/19 °C, under a 16-h photoperiod, and a target daily light integral of 15 mol·m–2·d–1. Berries were harvested twice weekly for three months and at harvest, yield, marketable yield, berry mass, and diameter. Berries were then cut into quarters, with ¼ being saved in a –80 °C freezer, and the other ¾ being used for destructive chemistry measurements. This included titratable acidity (TA), total soluble solids (TSS) content, pH, total anthocyanins, and the concentration and composition of flavor-related volatile organic compounds (VOCs). After 12 weeks of harvest, the highest TA was measured from berries harvested at 27/19 °C. ‘Albion’, and ‘Seascape’ harvested at 18/10 °C had the highest TSS, whereas the TSS of ‘Mara Des Bois’ and ‘San Andreas’ harvested at 15/7 °C was highest. The TSS/TA ratio was found to be correlated with day and night temperatures and a good indicator of consumer preference. Differences were also observed among cultivars and temperature treatments for anthocyanin and flavor-related VOCs. Our results collectively show that day and night temperatures influence the yield and flavor of strawberries.

Speakers

Nicholas Cooley

Michigan State University

Co-authors

Josh VanderWeide

Michigan State University

Roberto Lopez

Michigan State University

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Funding Source McIntire-Stennis

4:15pm CDT

CITR 1 - Enhancing efficacy of oxytetracycline trunk injection for Huanglongbing management in citrus: effects of volume, mode, and time of injection

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Foster 2

Huanglongbing (HLB), associated with phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas), is a major threat to citrus production worldwide, severely reducing tree health, yield, and fruit quality. In Florida, trunk injection of oxytetracycline (OTC) has emerged as a promising management strategy for HLB. Under this context, this study aimed to enhance the efficacy of OTC injection by evaluating different injection volumes, modes of injection (one or two-sided), and injection timing in HLB-affected ‘Valencia’ orange (Citrus sinensis) trees in southwest Florida. Two experiments were conducted with 8-year-old trees. The first experiment, implemented in two locations, assessed four combinations of different OTC volumes and modes of injection: 1) 50 mL (one-sided), 2) 100 mL (one-sided), 3) 100 mL (two-sided, 50 mL each side), and 4) 200 mL (two-sided, 100 mL each side), all delivering 0.825 g (a.i.) OTC (Rectify, AgroSource, Inc.) per tree. The second experiment compared early (May) and late (July) injections using 100 mL (two-sided, 50 mL each side), delivering 0.825 g (a.i.) OTC (Rectify) per tree. Injectors were placed on opposite sides of the trunk for the two-sided treatments. OTC solutions were prepared right before injection. In both experiments, treatments were compared against an untreated control. The experimental design was completely randomized, with 10 single-tree replications for the first experiment and 8 replications of 4 trees each for the second. Leaf samples were collected over time to analyze bacterial (CLas) titers and OTC residues, while canopy health, yield, and fruit quality were evaluated annually. For the second experiment, fruit development (size and peel color) was monitored monthly after OTC injection, and fruit yield and quality were assessed annually. Our results demonstrate that two-sided injection increases fruit yield more than one-sided injection and that the combination of two-sided injection and a larger volume of the injected solution may further enhance fruit yield compared to the untreated control. This improvement is attributed to better OTC distribution within the canopy, leading to greater bacterial suppression and tree recovery. Moreover, early (May) injection promotes fruit size by extending the fruit growth period, while late (July) injection enhances juice soluble solids content with a more compact fruit size. However, early injections result in greener fruit, which requires a longer maturation period to achieve the desired peel color and sugar content. These findings offer valuable insights for optimizing OTC trunk injection strategies to improve citrus health and productivity in HLB-affected citrus orchards.

Speakers

Deived Uilian de Carvalho

University of Florida

Co-authors

Caroline de Favari Tardivo

University of Florida

Jasmine de Freitas

University of Florida

Ute Albrecht

University of Florida/IFAS

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source USDA NIFA ECDRE (2021-70029-36056), Citrus Research and Development Foundation (22-001 and 23-002)

4:15pm CDT

NUTS - Microbial Community Varied Between Rhizosphere Soil And Roots Across Two Native Pecan Groves

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Strand 12A

Pecans [Carya illinoinensis (Wangenh.) K. Koch] are an economically significant nut crop, with native pecans naturally distributed across 14 U.S. states, primarily concentrated in Oklahoma, Texas, and Mexico. Oklahoma leads in native pecan production, contributing approximately 79% (13.8 million pounds) of the total U.S. native pecan production (USDA, 2023). Economically, native pecans are valuable due to their desirable kernel traits suitable for commercial processing and their unique oil profile, rich in polyunsaturated fatty acids, enhancing market demand in the food industry. Microbial communities in the rhizosphere, comprising diverse fungi and bacteria, are crucial for nutrient cycling, soil fertility, and plant health. Despite their recognized importance, microbial dynamics associated with native pecan groves remain poorly understood. This study aimed to evaluate microbial diversity associated with native pecan trees and how it varies with fertilization treatments and grove management. Two native pecan groves: A -Tod's (35°55′42″ N, 96°13′24″ W) (with short grass and cattle grazing) and B- Shelly’s (35°57′32″ N, 96°7′38″ W) (only growing hays without cattle) in Sapulpa, Oklahoma were used in this experiment. Two fertilizer treatments: control (no NPK: nitrogen, phosphorus, and potassium) and full NPK (recommended amount based on soil tests), were applied in March 2023. For each sampling event, five trees per NPK treatment were randomly selected from each grove. Root and rhizosphere soil samples were collected from each tree across three sampling times: February (before fertilizer application), May, and September (after fertilizer application). Microbial DNA was extracted and sequenced using fungal ITS and bacterial 16S rRNA primers using Illumina sequencing. Bioinformatics analysis (using Mothur v. 1.48 and R version 4.4.1) was performed to identify community structure and functional groups. The results revealed that fungal and bacterial community between rhizosphere soil and roots was significantly different in both groves. Fungal communities exhibit greater variation across fertilizer treatments, habitats (roots vs. rhizosphere soil), and groves (Tod's vs. Shelly's) than bacterial communities. In roots, Russula and Tuber genus were the most dominant in Tod’s grove, while Russula and Inocybe genus were the most dominant fungi genera in Shelly’s grove. The core bacterial communities in both groves were primarily dominated by families Xanthobacteraceae and Micromonosporaceae in roots and Chthoniobacteraceae, Xanthobacteraceae, and Planctomycetes in rhizosphere soil. These findings suggest that fertilizer treatments and grove management distinctly shape microbial communities, providing insights to optimize soil health and productivity in native pecan groves.

Speakers

Amandeep Kaur

Oklahoma State University

Co-authors

Lu Zhang

Oklahoma State University

Niels Maness

Oklahoma State University

Tingying Xu

Oklahoma State University

Wei Ren

Oklahoma State University

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv
Funding Source OSU Scott Pecan Research Professorship

4:15pm CDT

PH 1 - Non-destructive quality assessment of tomatoes through MQ gas sensors

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Foster 1

Fresh produce quality is a critical determinant of consumer preference and market value, with high-quality tomatoes often fetching premium prices. Traditional quality assessment methods, though effective, are typically labor-intensive, destructive, and impractical for real-time monitoring. In this study, we explore the potential of low-cost ($0.99 per unit) metal oxide semiconductor (MOS) gas sensors—MQ series (MQ2, MQ5, MQ6, MQ7, MQ9, and MQ135)—as a rapid, non-destructive, and cost-efficient tool for distinguishing high-quality tomatoes based on their cultivation in nitrogen-rich or nitrogen-deficient soils. Organic tomatoes, harvested from plants exposed to relatively high (High-N) and relatively low (Low-N) levels of bioavailable nitrogen (N) were enclosed in airtight containers equipped with MQ sensors to capture their volatile organic compound (VOC) emissions over 48 hours. Three replicates were used for each N level. Complementary laboratory-based quality assessments measured fresh weight, soluble sugar content, titratable acidity, pH, firmness, color space (Lab*), antioxidant capacity (DPPH assay), and total phenolic content. Gas chromatography-mass spectrometry (GC-MS) was utilized for VOC profiling. The resulting sensor and analytical data were preprocessed and normalized, followed by training 193 machine learning models with principal component analysis (PCA) at a 95% variance threshold in MATLAB. Significant differences were observed between High-N and Low-N treatments across several quality parameters. High-N tomatoes exhibited a 25.32% increase in average fruit fresh weight (p = 0.002), whereas Low-N tomatoes had 18.80% higher firmness (p = 0.020). Low-N tomatoes showed a 27.09% increase in antioxidant capacity (p = 0.0001), a possible indication of an adaptive response to N deficiency. Whereas VOC analysis revealed higher concentrations of octanoic acid, nonanoic acid, and 2-methyl-1-propanol in High-N tomatoes, with increases of 142.67%, 191.46%, and 37.72%, respectively, compared to Low-N tomatoes (p = 0.007, p = 0.020, p = 0.040). Sensor performance analysis demonstrated that MQ9 and MQ5 sensors were the most effective in differentiating between the two nitrogen treatments, with ensemble learning, neural networks, and support vector machines achieving 100% classification accuracy, followed by MQ135 and MQ2. Feature reduction criterion identified a minimal yet highly discriminative subset—including MQ9 sensor responses, octanoic acid, 4-heptanone, nonanoic acid, 1-penten-3-ol, 2-methyl-1-propanol, limonene, 3-methylbutanoic acid, 2-heptanone, fresh weight, and DPPH values—yielding classification accuracies of 97.06% during training and 89.29% in testing with a tri-layer neural network model. These findings underscore the potential of low-cost MOS gas sensors, particularly MQ9, as a viable, non-destructive alternative for real-time quality assessment of tomatoes.

Speakers

Ali Ahmad

Pennsylvania State University

Co-authors

Erin Rosskopf

USDA-ARS

Francesco Di Gioia

Pennsylvania State University

Jaime Lloret

Universitat Politècnica de València (UPV)

Jinhe Bai

USDA-ARS

Sandra Sendra

Universitat Politècnica de València (UPV)

Thais P Freitas

USDA-ARS

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WA Tree Fruit Research Commission

4:15pm CDT

VCM 1 - Assessing the Efficiency of Commercial Biostimulant Products on Tomato Plant Growth, Crop Yield, and Fruit Quality

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Strand 11B

Biostimulants are gaining popularity as a tool for enhancing plant growth, mitigating abiotic stress, and improving crop yield and quality. Defined as substances or microorganisms that stimulate natural plant processes. Although skepticism about their efficacy initially limited their use, a growing body of research evidence demonstrates their positive effects on crop systems under both controlled environments and field conditions. However, the continuous development of new biostimulant formulations reinforces the need for further validation under commercial agricultural conditions. This study evaluates the effects of eight commercial biostimulant protocols, each with different composition and modes of action on tomato (Solanum lycopersicum) growth, fruit quality, and yield. The objectives are to: 1) quantify the effects on plant growth with parameters such as plant height, stem diameter and leaf chlorophyll content) 2) assess the impact on yield and fruit quality at harvest. The experiment followed a randomized complete block design with three replicates, each comprising eight treatments. Each plot contained 25 tomato plants, and data were collected from 10 selected plants per plot. Biostimulants were applied weekly or biweekly, via drench or foliar spray, according to the manufacturer’s instructions. Growth parameters were measured throughout the experiment, while yield and quality assessments were at harvest and during postharvest storage. According to the analysis of variance, plant height was significantly affected by protocol. Protocol 5 was statistically superior to the control in two of the three replicates followed by protocol 8 with one statistical significance in the three replicates compared to the control. There was not any statistical difference in diameter of treated plants compared to the control, however plants treated with protocol 8 had the greatest diameter in two of the three replicates. For the chlorophyll content, treatment 1 was the only one that showed a significant increase compared to the control. In terms of color, protocol 2 and 5 significantly increased fruit brightness while protocol 5 and 7 enhanced color saturation and protocol 1 altered hue compared to the control. The firmness of fruits at harvest was 2.08 to 2.85 kg without any significant differences within the protocol. In yield, protocol 5 was statistical significance in marketable weight, number 8 was statistical significance in count and weight in unmarketable category. According to the above, there is a significant benefit of specific biostimulants as treatments 5 and 8 in promoting tomato plant growth and improving certain fruit quality parameters. Key words: Biostimulants, protocol, plant growth.

Speakers

Bryan Merlos Osorio

Southwest Florida Research and Education Center

Co-authors

Jessie Watson

Pavlos Tsouvaltzis

Southwest Florida Research and Education Center, University of Florida

Sotirios Tasioulas

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management

4:15pm CDT

WUM 1 - Vegetable seedlings production via seed magnetization and magnetized water

Tuesday July 29, 2025 4:15pm - 4:30pm CDT

Strand 11A

this study aimed to assess how irrigation water and seed magnetization affected the initial growth of okra, bell pepper, cucumber, lettuce, and eggplant seedlings. Five treatments and four replications were used for each species in the randomized block design (RBD) experiment. T1 was irrigation with tap water; T2 was neodymium magnetization of seeds plus irrigation with tap water; T3 was commercial magnetization of seeds plus irrigation with tap water; T4 was lack of seed magnetization plus irrigation with neodymium magnetized water; and T5 was lack of seed magnetization and irrigation with commercial magnetized water. We assessed the following: emergence speed index (ESI), average emergence time (AET), emergence percentage (E%), shoot dry matter (SDM), root dry matter (RDM), number of leaves (NL), root length (RL), stem diameter (SD), and plant height (PH). Normality and variance analysis were performed on the data, and the Tukey test was used to compare the means at a 5% probability level. The study's findings demonstrate the advantages of magnetically treated water for seedlings. Using water that has been magnetized by a neodymium magnetizer produced superior results for lettuce seedlings. The highest RL, NL, RDM, and ESI values were obtained for bell peppers when they were irrigated with water that had been magnetized by a neodymium magnetizer. The time it took for cucumber, eggplant, and okra seedlings to form was shortened by either magnetizing the seeds or watering them with tap water. Overall, the results of seed magnetism have been more noteworthy than those of irrigation water magnetization.

Speakers

Gustavo Haddad Souza Vieira

Full Professor, IFES campus Santa Teresa

Agronomist,Ph. D. in Agricultural Engineering. Full Professor. Irrigation, Agrometeorology, Horticulture, Coffee Crop.

Co-authors

Paola Alfonsa Vieira Lo Monaco

Ifes Santa Teresa

Rafaela Melim Grazzioti

Ifes

Robson Celestino Meireles

Ifes Santa Teresa

Tuesday July 29, 2025 4:15pm - 4:30pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Funding Source Prodif Ifes. Edital PRPPG 07/2025.

4:30pm CDT

CE 2 - Unraveling the Hormonal Regulation of Flowering in Perpetual Strawberry (Fragaria x ananassa) Cultivars

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Strand 12B

Strawberry (Fragaria × ananassa) is one of the most popular fruits consumed in the United States, valued for its taste, nutritional benefits, and economic importance. Achieving year-round production in the United States has become essential to meet the growing consumer demand for fresh, locally grown strawberries. Controlled environment agriculture (CEA), including greenhouse and vertical farm-based productions, hold great promise for year-round strawberry production. A key factor in achieving year-round strawberry production is understanding the regulations of flowering. While genetic aspects of flowering in strawberries have been widely studied, the role of hormonal regulation remains relatively understudied. This experiment aims to characterize the hormonal regulations of flowering in the perpetual strawberry cultivars (‘Albion’ and ‘Seascape’). We investigated the flowering time and pattern of two perpetual strawberry cultivars grown from bare-root transplants under greenhouse conditions. Additionally, we used an untargeted hormonomics approach using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) at three key developmental stages: 3-leaf, runnering, and flowering. The cultivar variations in runnering and flowering were observed. ‘Albion’ showed flowering approximately eight weeks post-transplantation, whereas ‘Seascape’ primarily exhibited vegetative growth, characterized by minimal flowering and significantly higher runner production than ‘Albion’. The hormonomics analysis identified 102 hormone-related compounds in ESI mode, spanning several hormonal pathways such as cytokinins (CK), tryptophan (Trp) derivatives, gibberellins (GA), melatonin, jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), auxins (IAA), and brassinosteroids (BR). CK was the most abundant group (27%), followed by Trp derivatives (23%) in both cultivars. Partial least squares–discriminant analysis (PLS-DA) showed that among the hormones, CK, GA, and precursor of JA and IAA are primary discriminants between two cultivars and different developmental stages. In the seascape, the accumulations of CK (N6-benzyladenine-7-glucoside, thidiazuron) and GA (gibberellin A5) increased as the developmental stage progressed. Conversely, accumulation of cis-12-oxo-phytodienoic acid (OPOD), a precursor for the JA biosynthesis, increased in the ‘Albion’ as developmental stages progressed. This obtained data reveals a complex interaction of phytohormones involved in the regulation of strawberry flowering. CK and GA accumulation are favorable for vegetative growth, while JA may play a significant role in strawberry flowering. These findings improve our understanding of phytohormonal regulation of perpetual strawberry flowering and could lead to effective strategies for managing flowering time and sustainable year-round strawberry production in CEA.

Speakers

Mahadi Hasan Redoy

University of Tennessee

Co-authors

Ethan W. Darby

The University of Tennessee

Tabibul Islam

University of Tennessee

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Poster # csv

4:30pm CDT

CITR 1 - Rehabilitation of young HLB-affected citrus trees through combination of IPCS and OTC trunk injection

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Foster 2

The combined use of Individual Protective Covers (IPCs) and oxytetracycline (OTC) trunk injection offers a promising strategy for managing huanglongbing (HLB) in young citrus trees by reducing environmental stress and preventing Candidatus Liberibacter asiaticus (CLas) inoculation. This study evaluated whether young citrus trees that were grown without IPCs for the first two years after planting and severely affected by HLB can be rehabilitated by OTC injections, and whether IPCs provide additional benefits beyond OTC alone. ‘Valencia’ sweet orange trees on US-812 and US-942 rootstocks, were organized in a randomized complete block design with three treatments: 1) no injection no IPC, 2) OTC injection no IPC, and 3) OTC injection IPC. Each treatment-rootstock combination consisted of 14 single-tree replications. Trunk injections were performed annually for two years (2023-2024) using Chemjet tree injectors, with solutions delivered into the rootstock. Comprehensive data were collected on the yield, juice quality, bacterial titers, disease state, flushing patterns, and psyllid infestation. No significant differences were observed between the rootstocks except for the juice quality, which was better in combination with US-812. OTC-injected trees consistently exhibited higher yields and improved juice quality, with no additional benefits from IPCs. A significant decrease in CLas titers was noted starting three months post-injection. Injected trees under IPCs had fewer HLB symptoms in the second year, and injected trees exhibited a significant increase in canopy density compared with non-injected trees. Trees with IPCs flushed less frequently during summer and winter than trees without IPCs. The psyllid infestation rate was the same in injected and non-injected trees, indicating that OTC treatment does not affect host attractiveness. These findings highlight the potential of OTC trunk injection to rehabilitate young HLB-affected citrus trees and enhance tree productivity. The longer-term role of IPCs in young tree rehabilitation is still under investigation.

Speakers

Larissa Nunes da Silva

UF/IFAS - Southwest Florida Research

Co-authors

Ute Albrecht

University of Florida/IFAS

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source USDA NIFA ECDRE 2022-70029-38481
Funding Option SCRI funded all or part of the research associated with this abstract

4:30pm CDT

NUTS - Screening Agrobacterium Strains for Gall-Inducing Potential in Pistachio

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Strand 12A

Our research is aimed at generating transgenic pistachio using Agrobacterium-mediated transformation. While previous studies have reported low transformation efficiencies in pistachio, questions remained regarding its susceptibility to Agrobacterium infection and which strains might facilitate successful transformation. Given that Agrobacterium strains differ in virulence across plant species and genotypes, we screened 23 diverse strains to identify those capable of infecting pistachio. These strains, representing various Ti-plasmid types and chromosomal backgrounds, were sourced from the J. Chang Lab at Oregon State University and the USDA’s local collection - primarily isolates from walnuts in California’s Central Valley. We inoculated in vitro-grown pistachio plantlets by wounding stems with blades saturated with each strain. Gall formation was observed in response to 16 strains in UCB-1 (Pistacia atlantica female × P. integerrima male) and 20 strains in Pistacia vera ‘Golden Hills’. These results demonstrate that pistachio is susceptible to infection by diverse Agrobacterium strains, with C58 being one of the most virulent.

Speakers

Ewelina Jacygrad

University of California Davis

Co-authors

Jeff Chang

Oregon State University

Richard Michelmore

University of California Davis

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv

4:30pm CDT

PH 1 - A Robust UHPLC Method Using Multiple Modifiers for Carotenoid Analysis of Tomatoes of Different Colors

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Foster 1

Carotenoids are natural pigments that give fruits and vegetables their yellow, orange, and red colors, and their consumption is associated with numerous health benefits. Most carotenoids occur in isomeric forms (primarily cis and trans); this poses challenges for efficient separation and identification during chromatographic analysis. Tomato (Solanum lycopersicum), an economically important crop, has high nutritional and health benefits, attributed mainly to carotenoids. Lycopene, a major carotenoid in tomatoes, predominantly exists in the trans isoform; however, the trans isoform is less bioavailable than the cis isoform. To accurately measure these isoforms in tomatoes and thus provide information for breeding tomatoes with more cis lycopene, we aimed to develop an Ultra-High Performance Liquid Chromatography (UHPLC) method based on mobile phase (MP) modifiers to measure a wide range of carotenoids (cis and trans) across different tomato varieties (heirloom and cherry) with different colors (green, yellow, orange, purple, and red). The chromatographic parameters, such as temperature (15-30 °C), flow rate (0.3-1.5 ml/min), column lengths (50, 150, and 250 mm), and gradients, and MP modifiers (water, acetonitrile, tetrahydrofuran, triethylamine, ammonium acetate, and ethyl acetate) were optimized. Among the tested parameters, methanol and tert-butyl methyl ether as MP, including ethyl acetate (10%) as a modifier, and C30 column (150 x 4.6 mm) at 20 °C gave the best resolution, allowing the separation of up to 20 peaks indicating individual compounds and isoforms in 35 min. The optimized UHPLC method was also validated for complete profiling, recovery, precision, limit of detection, and quantification. The complexity of the profile based on the number of peaks followed the following order: Orange Heirloom (15) > Orange Cherry (15), Red Cherry (15) > Red Heirloom (13) > Green Heirloom (13) > Purple Cherry (13) > Yellow Cherry (2). Among all the tested tomatoes, trans-lycopene, 5-cis-lycopene, and β-carotene were the predominant carotenoids, followed by 9- and 13-cis-lycopene, and for the first time, mutatoxanthin was detected in Orange Heirloom tomatoes. This method provided efficient peak separation resolution, although not all of them were identified as potential carotenoids; however, their identification could be confirmed by mass spectrometry analysis in future studies. The efficiency, separation, and quantification in this method make it robust for carotenoid analysis in any tomato variety regardless of color. USDA-NIFA-2024-51181-43464 supported this work through the Vegetable and Fruit Improvement Center and partially funded by the Texas A

Speakers

Braulio Cervantes

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Debanjan Chatterjee

Texas A

Debanjan Chatterjee, PhD, is a dedicated researcher specializing in natural products chemistry and pharmacological studies. He earned his B.Pharm in 2017, followed by an M.S. (Pharm) from the National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, in 2019... Read More →

Deepak Kumar Jha

Texas A

Vikas Dadwal

Texas A

I am experienced in phytochemical extraction and LC-MS metabolomics of pre and post-harvested fruits and vegetables. My research focuses on the development of plant-derived bioactive formulations and the assessment of their biological activity in vitro and in vivo. I am currently... Read More →

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Poster # csv

4:30pm CDT

VCM 1 - Effect of Biostimulant Application on Yield and Phytochemical Composition of Mustard greens

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Strand 11B

Current vegetable production faces the challenge of productivity with growing demand for environmentally sustainable crop management practices. Biostimulants present a promising and sustainable strategy for mitigating the adverse effects of unpredictable weather patterns on vegetable crops, thereby enhancing resilience to heat stress, water deficits, and various biotic and abiotic stresses. While biostimulants have shown promising effects in various agricultural applications, there is limited literature on biostimulants and their role in regulating plant growth and development under conventional open field production systems. Additionally, there remains a research gap concerning the optimal application methods and rates of various biostimulants across different vegetable crops. Hence, this study analyzed the effectiveness of two different biostimulants seaweed extract and humic acid on mustard greens (Brassica juncea) performance using conventional farming methods in open field conditions. The biostimulants were applied through both soil and foliar application at two different rates to evaluate their effects on the growth, yield, and nutritional quality of mustard greens. Data was collected on various parameters, including the number of leaves per week, fresh and dry weight at harvest, nutrient content including chlorophylls, carotenoids, and mineral nutrient composition. Yield and nutrient compositions were improved by the application of seaweed at high concentration. In conclusion, seaweed application can be beneficial to improve mustard greens production in open field conditions.

Speakers

Nandini Reddy Muraka

oklahoma state university

Co-authors

Niels Maness

Oklahoma state university

Steve Phillips

Oklahoma state university

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management
Poster # csv

4:30pm CDT

WUM 1 - H2grow System: A Climate Smart Solution for Water Conservation in Vegetable Production System

Tuesday July 29, 2025 4:30pm - 4:45pm CDT

Strand 11A

Agriculture continues to account for over 70% of global freshwater withdrawals, despite extensive research into water conservation methods in food production. A significant portion of this water usage is attributed to irrigation. In vegetable crops, the traditional raised bed system with plastic mulch can reduce irrigation application by minimizing evaporative losses. However, this system does not prevent water and nutrient losses to deep percolation or lateral movement outside the bed area. Therefore, this study evaluates an alternative raised bed system (H2grow), and compares its impact on water use, yield, and fruit quality in bell pepper production against the conventional raised bed system. Six treatments were tested, which included three nitrogen (N) application rates in both raised bed systems (bed type). A split-plot design was used, with bed type as the primary factor and nitrogen rates as the secondary factor. All treatments were replicated four times. Soil moisture sensors were used to trigger irrigation when soil moisture levels fall below 90% field capacity. Soil moisture, nutrient levels, and tissue nutrient content were monitored throughout the growing season. Yield and fruit quality (fruit wall thickness), were assessed at harvest. Preliminary results show that cumulative water use under the H2grow was 33% lower than the conventional raised bed, regardless of nitrogen application rates. This corresponds to a water savings of 1460 m³/ha. Although there were no significant differences in yield or wall thickness between bed types; the H2grow system showed promising potential over conventional beds with a p-value of 0.08 for yield and 0.06 for wall thickness. Nitrogen application rates had no significant effect on yield or fruit wall thickness, though fruit biomass was lowest under the low-N treatment. These findings demonstrate that the H2grow system significantly conserves water in bell pepper production and has the potential to reduce the water footprint in commercial vegetable production. As water conservation becomes an increasing concern in agriculture, this innovative technology offers a critical solution to address the growing challenge of freshwater use in food production.

Speakers

Timothy Ayankojo

Assistant Professor, Mississippi State University

Co-authors

Thomas Horgan

North Mississippi Research and Extension Center – Mississippi State University

Tuesday July 29, 2025 4:30pm - 4:45pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Poster # csv

4:45pm CDT

CE 2 - Enhancing Water Conservation in Hydroponically Grown Strawberries using Potassium Silicate

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Strand 12B

Deficit irrigation presents significant potential for water savings, making it increasingly popular worldwide as a method to reduce freshwater consumption over time. The low water productivity of strawberries is often attributed to excessive water use and the limited ability of cultivars to optimize fruit set and yield in hydroponic systems. This study aimed to evaluate three management strategies—cultivar selection, irrigation frequency, and potassium silicate application frequency—on the growth, water conservation, and production efficiency of hydroponically grown strawberries. The experiment followed a split-plot design, with 'Albion' and 'Chandler' cultivars as the main plot treatments, and a factorial arrangement of irrigation frequency (once/day vs. twice/day) and potassium silicate (AgSil16H) application frequency (6, 9, 12, 15 weeks) randomly assigned to the subplots. Results indicated that foliar application of potassium silicate enhanced plant vigor and contributed to water conservation in hydroponically grown strawberries compared to the control. Notably, a 12-week potassium silicate application boosted photosynthetic rates and improved water conservation, thereby enhancing plant productivity and water use efficiency. For 'Chandler' strawberries, potassium silicate treatment led to a 23% increase in net assimilation rate, a 29% rise in stomatal conductance, and a 33% reduction in transpiration loss. Additionally, electrolyte leakage decreased by 25%, while maintaining steady intercellular CO2 concentrations. Strawberry plants treated with potassium silicate and irrigated once daily reduced water usage by 35% compared to untreated plants. Furthermore, flowering occurred 4 days earlier in treated plants, while fruit set increased by 16% and flower drop decreased by 13% compared to controls. Among all treatments, the 'Chandler' cultivar, irrigated once per day and treated with potassium silicate for 12 weeks, showed superior growth and significant water savings over the control group. Potassium silicate treatment for 12 weeks also resulted in a 20% higher marketable fruit yield compared to the control. Therefore, potassium silicate (AgSil16H) demonstrated its potential as a promising fertilizer under deficit irrigation conditions, effectively conserving water and improving productivity in hydroponically grown strawberries.

Speakers

Prosanta Dash

Eastern Kentucky University

Co-authors

Aaliyah Waller

Eastern Kentucky University

TaKarehia Baltimore

Eastern Kentucky University

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Funding Source Eastern Kentucky University

4:45pm CDT

CITR 1 - Evaluation of Different Oxytetracycline Doses Delivered by Trunk Injection for HLB Management of Mature ‘Valencia’ Sweet Orange Trees

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Foster 2

The systemic delivery of oxytetracycline (OTC) by trunk injection has emerged as a viable strategy to diminish the impacts of the bacterial disease Huanglongbing (HLB) in Florida. This study aimed to determine the optimal OTC dose and best time of delivery to enhance tree health and productivity in mature HLB-affected citrus trees. It also investigated whether OTC effects persist after one single injection compared to two consecutive annual injections. The study began in 2023 at a commercial citrus grove in Polk County, Florida, using 18-year-old ‘Valencia’ (Citrus sinensis) trees grafted onto Swingle (C. paradisi × Poncirus trifoliata) rootstock. Four OTC doses (0.55 g, 0.825 g, 1.1 g, and 1.65 g of active ingredient per tree) were evaluated alongside two application times, spring and late summer, with a non-injected control for comparison. The experiment was a randomized complete block design with eight replications containing four trees. A commercial OTC formulation (ReMedium TI, 95% oxytetracycline hydrochloride) registered in Florida was applied using commercial tree injectors (FlexInject). Doses were applied in 100 ml acidified water through a single injector, except for the highest dose, which was split between two injectors and applied in a volume of 75 ml on opposite sides of the trunk. All trees received their designated doses in year 1, except for the non-injected controls. Only half of the trees injected in year 1 received a second dose in year 2. Trees were harvested in March 2024 and February 2025. Fruits were collected for fruit and juice quality analysis and to determine OTC fruit residue levels. Regardless of the dose, all OTC-treated trees produced more, larger-sized fruits, more total soluble solids (TSS), and a higher TSS-to-acid ratio compared to non-injected controls. The best results were obtained with the highest dose applied by split injections. There were no major differences between spring and summer injections except for the TSS content, which was higher and the percent acid, which was lower when trees were injected in late summer. However, fruit OTC residues were above the allowed maximum after late summer injections, suggesting that injections should be completed by the end of spring. Trees injected for two consecutive years produced significantly more, better-quality fruits than trees injected only once in the first year. These results confirm the efficacy of OTC trunk injections to enhance productivity and fruit quality under HLB-endemic conditions and provide important guidelines regarding dose and timing of injections.

Speakers

Gabriel Pugina

PhD candidate, University of Florida

Co-authors

Caroline de Favari Tardivo

University of Florida

Ute Albrecht

University of Florida/IFAS

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source Florida Citrus Research and Development Foundation (CRDF) #23-002

4:45pm CDT

NUTS - Developing a New Pecan Crop Coefficient to Account for Increased Growing Season Duration and Heat Units.

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Strand 12A

Pecan (Carya illinoinensis) is one of the major crops cultivated in Doña Ana County, Las Cruces, New Mexico, encompassing a total area of approximately 14,704 ha and serving as a significant contributor to New Mexico’s economy. The USDA’s National Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) reveals that pecan acreage in the Mesilla Valley, part of Doña Ana County, increased from 8778 ha in 2012 to 14,696 ha in 2021, marking a rise of 67.4%. Growing pecans, however, necessitates a substantial amount of water annually to maintain good crop quality and yield. The availability of surface water from the Rio Grande for irrigation has diminished due to prolonged drought in the region. Farmers are increasingly concerned about the availability of water for irrigation and are therefore seeking the best irrigation management practices to sustain crop production. The software used for estimating the irrigation water requirements of pecans utilizes crop coefficients as a function of cumulative heat units or Growing Degree Days (GDD), which are based on plant physiology. These GDD functions were developed over a decade ago and do not account for the recent trend of longer and warmer summer temperatures observed in the past decade, thus underestimating the irrigation water needs for pecans, particularly at the end of the growing season. This study indicates that in recent years, the duration of growing seasons has been increasing, and cumulative GDD varies from year to year. A new crop coefficient to account for these changes is proposed.

Speakers

Richard Heerema

Co-authors

A. Salim Bawazir

New Mexico State University

David DuBois

New Mexico State University

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv
Funding Source USDA NIFA Award No. 2021-69012-35916

4:45pm CDT

PH 1 - Estimation of γ-aminobutyric acid and other amino acids as metabolic precursors in tomatoes using a novel unbuffered UPLC-FLD analytical approach

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Foster 1

Tomato metabolism changes in response to environmental conditions such as heat, drought, and soil salinity. This response causes changes in amino acid levels, which are directly related to enzyme activity, photosynthesis, and stress responses. For example, measuring the increase of proline during drought is a biomarker for stress conditions. Qualitative and quantitative analysis of amino acid levels requires precise chromatographic conditions in controlled settings. To accomplish consistent amino acid separation, individual chemical groups require adjustments to chromatographic parameters such as mobile phase composition, pH levels, column type and size, temperature, absorbance/emission wavelength, and gradient combination. This study developed a precise ultra-high performance liquid chromatography (UPLC) approach with a fluorescence detector (FLD) to quantify various amino acids, including γ-aminobutyric acid (GABA), using optimized concentrations of a weak acid (formic acid) and weak base (triethylamine) as modifiers in water and acetonitrile mobile phases, respectively. Buffers are commonly employed in amino acid chromatography; however, excessive usage can result in precipitation and salt accumulation, blocking the pumps. They may also cause pH shifts under high pressure and temperature conditions. Optimized chromatographic conditions improve amino acid separation and quantification. A mobile phase of 0.2% formic acid in water (A) and triethylamine in acetonitrile (B) produced the best results, with maximal separation at 55°C. The gradient began at 90% A and gradually decreased until minute 20, when it returned to the beginning conditions. The injection volume remained steady at 5 µL, with FLD detection peaking at 360 nm. Distinct peaks formed at a 1.0 mL/min flow rate while the pressure was maintained at 1300 psi. Calibration R² results were between 0.97 and 1.0, indicating technique correctness. Separation of real samples found 18 chemicals with retention time changes ranging from 0.01 to 0.05 min. Tomato fruit samples were procured from two developmental stages and amino acid levels were measured. This will provide a benchmark for distinguishing the tomato varieties based on their stress-resilient behavior. This work was partially supported by USDA-NIFA-2024-51181-43464, USDA-NIFA-AFRI 2023-67013-39616 through the Vegetable and Fruit Improvement Center and Institute for Advancing Health Through Agriculture of the Texas A

Speakers

Vikas Dadwal

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Braulio Cervantes

Texas A

Debanjan Chatterjee

Texas A

Deepak Kumar Jha

Texas A

SANGEETA BALYAN

Texas A

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source This work was partially supported by USDA-NIFA-2024-51181-43464, USDA-NIFA-AFRI 2023-67013-39616 through the Vegetable and Fruit Improvement Center and Institute for Advancing Health Through Agriculture of the Texas A&M University.
Funding Option SCRI funded all or part of the research associated with this abstract

4:45pm CDT

VCM 1 - Effect of Biostimulants on Lettuce Growth Under Varying Water Availability

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Strand 11B

Biostimulants have the potential to enhance plant growth and improve resilience to environmental stresses such as drought. This study investigated the effects of biostimulant application on the growth and physiological responses of two lettuce cultivars, ‘Green Oakleaf’ and ‘Red Oakleaf’, grown in a greenhouse at Mississippi State University. Plants were grown in containers under three substrate field capacities (40%, 70%, and 100%) and treated with one of four biostimulant treatments: Tribus®, Huma Pro®16, Kelpak®, or an untreated control. Data collected included plant growth index (PGI), leaf SPAD readings, photosynthetic activity, fresh and dry weights, and leaf color. Water availability and cultivar significantly affected PGI, biomass accumulation, and SPAD readings. The 70% and 100% field capacities resulted in the highest fresh and dry weights, while ‘Red Oakleaf’ exhibited greater dry weight and SPAD values than ‘Green Oakleaf’. Biostimulant treatments had no significant effect on any of the measured parameters. These results indicate that water availability plays a critical role in greenhouse lettuce growth, while the biostimulants tested did not enhance plant performance under the conditions of this study.

Speakers

Zhiheng Xing

University of Georgia

Co-authors

Guihong Bi

Mississippi State University

Tongyin Li

Mississippi State University

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management

4:45pm CDT

WUM 1 - Micro-sprinkler Systems for Reduced Water Use during Establishment and Freeze Protection of Field-grown Strawberries in Florida

Tuesday July 29, 2025 4:45pm - 5:00pm CDT

Strand 11A

Strawberry production in Florida traditionally relies on impact sprinklers for bare-root transplant establishment and freeze protection, leading to significant water consumption and potential nutrient leaching and runoff. This study assessed micro-sprinkler systems as alternatives to enhance water use efficiency while maintaining crop performance. The objectives were to (1) evaluate micro-sprinklers in research and commercial settings and (2) assess sprinkler distribution uniformity under different wind conditions. Field trials at the Plant Science Research and Education Unit in Citra, FL compared four micro-sprinklers to an impact sprinkler (control), measuring water use, plant vigor, and yield. The tested systems utilized Mini Revolver, SuperNet Jet, Mini-Wobbler, and Xcel Wobbler micro-sprinklers. The irrigation systems were arranged in a randomized complete block design with four replications. Additionally, lower quarter distribution uniformity (DUlq) tests with catch cans were conducted to evaluate sprinkler efficiency for freeze protection across varying wind conditions in Citra. The best-performing micro-sprinkler system was evaluated on a commercial strawberry farm in Plant City, FL in comparison with the grower’s Rotator sprinkler system. In Citra, all micro-sprinkler systems used less water than the impact sprinkler for bareroot transplant establishment and freeze protection. Water use was lowest with the Mini-Revolver, which decreased water use by 66% during establishment and 64% during freeze protection without adversely affecting plant survival or yields. Similar reductions were observed at the commercial farm, with water savings reaching 58% during establishment and 63% during freeze events. Significant variation in DUlq in response to wind conditions was observed among the sprinkler systems. Wind speeds >7 mph decreased DUlq, with the Mini-Revolver resulting in the lowest DUlq. However, at wind speeds 7 mph, which would decrease freeze protection effectiveness.

Speakers

Carlene Chase

University of Florida

Co-authors

Davie Kadyampakeni

University of Florida

Josue St Fort

University of Florida

Michael Dukes

University of Florida

Shinsuke Agehara

University of Florida

Vivek Sharma

University of Florida

Tuesday July 29, 2025 4:45pm - 5:00pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Funding Source Southwest Florida Water Management District

5:00pm CDT

CE 2- Enhancing Strawberry Propagation Systems Through Photoperiod, Spectrum, and Intracanopy Lighting

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Strand 12B

The strawberry industry relies on the production of disease-free daughter plants (DPs). Challenges in open-field nurseries have prompted research into controlled-environment agriculture (CEA) as an alternative to improve DP yield and quality. Growing strawberry stock plants indoors with stolons (runners) oriented vertically downward has been shown to increase DP production. However, information on detailed plant architecture and plant-light interactions remains limited. This project evaluated the impacts of photoperiod, light quality, and light distribution on DP yield and quality through a series of experiments. Firstly, shortening the photoperiod from 20 to 12 hours while maintaining the same daily light integral increased DP yield by 18%. Spatial distribution analysis revealed that a majority (60%) of DPs developed under suboptimal light conditions (

Speakers

Moein Moosavi

PhD student, NC State University

Moein Moosavi-Nezhad is a Ph.D. student in the Horticultural Sciences department at NC State University, working in the Controlled-Environment Agriculture Lab under Ricardo Hernandez. He started working in CEA in 2016 at the University of Tehran focusing on plant-light interactions... Read More →

Co-authors

Ricardo Hernandez

NC State University

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Poster # csv

5:00pm CDT

CITR 1 - The Effects of Rootstock Selection and Oxytetracycline Trunk Injection on the Fruit and Juice Quality of the 'OLL-8' Sweet Orange Scion

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Foster 2

Citrus production in the State of Florida has been decimated by the disease Huanglongbing (HLB). This disease is associated with the phloem-limited, gram-negative bacteria Candidatus Liberibacter asiaticus (CLas) and is vectored by the Asian citrus psyllid (Diaphorina Citri). Since HLB was first identified in Florida in 2005 it spread rapidly and was considered endemic in the state by 2013, resulting in a nearly 90% decline in citrus fruit production. While breeding more tolerant or fully resistant cultivars is likely the best long-term solution, trunk injections of the antibiotic oxytetracycline were granted emergency use approval in October 2022 to combat the bacteria. Historically most of Florida’s citrus production has been sweet orange (Citrus sinensis (L.) Osbeck) cultivars including ‘Hamlin’ and ‘Valencia’ which were primarily destined for juice processing. Unfortunately, all known commercial sweet orange cultivars are susceptible to HLB infection leading to the rapid and drastic decrease in production across the state. Of the sweet orange cultivars that have been released by the University of Florida Institute of Food and Agricultural Sciences (UF-IFAS), Orie and Louise Lee (‘OLL’) lines have shown some degree of tolerance to HLB in cultivar field trials. In our experiment we evaluated the effects of rootstock selection and oxytetracycline (OTC) trunk injections on the fruit and juice quality of the ‘OLL-8’ sweet orange scion. Three of the evaluated rootstocks (‘US-942’, ‘US-897’, and ‘Swingle’) are industry standard diploids, while the other three rootstocks (‘UFR-2’, ‘UFR-4’, and ‘UFR-6’) are tetraploids released by the University of Florida. For each of these rootstocks there were trees that were injected with OTC and untreated control trees. Fruit were harvested at several time points and data were collected on juice quality attributes including titratable acidity in citric acid equivalents, total soluble solids, sugar/acid ratio, pounds-solids per box, and juice color, as well as fruit characteristics including mass, diameter, total yield, and premature fruit drop. The trees that were injected with OTC had significantly larger mean fruit diameter, higher mean ratio, and lower premature fruit drop than untreated controls. There was also evidence for statistically significant differences among rootstock selections in conjunction with the ‘OLL-8’ scion for each of the characteristics that were evaluated. These results indicate that rootstock selection and OTC-trunk injections can significantly improve fruit and juice quality of the ‘OLL-8’ sweet orange scion. However, more research is needed on the effects of OTC injections in different rootstock-scion combinations.

Speakers

Joe Volpe

University of Florida

Co-authors

Emily Worbington

University of Florida-IFAS CREC

John Chater

University of Florida

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source USDA Agricultural Marketing Service (AMS) MultiState Specialty Crop Block Grant through the California Department of Food and Agriculture project number 19-1043-002-SF

5:00pm CDT

NUTS - Almond Species Classification and Diversity

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Strand 12A

Almond species represent one of the most successful horticultural groups in the genus Prunus, Family Rosaceae. Classified to the subgenus Amygdalus, species occupy important positions in ecological habitats and include the commercially important tree crops: almond, peach, and nectarine as well as important rootstocks for almond, peach, nectarine, plums, prunes, and apricots. Almond has several wild types, including more than 40 species. It has been reported that these species were adapted and distributed to the increasingly xerophytic environments of Asia. Almond is one of the major nut crops in world production. The fruit and kernel have historically been an important source of food, as well as essences and oils used for making products ranging from medications to cosmetics. The almond wood is durable and fine-grained, making it valued for multiple uses, from woodworking to producing high-quality charcoal. In many regions, endemic almond species continue to play important ecological roles, including controlling erosion and acting as greenbelt filters for urban areas. The diverse germplasm possesses numerous traits of value for crop improvement, including improved resistance to biotic (pests and diseases) and abiotic stresses (drought, frost, and winter damage), as well as modified tree architectures and bearing habits. There also exists a long tradition for the use of this native germplasm as rootstocks for almond and other Prunus crops, particularly where tree size control and improved drought resistance are desired. Other traits useful for crop improvement include later flowering for frost avoidance, self-fruitfulness, and precocious cropping. Accurate assessment of genetic diversity and breeding value, however, depends upon a clear understanding of species properties and relationships. Gametophytic self-incompatibility in most species results in obligate outcrossing, enhancing both morphological and genetic variability within species. Because strong interspecific breeding barriers are not commonly present, considerable interspecies hybridization and subsequent introgression can also be found in the wild. While the resulting genetic and developmental uniqueness of almond and its wild relatives has resulted in it being classified in the genus Amygdalus in most European and Asian studies, this study also includes the more recent APG IV system of classification placing them within the genus Prunus.

Speakers

Alireza Rahemi

Morehead State University

Co-authors

Thomas Gradziel

University of California

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv

5:00pm CDT

PH 1 - Assessing postharvest outcome in d’Anjou pears sorted by a chlorophyll-carotenoid index based on hyperspectral images

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Foster 1

Large-canopy training systems commonly used in Washington pear orchards create sunlight exposure disparities among fruits. Pear ripening is influenced by sunlight exposure and variability contributes to non-uniform ripening postharvest outcomes. To enhance uniformity in fruit batches based on sunlight exposure, d ‘Anjou pears were sorted according to a newly adapted Chlorophyll-carotenoid index (Cri) based on Hyperspectral images. In September 2024, d’Anjou pears were harvested in three commercial orchards located across distinct growing regions in Washington and Oregon. Reflectance spectral information for each fruit was extracted from Hyperspectral images, and wavebands related to Chlorophyll and carotenoids (430, 662, 454, 549 nm) were subsequently used to calculate Cri values for each fruit. This index value allowed for sorting of fruit into batches under three sunlight categories: Low, Medium, and High. Fruit was kept in controlled atmosphere storage (3.0 % O2, 0.8 % CO2, 0 oC) and quality (Chlorophyll degradation (IAD), firmness (lb)), was studied after 4 months of storage plus 7 days at room temperature (20 oC). Fruit maturity indexes, at harvest, showed no differences between fruit categories. Chlorophyll degradation (IAD) on fruit surface showed that in two of the three orchards, low-exposure fruits exhibited lower values in comparison to high-exposure ones (P ≤ 0.01). Firmness values were significantly lower in high-exposure categories after cold storage and room temperature periods, landing at around 12 lbs and 3 lbs, respectively (P ≤ 0.01). No major differences in physiological disorders incidence between sunlight categories were observed. Further investigation needs to be conducted to determine how these categories behave in longer cold-chain storage scenarios.

Speakers

Oswaldo Gonzalez-Garcia

WSU TFRECT Postharvest Lab

Co-authors

Carolina Torres

Washington State University

Rene Mogollon

Washington State University

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WSDA Specialty Crop Block Grant Program "Non-destructive sorting at harvest to improve pear cold chain outcome"

5:00pm CDT

VCM 1 - Effect of Organic Soil Amendments on Yield and Phytochemical Contents of Collard Greens in Open Field Conditions

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Strand 11B

With increasing focus and shift towards soil health, sustainable soil management practices stand as critical approach to enhance the crop productivity and quality while improving production system as a whole. One method to improve soil health is through addition of soil amendments such as compost, animal manure and crop residues. However, there is limited literature on emerging organic amendments like biochar, vermicompost and peatmoss and their role in crop production in field-based conditions. Specifically, biochar has high cation exchange capacity and improves soil homeostasis, while vermicompost has more readily available nutrients. Several researchers have found synergistic effects when biochar and vermicompost were used in combination with high nutrient retention and uptake, supported by high activity of soil microorganisms. Similarly, peat moss is rich in organic matter and has high water absorption capacity. Although its use in soilless substrates has been widely explored, peat moss as soil amendment in open fields has limited literature. Hence, the current study investigated the role of organic soil amendments on yield attributes and nutritional profile of a leafy green vegetable, collard greens. Furthermore, soil parameters like organic matter content, soil nutrients and soil bulk density were observed before and after the crop period. Two open field trials were conducted in spring and fall under at Students Farm, Oklahoma State University, following certified naturally grown production practices. The soil amendment treatments were arranged in randomized complete block design within four blocks. Collard greens’ phytochemicals such as chlorophylls, carotenoids, flavonoids, phenols, and sugars were analyzed after harvest. Results show that vermicompost facilitated better crop performance by improving soil physical and chemical properties. The findings of this study provides sustainable horticulture practices by providing more information on added amendments and their role in improving soil health and enhancing crop quality, offering actionable insights for soil health focused production systems.

Speakers

Pradeep Paudel

Oklahoma State University

An MS student at Oklahoma State University, interested in the use of organic amendments for crop production and soil health improvement.

Co-authors

Bee Chim

Oklahoma State University

Niels Maness

Oklahoma State University

Shivani Kathi

Oklahoma State University

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management

5:00pm CDT

WUM 1 - Applying a consistent deficit irrigation in cantaloupe melons to improve crop water productivity

Tuesday July 29, 2025 5:00pm - 5:15pm CDT

Strand 11A

Deficit irrigation is an agricultural practice that can enhance crop water productivity (CWP) when yields are not affected, and be a technique to support crop production under persistent droughts and reduced agricultural water availability. Over two seasons, we evaluated grafted and ungrafted cantaloupe melon (Cucumis melo L.) under three consistent irrigation regimes: 100% of field capacity (FC; full irrigation), and 70% and 50% irrigation volumes of the full irrigation, resulting in moderate and severe deficit irrigation treatments, respectively. Although the deficit irrigation treatments accentuated drought stress through the season, plants in the moderate deficit irrigation (70% FC) maintained their plant water status and slightly lowered stomatal conductance (gs) and photosynthetic rate (Pn) when compared to full irrigation. Under severe deficit irrigation (50%), plants had lower water potential than the full irrigation, and a reduction of 65% in gs and 47% in Pn, when compared to the full irrigation. The yields of the 100% and 70% irrigation treatments were similar in one year and lower for the 70% FC in the second year. The severe deficit irrigation had on average a 40% lower yield than the full irrigation. Overall, the moderate deficit irrigation had a 25% reduction in applied water, and either a similar or a higher CWP, depending on year, when compared to the full irrigation. Melon grafting did not improve yield under deficit irrigation conditions; however, it increased yield under full irrigation and low environmental stress (i.e., year). This study shows that melons can acclimate to lower water availability and sustain yields under a constant, moderate deficit irrigation, which can be an alternative for growers that face long-season droughts and lower irrigation water allocation.

Speakers

Felipe Barrios Masias

University of Nevada, Reno

Co-authors

Heinrich di Santo

University of Nevada, Reno

Tuesday July 29, 2025 5:00pm - 5:15pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Funding Source Western Sustainable Agriculture Research and Education (WSARE) program, project SW20-918; and the Nevada DRIVE program at UNR

5:15pm CDT

CE 2 - Increasing Fertilizer Nitrogen Concentration Improves Strawberry Daughter Plant Quality but Does Not Increase Yield

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Strand 12B

Nitrogen (N) fertilizer recommendations exist for controlled environment strawberry (Fragaria ×ananassa) fruit production. However, optimal N fertilizer concentrations may differ for strawberry mother plants, given that vegetative growth rather than reproductive growth is preferred. Our objective was to evaluate the impact of N fertilizer concentration on strawberry daughter plant yield and quality. Strawberry ‘Albion’ and ‘Monterey’ were grown in a greenhouse in 19.1-cm diameter pots filled with a soilless substrate (50 perlite : 25 coco coir : 25 peat). Plants were fertigated with a modified strawberry nutrient solution (Yamazaki) to provide 50, 100, 150, 200, 250, or 300 mg·L-1 N. After 12 weeks of treatment, cultivar but not N concentration impacted total stolon number and total daughter plant number. ‘Monterey’ produced 129% more stolons and 72% more daughter plants than ‘Albion’. Likewise, cultivar but not N concentration impacted branch architecture and where daughter plant formation occurred. The percentage of plants that produced primary, secondary, tertiary, and quaternary stolons was 100%, 97%, 61%, and 7% for ‘Monterey’ and 100%, 82%, 12%, and 0% for ‘Albion’. The distribution of daughter plants produced on primary, secondary, and tertiary stolons was 75%, 24%, and 1% for ‘Albion’, whereas it was 56%, 40%, and 4% for ‘Monterey’. Daughter plant quality exhibited quadratic responses to an increase in N concentration. Calculated maximum values were at 149 mg·L-1 N for daughter plant crown diameter, 172 mg·L-1 N for daughter plant fresh weight, and 187 mg·L-1 N for chlorophyll content index. Daughter plant foliar %N increased linearly as N fertilizer concentration increased from 50 to 300 mg·L-1 N, from 1.76% to 2.86% in ‘Albion’ and from 1.48% to 3.33% in ‘Monterey’. Mother plants also responded quadratically to N fertilizer concentration. Mother plant height, width, crown diameter, fresh weight, and a qualitative root rating assessment were greatest at calculated N concentrations of 154 to 169 ppm N. Necrosis of leaf margins began to appear in mother plants supplied 200 to 300 mg·L-1 N due to high nutrient solution electrical conductivities (ECs). In summary, although N concentration did not impact daughter plant yield, an N fertilizer concentration of 150 mg·L-1 N would optimize daughter and mother plant quality without inducing EC stress.

Speakers

Jennifer Boldt

Research Horticulturist, United States Department of Agriculture

Co-authors

Erin Yafuso

USDA-ARS

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments
Poster # csv

5:15pm CDT

CITR 1 - Efficacy of Oxytetracycline (OTC) for Huanglongbing (HLB) Management in South Texas ‘Rio Red’ Grapefruit

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Foster 2

Citrus Huanglongbing (HLB), also known as citrus greening, is associated with Candidatus Liberibacter asiaticus (CLas), a phloem-limited bacterium transmitted by an insect vector, Asian Citrus Psyllid (ACP). Currently, there are no commercially viable treatment options available for HLB management. Trunk injection of Oxytetracycline (OTC) has been widely adopted as a treatment option in Florida. Currently, OTC is not approved for use in Texas citrus, and no OTC efficacy data is available. This study evaluated the efficacy of OTC in mitigating HLB and managing tree health in nine and 17-year old ‘Rio Red’ grapefruit (Citrus paradisi Macfadyen) trees on sour orange (Citrus aurantium L.) rootstock, on a randomized complete block design in two commercial orchards. RECTIFY™ (95% Oxytetracycline hydrochloride) was injected into tree trunks at two rates (0.55g and 1.1g per tree) using Chemjet® tree injectors during June-July 2023 and May 2024. Trees were evaluated for various attributes, including periodic (pre-treatment, three, six, and nine months after OTC injection) bacterial titer in leaf and root tissues and tree health monitoring (canopy color, canopy density, and HLB severity) for the same time intervals. Fruits collected at harvest maturity were evaluated for yield, fruit size, and juice quality (brix, titratable acidity, flavonoids, carotenoids). Additionally, pre-harvest fruit drop and trunk injection site damage were recorded. OTC residue was measured in whole fruit and juice using Ultra-High-Performance Liquid Chromatography coupled with tandem Mass Spectrometry (UHPLC-MS-TOF). Nine-year-old trees treated with 1.1g of OTC/tree in one of the sites showed a significant reduction of bacterial titers in leaf tissue. OTC treatment did not significantly improve yield. Canopy color showed noticeable improvement after the second OTC injection in the sites, whereas canopy density remained largely unaffected. After the second OTC injection, HLB severity and pre-harvest fruit drop were reduced, and improvement in fruit size was observed in 9-year-old trees. There is no significant improvement in juice quality. Damage caused by trunk injections healed rapidly in older trees than in younger trees. No OTC residue was detected in the juice and whole fruit at six months after the OTC injection. This is the first report on the efficacy of OTC for HLB management in Rio Red grapefruit in South Texas.

Speakers

Priyanka Kesoju

Texas A

Co-authors

Aditi Satpute

Texas A

Jong-Won Park

Texas A

Madhurababu Kunta

Texas A

Mamoudou Setamou

Texas A

Ram Mohan Uckoo

Wonderful Citrus

Ruth Galan

Wonderful Citrus

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Poster # csv

5:15pm CDT

NUTS - Flavor Matters: Expanding the Market Potential of Black Walnut through Consumer Sensory Insights

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Strand 12A

Black walnut (Juglans nigra L.) is a native nut species valued for its richness and nutritional profile, but its intense flavor can limit broader consumer appeal. To better understand sensory preferences, a consumer taste panel evaluated kernel flavor, texture, and overall kernel liking across eight cultivated walnut genotypes. Seven black walnut genotypes (HS, DL, HY, BW1, BW2, BW3, and BW4) and two English walnut (Juglans regia L.) samples were tested. One English walnut sample was standardized as the first sample, and the remaining samples were randomized in a William’s Latin Square design. One hundred participants rated these genotypes for overall kernel liking, flavor intensity, texture, aroma, and the intensity of specific flavors (e.g., bitter, walnut, nut, off flavors, woody). Welch's ANOVA and Games-Howell post hoc tests identified differences between genotypes for all attributes. All black walnuts differed significantly (p < 0.01) from English walnut in panelists’ ratings of overall kernel liking and flavor liking attributes. However, only HS did not significantly differ from English walnut in aroma liking. Principal component analysis revealed a strong positive correlation between overall liking and attributes such as flavor liking, texture liking, and aroma liking, and a negative correlation with perceived off-flavor and bitterness intensities. Regression analysis confirmed these findings and indicated that a unit increase in flavor liking was associated with a 0.74 unit increase in overall kernel liking. Conversely, a unit increase in off-flavor intensity resulted in a 0.056 unit decrease in overall kernel liking. Several accessions appear as promising candidates for cultivar development, supporting opportunities to expand consumer acceptance and the market potential of this underutilized native crop through targeted flavor improvement.

Speakers

Seth Wannemuehler

University of Minnesota

Co-authors

Brandon Miller

University of Minnesota

Herika Paula Pessoa

University of Minnesota

Neil Anderson

University of Minnesota

Ronald Revord

University of Missouri

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv
Funding Source This work was supported by the Physiology of Agricultural Plants program, project award no. 2023-67013-39512, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

5:15pm CDT

PH 1 - Adapting a Hyperspectral Chlorophyll-Carotenoid Index (Cri) to Standardize Postharvest Outcomes in d ’Anjou Pears

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Foster 1

In Washington state, pears are typically cultivated on trees with large canopies, which results in different levels of sun exposure and, therefore, fruit maturity variability at harvest and postharvest. Hyperspectral reflectance imaging has been previously used to detect sun stress and predict sunscald risk through a chlorophyll-carotenoid index (Cri; 430, 662, 454, 549 nm) on apples. The objective of this work was to adapt a non-destructive sorting index to standardize groups of fruit with predictive postharvest outcomes throughout the cold chain and treatments. d ‘Anjou pears were harvested from different canopy positions (internal, external, and random) in three commercial blocks during 2023. Hyperspectral images (640 x 840 px; 400–1100 nm) were captured from the exposed and unexposed sides of the fruit at harvest. The reflectance information was then extracted and pre-processed with Savizky-Golay and Standard Normal Variate filters. With this information, the Cri was calculated for every fruit. Cri values ranged from 0.9 to 3.6 for fruit from external canopy positions and 1.1 to 3.8 for those from internal ones. The analysis of variance showed significant differences in Cri values across fruit sides and tree positions (p < 0.01). These findings support the viability of using the chlorophyll-carotenoid index to sort pears with different sun stress levels at harvest. Further research is needed to evaluate the consistency in response of the different fruit groups when submitted to different cold chain scenarios and postharvest treatments.

Speakers

Rene Mogollon

Washington State University

Co-authors

Carolina Torres

Washington State University

David Rudell

USDA-RS Wenatchee

Oswaldo Gonzales-Garcia

Washington State University

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Funding Source WSDA SPECIALTY CROP BLOCK GRANT PROGRAM; Project Title: Non-destructive sorting at harvest to improve pear cold chain outcome.

5:15pm CDT

VCM 1 - Effects of Nitrogen Fertilization Rate and Timing on Yield and Fruit Quality of Strawberry in Florida

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Strand 11B

Nitrogen (N) is the macronutrient required in the largest amount by strawberry plants (Fragaria ×ananassa Duch.) and is often the primary factor limiting their yield. Florida’s sandy soils are highly prone to leaching of mobile nutrients like nitrate. Optimizing N fertilization is essential not only for maximizing economic returns but also for reducing the risks of environmental pollution caused by nitrate leaching and runoff. This study aimed to determine the growth stage-specific optimum N rates for the winter strawberry production system in Florida. Three field experiments were conducted in west-central Florida, each following a factorial design with four cultivars [‘Florida Brilliance’ (Brilliance), Florida MedallionTM 'FL 16.30-128' (Medallion), Florida PearlTM ‘FL 16.78-109’ (Pearl 109), and Florida Pearl® ‘FL 18.52-66’ (Pearl 66)] and five N rates (0, 0.56, 1.12, 2.24, and 3.36 kg/ha/d). Different N rates were applied during Weeks 3–8 (early growth) in Expt. 1, Weeks 9–14 (mid-growth) in Expt. 2, and Weeks 15–20 (late growth) in Expt. 3, with a baseline rate of 1.12 kg/ha/d before or after the treatment period. All experiments concluded at the end of Week 20, with total N application rates ranging from 94 to 235 kg/ha. Model fitting analysis was conducted to explain the yield response for N rates. In Experiment 1, marketable yield was fitted to linear models (r2=0.82−0.98) as a response to N rate, with slopes of 0.45, 0.45, 0.36, and 0.35 for Brilliance, Medallion, Pearl109, and Pearl66, respectively. Increasing the N rate from 1.12 to 3.36 boosted total marketable yield by 128%, 132%, 129%, and 126% for Brilliance, Medallion, Pearl109, and Pearl66, respectively, by the season's end. In Experiment 2, marketable yield of Medallion and Pearl66 followed linear models (r2=0.9−0.96) with slopes of 0.44 and 0.26, respectively, while other cultivars showed no significant slope differences. Increasing the N rate from 1.12 to 3.36 enhanced marketable yield by 137% for Medallion and 111% for Pearl66. In Experiment 3, no significant pattern was observed between N rates and marketable yield during the treatment period, but increasing the N rate slightly increased marketable yield at season's end for Brilliance (101%), Pearl109 (113%), and Pearl66 (104%), while negatively impacting Medallion (91%). Across all experiments, unmarketable yield, small fruit number, and soluble sugar content were not significantly (p

Speakers

Kalara Dissanayake

University of Florida

Co-authors

Shinsuke Agehara

University of Florida

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management
Poster # csv

5:15pm CDT

WUM 1 - Optimizing Woodchip Bioreactors for Nutrient Recycling and Pesticides Removal in Greenhouse Irrigation Return Water

Tuesday July 29, 2025 5:15pm - 5:30pm CDT

Strand 11A

Sustainable management of irrigation water is critical for soilless greenhouse production systems, particularly in ornamental plant cultivation, where agrochemical (pesticides, nutrients, and growth regulators) use is intensive. Recycled irrigation water carries agrochemicals from production surfaces, containers, substrates, and system components. Even at low concentrations, these compounds can be phytotoxic to sensitive crops or pose environmental risks if discharged. While recirculating irrigation systems improve water efficiency, they require the use of treatment technologies to remediate agrochemicals. Woodchip bioreactors, commonly used for nitrate removal, have also shown promise in remediating phosphates and pesticides. They provide a carbon source and growth matrix for diverse microbial communities. Typical anaerobic conditions facilitate denitrification, and the biofilm further increases the reactive surface area where pesticides can interact with degrading enzymes to enhance pesticide remediation. Integrating aerobic bioreactors as a secondary stage can promote dissolved organic carbon release and enhance degradation of certain pesticides. Hydraulic retention time (HRT) is a key design factor, influencing nutrient retention and pesticide removal by controlling contact time with bioreactor microbiomes. Shorter HRTs support nutrient recycling for irrigation reuse, while longer HRTs enhance nutrient and pesticide degradation through extended microbial processing. We evaluated the performance of a sequential two-stage non-aerated (stage 1) - aerated (stage 2) bioreactor configuration in reducing effluent pesticide concentration and load under varying hydraulic retention times (HRTs). Two two-stage systems, each consisting of two bioreactors, were installed at a Michigan wholesale greenhouse, treating recirculating operational water from an 11,500 m² production area. These systems operated for 160 days at HRTs of 30 (30HRT) and 60 minutes (60HRT) per stage, corresponding to bioreactor volumes of 1,135 L and 2,271 L per stage, respectively. Preliminary results indicate that both 30HRT and 60HRT systems treated an average daily volume of 36,225±2,395 L. Average recycled Total Nitrogen load was 91% and 2.6 kg d-1 for 30HRT, and 78% and 2.3 kg d-1 for 60HRTs, respectively. Phosphate and pesticide content is currently being analyzed, with early observations showing phosphate load shifts from non-aerated to aerated conditions. These results will be presented at the conference.

Speakers

Henry Gonzalez

Research Assistant/Ph.D. Student, Michigan State University

Co-authors

Gemma Reguera

Michigan State University

James Owen

USDA ARS

Jim Owens is a USDA-ARS Research Horticulturist located at the Application Technology Research Unit in Wooster, OH. Jim received his B.Sc. in Plant and Soil Science at the University of Kentucky, his M.Sc. in Environmental Science at the University of Rhode Island, and Ph.D. at North... Read More →

R. Thomas Fernandez

Michigan State University

Tuesday July 29, 2025 5:15pm - 5:30pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Poster # csv

5:30pm CDT

CE 2 - Interactive effects of CO2 concentration, light intensity, and far-red photons: Morphology, Photosynthetic Response, and Fruit Yield in Dwarf Tomato ‘Red Robin’

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Strand 12B

Carbon dioxide (CO₂) concentration and light conditions, including both intensity and spectral quality, are key environmental factors influencing plant growth, photosynthetic efficiency, and fruit production in tomatoes. Recent studies on greenhouse tomato varieties have reported that short-term exposure to elevated CO₂ concentration (800 ppm) and higher light intensity enhances plant growth and photosynthetic activities; additionally, long-term exposure to supplementary far-red photons increases dry mass partitioning to fruits, resulting in higher fruit yield. However, limited information is available regarding the interactive effects of CO₂ concentration, light intensity, and far-red photons in dwarf tomatoes for indoor production. Therefore, this study aimed to quantify the interactive effects of CO₂ level, photosynthetic photon flux density (PPFD; 400-700 nm), and supplementary far-red photon on growth, photosynthetic responses, and fruit production in dwarf tomato ‘Red Robin’. Plants were grown under two CO₂ levels (ambient: 400 ppm; elevated: 1500 ppm) × two light intensities [PPFD of 250 µmol m^-2 s^-1 (PPFD250) and 500 µmol m^-2 s^-1 (PPFD500)] × two supplementary far-red levels (0% or 15% of respective PPFD). Plants grown under elevated CO₂ generally exhibited increased plant height and stem biomass than those grown under ambient CO₂ levels. Elevated CO₂ improved fruit yield under low light intensity (PPFD250 with or without far-red supplementation) compared to ambient CO₂; however, this effect was not observed under high light intensity. Light intensity had a stronger impact on total leaf area and fruit mass under ambient CO₂. Specifically, under ambient CO₂, plants grown at PPFD500 showed lower total leaf area but higher fruit biomass than those grown at PPFD250. However, under elevated CO₂, the effects of light intensity became less pronounced, with no significant difference in fruit mass among the light treatments. Supplementation with 15% far-red photons did not cause any significant differences in tomato growth and morphology. Overall, these findings indicate that elevated CO₂ level significantly enhances fruit production under low light intensity treatments, regardless of supplementary far-red photons. However, the potential benefits associated with high light intensity treatments (PPFD500 and PPFD500 + 15% far-red photons) appear to diminish when plants were grown under elevated CO₂ conditions.

Speakers

Seonghwan Kang

Texas A&M

Co-authors

Shuyang Zhen

Texas A&M

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 2

Subject Growth Chambers and Controlled Environments

5:30pm CDT

CITR 1 - Lessons from Oxytetracycline Trunk Injection to Manage Citrus Huanglongbing in Florida

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Foster 2

Huanglongbing (HLB, aka citrus greening) has devastated citrus production around the world, especially in Florida where the disease has been endemic since 2013. HLB is associated with phloem-limited bacteria, Candidatus Liberibacter asiaticus, vectored by the Asian citrus psyllid, Diaphorina citri. Elimination of the disease vector is difficult because of its abundance and the high costs of frequent insecticide applications. Foliar applied therapies to treat infected trees are largely ineffective because of the systemic distribution of the bacteria. Trunk injection of oxytetracycline (OTC) has emerged as a possible therapy to systemically deliver and target the pathogen and restore tree health. Since the registration of trunk injection of OTC for commercial use in Florida, our lab has conducted numerous field studies to assess the efficacy of this therapy on a large scale and study the influence of various factors such as tree age, rootstock, OTC dose, and time and method of application. Overall, all studies revealed significant improvements in fruit production along with increases in fruit and juice quality after one year of application. Yield improvements after two years of application were cumulative, reaching up to two-fold or more. The magnitude of improvements depended on various factors. Young trees generally responded better than older trees, and tree responses varied based on the rootstock. The efficacy of the therapy also depended on the dose of OTC administered to the trees, with higher doses generally generating larger effects. Moreover, delivering OTC on multiple sides of a tree instead of on only one side enhanced its distribution and therefore, efficacy. Late season injections improved the juice quality more but increased the OTC residue content in the fruits. The currently allowed residue level is 10 ppb, which was not exceeded when injections occurred in spring or early summer. OTC is phytotoxic and can have adverse effects on the tree. Efforts are underway to reduce or eliminate these negative effects and improve efficacy. Alternative therapies to be used instead of, or in combination with OTC, are also under evaluation. Taken together, the systemic delivery of OTC by trunk injection has emerged as a viable and economically feasible therapy to manage HLB in Florida and has been widely adopted. Nevertheless, it is regarded as a short-term solution until other solutions become available.

Speakers

Ute Albrecht

University of Florida/IFAS

Co-authors

Caroline de Favari Tardivo

University of Florida

Deived de Carvalho

University of Florida/IFAS

Gabriel de Castro Marconi Pugina

University of Florida

Gerardo Moreno

University of Florida/IFAS

Igor Rodrigues

University of Florida/IFAS

Jasmine de Freitas

University of Florida/IFAS

Larissa Nunes da Silva

UF/IFAS - Southwest Florida Research

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source USDA NIFA ECDRE (project 2021-70029-36056) and Citrus Research and Development Foundation (projects 22-001, 23-002, 23-005, 23-036)
Funding Option SCRI funded all or part of the research associated with this abstract

5:30pm CDT

NUTS - Tapping into the Syrup Potential of Black Walnut: A Two-Year Evaluation of Sap Flow and Sugar Concentration

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Strand 12A

Eastern black walnut (Juglans nigra L.) is a long-lived perennial tree with significant potential for expanded cultivation and utilization. Renowned for its high-quality wood and nutritious nuts, it also presents opportunities for expanded horticultural application, including syrup production. Black walnut syrup has been suggested as a viable alternative or complement to maple syrup, offering a promising new species for syrup producers to explore. However, little is known about black walnut sap flow dynamics, sugar concentration, and how these traits respond to environmental conditions. This study evaluated sap flow patterns and sap quality during the 2024 and 2025 seasons using 25 mature trees from a research plot at the University of Minnesota Horticultural Research Center. Trees were tapped at the beginning of the sap season and monitored daily for sap volume and sugar concentration until the sap became cloudy, indicating bud break and the end of the collection period. Weather data were obtained from the Chaska, MN station via the Network for Environment and Weather Applications maintained by Cornell University. A linear mixed-effects model was used to evaluate the effects of year and genotype on sap volume and °Brix. Statistical models incorporating daily and lagged weather variables were used to assess environmental influences. Sap flow and sugar concentration varied across seasons and were not fully explained by single-day weather, suggesting more complex environmental dynamics. Total sap production was higher in 2024, with 307.4 L collected over 41 flow days. In 2025, the total sap volume was 227.6 L, collected over 37 flow days. In 2024, sap flow peaked in early March and followed a bell-shaped curve, while in 2025 the season began later and exhibited lower, more erratic daily yields. Average °Brix remained relatively stable across years, with slightly higher and more variable values in 2024. A subset of trees consistently exhibited high sap yield and sugar content across both years. The mixed-effects model revealed a significant year effect on °Brix, but not on sap volume, while genotype contributed to variation in both traits. These findings demonstrate that both genotype and seasonal conditions influence black walnut sap characteristics, supporting the potential for selecting high-performing trees to advance syrup production with this underutilized species.

Speakers

Herika Paula Pessoa

University of Minnesota

Co-authors

Brandon Miller

University of Minnesota

Neil Anderson

University of Minnesota

Seth Wannemuehler

University of Minnesota

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv
Funding Source This work was supported by the Physiology of Agricultural Plants program, project award no. 2023-67013-39512, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

5:30pm CDT

PH 1 - Demonstration of the functionality of apple citramalate synthase on ester production in transiently transformed banana fruit

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Foster 1

Citramalate synthase is proposed to be the first committed step in the formation of branched chain esters in apples based on detailed biochemical, pharmacological, isotopic, and molecular data. However, the function of the full citramalate pathway, from the formation of citramalate to the formation of the branched chain esters containing 2-methylbutyl and 2-methylbutanoate moieties has not been tested using a gain of function model. In this work, we report on the transient transformation of ripening banana fruit with functional and non-functional alleles of MdCMS (MdCMS_1 and MdCMS_2, respectively) and report on the compounds induced by the addition of this gene. Banana do not produce appreciable levels of citramalate and make little to no 2-methylbutyl and 2-methylbutanoate containing esters. Following the transformation event, citramalate accumulated in banana transformed with MdCMS_1, but not MdCMS-2. Similarly, banana with the functional form of MdCMS produced modest levels of 2-methylbutyl acetate and 2-methylbutyl butanoate esters. Fruit transformed with MdCMS_1 also accumulated isoleucine as a by-product of the enhanced pathway throughput. Finally, there was a marked enhancement of propyl esters, likely a function of an increase in alpha-ketobutyrate, which is an intermediate in the citramalate pathway between citramalic acid and 2-methylbutyl and 2-methylebutnoate esters. The data provide the last necessary evidence for the conclusively documenting function of citramalate synthase as a functional pathway in apple useful for the production of aroma active branched-chain esters.

Speakers

Nobuko Sugimoto

University of Georgia

Co-authors

Ozge Horzum

Ankara University

Philip Engelgau

Michigan State University

Randolph Beaudry

Michigan State University

Dr. Randolph Beaudry, Professor, MSU Department of Horticulture (MSc, PhD, University of Georgia). His appointment is 50% MSU Extension and 50% AgBioResearch. His research program includes both regional and international projects and focuses on the physiology of plant responses to... Read More →

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Foster 1

Oral presentation, Postharvest 1

Subject Postharvest
Poster # csv

5:30pm CDT

VCM 1 - Cultivar and Growth Stage-Specific Nitrogen Optimization for Enhanced Strawberry Yield and Efficiency in a Florida Sandy Soil

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Strand 11B

Nitrogen (N) is often the primary limiting factor in strawberry (Fragaria ×ananassa Duch.) production. Optimizing N fertilization is crucial for maximizing economic returns while minimizing environmental pollution risks. This study aimed to determine cultivar- and growth stage-specific optimum N rates for winter strawberry production in a subtropical sandy soil. Three field experiments (Expt. 1, 2, and 3) were conducted in west-central Florida, with four cultivars [‘Florida Brilliance’ (Brilliance), Florida MedallionTM (Medallion), Florida PearlTM (Pearl 109), and Florida Pearl® (Pearl 66)] and five N rates (0, 0.56, 1.12, 2.24, and 3.36 kg·ha–1·d–1). Different N rates were applied during Weeks 3–8 (early growth) in Expt. 1, Weeks 9–14 (mid-growth) in Expt. 2, and Weeks 15–20 (late growth) in Expt. 3, with a baseline rate of 1.12 kg·ha–1·d–1 outside the treatment period. All experiments concluded at the end of Week 20, with total N application rates ranging from 94 to 235 kg·ha–1. Model fitting revealed cultivar- and growth stage-specific yield responses to N rates. In Expt. 1, the best-fit models were linear for Brilliance, Medallion, and Pearl 109, with maximum yield increases of 102%, 109%, and 71%, respectively. For Pearl 66, the best-fit model was quadratic, with a maximum yield increase of 126% at 3.34 kg·ha–1·d–1. In Expt. 2, Medallion maintained a linear response with a maximum yield increase of 90%, whereas Brilliance followed a quadratic model, with a maximum yield increase of 70% at 2.27 kg·ha–1·d–1. Pearl 109 and Pearl 66 followed exponential plateau models, reaching 90% of their respective maximum yields with 89% and 73% increases at 1.64 and 2.09 kg·ha–1·d–1, respectively. In Expt. 3, no cultivar exhibited a significant model fit. Agronomic N use efficiency (ANUE, kg yield increase per kg N applied) showed contrasting results. In Expt. 1, only Pearl 109 exhibited a significant model fit, with a linear reduction of up to 30%. In Expt. 2, Medallion showed no significant model fit, whereas the other three cultivars reduced ANUE linearly by 27% to 38%. In Expt. 3, all cultivars followed exponential decay models, with maximum reductions of 57% to 63%. These results suggest that Medallion is the most responsive to N fertilization, while Pearl 109 is the least. Moreover, N fertilization efficiency could be improved by increasing its distribution during the early and mid-season growth stages and limiting late-season inputs.

Speakers

Kalara Dissanayake

University of Florida

Co-authors

Shinsuke Agehara

University of Florida

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management
Poster # csv

5:30pm CDT

WUM 1 - Seeding Woodchip Bioreactors Improves Nutrient and Pesticide Removal from Irrigation Return Water

Tuesday July 29, 2025 5:30pm - 5:45pm CDT

Strand 11A

Irrigation return water (IRW) from the nursery and greenhouse industries contains agrochemicals (pesticides, nutrients, and growth regulators) that pose significant phytotoxic and environmental risks within the operation and to the surrounding ecosystem. Agrochemicals can contribute to plant injury, eutrophication, groundwater contamination, and ecological toxicity. Woodchip bioreactors offer a cost-effective, sustainable solution for contaminant mitigation by supporting diverse microbial communities. Under anaerobic conditions, woodchip bioreactors facilitate nitrate reduction, while biofilms enhance pesticide degradation via enzymatic activity. Hydraulic retention time (HRT) regulates the duration of contaminant-microbiome interactions, balancing nutrient recycling in IRW at shorter HRTs and enhanced pesticide degradation at longer HRTs. However, newly established bioreactors typically experience a lag phase before reaching optimal contaminant removal efficiency due to the time required for microbial communities to develop. In this study, we investigated the potential of seeding new bioreactors with biofilms from established systems to accelerate this transition. Thirty-six woodchip bioreactors were evaluated under three HRTs (4, 14, and 24 hours) and three seeding levels (0%, 5%, and 10%) over 170 days. Simulated IRW containing nitrate, phosphate, and eight pesticides (acephate, atrazine, bifenthrin, chlorpyrifos, cyazofamid, oxyfluorfen, sulfoxaflor, and thiophanate-methyl) was used to assess performance. Preliminary results indicate that the 10% seeding at 4HRT yields the highest total nitrogen removal (6.2 g/day), compared to the 5% seeding at 4HRT (3.1 g/day) and the unseeded treatment at 4HRT (2.8 g/day). This suggests that a higher microbial load, combined with a shorter retention time, may be the most effective approach for removing Total Nitrogen.

Speakers

Henry Gonzalez

Research Assistant/Ph.D. Student, Michigan State University

Co-authors

Christopher M. Ranger

USDA ARS

Gemma Reguera

Michigan State University

James Owen

USDA ARS

R. Thomas Fernandez

Michigan State University

Silvia Valles Ramirez

USDA ARS

Tuesday July 29, 2025 5:30pm - 5:45pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Poster # csv

5:45pm CDT

CITR 1 - Optimizing Trunk Injections of Oxytetracycline for Citrus Huanglongbing Management

Tuesday July 29, 2025 5:45pm - 6:00pm CDT

Foster 2

In Florida and worldwide, citrus production is threatened by Huanglongbing (HLB), associated with phloem-limited Candidatus Liberibacter asiaticus (CLas). Oxytetracycline delivery by trunk injection has been approved to treat commercial citrus groves affected by this endemic disease. However, the commercially available formulations require acidification of the active ingredient (oxytetracycline hydrochloride, OTC) to a pH of 1.8-2.0 to dissolve and stabilize the antibiotic, which may cause trunk damage, chloride toxicity, and limits compatibility with other compounds. A novel adjuvant has been developed, using EPA-approved ingredients to dissolve and stabilize OTC at a neutral pH while maintaining efficacy. This study compares the efficacy of neutralized and acidified solutions of OTC with and without the addition of ZnSO4 to optimize HLB management. The efficacy of Streptomycin (STM) as an alternative to or combined with OTC was also assessed. A field trial was conducted in a commercial citrus orchard in southwest Florida using seven-year-old ‘Valencia’ sweet orange trees grafted on X-639 rootstock. The experimental design was a randomized block with ten treatments and eight replications, each containing four trees. Treatments included combinations of OTC, STM, and ZnSO4 with or without the adjuvant, and appropriate controls. Trees were injected in June 2024 with 100 mL of treatment solution on one side of the trunk using commercial (FlexInject, TJ BioTech) injectors. Leaves were collected to assess CLas titers and bacterial suppression. Phytotoxic effects in the canopy and trunk damage at the injection site were evaluated. Treatments containing the adjuvant and/or OTC caused significant phytotoxicity and more trunk damage. Trees were harvested in March 2025. Fruit yield was higher for all treatments containing OTC compared to the controls . The highest yield was measured when trees were injected with a combination of OTC and STM. The findings of this study led to the redesign of the neutral pH adjuvant to minimize tree damage and enhance OTC efficacy. The optimized formulation will be tested using the same experimental design in upcoming studies.

Speakers

Igor Rodrigues da Silva

Master's Student, UF/IFAS Southwest Florida Research

Co-authors

Jorge Pereira

NanoScience Technology Center

Swadeshmukul Santra

University of Central Florida

Ute Albrecht

University of Florida/IFAS

Tuesday July 29, 2025 5:45pm - 6:00pm CDT
Foster 2

Oral presentation, Citrus Crops 1

Subject Citrus Crops
Funding Source Citrus Research and Development Foundation (23-036)

5:45pm CDT

NUTS - From Greenhouse to Field: Investigating the Effects of Environmental Origin on Pecan Rhizosphere and Roots Microbial Assembly

Tuesday July 29, 2025 5:45pm - 6:00pm CDT

Strand 12A

It is essential to understand the influence of environmental conditions on plant-associated microbial communities for improving orchard management strategies. This study characterized the bacterial and fungal microbiomes associated with pecan (Carya illinoinensis) clonal rootstock cultivated under controlled greenhouse conditions and following transplanting into field environments. Microbial profiling focused on root and rhizosphere soil compartments across four rootstock genotypes (NMU03, NMU04, NMU05, and NMU155). Preliminary findings from MiSeq of 16S rRNA and fungal ITS regions revealed that microbial community composition clustered more strongly by where it planted than by sample type (root and rhizosphere soil compartments) or host genotype. Field samples were enriched with bacterial taxa such as Micrococcaceae, Azospirillaceae, and Clostridiaceae 1, while greenhouse samples exhibited higher relative abundances of Propionibacteriaceae and Microbacteriaceae. Similarly, distinct fungal assemblages such as Tremellaceae, Trichocomaceae, and Sordariomycetes_fam_Incertae_sedis were observed from the field samples while fungal taxa including Aspergillaceae, Stachybotryaceae, and Chaetomiaceae were detected in greenhouse roots, forming separate clusters based on hierarchical analysis. Preliminary findings from alpha diversity revealed more variation in fungal than bacterial communities. Overall, this study highlights the possibile dominant role of environmental conditions over host genotype in shaping root- and soil-associated microbiomes in pecan. Our preliminary results emphasize the importance of targeted microbiome-informed management strategies in orchard systems.

Speakers

Paul Oladimeji Gabriel

Graduate Research Assistant, New Mexico State University

Co-authors

Andra Andazola

New Mexico State University

Jennifer Randall

New Mexico State University

Tuesday July 29, 2025 5:45pm - 6:00pm CDT
Strand 12A

Oral presentation, Temperate Tree Nut Crops

Subject Temperate Tree Nut Crops
Poster # csv
Funding Source USDA-NIFA

5:45pm CDT

VCM 1 - Can biochar mitigate salinity effects on the growth and development for crossandra (Crossandra infundibuliformis)?

Tuesday July 29, 2025 5:45pm - 6:00pm CDT

Strand 11B

Increasing salt stress and water scarcity necessitate research on plant salinity tolerance. This study investigated the effects of biochar crossandra (Crossandra infundibuliformis) under saline conditions. Three biochar rates (0%, 15%, 25%) were incorporated into commercial substrates, with salinity treatments of control, medium, and high at 0.2 dS∙m-1, 2 dS∙m-1, and 4 dS∙m⁻¹ respectively. Growth parameters (growth index, chlorophyll content, number of flowers), biomass, and physiological responses (photosynthesis, transpiration, stomatal conductance rate) were evaluated over time. The results showed crossandra tolerated salinity up to 4 dS∙m⁻¹ with minimal effects on flower production, biomass, and physiological responses, though growth index and SPAD values declined. At 2 dS∙m⁻¹, 15% biochar improved growth index, SPAD, number of flowers, biomass, and physiological rates comparable to controls. These results suggest biochar can mitigate salinity effects for crossandra plants.

Speakers

Ping Yu

University of Georgia

Co-authors

Lilin Chen

University of Georgia

Tuesday July 29, 2025 5:45pm - 6:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 1

Subject Vegetable Crops Management
Poster # csv

5:45pm CDT

WUM 1 - Irrigation and Harvest Treatment Impacts on Romaine Lettuce Quality Grown in a Coarse-Textured Medium

Tuesday July 29, 2025 5:45pm - 6:00pm CDT

Strand 11A

In-situ resource utilization at the lunar surface has been proposed for food production during human exploration missions. However, lunar regolith’s sandy texture holds less plant-available water than most of Earth's fine-textured agricultural soils. Reduced gravity at the lunar surface limits drainage from containerized media, likely causing root-zone hypoxic stress without appropriate irrigation management. Sensor-based irrigation systems may mitigate these challenges by maintaining an optimal medium volumetric water content. Evaluating the palatability of crops is also crucial, though sensory evaluation is uncommonly included in crop production studies. Hence, this research aimed to quantify the effects of sensor- and time-based irrigation strategies on the development and growth of Lactuca sativa (lettuce) grown using two continuous harvesting techniques in a containerized Turface MVP medium, a coarse calcined clay aggregates. Lettuce seeds were sown in 48 containers filled with the Turface MVP (particle sizes 0.8-3.4 mm) premixed with 15N-3.9P-10K controlled release fertilizer. Additionally, 24 containerized media were left unseeded to serve as controls. The containerized media were randomly assigned to sensor- and time-based irrigation under “pick-and-eat” and “cut-and-sow” harvesting techniques. Sensor-based irrigation maintained volumetric water content at 0.40 m3·m-3 through frequent sensor scanning and automated irrigation when sensor readings fell below the setpoints, while the media at time-based irrigation management were irrigated to saturation once per day. Under the “pick-and-eat” method, sensor-based irrigation increased the leaf fresh and dry weights, and photosynthesis rate by 81%, 39%, 61%, respectively, compared with plants under time-based irrigation at the end of experiment. The “cut-and-sow” method resulted in lower leaf fresh and dry weights than the “pick-and-eat” under both irrigation treatments. However, sensor-based irrigation led to increases in the medium’s electrical conductivity, causing plants under salinity stress because the phosphorus, potassium, and magnesium concentrations in the leaf tissue increased compared with those under time-based irrigation. Sensor-based irrigation improved overall acceptability of samples under “pick-and-eat” in sensory testing, with 50% of respondents disliking the time-based samples. However, the "cut-and-sow" samples under time-based irrigation exhibited higher overall acceptability, though 75% or more testers liked both samples. Sensor-based irrigation improved the yield of lettuce under "pick-and-eat" method but caused salinity stress. Conversely, the "cut-and-sow" method led to lower yield, but improved plant palatability under time-based irrigation. Nevertheless, with higher yield, increased mineral content, and improved consumer acceptability, the “pick-and-eat” method under sensor-based irrigation demonstrates potential for sustaining continuous crop production.

Speakers

Nintya Avriantari

University of Wyoming

Co-authors

Brianna Drew

University of Wyoming

Chieh-Yun Chang

Utah State University

David Claypool

University of Wyoming

Drea Hineman

University of Wyoming

Gioia D. Massa

NASA Kennedy Space Center

Ji-Jhong Chen

University of Wyoming

Jill F. Keith

University of Wyoming

Scott B. Jones

Utah State University

Shawna M. McBride

University of Wyoming

Tuesday July 29, 2025 5:45pm - 6:00pm CDT
Strand 11A

Oral presentation, Water Utilization and Management 1

Subject Water Utilization and Management
Funding Source NASA EPSCoR Rapid Response Research (R3) Grant#: WY-80NSSC24M0162, Wyoming Space Grant Consortium Faculty Research Initiation Grant#: 80NSSC20M0113, University of Wyoming College of Agriculture, Life Sciences, & Natural Resources, Office of Research and Economic Development Designated, Department of Plant Sciences. Y-Cross Scholarship. United States Department of Agriculture National Institute of Food and Agriculture (NIFA) Plant Sciences Hatch Funds (WYO-631-22)

7:59am CDT

CE 3 - Oral Session

Wednesday July 30, 2025 7:59am - 8:00am CDT

Strand 12B

Presiding/Moderator

Makenzie Lee

Colorado State University

Wednesday July 30, 2025 7:59am - 8:00am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments

7:59am CDT

CHEX 2 - Oral Session

Wednesday July 30, 2025 7:59am - 8:00am CDT

Strand 12A

Presiding/Moderator

Annette Wszelaki

University of Tennessee

Annette Wszelaki is a Professor and the Commercial Vegetable Extension Specialist at the University of Tennessee. She has statewide responsibilities for developing a comprehensive educational program in commercial vegetable production. The main focuses of her extension program include... Read More →

Wednesday July 30, 2025 7:59am - 8:00am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture

7:59am CDT

LOCSY 2 - Oral Session

Wednesday July 30, 2025 7:59am - 8:00am CDT

Strand 11A

Presiding/Moderator

Catherine Simpson

Texas Tech University

Wednesday July 30, 2025 7:59am - 8:00am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems

7:59am CDT

VCM 2 - Oral Session

Wednesday July 30, 2025 7:59am - 8:00am CDT

Foster 1

Presiding/Moderator

Israel Joukhadar

New Mexico State University

Wednesday July 30, 2025 7:59am - 8:00am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management

7:59am CDT

VGBR 1 - Oral Session

Wednesday July 30, 2025 7:59am - 8:00am CDT

Foster 2

Presiding/Moderator

Carlos Avila

Texas A&M University

Wednesday July 30, 2025 7:59am - 8:00am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding

8:00am CDT

CE 3 - Optimizing Basil Growth Through Incremental Light Intensity and Photoperiod Adjustments in a Controlled Setting

Wednesday July 30, 2025 8:00am - 8:15am CDT

Strand 12B

Basil (Ocimum basilicum L. Genovese) is a highly valued and economically important herb with high culinary and medicinal qualities. Light intensity and photoperiod are the most influential environmental parameters affecting its growth, morphology, and biomass production under controlled environments. This study aims to evaluate the impact of gradually increasing light intensity and photoperiod on the growth and yield of basil while the total daily integral was the same at the end of cultivation. Four different treatments were used: (T1) constant light intensity (300 µmol m⁻² s⁻¹) and constant 16 h photoperiod (Control), (T2) constant light intensity with an increasing photoperiod (14 -16 -18 h), (T3) constant photoperiod (16 h) with an increasing light intensity (200 - 300 - 400 µmol m⁻² s⁻¹), and (T4) both dynamic light intensity and photoperiod increasing over time. The treatments were applied for 24 days in a growth chamber equipped with a drip hydroponic system, and the treatment dynamic changes were implemented every 8 days. Plants grown under increasing photoperiod and light intensity (T4) exhibited better morphological characteristics, more significant biomass accumulation (fresh and dry weight), and light use efficiency, measured as the proportion of light absorbed by PS II used in biochemistry than the other treatments. The results emphasize the relevance of adaptive lighting to optimize basil growth in indoor farming. Dynamic optimization of lighting can increase the utilization efficiency of light with positive implications for vertical farming and hydroponics cultivation. Future studies should explore the nutritional and olfactory profile to refine adaptive lighting approaches for vertical farming and hydroponic systems. Keywords: Basil, dynamic lighting, photoperiod, indoor farming, biomass accumulation, hydroponics.

Speakers

Nazmin Akter

University of California, Davis

Co-authors

Laura Cammarisano

University of California, Davis

MD SHAMIM AHAMED

University of California, Davis

Wednesday July 30, 2025 8:00am - 8:15am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Poster # csv

8:00am CDT

CHEX 2 - Delicata Squash Cultivar Trials in the Southeast

Wednesday July 30, 2025 8:00am - 8:15am CDT

Strand 12A

Cultivar trials are important to ensure that growers have up-to-date information on crop performance, including yield, disease and insect resistance, environmental adaptation, and quality for their region. Crops with lesser planted acreage are often overlooked, as cultivar trials can be expensive, time consuming, and labor intensive. Winter squash is commonly grown in Tennessee and North Carolina, with over 300 and 700 acres grown, respectively; however, there is little cultivar trial information available for many types of winter squash, such as delicata squash. Delicata squash (Cucurbita pepo ssp. texana) is a winter squash originating from North and Central America. This squash can have a vining or bush habit and typically cylindrical fruit that is buff color with green stripes. It is a customer favorite due to its thin, edible skin, for which it’s named, and sweet flavor. The objective of this trial was to compare the yield, fruit characteristics, disease resistance, and storage life of 10 cultivars of delicata squash. The cultivars evaluated were: ‘Bush Delicata,’ ‘Sweet Dumpling,’ ‘Sugar Loaf,’ ‘Honey Boat,’ ‘Candystick Dessert,’ ‘Zeppelin,’ ‘Jester,’ ‘Delicata JS,’ ‘Sweet Lightning,’ and ‘Ugly Dumpling.’ The trials were conducted in Crossville, TN and Waynesville, NC. Squash were direct seeded in 18-foot plots with 3 feet between plants and 6 feet between rows, with four replications per cultivar. Powdery mildew was rated on a 0-5 scale with 0 indicating no powdery mildew and 5 indicating that all plants were symptomatic. Yield calculations were based on 2,418 plants per acre. ‘Delicata JS’ had the highest yield (15,500 lbs. ac-1) and most marketable fruit but also had the highest number of unmarketable fruit. ‘Ugly Dumpling’ also had a high yield but had the highest incidence of powdery mildew. ‘Zeppelin’ had the lowest incidence of powdery mildew. All cultivars tested had a shelf-life of four weeks in cold storage.

Speakers

Annette Wszelaki

University of Tennessee

Co-authors

Brooke Keadle Emery

University of Tennessee

Wednesday July 30, 2025 8:00am - 8:15am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture

8:00am CDT

HSMP 2 - Production Potential of Virginia Mountain Mint (Pycnanthemum virginianum) in North Alabama

Wednesday July 30, 2025 8:00am - 8:15am CDT

Strand 11B

Herbal products with an estimated global market of $10.7 Billion in 2023 continue to gain popularity as health supplements. A lack of adapted, high yielding varieties, and production technology are major limiting factors for commercial production of ready-market herbs. The objective of this research was to address these limitations, and in the process develop production practices for a high-value multiple use herb, Virginia mountain mint (Pycnanthemum virginianum) that can be easily grown in North Alabama, USA. Mountain mint is used in the medicinal and confectionery industries and could serve as an alternative to pepper mint. Four Virginia mountain mint varieties were evaluated for growth and essential oil content and composition using replicated field trials. The greenhouse-grown plants of the four varieties, (M1, M2, M3 and M4) were transplanted onto raised beds, covered with plastic mulch with drip irrigation tubing underneath in mid-May, and grown using organic production methods. The crops were harvested at 135 (H1), 155 (H2), and 170 (H3) days after planting (DAP) to determine growth, biomass, essential oil yield, and composition. The chemical compositions of essential oils were determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography–flame ionization detection (GC-FID). Two of the four mountain mint varieties with high biomass showed consistently high yield potential in North Alabama. They were rich in isomenthone concentrations, which increased dramatically from 20% to 69% as the season advanced, whereas pulegone and thymol tended to decrease. The essential oil components varied with varieties and with time. The two mountain varieties with desirable essential oil composition offer potential for production as high-value medicinal crop in North Alabama.

Speakers

Srinivasa Rao Mentreddy

Alabama A

Co-authors

Lam Duong

Texas A

Trang Pham

Alabama A

Wednesday July 30, 2025 8:00am - 8:15am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Poster # csv

8:00am CDT

LOCSY 2 - Healthy Harvest: Outcomes from a Local Food, Health and Wellness Pilot Program

Wednesday July 30, 2025 8:00am - 8:15am CDT

Strand 11A

Background: Community Supported Agriculture (CSA) programs have been found to promote numerous positive health and nutrition behaviors, including increased consumption of fruits and vegetables and increased knowledge and self-efficacy in cooking skills. The CSA model can capitalize on this fact by connecting with institutional health and wellness programs. Employers and health insurance companies have funds to support employee wellness and are increasingly interested in programs that focus on the connection between high-quality, nutrient dense foods and health and wellness. The purpose of this study was to assess the impact of a workplace-based local food health and wellness educational curriculum that was tailored to CSA members. Methods: Family and consumer sciences Extension educators enrolled participants (n=41) in the pilot program in two counties in Florida. The educational curriculum had 6 modules that were delivered bi-weekly over 12 weeks. Each module paired a nutritional topic with local food. Nutrition topics included US dietary guidelines, menu planning, healthy cooking, fruits, vegetables, proteins, whole grains, and legumes. Local food topics included the economic importance of buying local food, ways to purchase local food, seasonal cooking, and regional food specialties. The program had both an in-person and online component, and included fact sheets, educational lectures, and on-farm videos of farmers explaining local crops. Researchers used a matched pre- and post-test design which used theory of planned behavior to assess participants’ knowledge, attitudes, beliefs, and intentions to purchase local food. The National Cancer Institute’s Short Fruit and Vegetable Screener was used to assess dietary changes. Wellness was assess using the Centers for Disease Control and Prevention’s Health-Related Quality of Life survey. Results: Participants significantly increased their fruit (p= 0.003) and vegetable (p=0.003) consumption. Participants had significant improvements in wellness indicators, including fewer days that pain limited their activity (p= 0.001), they experienced anxiety (p= 0.015), they felt sad (p=

Speakers

Catherine Campbell

University of Florida

Catherine Campbell, PhD, MPH, is Assistant Professor and Extension Specialist of Community Food Systems in the Department of Family, Youth and Community Sciences at University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS). She conducts social science research... Read More →

Co-authors

Annie Wallau

University of Florida

Cody Gusto

University of Florida

Wendy Wood

University of Florida

Wednesday July 30, 2025 8:00am - 8:15am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems

8:00am CDT

VCM 2 - Optimizing the transplanting date and density for Carolina strongback grafted watermelon nursery

Wednesday July 30, 2025 8:00am - 8:15am CDT

Foster 1

Grafting is an effective management strategy in watermelon crop against soil borne pathogens. Carolina strongback (SB) rootstock used for grafting, is resistant to both fusarium wilt and root knot nematodes which are devastating soil borne pest of watermelon. Recent experiments have shown that SB grafted plant have higher plant vigour and bear fruits 7-10 days later than regulate plants leading to farmers losing early profitable watermelon market. Similarly, grafted watermelon nursery is 4-5 times more expensive than regular nursery which leads to reluctance among growers for adoption of this effective management strategy. To fill these gaps for informed adoption of SB grafted nursery, a field experiment was conducted at Blackville SC. The experiment comprised of three transplanting times (April 1, 10 and 20) and four transplant densities (1800 non-grafted, 1800, 1550 and 1300 grafted plants/acre) in a split plot design. The highest plant vigour rating was observed in SB grafted nursery at 1800, 1550 and 1300 plants/acre as compared to 1800 non-grafted plants/acre. April1 and April 10 recorded the highest fruit yield at first harvest as compared to April 20 transplanting. Similar fruit yield was observed for different transplanting times and density at second, third and fourth picks. Transplanting of SB grafted plants at 1300 plants/acre recorded the highest total fruit yield as compared 1800 and 1550 grafted and 1800 non-grafted plants/acre. Highest gross and net returns were observed in 1300 grafted plants/acre as compared to 1800, 1550 grafted and 1800 non-grafted plants/acre. The experiment will be repeated in 2025 to collect two years of data.

Speakers

Bhupinder Jatana

Assistant Professor -Horticulture, Clemson University

Co-authors

Tom Sanders III

Clemson University

Yefan Nian

Clemson Unviersity

Wednesday July 30, 2025 8:00am - 8:15am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Poster # csv
Funding Source National Watermelon Association

8:00am CDT

VGBR 1 - Association mapping of Fruit Quality traits in Tomato (Solanum lycopersicum)

Wednesday July 30, 2025 8:00am - 8:15am CDT

Foster 2

Tomato fruit quality is directly related to marketability and consumer appeal. Unfortunately, consumers are increasingly discontent with the flavor and quality of the product they are purchasing and requesting tomatoes with improved flavor, aroma, texture, and appearance making it a high priority for breeding programs. Traditionally, the selection for fruit quality traits in breeding programs has been done using conventional phenotyping approaches, in which large populations need to be screened. Although this approach has resulted in the release of high quality-high yielding cultivars, it is very time-consuming, delaying cultivar release. An alternative approach to improve breeding efficiency involves the use of modern molecular breeding techniques. In this study, a diverse panel of 305 tomato genotypes, including 284 tomato breeding lines developed by Texas A

Speakers

Carlos Avila

Texas A&M University

Co-authors

Devi Kandel

Langston University

Kevin Crosby

Texas A

Kranthi Mandadi

Texas A

Wednesday July 30, 2025 8:00am - 8:15am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding

8:15am CDT

CE 3 - Air and Hydroponic Nutrition Solution Temperature Influences Phenolics, Flavonoids, and Antioxidant Activity of Greenhouse Grown 'Nufar' Sweet Basil (Ocimum basilicum)

Wednesday July 30, 2025 8:15am - 8:30am CDT

Strand 12B

Basil (Ocimum basilicum) is a widely cultivated culinary and medicinal herb valued for its aroma, flavor, and nutraceutical properties. During hydroponic greenhouse production, precise regulation of air and nutrient solution temperatures plays a crucial role in enhancing yield and nutritional quality. Basil's inherent sensitivity to temperature makes it crucial to optimize these factors, as they have a significant impact on its bioactive metabolite profile. This study aimed to determine the impact of air and nutrient solution temperature on bioactive metabolites in hydroponically grown sweet basil to maximize accumulation. In a greenhouse sweet basil ‘Nufar’ were propagated in ebb-and-flow hydroponic systems for two weeks then transplanted into deep-water culture hydroponic systems and grown for three weeks. Air temperatures ranged from 20 to 30°C with a 5°C difference in day and night temperature and deep-water culture nutrient solution temperatures ranged from 15 to 35°C. At harvest, total phenolics (TPs), total flavonoids (TFs), and antioxidant activity including ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric reducing antioxidant power), and DPPH (2,2-Diphenyl-1-picrylhydrazyl) were measured. Air and nutrient solution temperature interacted to influence all parameters measured, with nutrient solution temperature exerting a greater influence on metabolite accumulation and antioxidant activity than air temperature. As air temperature increased from 20.3 to 28.5°C, TPs and TFs decreased by 40% and 58%, respectively, while ABTS, DPPH, and FRAP antioxidant activity decreased by 18%, 67%, and 53%, respectively. Similarly, increasing the nutrient solution temperature from 14.6 to 24.9°C resulted in a 76%, 87%, and 84% decline in TPs, TFs, and FRAP antioxidant activity, respectively. A greater increase in nutrient solution temperature from 14.6 to 30.0 and 32.3°C led to a 95% reduction in DPPH and 57% reduction in ABTS antioxidant activity, respectively. Thus, if enhancing phenolics, flavonoids, and antioxidant activity of sweet basil ‘Nufar’ is a primary production goal, maintaining an air temperature of ~23°C and a low nutrient solution temperature of ~14°C is an effective strategy.

Speakers

Protiva Rani Das

University of Tenneessee, Knoxville

Co-authors

Conlan Burbrink

University of Tennessee - Knoxville

Kellie Walters

University of Tennessee, Knoxville

Nathan Tucker

University of Tennessee, Knoxville

Spencer Givens

University of Tennessee, Knoxville

Wednesday July 30, 2025 8:15am - 8:30am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Funding Source This work is supported by the Specialty Crop Research Initiative, project award no. 2022-51181-38331, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture
Funding Option SCRI funded all or part of the research associated with this abstract

8:15am CDT

CHEX 2 - Multistate Evaluation of Heat-Resistant Broccoli Cultivars for Spring Production in the Eastern United States

Wednesday July 30, 2025 8:15am - 8:30am CDT

Strand 12A

Spring broccoli production in the southeastern and mid-Atlantic United States has become increasingly vulnerable to high temperatures and variable rainfall. To address this challenge, a multistate trial was conducted to evaluate the performance of eight broccoli cultivars across seven states (NC, VA, GA, AL, MA, MI, IN). The objectives were to assess plant growth and yield performance under heat stress and to determine cultivar-specific normalized difference vegetation index (NDVI) thresholds that could predict marketable yield. Each trial site implemented a completely randomized block design with four replications and standardized plot dimensions (30 plants per plot in double rows on black plastic mulch). Fertility and irrigation were managed according to site-specific recommendations and monitored through soil testing and evapotranspiration estimates. UAV-based RGB and multispectral imagery was collected biweekly (4–12 weeks after transplanting) at midday under clear-sky conditions. Soil samples, weather data, and pest control measures were recorded at each location. Results showed that each cultivar exhibited a distinct NDVI profile correlated with crown greenness and morphology. Cultivars such as ‘Eastern Magic’ and ‘Green Magic’ maintained acceptable head quality and yield despite elevated temperatures, suggesting suitability for late spring planting. The use of NDVI imaging proved to be a promising tool for identifying cultivar vigor and optimizing management decisions during periods of heat stress.

Speakers

Emmanuel Torres Quezada

North Carolina State University

Co-authors

Andre Luiz Biscaia Ribeiro da Silva

Auburn University

Benjamin Phillips

Michigan State University

Jianyu Li

University of Massachusetts

Mark Reiter

Virginia Tech

Ted McAvoy

University of Georgia

Tomas Quezada Baez

North Carolina State University

Wenjing Guan

Purdue University

Wednesday July 30, 2025 8:15am - 8:30am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture

8:15am CDT

HSMP 2 - Cold Brew U.S.-Grown Specialty Teas Offer Unique Characteristics in Comparison to an Imported Brand Name Tea

Wednesday July 30, 2025 8:15am - 8:30am CDT

Strand 11B

Specialty tea made from Camellia sinensis has gained popularity in the U.S. This sensory evaluation study was conducted to understand consumer acceptance and preferences for cold brewed U.S.-grown black tea. Six cold brew black tea samples were evaluated: five from U.S. growers (‘Big Easy’, ‘Black Magnolia’, ‘Hawaii Black Assamica’, ‘Hawaii Black Sinensis’, ‘Summer Black’) and one from Taiwan (‘Sun

Speakers

Yan Chen

LSU AgCenter

Co-authors

Witoon Prinyawiwatkul

Louisiana State University

Zhimin Xu

Louisiana State University School of Nutrition and Food Sciences

Wednesday July 30, 2025 8:15am - 8:30am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Funding Source LSU AgCenter Collaborative Research Grant

8:15am CDT

LOCSY 2 - Produce Waste Dominates Household Food Waste: Results from a Citizen Science Study

Wednesday July 30, 2025 8:15am - 8:30am CDT

Strand 11A

Background: In the US, roughly one-third of food is wasted, with 37% of that waste occurring in homes. EPA estimates households discard 6.5 pounds weekly. Household food waste is difficult to study because it occurs in the privacy of homes. Citizen science is a research method that enlists community members to collect in real-world conditions in contexts that researchers do not have access. Objectives: The purpose of this study was to collect primary data on households food waste, the primary reasons people generate food waste, the types of packaging households typically discard, and individuals’ knowledge, attitudes, and beliefs about food waste. Methods: A total of 159 citizen scientists (86 Alachua County, 73 Sarasota County) recorded data on their household food waste for 14 days, including recording the total daily weight, types of food discarded, types of food packaging discarded, and reasons for food and packaging waste. Results: A total of 3,823 pounds of compostable food waste was discarded by citizen scientists in two-week period. Households in our study discarded more than 14 pounds of food waste per week, more than double EPA estimates. Fruits and vegetables are the food groups that create the most food waste, with an average of 2.7 servings of fruit and 8.5 servings of vegetables discarded per household over the two-week period. Dinner yielded the most food waste, with household having an average of 36 servings of food wasted at dinner. More than 90% of participants rely on date labels to determine if food is safe to eat, 86% discarded food because it was “old,” and 69% discarded food because of blemishes/damage. Discussion: This multi-county citizen science study provides an initial look at the sources of food and packaging waste in Florida households, and highlights opportunities for future Educational programs focused on how to store and prepare fresh produce could reduce the largest source of household food waste to help address this global problem at the household level.

Speakers

Catherine Campbell

University of Florida

Co-authors

Cody Gusto

University of Florida

Ziynet Boz

University of Florida

Wednesday July 30, 2025 8:15am - 8:30am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems
Funding Source This research was a part of the Integrated Food Waste Measurement and Predictions Supported by Agent-Based Models (IFWASTE) research project funded by the Foundation for Food and Agriculture Research and U.S. Department of Agriculture, National Institute of Food and Agriculture, Hatch project #1023901.

8:15am CDT

VCM 2 - Evaluating Rootstock for Fresh Market Tomato Yield, Quality and Sustainability

Wednesday July 30, 2025 8:15am - 8:30am CDT

Foster 1

Evaluating Rootstock for Fresh Market Tomato Yield, Quality and Sustainability Tsedeniya Getahun, Harlene Hatterman-Valenti, Collin Auwarter Department of Plant Science, North Dakota State University Fresh market tomatoes are widely grown by specialty crop producers in North Dakota due to their profitability in the fresh market/local foods segment. However, with North Dakota's short growing season, growers often use high-tunnels for season extension to protect the crop from early and late frost events. Unfortunately, tomato plants often face numerous soil and disease challenges due to limited growing space in the high tunnel. Inadequate leaching of soluble salts in the soil and limited crop rotation contributes to salt and disease inoculum buildup in the soil that threatens the health of tomato plants and may cause serious losses in high tunnels. This two-year project with the first year completed in 2024, aims to evaluate the improvement of tomato production by grafting an heirloom, fresh market and paste tomato cultivar with excellent fruit quality characteristics onto rootstocks that are resistant to various abiotic/biotic stresses under high tunnel production. Tomato scion ‘Bigboy’, ‘Brandywine’ and ‘San Marzano’ (indeterminate), and ‘BHN 589’ (determinate) were grafted on to six rootstocks: ‘Arnold’ (generative), ‘DR0141TX’ (generative and vegetative), ‘Estamino’ (generative), ‘Fortimino’ (vegetative), ‘Maxifort’ (generative) and ‘Multifort’ (generative). Scion selection significantly influenced marketable yield, whereas rootstock had no significant impact. This effect was observed in ‘Big Boy’ but not in ‘San Marzano’ or ‘Brandywine’. ‘Big Boy’ grafted onto ‘Multifort’ or ‘Fortamino’ produced the highest marketable yield, followed by ‘Arnold’, Maxifort’, and ‘DR014TX’, with the lowest yield observed in non-grafted Big Boy’. ‘DR0141TX’ and ‘Multifort’ increased stem diameter and San Marzano tomatoes grafted onto Maxifort, Multifort, and Fortamino had the tallest plants. The trial will continue for another year to further evaluate the benefits of grafting for high tunnel tomato production in North Dakota.

Speakers

Tsedeniya Getahun

North Dakota State University

Co-authors

Collin Auwarter

North Dakota State University

Harlene HattermanValenti

NDSU

Wednesday July 30, 2025 8:15am - 8:30am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Poster # csv

8:15am CDT

VGBR 1 - Identification of resistance loci for Septoria leaf spot in tomatoes

Wednesday July 30, 2025 8:15am - 8:30am CDT

Foster 2

Septoria Leaf Spot (SLS), caused by the fungal pathogen Septoria lycopersici, is a highly destructive foliar disease affecting tomatoes. SLS is most severe in the Northeast USA and North Carolina during periods of high humidity and elevated temperatures, which can lead to catastrophic yield loss. No quantitative trait loci (QTL) associated with SLS resistance have been reported. Therefore, the objective of this study was to map the QTL related to SLS resistance in tomatoes. An F2:4 mapping population consisting of 189 individuals derived from NC123S (susceptible) x Wisconsin 55 (moderately resistant) was assessed under both field and greenhouse conditions through artificial inoculation with a spore concentration of 15.3 x 10^4/mL at the Mountain Horticultural Crops Research and Extension Center, Mills River, NC, and Mountain Research Station, Waynesville, NC. The population was genotyped using the SPET (single primer enrichment technology) Allegro targeted genotyping method. SPET-derived SNP (single nucleotide polymorphism) molecular markers were used to construct a linkage map spanning 3810.2 cM. QTL analysis identified 12 QTLs associated with SLS resistance, including two major effects and ten minor effects, typical for at least two environments identified across the genome, explaining phenotypic variation (R² value) ranging from 3.7% to 13.5%. These results demonstrate that the genetic control of SLS resistance is polygenic. This study may provide a foundation for understanding the genetics of SLS resistance and marker-assisted selection (MAS) for transferring SLS resistance genes into elite tomato breeding lines.

Speakers

Dilip Panthee

North Carolina State University

Co-authors

Frank Louws

NCSU

Jackie Blume

North Carolina State University

Muhammad Irfan Siddique

North Carolina State University

Wednesday July 30, 2025 8:15am - 8:30am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding

8:30am CDT

CE 3 - Untargeted Volatilomics of 'Nufar' Sweet Basil (Ocimum basilicum) Under Varying Greenhouse Air and Hydroponic Nutrition Solutions

Wednesday July 30, 2025 8:30am - 8:45am CDT

Strand 12B

Basil (Ocimum spp.) is a widely cultivated aromatic herb known for its culinary, medicinal, and industrial applications. The composition of volatile organic compounds (VOCs) that give basil their characteristic aroma and flavor is greatly influenced by environmental conditions, particularly temperature. Hydroponic cultivation in greenhouses allows precise control over air and nutrient solution temperatures, providing an optimized system for studying the effects of temperature on VOC profiles. This study investigated the effect of air and nutrient solution temperature on sweet basil volatilomes. An untargeted volatilomics approach was used to characterize key volatile compounds in sweet basil influenced by the temperature during hydroponic production. Sweet basil (Ocimum basilicum ‘Nufar’) were propagated in ebb-and-flow hydroponic systems for two weeks then transplanted into deep-water culture hydroponic systems and grown for three weeks. Air temperatures ranged from 20 to 30°C with a 5°C difference in day and night temperature, and deep-water culture nutrient solution temperatures ranged from 15 to 35°C. At harvest, VOCs from leaf extracts were analyzed using gas chromatography–mass spectrometry (GC-MS). A total of 86 volatile compounds were identified across all treatments, encompassing aliphatic hydrocarbons, aliphatic alcohols, aliphatic acids, aromatic acids, aliphatic ketones, aromatic ketones, aliphatic aldehydes, aliphatic amines, esters, volatile phenylpropanoids, acid anhydrides, silicones, and furans. Among these, aliphatic hydrocarbons were the most abundant (48%), followed by aliphatic alcohols (22%). Multivariate statistical analyses, including principal component analysis (PCA), partial least squares–discriminant analysis (PLS-DA), and Pearson correlation-based heatmaps, were used to determine the key VOCs influenced by air and nutrient solution temperature interactions. PLS-DA analysis determined 18 candidate volatile metabolites with variable important projection (VIP) scores higher than > 1.5 as the significant discriminant for air and nutrient solution treatments. These findings will contribute to optimizing hydroponic production strategies for enhancing basil’s aromatic profile in controlled environment production.

Speakers

Protiva Rani Das

University of Tenneessee, Knoxville

Co-authors

Kellie Walters

University of Tennessee, Knoxville

Spencer Givens

University of Tennessee, Knoxville

Wednesday July 30, 2025 8:30am - 8:45am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Funding Source This work is supported by the Specialty Crop Research Initiative, project award no. 2022-51181-38331, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture
Funding Option SCRI funded all or part of the research associated with this abstract

8:30am CDT

CHEX 2 - Evaluating Cultivars, Fertilization Rates, and Irrigation Impacts in Young Peach Trees in Alabama

Wednesday July 30, 2025 8:30am - 8:45am CDT

Strand 12A

Current fertilization guidelines for peach production, established decades ago, are gradually being revisited due to emerging challenges – such as rerising fertilizer costs, nitrate leaching, excessive vegetative growth, and declining fruit quality. These guidelines recommend nitrogen applications of 67.25–78.5 kg/ha, may not fully reflect the variability across individual orchards, production goals, or environmental variability. In 2023, 216 peach trees were established in Clanton, Alabama, to evaluate the effects of three nitrogen fertilization levels (0%, 50%, and 100% of guideline rates) and irrigation on early tree development and nutritional status. The experimental design follows a split-split plot structure, with irrigation as the main plot factor (2 levels: irrigated vs. non-irrigated), fertilization levels as the subplot factor (3 levels: 0%, 50%, 100%), and cultivars (3 cultivars: 'AugustPrince', 'FirePrince', and 'RubyPrince') as the sub-subplot factor. Results from 2023 and 2024 indicate that irrigation significantly enhanced tree height and trunk diameter. Trees receiving 50% and 100% nitrogen performed similarly in growth and CO₂ assimilation, both outperforming unfertilized controls. However, nitrogen deficiency was observed in all 0% treatments and some 50% fertilized, irrigated trees, particularly ‘AugustPrince’ and ‘FirePrince’. ‘RubyPrince’ exhibited the longest terminal shoot length and bud density, followed by ‘FirePrince’ and ‘AugustPrince’, a pattern that aligned with cultivar ripening times. While irrigation improved assimilation and growth, its effect on terminal shoot length was not significant. These findings suggest that moderate fertilization, when paired with appropriate irrigation may help support early vegetative growth. Nonetheless regular nutrient monitoring remains critical. Future work will focus on evaluating yield and fruit quality on these treatments.

Speakers

Erwin Burgos

Auburn University, Horticulture Department

Co-authors

Bernardo Chaves-Cordoba

Auburn University

Dario Chavez

University of Georgia

Edgar Vinson

Auburn University

Juan Melgar

Clemson University

Melba Ruth Salazar Gutierrez

Auburn University

Wednesday July 30, 2025 8:30am - 8:45am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture
Poster # csv

8:30am CDT

HSMP 2 - Saffron (Crocus sativus); a High Value Low Input Crop for New Mexico

Wednesday July 30, 2025 8:30am - 8:45am CDT

Strand 11B

Saffron, scientifically recognized as Crocus sativus, is a perennial plant celebrated for its vibrant red stigmas. This crop has been cultivated for more than 3,000 years, originating in ancient Persia. The climate of northern New Mexico appears conducive to saffron cultivation, suggesting its viability for small-scale farmers in the area. The initiative seeks to introduce saffron as a low-input, high-value crop suited for New Mexico's agricultural landscape. Research performed during 2023 and 2024 indicates that saffron can flourish in this region's climate, demonstrating promising stigma yields in the initial years. This research program assesses how corm size, planting timing, and irrigation levels impact saffron flower and stigma production within both hoop house and open field systems at the Certified Organic Farm of the Alcalde Sustainable Agriculture Science Center of New Mexico State University. Results reveal that larger corms yield significantly more stigmas compared to smaller ones; specifically, corms larger than 10 produced over 5 kg/ha of dry stigma yield in their first and second years. However, there was no significant difference noted between yields from high tunnel versus open field systems. Additionally, planting saffron corms earlier—around mid-August—instead of later dates like late August or mid-September resulted in enhanced stigma production (approximately 6 kg/ha). Conversely, variations in irrigation treatments did not significantly affect first-year stigma yield. Measurements of total phenolic content (TPC) and antioxidant activity demonstrated that both saffron stigmas and flowers lacking stigmas are valuable sources of phenolic compounds, with saffron stigmas exhibiting higher TPC than those flowers without stigmas. In conclusion, the findings from this research indicate that saffron can be successfully cultivated even in an open field system in northern New Mexico. Employing larger corms and opting for mid-August planting could lead to increased yields in the first year.

Speakers

Saeid Zehtab Salmasi

Associate Professor and Research Director, New Mexico State University

Research Director of the Sustainable Agriculture Science Center of New Mexico State University in Alcalde

Co-authors

Robert Heyduck

New Mexico State University

Wednesday July 30, 2025 8:30am - 8:45am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Funding Source New Mexico State University

8:30am CDT

LOCSY 2 - Reinforcing Oklahomas Food Systems with Local Horticultural Production

Wednesday July 30, 2025 8:30am - 8:45am CDT

Strand 11A

The state of Oklahoma has a foundation in natural resources and agriculture. To date, despite growth and industry changes, Oklahoma has kept true to its history but operates through the lens of industrial agriculture. The horticultural market is largely untapped and overlooked within the state even with the ample resources, land availability, open market, and a population in need of nutritional supplementation. Connecting with and having conversations with Oklahoma vegetable and fruit producers reveal underlying problems within Oklahoma's local food system and programs which include the fundamentals of production, market accessibility, and distribution problems. These conversations have long-term implications on the future market of the state. The exploration of results found from the conversations will be explored in terms of programming available, and the future of Oklahoma’s food system. The current programming within the state has a variety of approaches to tackling the integration of a local food system or the promotion of specialty crops. The identification and systematic review of programming and policy will expose gaps and shortcomings in the Oklahoma food system. Identifying and understanding barriers in specialty crop producers will create opportunities to improve the methods of production in the state of Oklahoma. Through examining the states’ available resources, programming, and policies for fruit and vegetable producers in the state, a plan for success can be created to increase market access and profitability for producers while also increasing access to local produce for consumers in Oklahoma. The evaluation of Oklahoma’s policies and specialty crop programs or support networks have long term implications on the success of current markets for local vegetable and fruit producers, their challenges they face, and opportunities that lie ahead. The implications of this review will result in a better understanding, connection, and future resources to nurture and support the horticultural market. Keywords: Horticulture, local production, market accessibility

Speakers

Sophia Darrow

Oklahoma State University

Co-authors

Justin Quetone Moss

Oklahoma State University

Wednesday July 30, 2025 8:30am - 8:45am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems

8:30am CDT

VCM 2 - Evaluating field performance of different watermelon scions grafted with common rootstocks

Wednesday July 30, 2025 8:30am - 8:45am CDT

Foster 1

The goal of the project is to understand the suitability of different scions when grafted onto commonly used watermelon rootstocks in California. This scion variety trial was conducted in 2024 within a commercial watermelon field near Stockton, California. Six different scions (Captivation, Fascination, Citation, Embasy, Melody, and Summer Breeze), categorized by horticultural characteristics such as maturity, fruit size, and color, were grafted onto three widely used watermelon rootstocks in California (Camelforce, Cobalt, and Carolina Strongback). The three rootstocks are grouped into interspecific hybrid squash (Cucurbita maxima x Cucurbita moschata) and Citron (Citrullus amarus). The field experiment was arranged as a randomized block design including eighteen treatments replicated three times. Each plot was 60 ft long and contained 10 triploids and 3 grafted pollenizers (Sentinel). The field was mechanically transplanted on May 14, 2024. In-season plot maintenance included vine separation multiple times to ease data collection and harvest. Canopy coverage was measured using a handheld crop sensor starting at 10 days after transplanting and thereafter at an approximate interval of two weeks for a total of eight measurements. With the help of farm crew, three harvests were conducted on August 5, 12, and 26. Total yields from each harvest and fruit quality taken from the first harvest were recorded and compared among the rootstock-scion combinations. For quality assessment, fruit length and width were measured by yardstick. Fruit flesh firmness was measured using a fruit penetrometer at the spots 1/3 and 2/3 distance from the blossom end after a melon was cut in half. Rind thickness at the blossom and stem ends were measured with a caliper. Sugar content (⁰Brix) was measured by scooping the center flesh of each half and reading the results through a portable reflectometer. Canopy coverage showed no significant differences among the treatments. For yield, four out of six scions (Fascination, Citation, Embasy, and Melody) produced the highest total yield (ton/acre and no/acre) when they were grafted onto Camelforce, while Captivation and Summer Breeze resulted in higher total yield when grafted with Carolina Strongback. A notable difference was observed in fruit quality for ⁰Brix and firmness that Carolina Strongback produced the lowest firmness and highest ⁰Brix when grafted with all six scions. These results provide a helpful advantage for growers in California who are considering grafting in their production. Continuous assessments will be conducted to further aid in the understanding of field performances from different rootstock-scion combinations.

Speakers

Zheng Wang

Univ. of California Cooperative Extension

Co-authors

Fayrouz Buojaylah

University ofr California, Cooperative Extension Stanislaus County

Yaritza Castrejon

UC Cooperative Extension

Wednesday July 30, 2025 8:30am - 8:45am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Poster # csv

8:30am CDT

VGBR 1 - Evaluation of Drought Tolerance in USDA Tomato USDA Germplasm Using Morphological and Physiological Approaches

Wednesday July 30, 2025 8:30am - 8:45am CDT

Foster 2

Drought is a major abiotic stressor that significantly reduces the growth and yield of tomato (Solanum lycopersicum L.). To mitigate its adverse effects, the development and utilization of drought-tolerant cultivars, combined with advanced breeding strategies, offer sustainable solutions. In this study, a total of 157 USDA tomato accessions were evaluated under controlled greenhouse conditions using a randomized complete block design with four replications, incorporating both a water-deficit treatment and a well-watered control group. The results identified ten accessions, including PI 487624, PI 127828, PI 379018, PI 365903, PI 390515, PI 390663, PI 128657, PI 266376, PI 126444, and PI 298933, as drought tolerant, with leaf wilting and leaf rolling scores of less than four. Broad-sense heritability estimates ranged from 50 percent to approximately 58 percent, indicating a moderate genetic influence on drought tolerance. Correlation analysis revealed strong positive associations ranging from 0.50 to 0.99 among leaf wilting, leaf rolling, plant freshness, leaf thickness, and SPAD chlorophyll content, while negative correlations ranging from -0.40 to -0.81 were observed for plant fresh weight, leaf thickness, Quantum yield of Photosystem II (Phi2), and SPAD chlorophyll content traits. These findings provide valuable insights into tomato breeding programs focused on improving drought resilience in elite cultivars. We plan to expand the evaluation to a broader set of accessions and employ genome-wide association studies and genomic prediction to identify single nucleotide polymorphism markers and candidate genes associated with drought tolerance. The integration of genome-wide association studies and genomic prediction will facilitate marker-assisted selection and genomic selection, improving the efficiency of breeding programs aimed at developing drought-resilient tomato cultivars.

Speakers

Kenani Chiwina

University of Arkansas

Co-authors

Ainong Shi

University of Arkasnas

Awais Riaz

University of Arkansas

Beiquan Mou

Sam Farr U.S. Crop Improvement and Protection Research Center, U.S. Dept. of Agriculture, Agricultural Research Service (USDA-ARS)

Derrick Harrison

university of arkansas

haizheng xiong

University of Arkansas

Hanan Alkabkabi

university of arkansas

Ibtisam Alatawi

university of arkansas

Muhammad Ullah

university of arkansas

Qun Luo

university of arkansas

Renjie Du

university of arkansas

YUEJUN QU

University of Arkansas

Wednesday July 30, 2025 8:30am - 8:45am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding

8:45am CDT

CE 3 - Growing Environment Has a Greater Effect on Containerized Basil Growth than Fertilizer Type or Concentration

Wednesday July 30, 2025 8:45am - 9:00am CDT

Strand 12B

Current practices aim to produce quality containerized culinary herbs at the end of greenhouse production, but the effects of fertilization choices during production on the post-production performance of these crops in the retail and consumer environment are unclear. This study aimed to quantify the effects of fertilizer type, source, and concentration applied during the greenhouse production phase on the post-harvest performance of containerized culinary herbs during the retail and consumer phases. Seedlings of sweet basil (Ocimum basilicum ‘Nufar’) were transplanted into 11.4 cm-diameter containers filled with certified organic soilless substrate compromised of peat moss and coarse perlite and irrigated with solutions containing 100, 200, or 300 mg∙L –1 N from a conventional or organic water-soluble fertilizer (WSF) starting at transplant and throughout the end of the greenhouse phase, seedlings were; or were transplanted into the same organic substrate with amended with 0.25, 0.5 or 0.75 kg N∙m-3 from conventional controlled-release (CRF) or organic slow-release fertilizer (SRF) and irrigated with clear tap water Plants were grown in three different phases: 1) in a greenhouse for 21 d with 22°/18° day/night air temperatures and 12 mol∙m–2∙d –1 daily light integral (DLI) to simulate the greenhouse production phase; in a growth chamber for 7 d at 20° constantly with a DLI of 1 mol∙m–2∙d –1 to stimulate the retail phase; and, after harvesting shoots above the second node, an additional 21 d in a growth chamber with the same conditions to simulate the consumer phase. One-third of the plants were harvested at the end of each phase and data was collected. During production, conventional WSF produced plants 1.3-5.7 cm taller than all other treatments, but by the consumer phase there were no differences across all fertilizer treatments. The optimum fertilizer type and concentration for basil varied between conventional and organic sources. Fresh mass of basil was greatest for plants receiving conventional WSF, which were 4-9.5 g greater than plants which received conventional CRF. However, plants receiving organic SRF had a fresh mass which was 2.1-3.9 g greater than plants receiving organic WSF treatments. Fertilizer treatments did not affect the rate of biomass accumulation, but the phase did. The relative growth rate was lowest in the consumer phase compared to the greenhouse production and retail phases. The results of this study indicate fertilizer type, source, and concentration do not impact containerized basil growth and development in the post-harvest consumer environment.

Speakers

Nicole Arment

Iowa State University

Co-authors

Christopher Currey

Iowa State University

Jennifer Boldt

United States Department of Agriculture

Wednesday July 30, 2025 8:45am - 9:00am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Poster # csv

8:45am CDT

CHEX 2 - Comparing soil amendments, fertilizer rate, and pruning techniques in southern highbush blueberry production

Wednesday July 30, 2025 8:45am - 9:00am CDT

Strand 12A

Blueberry has a high cost of establishment, requiring the incorporation of soil amendments and the use of chemical fertilizer to obtain high fruit yield and quality. Reducing establishment and fertilizer costs in blueberry production without affecting yield and fruit quality is key for blueberry producers. In this project we evaluated the impact of reducing fertilization, using biochar as a soil amendment, and the effect of different pruning techniques on plant nutrient status, plant growth and development, and fruit production and quality. Despite the importance of these cultural practices, there is a lack of research that explores the impact of combining varying fertilization rates, soil amendments, and different pruning techniques in Georgia. To test these three factors an experimental plot was designed in a factorial arrangement with two soil amendments: 1) 33% v/v pine bark and 2) 9% v/v biochar; three fertilization rates: 1) Commercial fertilization (lb/acre): N 90, P 75, K 75; 2) half commercial fertilization N 35, P 35, K 35; and 3) potassium only: N0, P0, K 35, and two pruning treatments: 1) winter hand pruning summer hand - tipping and 2) summer hedge. Each treatment was randomly assigned three replications and four plants per replication. Our results indicated that the highest net income was obtained from the treatment in which the soil was amended with pine bark; plants were treated with half of the fertilizer rate and hedged after harvest. Blueberry plants that were hand-pruned had bigger and heavier berries. Plants that were hedged after the harvest had higher yields and it did not affect plant growth. In addition, reducing the fertilization rate to half did not affect the yield and fruit quality parameters of berries harvested. Furthermore, the treatment in which plants received only potassium fertilizer resulted in notable decreases in berry weight, firmness, and plant growth. The use of biochar as a soil amendment significantly enhanced TSS and anthocyanin content, but the concentration of K, Mg, and Mn in the berries was lower than those of plants in which the soil was amended with pine bark treatment.

Speakers

Natalia Espinoza

University of Georgia

Co-authors

Zilfina Rubio

University of Georgia

Wednesday July 30, 2025 8:45am - 9:00am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture
Funding Source Georgia Department of Agriculture

8:45am CDT

HSMP 2 - Effect of Mycorrhiza Inoculation on Growth and Phytochemical Production of Shiso Cultivars Treated with Complex Salts

Wednesday July 30, 2025 8:45am - 9:00am CDT

Strand 11B

Soil salinity, often governed by complex ion mixtures, remains a significant challenge in agriculture. However, most salinity research focuses on simple salts like sodium chloride. To develop effective salinity mitigation techniques in real-world applications, it is crucial to understand the impact of complex salts on plant physiology. Endophytic mycorrhizal fungi offer a promising method to mitigate salinity stress in plants by colonizing the plant roots. Shiso (Perilla frutescens L.) is a valuable culinary herb with rich source of phytochemicals. This study investigated the interaction of mycorrhizal inoculation and complex salinity on two shiso cultivars, Asia IP and Britton, and impacts on plant growth and phytochemical composition. Two replicated trials were designed to assess the effect of three different salinity rates (1, 3, 5 dS/m and control DI water) on both inoculated and non-inoculated shiso cultivars. Plant parameters like plant height, shoot and root fresh and dry weight along with root length were measured. Phytochemicals, total phenolic content (TPC) and total flavonoid content (TFC), proline and chlorophyll were also measured. Results showed that complex salts significantly reduced the overall fresh and dry biomass in both cultivars across both trials. The interaction of salinity and cultivar affected TPC of shiso in the first trial whereas only cultivar affected TPC in the second trial. No effect of salinity was seen in the second trial. However, TFC was significantly reduced by salinity in the second trial and no effect of salinity was seen in the first trial. Greater TFC was found in the Britton cultivar across both experiments. Proline content was increased steadily with increases in salinity rate across both trials. Greater proline content was found in the Britton cultivar in both trials. Chlorophyll content of shiso was unaffected by cultivar and salinity rates. The effect of salinity was cultivar dependent on growth and phytochemicals which was found in this experiment where Britton cultivar was more severely affected by salinity. These results show that complex salt negatively impacts the growth of shiso with no beneficial impact in increasing phytochemicals. Additionally, mycorrhizal inoculation was unable to mitigate the negative effect of salinity in shiso cultivars. Selection of effective mycorrhizal products is necessary in order to see their beneficial effects, so more screening should be done in the future. Further in-depth research is also required to fully understand the relationship of complex salts and mycorrhizal inoculation in shiso.

Speakers

Abishkar Regmi

Graduate Research Assistant, Texas Tech University

Co-authors

Catherine Simpson

Texas Tech University

Haydee Laza

Texas Tech University

Jillella Raja Shekhar Reddy

Texas Tech University

Lindsey Slaughter

Texas Tech University

Mahitha Kamireddy

Texas Tech University

Naima Moustaid-Moussa

Texas Tech University

Wednesday July 30, 2025 8:45am - 9:00am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Poster # csv

8:45am CDT

LOCSY 2 - Characterization of Nutrient Composition from Municipal and Commercial Compost Generated in Arkansas

Wednesday July 30, 2025 8:45am - 9:00am CDT

Strand 11A

Compost is treated as a waste product by many regulatory agencies, monitored and assessed only for its potential to harm humans or to harm the environment. However, horticulture practitioners are the number one consumer of compost, whether in nursery production, vegetable production, or home landscaping and gardening. In Arkansas, no state regulations require reporting chemical or physical characteristics of compost such as plant nutrient content, pH, bulk density, or organic matter content. Therefore, a statewide survey of participating Arkansas Department of Energy and Environment permitted composting facilities was conducted to characterize the availability of compost throughout the calendar year, the variability in plant nutrient content and physical characteristics. A total of 11 compost sites were sampled from nine compost production operations in Arkansas, including water treatment facilities, commercial depackaging companies, and municipal compost facilities. Yard waste (YW) was a component of all compost feedstocks, but some facilities could further handle food waste (FW) or biosolids (BS). Dry matter analysis found that composts from YW alone contained 1.31% to 1.92% N; composts from YW plus FW contained 2.57% to 3.70% N; and composts from YW BS contained 1.25% to 2.80% N. Major disparities were observed dry matter Na content when FW was included in compost. Composts including FW contained 2,185 to 7,672 mg/kg Na while composts from YW or YW BS contained 167 to 402 mg/kg Na. Present findings indicate that compost feedstocks affect the resulting nutrient content, particularly when introducing FW. Substrate testing beyond the standard testing for pathogens and trace metals will be critical for effective use of composts as a substrate or soil amendment in horticulture systems.

Speakers

Matthew Bertucci

University of Arkansas

Co-authors

Rachel Woody-Pumford

University of Arkansas

Wednesday July 30, 2025 8:45am - 9:00am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems
Poster # csv

8:45am CDT

VCM 2 - Assessing Different NM Type Green Chile Transplant Methods for Mechanical Harvest

Wednesday July 30, 2025 8:45am - 9:00am CDT

Foster 1

New Mexico green chile is a labor-intensive crop, with harvesting posing increasing challenges due to labor shortages and rising costs. To meet growing consumer demand, farmers are transitioning to mechanical harvesting, traditionally reliant on direct seeding, which promotes strong taproots and minimizes uprooting. However, transplant seedling establishment, which allows multiple harvests, produces a root system less suitable for mechanical harvesting. This study evaluated transplant sowing methods to develop taproots compatible with efficient mechanical harvest. In 2024, ‘NuMex Odyssey’ was planted using three methods, direct seeding, ihort® Q plugs, and paperpots®, at the NMSU Agricultural Science Center in Los Lunas, NM. The study employed a randomized complete block design with five replications. Plant architecture, root, and yield data were collected. Preliminary findings show no statistical difference in marketable green fruit yield among the planting methods during mechanical harvest. However, taproot lengths of ihort Q plugs and direct-seeded plants were significantly longer than those of paper pot transplants. These results suggest that taproot length did not impact marketable green fruit yield during mechanical harvest. The findings indicate that ihort Q plugs and paper pot transplanting methods have potential for efficient mechanical harvesting of New Mexico green chile.

Speakers

Israel Joukhadar

New Mexico State University

Co-authors

Danise Coon

New Mexico State University

Stephanie Walker

New Mexico State University

Wednesday July 30, 2025 8:45am - 9:00am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Funding Source USDA Plant Breeding Partnership

8:45am CDT

VGBR 1 - Understanding the molecular basis of Blossom-end rot in tomato

Wednesday July 30, 2025 8:45am - 9:00am CDT

Foster 2

Blossom-end rot (BER) is a physiological disorder in tomatoes that renders the fruit to be unmarketable. In tomato, BER initiates around 7-10 days post anthesis (DPA) at the distal end of the fruit as a water-soaked symptom that can progress into a necrotic lesion covering the entire fruit during development. Calcium deficiency in the distal end of the fruit is thought to trigger BER initiation. In this study, we have used near isogenic lines (NILs) that segregate for BER and harbors quantitative trait loci (QTLs) BER11.1 and BER11.2. Physiological characterization indicated lower calcium concentration and reduced number of vascular bundles in the distal inner and distal pericarp tissue in the susceptible fruit in comparison to the with resistant fruit. To further delineate the molecular mechanisms underlying BER development and to identify the potential candidate gene(s) underlying QTL BER11.1

Speakers

ranveer singh

university of georgia

Co-authors

Esther van der Knaap

Institute of Plant Breeding, Genetics, and Genomics, University of Georgia

Manoj Sapkota

University of Georgia

Savithri Nambeesan

University of Georgia

Yasin Topcu

University of Georgia, Institute of Plant Breeding, Genetics, and Genomics

Wednesday July 30, 2025 8:45am - 9:00am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding
Poster # csv
Funding Source United States Department of Agriculture-National Institute of Food and Agriculture (USDA-NIFA); award number: 2020–67013-30912

9:00am CDT

CE 3 - Analyzing the Impact of CO2 Concentration, Air and Root-Zone Temperature on Hydroponic Culinary Herb Production

Wednesday July 30, 2025 9:00am - 9:15am CDT

Strand 12B

Basil (Ocimum basilicum) and sage (Salvia officinalis) are some of the most popular fresh cut culinary herbs, but little information is available on how to cost-effectively maximize their growth and development in controlled environments. Given that cut herbs are sold by fresh mass, the goal is to maximize harvestable fresh mass, while not increasing production time, space, or energy inputs. Therefore, our objective was to determine the most effective root-zone temperature (RZT) in combination with carbon dioxide (CO2) concentration and reduced air temperature (AT) to maximize culinary herb yield. Seeds of basil ‘Genovese’ and sage were sown into 200-cell (2.5 cm × 2.5 cm) rockwool plugs and germinated for two and four weeks, respectively. Twelve seedlings of each species were transplanted into each of six 250 L, 0.9-m-wide by 1.8-m-long deep-flow hydroponic tanks among three walk-in growth chambers. Plants were grown under a total photon flux density of 260 µmol∙m–2∙s–1 for 16 h. The nutrient solution within the tanks was heated to 24, 28, or 32 °C. Additionally, AT and CO2 concentration setpoints of 20 and 23 °C and of 450 and 900 μmol∙mol‒1, respectively, were maintained for a total of 12 treatments. Basil and sage were harvested three and four weeks after transplant, respectively. Of AT, RZT, and CO2, AT was the largest contributing factor to shoot fresh mass (SFM) accumulation for both species. Increasing the air temperature from 20 to 23 °C resulted in a SFM increase of 100 and 180% in sage and basil, respectively. SFM of sage was not influenced by increasing CO2 from 450 to 900 μmol∙mol‒1 and resulted in a 12% decrease in basil SFM. However, at the high CO2 concentration, specific leaf area was 4 and 12% lower for sage and basil, respectively, resulting in greater biomass accumulation per cm2 of leaf area. RZT had no effect on basil SFM, but SFM of sage was greatest when the nutrient solution was heated to 24 and 28 °C. By maintaining an AT of 23 °C, RZT of 28 °C, and CO2 concentration of 450 μmol∙mol‒1, the SFM of both basil and sage can be maximized without further increasing RZT or CO2 concentration.

Speakers

Seth Benjamin

Michigan State University

Co-authors

Roberto Lopez

Michigan State University

Wednesday July 30, 2025 9:00am - 9:15am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Poster # csv

9:00am CDT

CHEX 2 - High Tunnel vs Open Field: Comparing Production Systems for Southern Highbush Blueberries

Wednesday July 30, 2025 9:00am - 9:15am CDT

Strand 12A

Southern highbush blueberry (SHB) cultivars are susceptible to spring frost damage, which can significantly reduce both yield and fruit quality. To mitigate the impacts of frost, alternative production systems, such as high tunnels, have been explored for their potential to improve SHB production. This study evaluated the performance of three SHB cultivars (‘Meadowlark’, ‘Victoria’, and ‘Jewel’) under high tunnels (HTs) and open fields (OFs). Stomatal conductance (SC), stomatal density (SD), stomatal area (SA), fruit quality, and quantity were measured, and weather variables were recorded. Data were analyzed using Proc Glimmix and Tukey’s HSD test was applied for mean separation (p ≤ 0.05). SC varied significantly by cultivars (p < 0.001) and production systems (p < 0.001), with higher SC observed in OFs. ‘Meadowlark’ exhibited the highest SC followed by ‘Jewel’ and ‘Victoria’. SD and SA were significantly influenced by the production systems and leaf stage, with all three leaf stages in OFs showing the highest SD and SA compared to HTs. SD was greater in younger leaves and decreased with leaf age, whereas SA was higher in mature and older leaves. Cultivars also affected SD and SA, with ‘Meadowlark’ showing the highest SD and SA, followed by ‘Victoria’ and ‘Jewel’. The yield was higher in HTs across all cultivars, with ‘Victoria’ producing the highest yield followed by ‘Jewel’ and ‘Meadowlark’. Single berry weight was significantly affected by both cultivars and production systems (p = 0.0004), with ‘Meadowlark’ and ‘Victoria’ producing larger berries in HTs, while ‘Jewel’ had the smallest fruit in both systems. Brix levels were cultivar dependent (p = 0.0005), with ‘Meadowlark’ exhibiting the highest values. Firmness was influenced by cultivars (p < 0.001) and among three cultivars, ‘Meadowlark’ had the highest firmness, while ‘Jewel’ had the lowest. In conclusion, SHB cultivars in HTs likely optimized their water use efficiency by reducing SC, SD, and SA. ‘Victoria’ demonstrated superior yield performance, while Brix value and firmness were higher in ‘Meadowlark’, resulting in better fruit quality. Additionally, HTs enhance total yield, berry weight, Brix, and firmness in SHB cultivars. Overall, this comparison highlights system-specific effects on cultivar performance, emphasizing the practices for southern highbush blueberry production.

Speakers

Samjhana Wagle

Auburn University, Horticulture Department

Co-authors

Bernardo Chaves-Cordoba

Auburn University

Elina Coneva

Auburn University

Eric Stafne

Mississippi State University

Kathy Lawrence

Auburn University

Wednesday July 30, 2025 9:00am - 9:15am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture
Poster # csv

9:00am CDT

HSMP 2 - Increasing Micronutrient Concentrations Does Not Mitigate High pH-Nutrient Solution-induced Growth Suppression

Wednesday July 30, 2025 9:00am - 9:15am CDT

Strand 11B

Many hydroponic fresh-cut herb producers in the United States utilize water sources with a high pH. Nutrient solutions with a high pH can prevent essential nutrients from being accessible for plant growth and development, especially micronutrients. The objectives of our research were to better understand how the growth of culinary herbs is impacted by supra-optimal pH and determine if supplemental micronutrients are an effective mitigation technique. Two week old seedlings of basil (Ocimum basilicum ‘Nufar’), and three week old seedlings of dill (Anethum graveolens ‘Hera’), parsley (Petroselinum crispum ‘Giant of Italy’), and sage (Salvia officinalis), grown in phenolic foam cubes were transplanted into one of six deep-flow technique (DFT) systems in a greenhouse. Herbs were grown in nutrient solutions with a pH of 6.0. 7.0, and 8.0, and either with a 1X or 2x micronutrient concentration. The DFT systems contained nutrient solutions made with tempered municipal water supplemented with a complete water-soluble fertilizer (16N-2.2P-14.3K) to create a target electrical conductivity of 2.0 dS·m–1, plus a supplemental micronutrient blend provided from the manufacturer to increase micronutrient concentrations for 2x micronutrient treatments. The nutrient solution pH was maintained through a dosing system using 2% H2SO4 v/v or 2% KOH w/v as the acid and alkali, respectively. One-third (by vol.) of the nutrient solution was renewed with freshly mixed fertilizer each week of production. Target greenhouse environmental conditions consisted of day and night air temperatures of 22 °C and 18 °C respectively, and a daily light integral of 12 mol∙m–2∙d–1. The experiment was replicated four times over time, and data was collected four weeks after herbs were transplanted into DFT systems. There were no significant interactions between micronutrients and pH. While high pH decreased dill, parsley, and sage shoot height, width, and fresh mass, providing supplemental micronutrients in the nutrient solution did not mitigate growth suppression induced by high pH. Additionally, all species had significantly shorter roots at a high pH of 8.0 compared to a moderate pH of 6.0, without a subsequent reduction in root mass. This study indicates nutrient solutions with a high pH can severely limit the growth of culinary herbs. While providing supplemental micronutrients does not alleviate the impact of high pH, producers can rely on other methods, such as acid injection, to lower the nutrient solution pH to maximize nutrient uptake.

Speakers

Hannah Kramer

Iowa State University

Co-authors

Christopher Currey

Iowa State University

Jennifer Boldt

United States Department of Agriculture

Wednesday July 30, 2025 9:00am - 9:15am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Poster # csv

9:00am CDT

LOCSY 2 - Results of an Employer-funded Cost-offset Community Supported Agriculture Program

Wednesday July 30, 2025 9:00am - 9:15am CDT

Strand 11A

Background: Community-supported agriculture (CSA) programs have been found to promote health and nutrition, and consumers frequently cite healthfulness as a motivation for local food purchasing. The CSA model can capitalize on this fact and expand their customer base by partnering with healthcare providers or insurance companies that provide cost-offsets for people to enroll in CSA programs. The purpose of this study was to pilot test the impact of an employer-sponsored cost-offset CSA program. Methods: University of Florida (UF), Institute of Food and Agricultural Sciences Extension developed a collaborative partnership between cooperative Extension, local farms, and the UF Human Resources’ Office of Worklife to fund a cost-offset CSA program. Results: Seventy-seven employees purchased a cost-offset CSA membership. Participants were predominantly female (86%) and in staff positions (72%). Roughly a quarter of participants received food assistance (26%). The most prevalent motivations for joining the program were to support local farms (100%) and the local economy (96%). Ninety-two percent of participants joined the program to improve their diet and to eat food that tastes better. Some participants (36%) joined the program because they had been interested in join a CSA anyway. More than 80% of respondents were satisfied with all aspects of the program. Aspects that participants were not satisfied with was the cost of the CSA membership (18%) and the lack of information about the produce included in the CSA (16%). The overwhelming majority perceived that it improved their diet (92%), increased their fruit and vegetable consumption (88%), and increased their ability to cook seasonal produce (88%). Most participants (78%) indicated they would join a CSA again, with 86% saying they would join with the same farm again. Discussion: Feedback from participants was positive, with participants emphasizing personal benefits like weight loss and discovering new foods. Many indicated that this program was more valuable to them than traditional webinars or programs offered by the office of worklife. The farms appreciated that the program connected them with new customers and the ongoing partnership with UF, which has now entered its third year. Collaborative partnerships take time and effort to develop but can yield ongoing benefits for local farms and community food systems.

Speakers

Catherine Campbell

University of Florida

Co-authors

Cody Gusto

University of Florida

Wednesday July 30, 2025 9:00am - 9:15am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Subject Local Food Systems

9:00am CDT

VCM 2 - Does Winter Chill Accumulation Affect Transplant Quality and Field Performance of Strawberry Bare-root Transplants?

Wednesday July 30, 2025 9:00am - 9:15am CDT

Foster 1

Bare-root transplants are the primary planting material used in strawberry production. They are grown in open-field conditions and dug up at maturity before shipment to fruit production sites. Delayed digging exposes transplants to different amounts of winter chilling (

Speakers

Weining Wang

University of Florida

Co-authors

Shinsuke Agehara

University of Florida

Wednesday July 30, 2025 9:00am - 9:15am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Poster # csv

9:00am CDT

VGBR 1 - Towards Mechanical Harvest: Leveraging Genomic Selection to Increase Fruit Firmness in Fresh Market Tomato

Wednesday July 30, 2025 9:00am - 9:15am CDT

Foster 2

Fresh market tomato (Solanum lycopersicum) is one of the most important vegetable crops in the US, but this labor-intensive industry faces severe labor shortages and rising production costs amid heavy competition from lower-cost imports. With labor accounting for over 30% of total production expenses, much of which is due to harvesting, the industry's long-term sustainability depends on developing more labor-efficient systems. Mechanical harvesting presents a promising solution, but tomato fruit are highly susceptible to bruising, a challenge that could be amplified by mechanized handling. Fruit firmness plays a crucial role in resistance to internal bruising, making it a key breeding target for improving harvest efficiency and post-harvest quality. The UF/IFAS tomato breeding program has developed tomato lines with traits beneficial for mechanical harvesting, including compact growth habit (CGH) and increased fruit firmness. To investigate the genetic basis of fruit firmness in CGH lines, bi-parental populations were developed from firm and soft inbred parents. Genome-wide association analysis identified multiple minor-effect QTLs, confirming the quantitative nature of this trait in the population. Variance component analysis revealed that fruit firmness is primarily controlled by additive genetic variance, suggesting a strong potential for improvement through selection with appropriate strategies such as genomic selection (GS), which has been successfully used to improve quantitative traits in many crop species. GS models were successfully trained to predict fruit firmness, demonstrating the feasibility of integrating GS into the UF/IFAS tomato breeding program. Model optimization, including adjustments to training population size, marker density, and the incorporation of significant QTLs as fixed effects, improved prediction accuracy and computational efficiency. This study confirms the presence of significant fruit firmness variability in UF/IFAS germplasm, supporting its use in breeding firmer CGH tomatoes suited for mechanical harvest. Future research will refine GS models by incorporating multi-trait and multi-environment analyses, leveraging variance-covariance relationships to enhance prediction accuracy and accelerate genetic gains.

Speakers

Jessica Chitwood-Brown

University of Florida

Co-authors

Leonard Gaspar

University of Florida IFAS GCREC

Samuel Hutton

University of Florida

Wednesday July 30, 2025 9:00am - 9:15am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding
Poster # csv

9:15am CDT

CE 3 - Evaluating Hydroponic Production Systems for Three Edible Flower Species

Wednesday July 30, 2025 9:15am - 9:30am CDT

Strand 12B

The hydroponic industry is valued at close to 1 billion dollars in North America and is expected to grow over the next 5 years. Hydroponic crop production in controlled environments has the advantage of year-round production opportunities and has been well-established for some vegetable crops, such as cucumber (Cucumis sativus) and tomato (Solanumlycopersicum). One area for growth includes edible flowers which have potentially increased use in the medical field for human health benefits and culinary arts as ingredients and garnishes. Considering the limited information about edible flower hydroponic production, we initiated research to evaluate two popular hydroponic production methods for three different edible flower species; dahlia (Dahlia xhybrida ‘Figaro Red Shade’), zinnia (Zinnia elegans ‘Zesty Scarlet’), and dianthus (Dianthus chinensis ‘Venti Parfait’). These species were grown in three treatments: two hydroponic systems, deep water culture (DWC) and nutrient film technique (NFT), and a traditional peat-based substrate. Plants were fertilized with General Hydroponics FloraSeries using the medium feed nutrient schedule. Data collected included plant biomass, flower biomass, and antioxidant and polyphenol concentrations. After 14 weeks, dahlia and zinnia grown in the DWC system produced significantly more plant biomass, flower numbers, and flower biomass compared to the NFT and substrate treatments. Dahlia plants in DWC also flowered ~ 10 days earlier than the other treatments. No significant differences were observed with dianthus plants between the treatments, except for lower flower numbers and flower fresh weight for NFT compared to the DWC and substrate treatments. Phytochemical analysis for antioxidant composition using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays and polyphenolic content through Folin-Ciocalteu assays will be conducted. The results of our initial study suggest that growing dahlia and zinnia on DWC hydroponic systems in our applied conditions has potential as an edible flower production system. However, dianthus may not be suitable for hydroponic system production, or additional modifications to hydroponic systems need to be evaluated to determine feasibility.

Speakers

Makenzie Lee

Colorado State University

Co-authors

Chad T. Miller

Colorado State University

Wednesday July 30, 2025 9:15am - 9:30am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Poster # csv

9:15am CDT

CHEX 2 - Flower Mapping as a Tool to Predict Near-Future Strawberry Yield in Controlled Environment Agriculture Systems

Wednesday July 30, 2025 9:15am - 9:30am CDT

Strand 12A

Strawberry (Fragaria × ananassa) production in the United States is a $2.5 billion industry, traditionally dominated by field cultivation. Controlled Environment Agriculture (CEA) is emerging as a promising alternative, offering year-round production and greater control over growing conditions. Despite its potential, strawberry cultivation in CEA systems remains cost-intensive, primarily due to high labor requirements. Additionally, strawberry production follows a cyclical pattern, with fruit developing in discrete peaks known as flushes. These fluctuations present challenges for consistent resource management, labor planning, and market supply, highlighting the need for predictive tools to optimize production efficiency. Our primary research objective is to develop a strawberry growers’ decision support tool for crop management through yield prediction based on flower mapping, a method of describing floral developmental stages through meristem dissection. Using a soilless hanging gutter system designed to mimic a commercial greenhouse production system, we grew a widely used cultivar Albion. The greenhouse maintained average daytime and nighttime air temperatures of 22.5 ± 3.1°C and 18.2 ± 2.8°C, respectively. Daily light integral (DLI) averaged 20.0 ± 3.0 mol·m⁻²·d⁻¹, daytime CO₂ concentration averaged 580 ± 207 ppm, and vapor pressure deficit (VPD) averaged 1.0 ± 0.6 kPa. Supplemental lighting provided a 16-hour photoperiod with a photosynthetic photon flux density (PPFD) of ~250 μmol·m⁻²·s⁻¹. Plants were fertigated through a drip irrigation system and grown in a commercial strawberry substrate composed of 100% coconut coir fiber. We performed weekly flower mapping on randomly sampled plants and yield measurements for the rest of plants for 19 weeks. We hypothesized that yield of a future week can be predicted based on counts of floral buds at each of 11 developmental stages. We found that floral meristem stages 4 and 5 (when calyx and trichomes differentiate on the floral bud) exhibit significant positive correlations with yield occurring nine weeks later. In addition, stage 11 meristems (anthesis) showed a significant positive correlation with yield occurring three weeks later. The remaining developmental stages exhibited weaker correlations and were less reliable predictors of upcoming yield. By using these key developmental stages, we will develop a methodology for forecasting near-future yield. This will help U.S. greenhouse strawberry growers to make informed decisions about resource allocation, labor scheduling, and market planning, ultimately optimizing yield and production efficiency in CEA systems. Our research outcomes lay the groundwork for more comprehensive yield predictions in the future.

Speakers

Katelyn Fulcher

OSU

Co-authors

Chieri Kubota

The Ohio State University

Wednesday July 30, 2025 9:15am - 9:30am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture
Funding Source Seitz Graduate Scholarship Fund in Controlled Environment Agriculture

9:15am CDT

HSMP 2 - Ammonium to Nitrate and Nitrogen to Phosphorous Ratios of Commercial Fertilizers have Limited Impact on Containerized Herb Growth

Wednesday July 30, 2025 9:15am - 9:30am CDT

Strand 11B

Today, fresh herbs can be sourced as live container-grown plants year-round in the produce section of most retailers. Commercial fertilizers are selected based on several factors, including the ratio of ammonium- and nitrate-nitrogen and phosphorous concentration. The objective of this research was to quantify the effects of increasing phosphorus concentrations alongside different ratios of nitrate and ammoniacal nitrogen concentrations in commercial water-soluble fertilizers on the post-production performance of containerized culinary herbs. Seedlings of sweet basil (Ocimum basilicum ‘Genovese’) were transplanted into 11.4 cm-diameter containers filled with soilless substrate compromised of peat moss and coarse perlite. Upon transplant and throughout the experiment, seedlings were irrigated with commercially available water-soluble fertilizer (WSF) solutions variying in potential acidity (PA) or potential basicity (PB) and the ratio of nitrogen to phosphorous (N:P), including: 15N-0.9P-12.5K (PB 195 CCE/ton; 167N:10P); 15N-1.8P-16.6K (PB 77 CCE/ton; 83N:10P); 15N-2.2P-12.5K (PB 69 CCE/ton; 68N:10P); 15N-4.8P-14.1K (PA 58 CCE/ton; 15N-7P-24.1K (PA 122 CCE/ton; 21N:10P); and 20N-4.4P-16.6K (PA 401 CCE/ton; 45N:10P); 31N:10P). Plants were grown in two different phases: 1) in a greenhouse for 28 d at 22°/18° and 12 mol∙m–2∙d–1 to simulate a greenhouse production phase; and 2) in a growth chamber for 7 d at 20° ADT and 1 mol∙m–2∙d–1, to simulate a production and retail environment, respectively. After each phase, data was collected on half of the plants.. Plant height increased by 1.7 cm across treatments between the end of the greenhouse phase and the end retail phase. The relative growth rate of fresh mass accumulation decreased from 5.7 g∙d–1 during production to 1.2 g∙d–1 during the retail phase. Similarly, relative growth rate of dry mass accumulation decreased from 0.5 g∙d–1 during production to -0.2 g∙d–1 during the retail phase. The pH during the greenhouse phase was higher for basil fertilized with higher-nitrate formulations compared to those receiving fertilizers with more ammonium, but these differences were diminished during the retail phase. The results of this study indicate environment has a greater impact on plant growth and development than both the potential basicity or acidity and phosphorus content of fertilizer provided.

Speakers

Nicole Arment

Iowa State University

Co-authors

Christopher Currey

Iowa State University

Jennifer Boldt

United States Department of Agriculture

Wednesday July 30, 2025 9:15am - 9:30am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants
Poster # csv

9:15am CDT

LOCSY 2- School Gardening Leadership Certificate Program – Training School Teachers Sustainable Horticulture Practices

Wednesday July 30, 2025 9:15am - 9:30am CDT

Strand 11A

Seeding Success - The Louisiana Farm to School (F2S) Program sponsors a four-day intensive training targeting teachers and those that support school gardening and integrating gardens into the curriculum. The training has been offered each summer for the past five years with classroom and hands-on horticulture training in the mornings and in the afternoons, demonstration of classroom lessons linked to state standards, taste tests, and integration of farm to school into the classroom. The horticulture program focuses on the horticulture extension materials developed for the F2S program under the Sustainable School and Home Garden series, including the Louisiana Planting Guide and individual crop guides with all the materials available on the seedstosuccess.com website. Hands-on horticulture activities such as vermicomposting, composting, seeding and “bumping up” and planting transplants are introduced each day that are designed to be used in schools. All of the activities are intended to support the development and maintenance of school gardens and curriculum development. Participants provided feedback on the training and overwhelming benefited from the School Gardening Leadership Certificate Program. Data from the extension program will be presented including data on program, specific topics, and analytics.

Speakers

Carl Motsenbocker

Professor, Executive Director Louisiana Farm to School Program, Louisiana State University

Dr. Carl Motsenbocker is a professor of horticulture and sustainable agriculture at Louisiana State University. Motsenbocker is Executive Director of the Louisiana Farm to School Program and teaches Organic Gardening, Sustainable Agriculture and Vegetable Crops at LSU. Motsenbocker... Read More →

Co-authors

Denise Cummins

School of Plant, Env. and Soil Sciences

Issabella Frank

Louisiana State University Agricultural Center

Wednesday July 30, 2025 9:15am - 9:30am CDT
Strand 11A

Oral presentation, Local Food Systems 2

Funding Source USDA Child Nutrition Funds

9:15am CDT

VCM 2- Investigating Heat Tolerance and Physiological Responses of Late-Planted Tomatoes in Oklahoma

Wednesday July 30, 2025 9:15am - 9:30am CDT

Foster 1

Consumers seek locally grown tomatoes for their superior flavor, making them a valuable crop for local vegetable growers. Tomato production can be difficult with the temperature requirements for fruit set, development, and ripening. Optimum growing conditions are available for a short period in Oklahoma, causing a distinct decline in production during late July and August. A field experiment was designed to investigate the success of late planted, heat tolerant tomatoes in Oklahoma field conditions, as well as explore the relationship between physiological responses and season-long temperatures. The experiment utilized a split plot design with three transplanting dates as whole plot and five cultivars as subplot. ‘Red Snapper’ and ‘Laguna Red’ were selected as potential heat sensitive cultivars. ‘Bella Rosa’, ‘Volante’, and ‘Florida 91’ were selected as heat tolerant cultivars, based on previous trial information. Planting occurred on April 23, May 9, and May 23 to represent early, mid, and late plantings dates, respectively. Physiological measurements were collected every two weeks and included electrolyte leakage, net photosynthetic rate, stomatal conductance, leaf temperature, and chlorophyll fluorescence. Plants were harvested routinely from June to the end of August. Cultivars were not found to be significantly different in the trial for yield or physiological responses. The early planting date was the most productive, compared to mid and late. Yield dropped dramatically for all planting dates in August. There was a strong positive correlation between electrolyte leakage and temperature and a moderate negative correlation between photosynthetic rate and average daily temperature. These correlations indicate that physiological parameters may be able to provide insight into late season thermotolerance. Future research will involve cultivar screenings in controlled environments to promote a wider range of responses to temperature.

Speakers

Courtney DeKalb-Myers

Co-authors

Justin Quetone Moss

Oklahoma State University

Wednesday July 30, 2025 9:15am - 9:30am CDT
Foster 1

Oral presentation, Vegetable Crops Management 2

Subject Vegetable Crops Management
Poster # csv

9:15am CDT

VGBR 1 - “Seed to Seed in 100 Days”: Development of a Low-Cost Speed Breeding Protocol for Chile Peppers (Capsicum annuum L.)

Wednesday July 30, 2025 9:15am - 9:30am CDT

Foster 2

Speed breeding is a technique that utilizes controlled environments and optimal lighting (photoperiod) conditions to accelerate germination, development, and maturity of plants. One of the major constraints for its adoption and implementation in vegetable breeding programs is the high cost associated with growth chambers. The objective of this study is to develop a Speed Breeding protocol for chile peppers using an improvised, low-cost growth chamber constructed using polyvinyl chloride (PVC) plastic, greenhouse film, mylar reflective film, full-spectrum and far-red light-emitting diode (LED) growth lights. Four C. annuum L. genotypes, namely, NuMex Lotalutein (a serrano type), NuMex Odyssey (New Mexican), NuMex Las Cruces (cayenne), and Early Jalapeno (jalapeno) were planted in two randomized flat trays, using SunGro propagation soil, and watered twice daily. After reaching the 2-3 leaf stage, the treatments (control and Speed Breeding, SB) were transplanted into 8” pots, incorporating sterilized and LM-AP soil mixtures. The control group was cultivated in standard greenhouse conditions for growing chile peppers, exposed to normal daylight intensity and duration, and an average temperature of 21°C and humidity of 40%. The chamber was also constructed in the same greenhouse. From weeks 1 to 5 after planting, the SB-treatment was subjected to 20h/4h light/dark conditions daily, and 9h/15h light/dark after week 5. Light intensity was increased by ~100 photosynthetic active radiation (PAR) weekly after week 5, from ~150 PAR to ~800 PAR. Data was recorded weekly to examine the effects of treatment on germination rate, plant size, leaf number and color, number of flowers, buds, and fruits, and days to flower and fruit. There were significant differences (Tukey HSD, P < 0.05) between treatments for germination rates, number of buds, fruits, leaves, and days to flowering. The SB-treated pepper plants exhibited faster and higher germination, darker green leaves, and a higher number of buds and fruits compared to the control. For instance, SB plants started flowering, on average, about 20 ± 5 days earlier, germinated 5 ± 1 days earlier, and had, on average, 15 ± 2 more buds than the control. Notably, all genotypes under the SB-treatment had at least one fully mature fruit ~106 days after sowing. These results suggest that, at minimal costs, there is a potential to achieve increased generation times to accelerate cultivar development and genetic improvement in chile peppers.

Speakers

Shahab Nourbakhsh

New Mexico State University

Co-authors

Amanda Velazco

New Mexico State University

Dennis Nicuh Lozada

New Mexico State University

Uriel Martinez

New Mexico State University

Wednesday July 30, 2025 9:15am - 9:30am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding
Poster # csv

9:30am CDT

CE 3 - Effect of Substrate and Nutrient Levels on Ginger Growth and Yield Under Controlled Environment

Wednesday July 30, 2025 9:30am - 9:45am CDT

Strand 12B

Domestic production of ginger is increasing, as it is used in a variety of culinary and medicinal applications due to its unique flavor and potential health benefits. However, some growing parameters, such as growing media and fertigation levels, have not yet been optimized for containerized production. Therefore, the objective of this study was to evaluate the growth and rhizome yield of ginger (Zingiber officinale) using different soilless substrates and nutrient levels under greenhouse conditions. Two separate experiments were conducted, each lasting six months. In Experiment 1, six substrates were evaluated: 100% coir (control), 100% peat, peat-bark mixtures at 75%-25%, 50%-50%, and 25%-75%, and 100% bark. In this setup, 1-2 sprouted ginger rhizomes were transplanted into each 12 L nursery container and harvested after 3 and 6 months of transplanting. In Experiment 2, five nitrogen-based nutrient levels (50, 100, 200, 300, and 500 ppm N) were evaluated. In this setup, 1-2 sprouted ginger rhizomes were transplanted into grow bags filled with coconut coir pith and husk chips. In both experiments, treatments were arranged as completely randomized design with six replicates. Physical growth parameters, such as the number of stems, relative chlorophyll content, number of roots, unemerged buds, and fresh and dry weight of stems, roots, and new rhizomes, were measured. According to the data from Experiment 1, no significant differences were observed among the substrates, except for the fresh and dry weight of stems and the dry weight of roots at mid-harvest in the peat-bark 25%-75% combination. In contrast, nutrient level significantly influenced all ginger growth parameters except chlorophyll content. Ginger grew well under low nutrient levels (50 to 100 ppm N). The overall growth differences between 50 and 500 ppm N ranged from 6% to 68%. For example, the fresh and dry weight of new rhizomes were 65.7% and 49.1% greater at the 50 ppm N nutrient level, respectively. The results demonstrated that ginger plants prefer well-draining substrates with low nutrient levels under controlled-environment production.

Speakers

Milon Chowdhury

Kentucky State University

Co-authors

James Altland

USDA-ARS

Uttara Samarakoon

The Ohio State University

Wednesday July 30, 2025 9:30am - 9:45am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Funding Source Evans-Allen funds

9:30am CDT

CHEX 2 - Soilless substrate hydrology can improve plant morphological development and predict stomatal regulations under harsh growing conditions

Wednesday July 30, 2025 9:30am - 9:45am CDT

Strand 12A

The global increase in ornamental crop production has driven horticultural researchers to better understand the efficiency and sustainability of production input. Soilless substrates serve a crucial role in supporting outdoor nursery-grown plants, where container substrates must maintain sufficient moisture supply to the rootzone and continuously sustain shoot water loss. Nursery producers regularly face a changing climate, where unprecedented droughts, prolonged and increased air temperatures, and subsequent mandated water application restrictions present challenges for profitable harvests and yields. To date, there are little to no means in predicting container nursery stock performance, especially when grown in substrates with different water supply capacities (i.e., water storage and hydraulic transfer properties). Models have been used to predict plant responses to water stresses in soil systems based on dynamics of hydraulic conductance in the soil-plant-atmospheric-continuum (SPAC); though, no SPAC models have been applied to horticultural plants grown in soilless substrates. To better prepare for climate-challenges in nursery production systems, new methods of understanding substrate capabilities to withstand harsh growing conditions are needed. The study herein uses predictive tools (i.e., SPAC models) derived from measured data, namely substrate and plant hydraulic characteristics, to understand how plants respond (i.e., physiological output; water loss) when grown in harsh growing conditions (e.g., drying substrate and atmosphere). Plants were grown in four differing bark particle diameters: (1) 6.3 mm. Substrate water potential were maintained between -50 and -100 hPa to produce plants at similar water availabilities. Substrate hydraulic conductivity decreased as particle size increased, highlighting different water transfer properties across substrates at similar water availabilities. Plants produced in finer textured substrates had greater root and shoot morphological development, including greater fine root growth and aerial biomass. No differences were detected in root and shoot hydraulic conductance. The SPAC models showed that plants grown in finer textured substrates were able to maintain physiological function longer under drying substrate or atmospheric conditions, while plants grown in substrates with lower water transfer properties sharply decreased physiological output (i.e., faster stomal closure). The hydraulic models applied herein can inform growers that producing plants in finer textured substrates, or substrates that have greater hydraulic conductivity, can enable plants to maintain physiological functions even in harsh growing conditions.

Speakers

Kristopher Criscione

Virginia Tech

Co-authors

Brett Wolfe

Louisiana State University

Jeb Fields

University of Florida

Wednesday July 30, 2025 9:30am - 9:45am CDT
Strand 12A

Oral presentation, Commercial Horticulture 2

Subject Commercial Horticulture
Poster # csv

9:30am CDT

HSMP 2 - Peak Separation by Derivative Spectroscopy Applied to FTIR Analysis for Detection and Quantification in lavender Essential Oils

Wednesday July 30, 2025 9:30am - 9:45am CDT

Strand 11B

Lavender (Lavandula sp) is an important source of high-quality perfumes and has multiple medicinal properties, such as anti-anxiety, anti-depressant, and hypnotic properties. Due to its high market price and medicinal value, lavender essential oil was analyzed. There is a need for rapid, robust, easy, accurate, and cost-effective methodologies for quality control of essential oils from medicinal and aromatic plants. This research evaluated the ability of Fourier transform infrared (FTIR) spectroscopy techniques to identify the of lavender essential oil. Principal component analysis (PCA) was successfully used with 100% accuracy to differentiate lavender essential oil samples from three cultivars. The essential oils linalool and linalyl were identified. The results demonstrated that FTIR spectroscopy can be used as a reliable, robust, rapid, accurate, and low-cost analytical technique for quality assessment of Lavandula essential oil. This study aimed to develop a new and rapid spectroscopic method using chemical modeling techniques for the qualitative and quantitative identification of essential oils in three lavender essential oil species (Lavandula angustifolia, Lavandula intermedia, and Lavandula stoechas). Fifty-two principal component analysis (PCA) models were created, and the one with the best statistical results was evaluated. The best discrimination and quantitative analysis models were found to be those using standardized spectra. The results obtained demonstrated the possibility of successfully detecting the essential oils of three lavender species within a wide concentration range, without the use of any toxic chemicals or pretreatments. The results showed that FTIR models were able to accurately predict all constituents and identify essential oils in lavender. Lavender essential oil was extracted from lavender samples using the Soxhlet technique using 70% alcohol and compared using Fourier transform infrared (FTIR) spectroscopy. FTIR analysis of the pure essential oil extracted from three lavender species revealed distinct peaks for linalool and linalyl, the two main chemical components.

Speakers

Keefah AL-Garallaa

Mississippi State University

Co-authors

Ishmael Apachigawo

Mississippi State University

Richard Harkess

Mississippi State University

Wednesday July 30, 2025 9:30am - 9:45am CDT
Strand 11B

Oral presentation, Herbs; Spices and Medicinal Plants 2

Subject Herbs Spices and Medicinal Plants

9:30am CDT

VGBR 1 - Watermelon Glycemic Index Footprint: Management through Production System, Breeding and Precision Dieting

Wednesday July 30, 2025 9:30am - 9:45am CDT

Foster 2

Watermelon is a preferred fruit in the Caribbean and all over the world and is the second most consumed cucurbit by harvest weight in the Virgin Islands after cucumber. While quality of water of watermelon is commonly judged by sweetness, the ratios of types of sugars are hardly considered. Watermelon is classified as one of the fruits with very high glycemic index, GI – the measure by which a dietary intake increases the blood sugar compared to pure glucose whose GI is 100. Watermelon is normally promoted as a highly nutritious as it is one of the best sources of potassium, but can be both a blessing and curse, especially for consumers with high blood sugar-related ailments. Here we report on preliminary efforts we are making to produce watermelons that have reduced GI. We are using hybridization as well as exploiting genotype-by-environment interactions to influence sugar composition in fleshy fruit tissues. We have obtained three hybrids that have at least 22% reduced glucose and at per brix compared to the parents. We are also testing a series of shadehouse systems, two of which show the potential to lower glucose ratio in the fruits. We hope to refine these methods and evaluate the watermelon lines for yield and sugar trait stability before recommending plant materials and production systems to interested farmers. Key words: Hybrids, sugar, glycemic index, genotype by environment, production system, sucrose, watermelon.

Speakers

Henry Awika

University of the Virgin Islands

Co-authors

Donna Gonzalez

University of the Virgin Islands

Hannah Hazard

University of Wisconsin Oshkosh- Oshkosh

Johnson Southwell

University of the Virgin Islands

Wednesday July 30, 2025 9:30am - 9:45am CDT
Foster 2

Oral presentation, Vegetable Breeding 1

Subject vegetable Breeding
Poster # csv
Funding Source USDA-AMS-SCBG-VIDA

9:44am CDT

TECH - Oral Session

Wednesday July 30, 2025 9:44am - 9:45am CDT

Strand 11A

Presiding/Moderator

Marcelo Barbosa

University of Georgia

Wednesday July 30, 2025 9:44am - 9:45am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture

9:44am CDT

VSF 1 - Oral Session

Wednesday July 30, 2025 9:44am - 9:45am CDT

Foster 1

Presiding/Moderator

David Bryla

USDA

Wednesday July 30, 2025 9:44am - 9:45am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits

9:45am CDT

CE 3 - Quantifying Effects of pH on the Growth of Fresh-cut Culinary Herbs in Recirculating Nutrient Solutions

Wednesday July 30, 2025 9:45am - 10:00am CDT

Strand 12B

Hydroponic production systems with recirculating nutrient solutions are routinely monitored and adjusted to maintain a target pH value. Supra-optimal or sub-optimal pH values can lead to nutrient deficiencies or toxicities, respectively, reducing crop quality and yields. The objective of our research was to determine appropriate nutrient solution pH ranges for herbs grown in recirculating nutrient solutions. Two week old seedlings of basil (Ocimum basilicum ‘Nufar’), and three week old seedlings of dill (Anethum graveolens ‘Hera’), parsley (Petroselinum crispum ‘Giant of Italy’), and sage (Salvia officinalis), grown in phenolic foam cubes were transplanted into one of six deep-flow technique (DFT) systems in a greenhouse with different pH treatments. Treatments consisted of pH setpoints of 4.5, 5.0, 5.5, 6.0, 6.5, and 7.0. DFT systems contained nutrient solutions made with tempered municipal water supplemented with a complete water-soluble fertilizer (16N-2.2P-14.3K) to maintain a target electrical conductivity of 2.0 dS·m–1. The nutrient solution pH was maintained through a dosing system using 2% sulfuric acid and 2% potassium hydroxide as the acid and alkali, respectively. One-third (by vol.) of the nutrient solution was renewed with freshly mixed 16N-2.2P-14.3K fertilizer each week of production to ensure adequate nutrients in the nutrient solution. Greenhouse target environmental conditions consisted of day and night temperatures of 22 °C and 18 °C respectively, and a daily light integral of 12 mol∙m–2∙d–1. The optimal pH for culinary herb growth varied by species. Basil fresh mass was optimized at pH of 5.5 and decreased by 41.7% when grown at pH 7.0 compared to basil grown at pH of 5.0. Basil grown at pH of 7.0 was 3.38 cm shorter than plants grown at pH of 6.0. Similarly, dill and parsley had the greatest fresh mass when grown at pH of 5.0 and 5.5, respectively, and fresh mass was reduced by 40% and 33 %, respectively, when grown at pH of 7.0 compared to their optimum pH. In contrast, sage growth increased with pH, with a 17% increase in fresh mass between pH of 4.5 and 7.0. The results of this study indicate herbs may be able to grow throughout a broader range of pH values than originally thought, if nutrients do not become limited. Furthermore, when possible, hydroponic culinary herb producers can group species with similar pH requirements to maximize yields.

Speakers

Hannah Kramer

Iowa State University

Co-authors

Christopher Currey

Iowa State University

Jennifer Boldt

United States Department of Agriculture

Wednesday July 30, 2025 9:45am - 10:00am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 3

Subject Growth Chambers and Controlled Environments
Poster # csv

9:45am CDT

TECH - AI-Driven Yield Forecasting Using UAV-Based Imagery: Insights from a Pecan Orchard

Wednesday July 30, 2025 9:45am - 10:00am CDT

Strand 11A

Forecasting yield is a timely opportunity to make anticipated harvesting decisions on the grown crop and understand field variability. Such information is a remarkable contribution to the precision agriculture context. However, developing such an approach is challenging for perennial crops such as pecan. These crops present slight canopy changes, which often do not reflect the upcoming yield. Consequently, waiting for the harvest date is the only approach to obtain yield data. Conversely, the advent of image-based data and artificial intelligence techniques has proven their applicability in addressing this issue. Therefore, our objective was to analyze whether UAV multispectral images and AI-based data analysis are suitable for developing forecasting models for yield in pecan trees. Hence, we began collecting multispectral images approximately five months before the harvesting date. Each data collection date had an interval of fifteen days, totaling ten multispectral image sets. Subsequently, we processed the images to generate ten orthomosaics (one for each date). The orthomosaics were used to calculate numerous vegetation indices, texture data, and the canopy area to be used as inputs for the forecasting models. At the harvest date, we measured the yield of 78 individual plants across two pecan fields. Before developing the forecasting models, we performed a correlation analysis to better understand the relationship between the image data and yield. Afterward, we developed the forecasting models using machine learning algorithms, namely, multiple linear regression, decision tree, support vector machine, and random forest. The dataset was split into 70% (n = 55) for training and 30% (n = 23) for testing. The training dataset was used to train the forecasting models, while the testing dataset was used to assess the models’ effectiveness regarding precision (coefficient of determination, R²) and accuracy (mean absolute error, MAE; and root mean squared error, RMSE). All the models produced interesting results and could be implemented to forecast yield in pecan trees. However, random forest outperformed the others (high precision and accuracy) and, therefore, was the remaining model for this study. Forecasting yield in pecan trees presented increased effectiveness, improving the models’ performance early on and establishing higher accuracies closer to the harvesting date. We also performed a feature importance analysis, where predominantly the texture data contributed better to the models’ performance. Certainly, our findings are timely and support pecan growers and stakeholders in making better decisions for harvesting with anticipated and accurate yield data without waiting for the harvesting date.

Speakers

Marcelo Barbosa

University of Georgia

Co-authors

Lenny Wells

University of Georgia

Luan Oliveira

University of Georgia

Lucas Sales

University of Georgia

Agronomy Engineer graduated from the Federal University of Paraíba. With experience in the management and cultivation of Ornamental Plants, through a year of experience working in Greenhouses in the state of New Hampshire, USA. Experienced in the management and cultivation of vegetables... Read More →

Regimar dos Santos

University of Georgia

Bachelor's degree in agronomic engineering from the Federal University of Mato Grosso do Sul, Brazil at 2021. Master's degree in plant production with an emphasis on computational intelligence in genetic improvement at 2022, with a doctorate in progress at the state university of... Read More →

Victor Martins

University of Georgia

Wednesday July 30, 2025 9:45am - 10:00am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture

9:45am CDT

VSF 1 - Evaluating drought tolerance of southern highbush and rabbiteye blueberries

Wednesday July 30, 2025 9:45am - 10:00am CDT

Foster 1

Blueberries (Vaccinium sect. Cyanococcus) are prone to drought due to their shallow root system and limited ability to uptake water from the soil. Previous research has shown rabbiteye (Vaccinium virgatum) blueberries to be more tolerant than highbush varieties (Vaccinium corymbosum L.) to abiotic stresses. However, little is known about their response to drought and whether there are ecotype- or cultivar-specific responses. In order to breed for more drought-tolerant cultivars, this study aims to identify drought tolerant mechanisms within existing cultivars of both southern highbush (SHB) and rabbiteye (RE) blueberries. We evaluated seven cultivars of southern highbush and rabbiteye blueberry for physiological response and fruit quality characteristics under water deficit and recovery across two consecutive years. Overall, drought was found to decrease photosynthesis, stomatal conductance, electron transport rate, leaf relative water content, specific leaf area, chlorophyll content, maximum rate of Rubisco carboxylation (Vcmax) and maximum rate of RuBP regeneration (Jmax). Additionally, drought treatment was found to significantly decrease yield and average berry weight while increasing total soluble solids and berry firmness. Misty (SHB) was identified as the most drought tolerant cultivar due to maintenance of CO2 assimilation, stomatal conductance, and yield under drought conditions across both years, while Suziblue (SHB), Powderblue (RE), and Vernon (RE) were found to be more sensitive to water deficit. Star (SHB) was tolerant of drought in the short term but performed worse under repeated drought events.

Speakers

Savannah Busby

Auburn University

Co-authors

Alvaro Sanz Saez

Auburn University

Courtney Leisner

Virginia Tech

Sajid Hanif

Auburn University

Sushan Ru

Auburn University

Tanzeel Rehman

Auburn University

Wednesday July 30, 2025 9:45am - 10:00am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits
Poster # csv

9:59am CDT

ORGH 1 - Oral Session

Wednesday July 30, 2025 9:59am - 10:00am CDT

Foster 2

Presiding/Moderator

Samantha Pratt

Oklahoma State University

Wednesday July 30, 2025 9:59am - 10:00am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic

10:00am CDT

ORGH 1 - Effect of Microalgae Application on Yield and Nutrient Composition of Arugula

Wednesday July 30, 2025 10:00am - 10:15am CDT

Foster 2

Effect of Microalgae Application on Yield and Nutrient Composition of Arugula Sam Pratt1*, Shivani Kathi1, Steve Phillips2, and Justin Moss1 1Department of Horticulture and Landscape Architecture, Oklahoma State University, Stillwater, OK, 74078 2Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, 74078 *Presenting author- Samatha.pratt@okstate.edu Chlorella (Chlorella vulgaris) has been used as a biofertilizer in horticultural crop production in controlled environment production systems. However, research gaps exist in the application of chlorella biofertilizer in field-based production systems. The goal of this research is to assess the impact of microalgae biofertilizers on crop productivity and nutritional quality of arugula grown in open-field using certified naturally grown production practices. To understand the impact of microalgae biofertilizer on soil nutrient and organic matter content, soil testing was done before and after treatment. Treatments included 50% and 100% nitrogen fertilizer and chlorella applied through foliar, soil and foliar soil application. Chlorella application began a week after transplanting. Data was collected on number of leaves per throughout the study and fresh and dry weight at harvest. Plant samples were analyzed for nutrient composition of leafy greens (chlorophyll, carotenoids, and mineral nutrients composition). Results show that soil applied chlorella was more effective application method regarding the overall impact on yield. Continued research on the addition of Chlorella in crop production can offer additional nitrogen sources for low chemical input and organic based production systems.

Speakers

Samantha Pratt

Oklahoma State University

Wednesday July 30, 2025 10:00am - 10:15am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Poster # csv

10:00am CDT

TECH - Towards developing a unified model for non-destructive sugar content estimation in persimmon independent of genetic variability

Wednesday July 30, 2025 10:00am - 10:15am CDT

Strand 11A

Non-destructive estimation models often require cultivar-specific calibrations due to spectral differences arising from genetic variability. Integrating diverse cultivars into a single model can reduce costs and simplify data collection. However, in persimmons, the abundant and variable proanthocyanidins in the fruit overlap with spectral regions used for sugar estimation, rendering accurate prediction with a single model challenging. In this study, we attempted sugar estimation in diverse persimmon cultivars using near-infrared (NIR) spectroscopy and hyperspectral imaging. A total of 989 spectral measurements were acquired from 34 persimmon cultivars. Regression models employing various pre-processing and modeling techniques achieved a maximum R² of 0.786, indicating the feasibility of modeling sugar content across diverse cultivars with a unified approach. Furthermore, by designing a cover for the NIR sensor and combining it with SNV pre-processing, we demonstrated that stable spectra for sugar estimation can be obtained under outdoor conditions. With further improvements in accuracy, this approach is expected to facilitate rapid fruit quality evaluation and contribute to optimized production.

Speakers

Soichiro Nishiyama

Kyoto University

Co-authors

Airi Tomata

Kyoto University

Ryutaro Tao

Kyoto University

Wednesday July 30, 2025 10:00am - 10:15am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv

10:00am CDT

VSF 1 - Water Requirements for Establishing a New Planting of Northern Highbush Blueberry in Western Oregon

Wednesday July 30, 2025 10:00am - 10:15am CDT

Foster 1

Regional recommendations for blueberry irrigation exist, but few studies report the actual amount of water needed. The goal of this multiyear project was to determine the water requirements for growing northern highbush blueberry (Vaccinium corymbosum) in the U.S. Pacific Northwest. Weighing lysimeters were used to measure crop evapotranspiration (ETc) of three cultivars with various ripening seasons, including ‘Duke’ (early season), ‘Top Shelf’ (mid-season), and ‘Aurora’ (late season). Each lysimeter was constructed from steel and included a large soil tank (1.5-m wide × 0.9-m long × 1.0-m deep) positioned on four hermetically sealed, shear-beam load cells, housed inside an underground chamber. Plants were spaced 0.9 × 3.0 m apart in the lysimeters (one plant/lysimeter) and surrounding field (0.4 ha) and managed using standard industry practices, including raised planting beds mulched with Douglas fir (Pseudotsuga menziesii) sawdust, grass alleyways between the beds, irrigation with two lines of drip tubing per row, and fertigation with nitrogen and other nutrients as needed. During the first year after planting, ETc totaled 94–104 mm, depending on the cultivar, or 18–19% of total potential evapotranspiration (ETo) from initiation of the measurements on 1 June to when irrigation was turned off for the season on 23 September 2023. That year, crop coefficients (Kc), calculated by dividing ETc by ETo obtained from a nearby agricultural weather station, averaged 0.11, 0.15, 0.27, and 0.41 each month from June through September, respectively. The following year, the plants were lightly cropped (0.2–0.8 kg of marketable fruit per plant), and ETc totaled 175–343 mm, or 30–59% of total ETo. At that point, Kc averaged 0.31, 0.34, 0.45, 0.61, and 0.61 each month from 14 May to 30 September, which was the entire timeframe in which the plants were irrigated. This project is ongoing and will continue until the plants reach full production. Once the study is finished, a set of seasonal Kc curves will be developed for each cultivar and uploaded to regional websites called AgriMet and AgWeatherNet, where they will be used to automatically calculate irrigation water requirements using meteorological data from local weather stations.

Speakers

David Bryla

USDA

Co-authors

Camilo Souto

Universidad de Concepción

Scott Orr

USDA

Wednesday July 30, 2025 10:00am - 10:15am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits
Poster # csv

10:14am CDT

FRBR 1 - Oral Session

Wednesday July 30, 2025 10:14am - 10:15am CDT

Strand 12A

Presiding/Moderator

Vance Whitaker

University of Florida

Wednesday July 30, 2025 10:14am - 10:15am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding

10:14am CDT

PH 2 - Oral Session

Wednesday July 30, 2025 10:14am - 10:15am CDT

Strand 12B

Presiding/Moderator

Jagjit Singh

Graduate Research Assistant (MS), Auburn University

Wednesday July 30, 2025 10:14am - 10:15am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest

10:14am CDT

TCHG 1 - Oral Session

Wednesday July 30, 2025 10:14am - 10:15am CDT

Strand 11B

Presiding/Moderator

Alicia Thomas

Assistant Professor of Practice, Texas Tech University

Wednesday July 30, 2025 10:14am - 10:15am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods

10:15am CDT

FRBR 1 - Breeding Medallion™ ‘FL 16.30-128’ Strawberry

Wednesday July 30, 2025 10:15am - 10:30am CDT

Strand 12A

Florida Medallion™ ‘FL 16.30-128’ strawberry (Fragaria x ananassa; hereafter referred to as Medallion; U.S. Patent PP33,451) was released from the University of Florida in 2020. By 2024 this cultivar occupied approximately 15% of acreage in central Florida. The unique characteristics of this cultivar, in particular its early yields and fruity flavor, point to the breeding strategy employed in its development. Medallion originated from a 2016 cross between two unreleased selections. Marker-assisted selection was applied to this cross using a PCR-based marker for the FaFAD1 gene controlling production of gamma-decalactone, a volatile imparting fruity flavor. Seedlings homozygous for the functional allele were retained. At the advanced selection stage, trials of Medallion were conducted at the research plots of the University of Florida Gulf Coast Research and Education Center (GCREC) in Wimauma, FL and fruit were harvested for sensory and chemical analyses over five seasons. The increased dosage of the FaFAD1 gene resulted in high production of gamma-decalactone. Trained sensory panels perceived improved sweetness and strawberry flavor intensity of Medallion to be above the current industry standard ‘Florida Brilliance’. Additional background and data will be presented illustrating the early yield of this variety and other characteristics making it suitable for the central Florida industry and suggesting future breeding strategies for improving strawberry flavor.

Speakers

Vance Whitaker

University of Florida

Co-authors

Anne Plotto

USDA ARS

Cheryl Dalid

University of Florida

Jinhe Bai

USDA ARS

Luis Osorio

University of Florida

Mark E. Porter

University of Florida

Natalia Peres

University of Florida

Wednesday July 30, 2025 10:15am - 10:30am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Poster # csv

10:15am CDT

ORGH 1 - Effect of Organic Fertilizer on Broccoli Yield and Soil N Mineralization

Wednesday July 30, 2025 10:15am - 10:30am CDT

Foster 2

Organic vegetable farmers use a wide variety of nitrogen (N) fertilizers from commercial products (made from animal and seed meals) to manures and composts. These organic N sources must undergo mineralization and nitrification to become plant available inorganic N (microbial processes). How much and when nitrogen becomes available can be highly variable dependent on product characteristics and local weather conditions, and this subsequent N availability can greatly impact yield. The objective of this study was to determine nitrogen mineralization, head timing, and overall yield from seven different organic fertilizer treatments on fall broccoli (Brassica oleracea ‘Castle Dome’). Studies were conducted over two years at the UGA Durham Horticulture Farm on certified organic land and organic fertilizers (with the exception of the control) were applied to provide a rate of 134 kg N ha-1. Fertilizers ranged from processed animal meals to composts and fresh poultry litter. Nitrogen mineralization was measured using in-situ soil cores and ranged from 0 (immobilization) to 100% of the N applied. Significant N was observed from the soil only treatment which provided on average 100 kg N ha-1 over the growing season. In both years, overall higher yields were observed with blood meal and lowest yields were observed with compost/control treatments. Fertilizer type impacted the timing of heading and overall harvest windows.

Speakers

Kate Cassity-Duffey

University of Georgia

Co-authors

Miguel Cabrera

University of Georgia

Timothy Coolong

University of Georgia

Wednesday July 30, 2025 10:15am - 10:30am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Funding Source SARE

10:15am CDT

PH 2 - Exploring the Effect of Postharvest Storage on Composition Changes in Selected Muscadine Grape (Vitis Rotundifolia Michx.) Cultivars

Wednesday July 30, 2025 10:15am - 10:30am CDT

Strand 12B

Muscadine grapes are native to the southeastern U.S. and are known for their unique flavor and aroma. Rapid postharvest deterioration of muscadine berries is a major barrier in market expansion. This study investigated the change in muscadine berries’ general composition over a four-week storage period. The vines were planted at the Chilton Research and Extension Center, Clanton, AL in a randomized complete block design with four single plant replications. Berries from the perfect-flowered cultivars ‘Hall’, ‘Paulk’, and ‘Southern Home’, and from the pistillate cultivars ‘Eudora’ and ‘Supreme’ (standard) were studied. Experimental vines were harvested on Aug. 2 and Sept. 4, 2024. One-pound clamshells were filled with berries collected from each experimental vine. Fresh samples (Week 0) were compared for berry quality changes occurring after 1, 3, and 4 weeks of cold storage at 4°C and 85% RH. After completing each storage period exposure, the berry samples were allowed to rest for 1 hour at room temperature. The change in berry weight and firmness was recorded after each storage treatment and 5 berry subsample was frozen at -80°C for later analysis of total soluble solids (TSS), titratable acidity (TA), TSS:TA ratio and pH. Our results indicate that the 4 Weeks storage period led to a significant weight loss of 11.3% in ‘Paulk’ and 7.6% in ‘Supreme’ berries in comparison to Week 0. It was found out that both cultivar and storage duration were accountable for the significant firmness reduction with ‘Paulk’ and ‘Supreme’ experiencing 51.4% and 46.2% reduction by Week 4 in storage. Titratable acidity increased significantly over time in all cultivars. The highest TA at Week 4 (0.67) was recorded for ‘Southern Home’, while ‘Paulk’ berries had the lowest TA (0.44), indicating strong cultivar effect (p < 0.0001). After the first week of storage, berries of ‘Hall’ were significantly sweeter than ‘Paulk’, while at Week 4, all cultivars had similar sweetness. Due to an increasing acidity trend, fruit pH decreased with increase in storage time exposure. Both cultivar and storage duration affected the berry pH. TSS:TA ratios varied significantly by cultivar and storage period duration with ‘Supreme’ maintaining its sweetness level throughout the four weeks of storage. Overall, the prolonged storage period resulted in significant firmness reduction and increased acidity with ‘Paulk’ exhibiting the highest reduction of berry firmness while ‘Supreme’ consistently maintained sweetness level over the 4-week period.

Speakers

Jagjit Singh

Graduate Research Assistant (MS), Auburn University

Co-authors

Bernardo Chaves-Cordoba

Auburn University

Edgar Vinson

Auburn University

Elina Coneva

Auburn University

Marlee Trandel Hayse

Auburn University

Melba Ruth Salazar Gutierrez

Auburn University

Wednesday July 30, 2025 10:15am - 10:30am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source USDA-SCBG-ADAI and Southern Region Small Fruit Consortium (SR SFC)

10:15am CDT

TCHG 1 - AI-Driven Learning in Horticulture: Insights from a Nursery Business Plan Project

Wednesday July 30, 2025 10:15am - 10:30am CDT

Strand 11B

In today’s rapidly evolving digital world, education has undergone a significant transformation. By utilizing Generative Artificial Intelligence (AI) tools, educators can offer personalized learning experiences, generate adaptive content, and provide real-time support to students. This study integrated Generative AI tools into the HORT 431 Nursery Production and Management course to develop and enhance the “Nursery Business Plan” assignment. The objective was to improve student brainstorming and writing skills through AI-assisted processes while fostering critical thinking, creativity, teamwork, and reflective practices. Students worked in teams to develop their nursery business plans, utilizing tools like ChatGPT and Copilot to generate ideas and create structured outlines. Each team also developed a logo for their proposed business, adding a creative dimension to the assignment and allowing exploration of branding and marketing concepts. Multiple rounds of feedback from AI tools enabled students to refine their drafts and improve the quality of their writing, emphasizing the importance of revision and continuous improvement. Teams submitted reflections on their experiences with AI tools, including what worked well, the effectiveness of different prompts, and the role of human oversight. At the end of the semester, teams submitted their finalized nursery business plans and defended them through oral presentations. Overall, this project provided a holistic learning experience aimed at preparing students for their future careers.

Speakers

Navreet Mahal

Instructional Assistant Professor, Texas A&M University

Wednesday July 30, 2025 10:15am - 10:30am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

10:15am CDT

TECH - Evaluating Leafy Greens Under Opaque and Thin-Film Semi-Transparent Photovoltaic Arrays

Wednesday July 30, 2025 10:15am - 10:30am CDT

Strand 11A

Combining green roofs with solar modules can protect plants and produce energy in cities. Growing crops in this system is called rooftop agrivoltaics (RAV) and can complement current urban agriculture efforts. We evaluated a group of five leafy green crops (arugula, kale, lettuce, spinach, and Swiss chard) under different solar modules over two years at two locations. Data measurements were taken for fresh and dry weight (FW, DW) stomatal conductance (SC), plant size at harvest (PSH), and microclimate data. Treatments included a polycrystalline opaque silicon module, a cadmium telluride (CdTe) frameless opaque module, a 40% semi-transparent CdTe module, and a full sun control. Four of the five leafy greens produced higher FW and DW under the 40% semi-transparent modules compared to other treatments and the full sun control, except spinach. Most species also produced larger PSH under the PV module treatments compared to the full sun control. Leafy greens under the module treatments resulted in lower SC, however, lettuce and Swiss chard grown under the semi-transparent module treatment produced higher SC compared to all other treatments. This research shows that incorporating photovoltaics on rooftop gardens influences the yield and stomatal conductance of select leafy green crops. While FW and DW mostly decreased under the deep shade treatments (opaque module, frameless module, and bifacial module) SC decreased, possibly due to less solar radiation on the leafy greens, reducing water use. Understanding the growth characteristics and growing environment of high value crops like leafy greens will increase understanding of what food crops are suitable for RAV systems.

Speakers

Armando Villa-Ignacio

Colorado State University

Co-authors

Jennifer Bousselot

Colorado State University

Maria Chavez

New Mexico State University

Wednesday July 30, 2025 10:15am - 10:30am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv
Funding Source Colorado Department of Agriculture Specialty Block Grant

10:15am CDT

VSF 1 - Investigating Humic Acid for the Recovery of Blueberry Fields after Hurricane Helene

Wednesday July 30, 2025 10:15am - 10:30am CDT

Foster 1

The southeastern United States is a major producer of blueberries (Vaccinium corymbosum), however extreme weather events pose significant threats to blueberry production. On September 24, 2024, Hurricane Helene made landfall in Georgia, causing substantial damage to commercial blueberry fields, including uprooted or leaning plants, broken branches, and defoliation. Our project examines the effectiveness of staking leaning plants and humic acid application to enhance the recovery of blueberry plants after hurricane damage. Trials were conducted in five commercial sites with three different cultivars: ‘Farthing’, ‘Legacy’, and ‘Optimus’. Treatments included staking of leaning plants and the application of humic acid alone or in combination. Plant physiological responses were assessed using SPAD (chlorophyll content), leaf area index (LAI), chlorophyll fluorescence, and stomatal conductance (Gsw). Preliminary data indicate that staking leaning plants improved light interception, chlorophyll content, and photosynthetic efficiency in damaged blueberries. The application of humic acid did not result in enhanced plant recovery beyond staking alone. Root and canopy assessments are ongoing and will help determine whether the practice of staking damaged plants and the incorporation of humic acid contributes to long-term plant recovery. Our study will help blueberry producers implement evidence-based strategies to increase the resilience of blueberry fields following extreme weather events.

Speakers

Federica Rossi

University of Georgia

Co-authors

Amit Godara

The University of Georgia

Fabian Bismarck Reyes Rivas

University of Georgia

Luan P de Oliveira

University of Georgia

Maria Theodorakopoulou

University of Georgia

Vinicius Araujo

University of Georgia

Zilfina Rubio

University of Georgia

Wednesday July 30, 2025 10:15am - 10:30am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits
Poster # csv
Funding Source USDA-NIFA-AFRI

10:30am CDT

FRBR 1 - The Effects Of High Daily Light Integral LED Lighting On Strawberry Runner Production, And The Genotype-Specific Responses

Wednesday July 30, 2025 10:30am - 10:45am CDT

Strand 12A

Strawberries rank among the most economically significant horticultural crops in the United States, with a production value of approximately $3.4 billion in 2023. Year-round demand and widespread popularity necessitate extensive efforts to improve fruit quality, yield, and production in controlled environment agriculture (CEA). As part of these initiatives, optimizing runner production for the year-round availability of planting materials is crucial. The importance of photoperiod and light intensity in runner production has been highlighted previously; however, a thorough exploration of the relationship between the total light quantity received during the entire experimental period and runner production is lacking. This study assessed the responses of strawberry genotypes to sunlight and high-performance LED lighting in runner production. Continuous measurements of photosynthetic photon flux density (PPFD) and daily light integral (DLI) provided an accurate assessment of light exposure during the cultivation period across eight strawberry accessions. In a glasshouse under sunlight, plants experienced variable light conditions due to fluctuating weather, with an average DLI of approximately 10 mol m⁻² d⁻¹, whereas under LED lighting in a growth chamber, a stable DLI of 44.1 mol m⁻² d⁻¹ was recorded. No runner formation was observed under sunlight over 44 days, whereas minimal production in two accessions, PI 551445 and PI 616509, was observed within 12 days following the previous 44-day experimental period, with each accession producing one runner. In contrast, stable and high DLI led to significantly higher runner production. When an ANOVA test was conducted using only runner count data from the stable and high DLI conditions, significant differences in runner formation were observed among the tested strawberry accessions (F value = 2.91, p = 0.03). Accessions PI 616509 and PI 679822 produced the most runners, averaging 6.5 and 4.5, respectively, whereas PI 551692 and PI 551445 produced none and one runner, respectively. These results suggest that strawberry runner production depends on cumulative light exposure and genetic makeup. Overall, these findings provide valuable insights into optimizing strawberry runner production in CEA, demonstrating that stable, high-intensity LED lighting can effectively overcome the limitations of variable natural light and enhance year-round production efficiency.

Speakers

Jaebum Park

Texas A

Co-authors

Krishna Bhattarai

Texas A

Wednesday July 30, 2025 10:30am - 10:45am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Funding Source Hatch Project 8483-0-H-DALL and Multistate Hatch Project 7001-0-MSH-DALL to Krishna Bhattarai

10:30am CDT

ORGH 1 - Leveraging Rendered Animal and Treated Manure Products For Nutrient Management and Anaerobic Soil Disinfestation in Organic Watermelon Production

Wednesday July 30, 2025 10:30am - 10:45am CDT

Foster 2

Nutrient and weed management are two of the biggest challenges in organic vegetable production systems. Anerobic soil disinfestation (ASD) is an effective method to manage the weeds and soil borne pathogens in organic production systems. In ASD, a carbon source is added to soil followed by watering to saturation and covering with plastic mulch to create anerobic soil conditions. Rendered animal and treated manure products have significant content of plant nutrients and carbon and can serve both as organic fertilizer and carbon source for ASD. A field experiment was conducted using three different carbon sources meat and bone meal (MBM; rendering product), MBM Sulfur and treated manure solids with objective to evaluate the effect of different carbon sources and their application rates on nutrient management and ASD in organic watermelon under traditional and novel charter next generation plastic mulch. We will be evaluating the treatment effect on soil cumulative anaerobicity, percent weed coverage, yellow nutsedge rhizome viability, plant vigor ratings, shoot and root biomass, periodic nutrient leaching, soil nitrogen and phosphorus content, plant tissue nutrient content (root and shoot), soil pH, soil C, N and P mineralization enzymes and soil microbial biomass. In results, MBM with sulfur at 150% recorded the highest cumulative anaerobicity and low weed coverage suggesting that it could be an excellent tool for soil nutrient management and weed control in organic production system.

Speakers

Ashok Sah

Clemson University

I am a Ph.D. student working on anaerobic soil disinfestation (ASD) technique, its application for nutrient and weed management in horticultural crops (watermelon).

Co-authors

Anastasia Thayer

Clemson University

Bhupinder Jatana

Clemson University

Brian Ward

Clemson University CREC

Chandrasekar Kousik

USDA

Matthew Cutulle

Clemson

Wednesday July 30, 2025 10:30am - 10:45am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Funding Source USDA

10:30am CDT

PH 2 - Insights into the Postharvest Quality of Brassica Leafy Greens Grown in the Southeastern United States

Wednesday July 30, 2025 10:30am - 10:45am CDT

Strand 12B

Brassica leafy greens are important vegetable crops in the Southern United States, where they are commercialized in whole and fresh-cut formats. Their consumption is associated with health benefits as these crops are rich in bioactive compounds with antioxidant activity. Several factors contribute to the postharvest quality of Brassica leafy greens. Preharvest seasonal variations associated with environmental variables can have a significant influence on shelf-life and quality maintenance and have been reported in various Brassica species. The effect of postharvest temperature management and mechanical stress induced by fresh-cut processing has also proven to be critical in organoleptic and nutritional quality; however, none of these factors have been systematically studied in collards, kale and turnip greens. This project aimed to address this knowledge gap by investigating the postharvest performance of whole and fresh-cut kale, turnip greens and collards during storage at different temperatures (2, 5 and 7°C) for up to 28 days in two growing seasons (fall and winter-spring). Cooling delays after harvest were imposed on some experiments. We also characterized the shelf-life of commercial and traditional collards ('landraces') commonly grown in the Southeast. Organoleptic (color, marketability scores, total soluble solids) and compositional (total chlorophyll, carotenoids, total polyphenols, lycopene, vitamin C and ammonia contents) were monitored during postharvest storage. Results revealed there was significant quality variation in fresh-cut kale, collards and turnip greens, which could attributed to genotypic differences and preharvest factors in each growing season. High shelf-life variability among commercial collards and landraces was observed. Moreover, postharvest storage at abusive temperatures accelerated quality deterioration in fresh-cut collards to a greater extent than in whole leaves. Collectively, these findings highlight that adjusting postharvest practices to seasonal shelf-life variations can contribute to minimizing food losses and optimizing produce supply chain performance. Furthermore, postharvest temperature regimes are critical in influencing the visual quality and nutrient retention of whole and fresh-cut collards during storage.

Speakers

Karin Albornoz

Assistant professor, Clemson University

Co-authors

Zenaba Abdissa

Clemson University

Wednesday July 30, 2025 10:30am - 10:45am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source South Carolina Department of Agriculture, NIFA USDA

10:30am CDT

TCHG 1 - Exploring Artificial Intelligence Literacy Among Two-Year Horticulture Students

Wednesday July 30, 2025 10:30am - 10:45am CDT

Strand 11B

The integration of Artificial Intelligence (AI) tools in educational settings has transformed traditional teaching methods, offering enhanced personalization and efficiency. However, ensuring the safe and ethical use of AI among college-level learners remains a critical challenge, particularly in specialized fields like horticulture. This study explores the implementation of AI practices in the classroom with 15 two-year (associates degree) horticulture students, focusing on cultivating technical competence, ethical awareness, and industry relevance. Students were asked about their previous experience with AI and if they could detect which bodies of text were AI-generated versus human-generated. Students were then analyzed via an exercise by their ability to detect fact accuracy, depth of the topic, bias, and awareness of content ownership. Data was taken by observation and data collection. Results indicate that structured guidelines and instructor-led interventions significantly improve students' ability to responsibly use AI while understanding its limitations and potential biases. The study highlights the importance of embedding AI literacy within horticulture curricula to build student success of using the technology appropriately and fostering a culture of ethical AI utilization. These findings can be used to influence the introduction and usage of AI as a tool in two-year program horticulture curriculum.

Speakers

Melinda Knuth

North Carolina State University

Wednesday July 30, 2025 10:30am - 10:45am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

10:30am CDT

TECH - Sensing the Airborne Alerts of Arugula Grown Under Salt Stress Using Low-Cost MQ Gas Sensors

Wednesday July 30, 2025 10:30am - 10:45am CDT

Strand 11A

Real-time monitoring of crop health is pivotal for advancing precision agriculture, enabling timely interventions to mitigate abiotic stress impacts. This study presents a novel and non-destructive approach for detecting salt stress in hydroponically grown arugula (Eruca sativa L.) using low-cost MQ gas sensors. Arugula seedlings, 11 days post-germination, were transplanted to a deep-water culture (DWC) hydroponic system in the greenhouse facility of The Pennsylvania State University. Salt stress was induced 9 days after planting by supplementing a modified Hoagland nutrient solution with sodium chloride (NaCl) at three concentrations: 0 mM (control), 40 mM, and 80 mM. Electrical conductivity (EC), pH and temperature parameters were regularly monitored during the cultivation period. Three MQ gas sensors—MQ2, MQ135, and MQ137—were integrated into a dome-shaped enclosure positioned over individual net pots, each containing four plants. To achieve a comprehensive volatile organic compound (VOC) profile, sensor units were strategically positioned on multiple plants within each treatment group. A total of 144 plants per treatment were cultivated, and two sets of sensor units recorded VOC emissions for 8 consecutive days. Salt stress significantly influenced plant growth, with fresh weight (FW) and leaf area decreasing as salinity increased. The 80 mM treatment exhibited the lowest FW and leaf area (61.69 ± 2.7 g, p-value = 0.015; 1434.25 ± 58 cm², p-value = 0.003), followed by the 40 mM treatment. All three MQ sensor responses revealed distinct VOC emission patterns correlating with salt stress levels. These sensor outputs were leveraged to train three machine learning models—K-Nearest Neighbors (KNN), Support Vector Machine (SVM), and Random Forest—to classify stress-induced VOC signatures. Among these, the cubic KNN model demonstrated superior predictive performance, achieving 98.73% accuracy, 98.74% precision, 98.73% recall, and an F1 score of 0.98 for the test dataset. These findings underscore the potential of cost-effective MQ gas sensors for real-time, non-invasive stress detection in crops, offering a promising tool for precision agriculture and early stress diagnosis. The integration of VOC sensing with machine learning models provides a scalable solution for enhancing crop management strategies in controlled environments.

Speakers

Ali Ahmad

Pennsylvania State University

Co-authors

Francesco Di Gioia

Pennsylvania State University

Jaime Lloret Mauri

Universitat Politècnica de València

Sandra Sendra Compte

Universitat Politècnica de València

Wednesday July 30, 2025 10:30am - 10:45am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv
Funding Source This work was supported by the USDA-NIFA Specialty Crop Block Grants # C940001528 “Advancing the Sustainability of Indoor Urban Agricultural Systems”, the USDA-ARS Penn State Cooperative Agreement: 58‐6034‐3‐016 and by the Grant PRE2021-100809 funded by MICIU/AEI/10.13039/501100011033 and by European Social Fund Plus (ESF+). F. Di Gioia’s contribution was supported by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project no. PEN04723 and Accession no. 1020664.
Funding Option OREl or ORG funded all or part of the research associated with this abstract

10:30am CDT

VSF 1 - Drip Irrigation Strategies for Improved Blueberry Production in Substrate

Wednesday July 30, 2025 10:30am - 10:45am CDT

Foster 1

Substrate production in pots has emerged as a popular method for growing highbush blueberry (Vaccinium corymbosum). However, there is limited knowledge on the best strategies for irrigation in substrate. To address this issue, a multiyear study was conducted in a retractable-roof greenhouse using ‘Legacy’ blueberry to determine an optimal combination of drip emitters (two, four, or eight emitters per pot) and irrigation set point (-2 or -4 kPa) and frequency (a single continuous pulse of up to 45 minutes or short 3-minute pulses every 15 minutes to reach container capacity). The plants were grown in 25-L pots filled with a mix of peat, coir, and perlite. Tensiometers were installed horizontally into the center of the pots to monitor the matric potential and to determine when to trigger irrigation. Irrigation was triggered automatically using a data logger and applied until the pots reached container capacity determined by small weighing lysimeters. Yield was highest in plants with eight emitters in the second year (first year of fruit production), but this difference diminished in year 3. A similar relationship was observed for aboveground biomass. Root size was also highest with eight emitters. Leachate pH and EC were mostly similar among treatments, but EC was more uniform throughout the pot with eight emitters. In contrast, the lower set point and shorter irrigation frequency decreased the ability of the pots to reach container capacity, particularly when the plants were irrigated with only two emitters per pot. Overall, the plants grew best when irrigation was triggered at -2 kPa and applied in single continuous pulses with four or eight emitters per pot.

Speakers

Scott Orr

Oregon State University

Co-authors

Camilo Souto

Universidad de Concepción

Cora Bobo-Shisler

Oregon State University

David Bryla

USDA

Wednesday July 30, 2025 10:30am - 10:45am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits
Poster # csv

10:45am CDT

FRBR 1 - AI-optimized Strawberry Breeding in Florida

Wednesday July 30, 2025 10:45am - 11:00am CDT

Strand 12A

Plant breeding is a lengthy and demanding research. Traditional strawberry breeding requires many man-hours to manually measure plant characteristics, record data, and evaluate various desired traits. Also, human biases and prior perceptions or expectations can play a role in skewing the results. Thus, the plant breeding program at the University of Florida has developed AI tools to assist in different stages of breeding research. Developed AI models have offered accurate and quick data analysis to identify and quantify plant phenome (anatomical characteristics and traits). This reduction in the number of manhours to manually measure, record data, and perform destructive sampling, has greatly increased the ability to screen more breeding lines with fewer resources (time, plants, and money). These AI models can accurately with a high level of consistency measure the size of plant canopy, flowers, runners, and fruit maturity repeatedly throughout the season to create an individual profile of each tested breeding line. Five YOLOv8 based (computer vision) models were trained for strawberry runner detection including GI, UL-AI, SL-AI, Hybrid I (GI SL-AI), and Hybrid II (GI SL-AI UL-AI). Hybrid II model achieved 91% precision accuracy and 83% mAP50 (mean average precision at IoU of 50%). The use of AI image and video analysis has been reducing the time and resources needed to develop new varieties.

Speakers

Wael Elwakil

Extension Agent II, University of Florida

Co-authors

Xu Wang

University of Florida

Xue Zhou

University of Florida

Wednesday July 30, 2025 10:45am - 11:00am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Poster # csv

10:45am CDT

ORGH 1 - Short-Term Effects of Organic Cover Crops on Macronutrient Cycling and Soil Properties

Wednesday July 30, 2025 10:45am - 11:00am CDT

Foster 2

This study presents the evaluation of ten organic cover crops on soil fertility and macronutrient accumulation within their biomass. Field trials were conducted at the organic farm of Tennessee State University using a randomized complete block design with four replications under National Organic Program (NOP) management practices. The cover crops assessed includes barley, crimson clover, daikon radish, field peas, hairy vetch, mammoth red clover, medium red clover, tillage radish, white clover, and winter rye. Each plot measured 16 ft x 7 ft within a whole plot size of 190 ft x 63 ft. Cover crops were sown using a seed drill, adhering to USDA and SARE recommended seed rates. Soil Samples were collected at a foot depth both before and after cover crops termination to analyze the variations in soil properties such as pH, phosphorus, potassium, calcium, magnesium, zinc, iron, manganese, boron, sodium, and organic matter. Aboveground biomass was clipped from 1ft2 quadrants across all replications, dried at 60oC for 72 hours. Samples were grinded to a fine powder using a 1100-watt Ninja blender and analyzed for nitrogen and carbon content using Near-Infrared Spectroscopy (NIRS). Results indicated that most of the cover crops increased soil organic matter, phosphorus, sodium, magnesium, and iron. In contrast, declines were observed in soil pH, potassium, manganese, calcium, boron, zinc. Significant differences were observed in the nitrogen and carbon accumulation among cover crops. Hairy vetch showed the highest nitrogen (4.24%) and carbon (46.62%) content, while barley and daikon radish had the lowest nitrogen (1.55%) and carbon (40.66%) content, respectively. The carbon to nitrogen (C:N) ratio ranged from 11:1 to 30.1:1, with legumes generally exhibiting lower ratios (11:1 to 15.3:1) demonstrating higher decomposition and quicker nutrient release. In contrast non-legumes had the higher ratios (25.4:1 to 30.1:1), suggesting slower nutrient release. These findings highlight the short-term impacts of different organic cover crops on soil fertility and nutrient cycling. The variation in macronutrient accumulation and C:N ratios provides practical insights for the growers in selecting appropriate cover crops to enhance soil health and support sustainable agricultural systems.

Speakers

Sai Prakash Naroju

Tennessee State University

Co-authors

Dilip Nandwani

Tennessee State University

Shahidullah Chowdhury

Tennessee State University

Wednesday July 30, 2025 10:45am - 11:00am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Funding Source TSU Co-Operative Extension

10:45am CDT

PH 2 - Lettuce Postharvest Quality in Response to The Increase of Phosphorus Fertilizer

Wednesday July 30, 2025 10:45am - 11:00am CDT

Strand 12B

Florida ranks third in the United States for lettuce production with approximately 90% of commercial lettuce cultivated on organic soils in southern Florida. These organic soils require phosphorus (P) inputs to sustain economic production and ensure lettuce shelf-life. Lettuce shelf-life depends on quality factors such as firmness, appearance, color, texture, decay, discoloration, and wilting. Optimal P fertilizer management is necessary to improve yield, market quality, and ensure postharvest quality (shelf-life). Over-fertilization can reduce quality, while deficiencies can limit yield and shelf life. Therefore, the objective of this research was to understand how different rates of P affect the lettuce shelf-life across four cultivated morphological types. Two field trials were conducted at the Everglades Research and Education Center in Belle Glade, FL, during the lettuce growing seasons (spring, fall, and winter). Experiments were set as a split-plot designed in which P fertilizer rates (0, 48, 97, 150, 195, and 210 lbs P2O5 acre-1) were considered as the main plot and four lettuce types (romaine, iceberg, butterhead, and leaf) as the subplot. Ammonium polyphosphate (11-37-0) was used as the source of P fertilizer. Shelf-life was evaluated over 10 days at 15 °C and 90% RH using visual ratings of 9 (excellent) to 1 (poor) following the protocol for an accelerated shelf-life testing. The estimated shelf-life was considered as the number of days when lettuce reached an acceptable appearance on the rating scale of ≥5 and multiplied by a factor of 2 (2-fold factor proportional to the deterioration rate). The results indicate varying responses to P fertilizer application in shelf-life that were significantly morphological-type dependent. Overall, leaf lettuce had the shortest shelf-life and iceberg lettuce had the longest shelf-life. Butterhead had an acceptable estimated shelf-life rating of 5 at 24 days at 210 lbs. P2O5 acre-1 while romaine and leaf had a shelf-life rating of 5 at 22 and 21 days at 210 lbs. P2O5 acre-1, respectively. In addition, crisphead had an acceptable estimated shelf-life rating of 5 above 35 days at 150 lbs. P2O5 acre-1. However, an acceptable shelf-life was maintained at 48, 150, or 195 lbs. P2O5 acre-1 in iceberg lettuce over 30 days. Together these results demonstrate that there is no effect of increasing the rate of P2O5 acre-1 to maintain economic yields on the lettuce shelf-life. Rather, shelf-life quality increases with P inputs.

Speakers

German Sandoya Miranda

Associate Professor, University of Florida EREC

Co-authors

Adrian Berry

University of Florida

Jairo Arcos Jaramilo

University of Florida EREC

Jesse Murray

University of Florida EREC

Shabnam Sadeghibaniani

University of Florida EREC

Steven Sargent

University of Florida/IFAS

Professor and Extension Postharvest Specialist

Wednesday July 30, 2025 10:45am - 11:00am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv

10:45am CDT

TCHG 1 - Integrating Virtual Reality Application in an Online Plant Propagation Course to Increase Comprehension

Wednesday July 30, 2025 10:45am - 11:00am CDT

Strand 11B

There has been increased interest in Virtual Reality (VR) applications in academic settings. Instructors aim to create and enhance tangible experiences for students in their courses, especially for online classes. These VR applications can be of significant interest for horticulture courses, considering many core curriculum courses include laboratory or hands-on learning components. Including VR applications for online students to experience these activities has the potential to increase engagement and learning outcomes. Feedback from students in the online HORT 260 Plant Propagation course at Colorado State University indicated accessibility challenges with materials and the ability to successfully execute course assignments taught online. More specifically, they noted the unit on greenhouse mist systems was not as comprehensive or tangible as they needed to complete an assignment on designing mist systems. With this in mind, we developed a VR mist system media component for the course using ThingLink software and annotated 360° images. For our study, students received static, annotated images in a PowerPoint presentation and the VR 360° images which the students could review. Assessment quizzes were created with one pertaining to the static images and the second to the VR 360° images. Five questions in each quiz were identical and asked about mist system concepts, and each quiz had 2 to 3 questions about the ability to understand concepts using the media. The second quiz also asked students to compare the two approaches, their general experience with VR in the classroom, and an open-ended feedback question. In total, 47 students participated between the Spring 2024 (n=7) and Fall 2024 (n=40) semesters. The questions included in both surveys did not yield statistical differences when their answers were compared. When asked about their perceptions of VR material, 66% of the respondents indicated that the VR material made concepts easier to visualize. Students were surveyed about their overall use and experience with VR in the classroom. Of the respondents, 42% had experienced VR before and 81% indicated they would like more VR material incorporated into the curriculum. Additionally, common themes were observed in the open-ended responses, including the desire for further improvement of VR material, an appreciation for increased visibility of concepts, and the desire for access to many forms of media like VR videos. Considering students’ perceived comprehension and confidence in the course concepts, further VR implementation in the course would be a worthwhile pursuit.

Speakers

Makenzie Lee

Colorado State University

Co-authors

Amy Lentz

Colorado State University

Chad T. Miller

Colorado State University

Wednesday July 30, 2025 10:45am - 11:00am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

10:45am CDT

TECH - Feasibility of Small- and Urban-Farm Agrivoltaics: Integrating Solar Energy Production with Specialty Crop Production

Wednesday July 30, 2025 10:45am - 11:00am CDT

Strand 11A

Land use is a major concern for our society, which impacts governmental regulations, industry and agriculture, and individual property owners. Agrivoltaics (APV) includes the combination of agriculture and photovoltaics energy production on a single plot of land. APV has been proposed as a way to integrate agriculture into large-scale photovoltaic arrays or integrate energy production into established agricultural operations. The objectives of this project were to establish replicated APV research trials with fixed vertical panel photovoltaic arrays and investigate the feasibility of growing various warm- and cool-season crops between them. Warm-season crops included tomato, watermelon, bush bean, and zucchini. Cool-season crops included fall-planted lettuce and beets as well as spring-planted spinach and lettuce. Vertical panels were constructed with four replications that examined systems effects of APV compared to the open-field. A split-plot randomized complete block design was utilized, whereby main plots included system and sub-plots were the crops. For each crop, yield, marketability, quality, and economic data were collected. Crop quality parameters tested included: visual quality, color, firmness, titratable acidity, and total soluble solids. Additionally, PAR sensors were located within crop rows to characterize light availability at the replicated site as well as at another solar array. Sensors were placed approximately 2.5’ above the ground surface to generally mimic mature plant canopy height, transversely across the expected light-treatment area. From the first year of study, similarities among the two systems (APV and open-field) were more numerous than significant differences. Only one statistically-significant treatment effect was found on crop yield, among one of two lettuce varieties grown in the fall (P

Speakers

Alex Thill

Kansas State University Olathe

Co-authors

Cary Rivard

Kansas State University

Eleni Pliakoni

Kansas State University

George Yang

Kansas State University

Logan Britton

Kansas State University

Wednesday July 30, 2025 10:45am - 11:00am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Funding Source KSU GRIP Project

10:45am CDT

VSF 1 - Dissecting the Flower Bud Initiation and Dormancy Responses of Everbearing Blueberry Genotypes

Wednesday July 30, 2025 10:45am - 11:00am CDT

Foster 1

Day length and temperature interactively influence flower bud initiation in blueberry (Vaccinium corymbosum interspecific hybrids) plants. When days are short and temperatures are low, blueberry plants initiate flower buds rather than vegetative buds. Night interruption and/or warmer temperatures limit flower bud initiation. Once differentiated, flower buds enter endodormancy, restricting reproductive development to specific times of the year. Some genotypes in the University of Florida Blueberry Breeding and Genomics program have been observed to bloom in the middle of the summer under long days and warm temperatures. To investigate this phenomenon, we conducted a controlled-environment experiment to assess flower bud initiation and dormancy responses in a summer-blooming genotype, ‘FL16-64’, compared to the standard southern highbush cultivar ‘Arcadia’. Plants were grown in growth chambers with factorial combinations of temperature and photoperiod treatments. Temperature regimes mimicked Florida field conditions: warm (28 °C day / 20 °C night) and cool (18 °C day / 10 °C night). Photoperiods included short (8 hours), neutral (12 hours), long (16 hours), and interrupted (8 hours 1 hour of night interruption) day lengths. There were 6 plants of each genotype per temperature-photoperiod combination. Results showed that warm temperatures promoted vegetative growth in both genotypes. ‘Arcadia’ developed flower buds primarily under short days and cool temperatures, and these buds entered endodormancy after differentiation. In contrast, ‘FL16-64’ initiated flower buds across all temperature and photoperiod treatments. Moreover, flower bud development was enhanced under warmer temperatures and neutral day lengths. Notably, these buds bypassed dormancy and progressed directly to bloom. These findings indicate that ‘FL16-64’ exhibits day-neutral flower bud initiation and some of its flower buds lack endodormancy, characteristics consistent with an everbearing growth habit. Everbearing blueberry genotypes could be used to produce blueberries during the domestic off season in Florida.

Speakers

Gerardo Nunez

University of Florida

Co-authors

Patricio Munoz

University of Florida

Sarah da Silva Benevenute

University of Florida

Wednesday July 30, 2025 10:45am - 11:00am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 1

Subject Viticulture and Small Fruits
Poster # csv
Funding Source Florida Department of Agriculture and Consumer Services (Contract# 28699)

11:00am CDT

FRBR 1 - Prevalence of powdery mildew in greenhouse production of strawberry

Wednesday July 30, 2025 11:00am - 11:15am CDT

Strand 12A

Powdery mildew (PM) is a significant fungal disease in controlled environment horticulture (CEH). PM damages are increasingly being reported in fungicide-untreated and late planted open fields. Both field and protected systems in the major production regions of the world are facing heightened challenges due to the increasing disease occurrences. While PM has been efficiently managed by spraying chemical fungicides in field production, frequent use increases the risk of resistance development in pathogens. Additionally, fungicidal sprays may not be feasible to all CEH farms due to infrastructural restrictions or organic mode of production. The expansion of CEH production in Texas has created opportunities to extend strawberry cultivation from coastal regions to inland areas. However, PM management needs to be addressed given the conducive growing conditions in CEH. To study the prevalence of the disease, we evaluated 24 and 12 strawberry accessions arranged in a completely randomized design in two replications in the greenhouse and growth room conditions, respectively. In the absence of fungicide treatments, natural infections led to PM development within two weeks after transplanting. Disease ratings revealed incidence rates of 72% in the growth chamber and 49% in the greenhouse. The correlation between the two replications was 0.88 and 0.87, respectively. Accessions that exhibited little to no PM symptoms may be valuable for understanding host resistance mechanisms and could be utilized in breeding resistant cultivars in the future.

Speakers

Krishna Bhattarai

Texas A

Wednesday July 30, 2025 11:00am - 11:15am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Funding Source Multistate Hatch Project 7001-0-MSH-DALL & Hatch Project 8483-0-H-DALL

11:00am CDT

ORGH 1 - Biostimulants to complement organic fertilizers in organic transplant production

Wednesday July 30, 2025 11:00am - 11:15am CDT

Foster 2

The increasing demand for sustainable agricultural practices has driven the adoption of organic farming and increased demand for organic transplants. However, transplant growth is often lower in organic fertilizers compared to conventional fertilizers. This is most likely caused by low nutrient availability in organic fertilizers. On the other hand, increasing organic application rates has the potential to induce salinity stress/toxicity. We hypothesize that biostimulants can complement organic fertilizers in crop production by enhancing nutrient uptake and increasing crop tolerance to abiotic stress and thus close the yield gap between organic and conventional fertilizers. In this study, we tested three biostimulants: humic acid and molasses (MicroLife Soil and Plant Energy) and two microbial based biostimulants with different beneficial microorganism populations (MicroGrow CM and MicroGrow Supreme). Four organic fertilizers were tested with biostimulants, two of which were animal-based fertilizers: Sustane (4-6-4, turkey manure) and Drammatic (2-4-1, derived from fish scrap) and two of which were plant-based fertilizers: Nature Safe (7-7-7, corn steep liquor) and Pre-Empt (fermented sugarcane molasses). After applying to peat-based substrate, we analyzed the leachate nutrient availability weekly. Both fertilizer and biostimulant affected available nutrient concentrations in substrate. Additionally, transplant performance was evaluated to determine the effect of biostimulant and organic fertilizer combination on transplant growth, mineral nutrition, and physiological responses. Transplant growth varied across the different combinations of biostimulants and organic fertilizers tested, suggesting potential interactions between these factors. Some biostimulant treatments, particularly in combination with specific organic fertilizers, showed a trend towards improved early growth compared to the organic fertilizers alone. These results showed synergistical effects between biostimulants and organic fertilizers, indicating the positive role of biostimulants in organic transplant production.

Speakers

Jun Liu

Texas A

Co-authors

Genhua Niu

Texas A

Joseph G. Masabni

Texas A

Wednesday July 30, 2025 11:00am - 11:15am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Funding Source Specialty Crop Multi-State Program grant TX-SCM-21-05, Hatch Project TEX07726, and Specialty Crop Block Grant GSC2022030.

11:00am CDT

PH 2 - Fruit Maturity Highly Affects Controlling Necrotic Peel Disorders By Mediating Major Metabolisms in Cold-stored Hardy Kiwifruit (Actinidia arguta)

Wednesday July 30, 2025 11:00am - 11:15am CDT

Strand 12B

The incidence of necrotic peel disorders during cold storage is a severe CI symptom observed in hardy kiwifruit, impacting fruit visual quality. This study focuses on understanding the mechanisms of necrotic peel disorder in ‘Daebo’ hardy kiwifruit cultivar during cold storage. This research aimed to investigate the effects of different soluble solids content (SSC)-based fruit maturity at harvest on the severity of peel disorder after storage and to present the associated biochemical alteration using integrated transcriptomic, antioxidant, and lipidomic analyses. The fruit of ‘Daebo’ hardy kiwifruit cultivar harvested at various SSC levels, including 5.5%, 6.1%, and 7.2%, were cold-stored for upto four weeks. Fruit harvested at 5.5% SSC exhibited the highest severity of necrotic peel disorder, accompanied by significant weight loss and elevated reactive oxygen species (ROS) levels. The enhanced activities of antioxidant scavenging enzymes, such as superoxide dismutase and ascorbate peroxidase, were observed, indicating the response of fruit to oxidative stress. However, lower enzymatic activities of dehydroascorbate reductase and glutathione reductase were insufficient to restore the ascorbic acid-glutathione cycle. In contrast, the 7.2% SSC fruit contained higher concentrations of phenolic compounds, suggesting their role as natural antioxidants in mitigating oxidative damage. Additionally, lipid analysis revealed increased levels of phosphatidylcholine and fatty acids during fruit maturation, which are crucial for membrane stability. Notably, the differences in phosphatidic acid concentrations between SSC levels indicated its potential role in ROS scavenging. Overall, this study elucidates the biochemical mechanisms contributing to necrotic peel disorder in hardy kiwifruit during cold storage, highlighting the importance of SSC at harvest in managing fruit quality. These findings can comprehensively understand necrotic peel disorder and fruit maturity in hardy kiwifruit.

Speakers

Hyowon Park

Chung-Ang University

Co-authors

Jinwook Lee

Chung-Ang University

Uk Lee

National Institute of Forest Science

Yonghyun Kim

National Institute of Forest Science

Wednesday July 30, 2025 11:00am - 11:15am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Funding Source This work was financially supported by a grant (Grant Number FP0802-2022-02-2025) from the National Institute of Forest Science (NIFoS) in the Republic of Korea.

11:00am CDT

TCHG 1 - Generative AI in the online classroom: lessons from a plant physiology course

Wednesday July 30, 2025 11:00am - 11:15am CDT

Strand 11B

Generative AI has the potential to transform instruction, especially in the online environment. As technology continues to change the educational paradigms we have been accustomed to, we need to understand how students utilize AI in the classroom. We describe results from self-reported student surveys in an online plant physiology course. Students could use AI or not to complete their work, however, regardless they had to report after each assignment. The discussions and lab reports are part of the course’s normal assessment activities. Additionally, students reported the time spent completing the assignment, and wrote a summary to include: (1) how did AI help you complete the assignment? (2) What did you do to revise or further improve it? (3) Did you cross-check the AI-generated information, i.e. factual and references? Of the AI tools students reported using, ChatGPT was used most (80%), followed by CoPilot, Gemini, and Google image search. The most common reason for AI use was to help with concept understanding (43%), followed by draft a script or outline (17%), proofreading and improve writing (11%), generate ideas (8%), and identify plants (5%). In fewer than 1% of the cases, students reported that AI helped them with troubleshooting. Students cross-checked the AI-generated information 76% of the time. There was no significant difference in time spent completing an assignment between students who reported that they used AI compared to the ones that did not use AI. Implementation of any new tool in education requires thoughtful planning, consideration, and support. Schools and educational institutions should provide robust training programs to equip teachers with the necessary skills and knowledge to use AI tools effectively and confidently. This guidance should include not only the technical aspects, but also ethical considerations, potential limitations, and best practices to integrate it into their instruction methodology.

Speakers

Svoboda Pennisi

University of Georgia

Co-authors

Christy Rich

University of Georgia

Dan Ye

Michigan Technological University

David Jespersen

University of Georgia

Wednesday July 30, 2025 11:00am - 11:15am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

11:00am CDT

TECH - A Graph Convolutional Network Approach for Hyperspectral Image Analysis of Blueberries Physiological Parameters Under Drought Stress

Wednesday July 30, 2025 11:00am - 11:15am CDT

Strand 11A

Blueberries are extremely susceptible to drought due to their shallow root systems and limited water regulation capabilities. Climate change exacerbates drought stress in major blueberry production regions, which affect key physiological traits, such as leaf water content (LWC), photosynthesis (A), stomatal conductance (gs), electron transport rate (ETR), photosystem II efficiency (φPSII) and transpiration rate (E). Current phenotyping methods for measuring these physiological traits are time-consuming and labor-intensive as well as limited by the need for specialized equipment. To address this, a high-throughput phenotyping (HTPP) platform integrated with hyperspectral camera and a novel graph convolutional network (GCN)-based model, Plant-GCN, was developed to predict physiological traits of blueberry plants under drought stress. Spectral reflectance obtained from the hyperspectral images were transformed into a graph representation, with each plant represented as a node, spectral reflectance as node features, and edges defined by spectral similarities. The Plant-GCN model utilizes graph convolutional layers that aggregate information from neighboring nodes, effectively capturing complex interactions in the spectral signature and enhancing the prediction of physiological traits. Plant-GCN achieved a coefficient of determination (R²) of 0.89 for LWC, 0.94 for A, 0.89 for gs, 0.92 for ETR, 0.93 for φPSII and 0.89 for E on the test dataset. The performance of the proposed Plant-GCN model was compared with multilayer perceptron (MLP), partial least squares regression (PLSR), support vector regression (SVR), and random forest (RF), and it consistently outperformed all these models as well as data published in other reports. The high-throughput phenotyping system enabled efficient large-scale data collection, while the Plant-GCN model captured long-range spectral relationships significantly improved the prediction of physiological traits. The high predictability of the models could facilitate the screening of blue-berry cultivars for the specified traits allowing the selection and breeding of new drought tolerant cultivars in the future.

Speakers

Md Hasibur Rahman

Auburn University

Co-authors

Tanzeel Rehman

AUBURN UNIVERSITY

Wednesday July 30, 2025 11:00am - 11:15am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv

11:15am CDT

CITR 2 - Nutrient Management and Rootstock Performance Enhance Nutrient Uptake, Tree Growth and Development, and Fuit Yield and Postharvest Fruit Quality of Sweet Orange

Wednesday July 30, 2025 11:15am - 11:30am CDT

Foster 1

Crop protection measures, cultural practices, nutrient and irrigation management, rootstock selection, and other studies have been conducted to alleviate the devastating bacterial disease of huanglongbing (HLB, aka citrus greening) in recent years. However, there is no single cure for HLB caused by Candidatus Liberibacter asiaticus, which is spread by the Asian citrus psyllid, Diaphorina citri Kuwayama. The objectives of the study were to assess whether tree growth, soil and leaf tissue nutrient concentrations, fruit yield, and postharvest quality can be improved through improved nutrient management using selected rootstocks. The study was conducted on ‘Hamlin’ citrus trees [Citrus sinensis (L.) Osbeck] budded on Cleopatra mandarin (Citrus reshni) or Swingle rootstocks [Citrus paradisi Macf. Poncirus trifoliata (L.) Raf.] from 2019 – 2021. The study was conducted in a split plot design with two rootstocks as main plots, three nitrogen rates (168, 224, and 280 kg ha-1) as sub-plots, and secondary macronutrients (control, Ca or Mg-thiosulfates at 45 kg ha-1 each, and a combination of Ca and Mg at 22.5 kg ha-1 each) replicated four times. Results indicated that soil ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N) were significantly accumulated in an oscillating (between spring and summer seasons) pattern for soil NH4-N and persistent accumulation of NO3-N on both rootstocks. Leaf Ca and Mg nutrient concentrations were significantly greater in Cleopatra than Swingle rootstocks. Trees on Swingle rootstocks react greater than those on Cleopatra rootstocks. Control trees had a lower LAI than those that received either Ca and/or Mg treatments, and the impact is significantly prevalent on Swingle than on Cleopatra rootstocks. Trees on Cleopatra had greater canopy volumes than Swingle rootstocks. However, the impact of secondary macronutrients manifested only after the third year of the study. Fruit yield significantly increased with a magnitude of 1.8× in the trees that received combined Ca and Mg treatments than a control tree. Greater fruit total soluble solids were detected in trees that received Mg or combined Ca and Mg treatments. Hence, nutrient management can enhance tree growth, fruit yield, and postharvest quality and can be used as an immediate solution until the HLB can be permanently eradicated.

Speakers

Alisheikh Atta

University of Florida

Alisheikh Atta currently works at the Department of Soil, Water, and Ecosystem Science, University of Florida. Alisheikh does research on HLB-affected citrus nutrient and water management. He studies the impact of plant nutrients on the performance of citrus trees, irrigation water... Read More →

Co-authors

Davie kadyampakeni

University of Florida

Kelly Morgan

University of Florida

Mark Ritenour

University of Florida

Wednesday July 30, 2025 11:15am - 11:30am CDT
Foster 1

Oral presentation, Citrus Crops 2

Subject Citrus Crops
Poster # csv

11:15am CDT

FRBR 1 - Machine Vision for Detecting and Quantifying Fruits and Flowers to Evaluate Concentrated Fruit Set in Tomato

Wednesday July 30, 2025 11:15am - 11:30am CDT

Strand 12A

Fresh market tomato is one of the most valuable crops in the US. However, production relies heavily on manual labor, which can account for over 30% of the total per-acre cost, with a large portion attributed to harvesting. In the southeast US, most tomato plants are staked and tied, and fruit are hand-harvested multiple times as they mature, increasing labor costs and operational inefficiencies. Compact Growth Habit (CGH) tomato varieties have a shorter stature that does not need to be staked and allow for more labor-efficient harvesting options, providing a promising alternative to traditional production. A key breeding objective for CGH tomato is to develop lines with a more concentrated fruit set (CFS), defined as a higher proportion of fruits reaching maturity synchronously. This trait would enable once-over harvesting, substantially reducing labor inputs while improving operational efficiency. Furthermore, the successful implementation of once-over harvest strategies in CGH tomatoes may facilitate the adoption of mechanized harvesting systems, addressing labor shortages and enhancing scalability in fresh market tomato production. This study aims to develop a computer vision model to automate detecting and quantifying tomato fruits and flowers in CGH breeding trials. High-resolution RGB images of top-view canopies were collected from experimental plots during the spring and fall seasons of 2024, capturing phenotypic variability across diverse environmental conditions and growth stages. The dataset is undergoing preprocessing, annotation, and augmentation to enhance model robustness. A YOLO-based object detection model will be trained to classify and quantify flowers and fruits. Model performance will be assessed using standard evaluation metrics, including precision, recall, and F1-score. By accurately detecting and quantifying fruits and flowers across developmental stages, this system will enable breeders to analyze flowering progression and identify CGH tomato lines with improved CFS, supporting the selection of varieties optimized for once-over harvesting. Preliminary model training using 1,370 training images, 116 validation images, and 335 test images in roboflow using YOLOv11 yielded promising results, with a mAP@50 of 94.7%, precision of 85.1%, and recall of 91.0%, demonstrating the model's potential to support phenotyping for concentrated fruit set. Future research will focus on enhancing detection accuracy, expanding dataset diversity, and integrating multispectral imaging techniques to optimize model performance and applicability across different environments.

Speakers

Shubham Singh

University of Florida

Co-authors

Daeun Choi

University of Florida

Jessica Chitwood-Brown

University of Florida

Xu Wang

University of Florida

Wednesday July 30, 2025 11:15am - 11:30am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Poster # csv

11:15am CDT

ORGH 1 - Long-term Application of Animal and Forest Waste on a Vineyard and its Effect on Yield and Soil Health

Wednesday July 30, 2025 11:15am - 11:30am CDT

Foster 2

Increased concerns over the last several decades on environmental quality have stimulated farmers to accept organic farming as an alternative to inorganic agriculture. Muscadine (Vitis rotundifolia var. Summit) is native to the southeastern United States and has been cultivated for over 400 years. Muscadine and its products are highly nutritious and a good source of antioxidants and dietary fiber that have positive effects on health. Muscadine was grown on Memphis Silt Loam soil (Typic Hapludalph, silty, mixed, thermic). Three treatments of organic manures (cow-C; poultry-P; cow poultry-CP) with gypsum and pine mulch were applied in a CRD. Control received inorganic fertilizers and traditional cultural practices. Dolomitic lime was applied every 2 to 3 years to balance the soil pH of the soil and the pine needle was continuously applied as a thick mulch to bring down the soil pH to neutral and also to prevent moisture evaporation from basins where fresh animal waste was applied. This thick layer of pine needle mulch helped avoid irrigation even during the hottest summer. While strictly following the protocol, soil samples were collected and analyzed at Cornell Soil Health Lab, Cornell University, Ithaca, NY, after 17 years of continuous organic research with the same treatments. The experimental design for data analysis was a completely randomized design with three replications for each treatment. Leaf area index (LAI), percent canopy cover, stem diameter, and yield were higher in organic plants. There was no significant difference in diameter, length, and degree brix of the fruit. Soil compaction was always higher in control with lower soil moisture content and the compaction was lower in organic treatments due to higher level of organic matter content. Concentrations of nitrate-N and P were higher in the surface soil treated with organic manures, but there was no trend in N or P enrichment in the lower layers of the soil. A comprehensive assessment of soil health done by Cornell Soil Health Lab showed the following: physical aggregate stability 19.0 25, biological organic matter 4.0 85, biological ACE soil protein index 6.8 43, biological soil respiration 0.8 75, biological active carbon 747 90 and chemical soil pH 7.1 100 with an overall quality score of 72 (Excellent). The results suggest that the controlled application of animal and forest wastes in basins of fruit trees can be an agronomically and environmentally sound practice to increase yield and keep the soil and humans healthy.

Speakers

Girish Panicker

Alcorn State University

Dr. Girish Kumar Panicker, Professor of Plant and Soil Sciences and Director of Conservation Research, at Alcorn State University, Mississippi, is an authority on cover and management (C-factor) research on horticultural crops and is an internationally renowned agricultural scientist... Read More →

Co-authors

Willie Mims

Alcorn State University

Wednesday July 30, 2025 11:15am - 11:30am CDT
Foster 2

Oral presentation, Organic Horticulture 1

Subject Organic
Funding Source USDA/NIFA

11:15am CDT

PH 2- Investigate the Molecular Mechanisms of Postharvest Senescence in Vegetables

Wednesday July 30, 2025 11:15am - 11:30am CDT

Strand 12B

Postharvest longevity of perishable produce remains a challenge in the global fresh market supply chain. Postharvest longevity is determined by the rates of ripening and senescence, which are influenced by harvest time and storage conditions. Ripening and senescence are predominantly regulated by ethylene, which produces a plethora of metabolic effects within the harvested produce, leading to physiological and developmental changes during postharvest. Broccoli (Brassica oleracea L. var. italica) are prone to yellowing and wilting due to the relatively high respiration rate and tissue senescence during postharvest handling, transportation, and storage, which greatly affects the quality and reduces market value that led to the problem of food waste and loss. Broccoli florets treated with hydrocooling, 1-MCP (ethylene inhibitor) and controlled atmosphere (CA) can delay the senescence. However, little is known about the mechanisms on how those treatments worked at the molecular level. Here, we combined a physiological, biochemical, and genomics analyses on the postharvest broccoli and identified a core gene regulatory network governing senescence-associated developmental events, ethylene-regulated signaling pathways, and activation of stress responses. Additionally, we developed genome-editing toolkits by CRISPR/Cas9 system to understand deterioration of broccoli as well as through machine learning approaches to aid development of an innovative and easy-to-use accessibility tool to accurately estimate the freshness of produce. The findings give insights into ethylene biosynthesis and signal transduction at the tissue-specific level in broccoli and provide guidance on how to extend broccoli shelf life and reduce its economic losses, which also generate genetics and molecular recourses for marker-assistant breeding and expand the general scientific knowledge of regulating senescence of Brassicaceae family.

Speakers

Tie Liu

University of Florida

Wednesday July 30, 2025 11:15am - 11:30am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv

11:15am CDT

TCHG 1 - Beyond Plant Knowledge: Cultivating Soft Skills through International Horticulture Experiences

Wednesday July 30, 2025 11:15am - 11:30am CDT

Strand 11B

As horticulture careers increasingly demand adaptability, communication, and cross-cultural understanding, developing soft skills is essential for preparing future professionals. This study examined how participation in a faculty-led horticulture study abroad program influenced student growth in interpersonal and professional competencies. The program, Flowers and Photography in Europe, combined visits to botanical gardens, public green spaces, and production facilities across Spain, France, and Italy. Students engaged in group travel, horticultural site visits, and guided cultural immersion while completing reflective prompts centered on navigating unfamiliar environments and understanding cultural perspectives. Pre- and post-program surveys assessed student confidence in these areas, while reflective writing provided qualitative insights. Results indicated that navigating diverse environments and interpreting horticultural practices abroad fostered stronger communication skills, cultural awareness, and confidence in professional interactions. Students also reported greater appreciation for the social role of horticulture in global settings. These findings suggest that integrating intentional reflection into experiential learning abroad can help students connect horticultural content with essential career skills, offering a well-rounded model for global horticulture education.

Speakers

Julie Campbell

University of Georgia

Co-authors

Jessica Holt

The University of Georgia

Wednesday July 30, 2025 11:15am - 11:30am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv
Funding Source Association of Public and Land-Grant University's Academic Programs Section - Innovative Teaching Award

11:15am CDT

TECH - Advanced Spatio-Temporal Modeling for Bacterial Leaf Scorch Disease Scouting in Pecan Orchards

Wednesday July 30, 2025 11:15am - 11:30am CDT

Strand 11A

Bacterial leaf scorch is a harmful disease for pecan production, which can cause premature canopy defoliation, reduced kernel weight, and significant yield losses. The disease can cause a 10-13% reduction in shell nut weight and a 14-19% decrease in kernel weight, adversely affecting the quality and quantity of pecan yields. Early detection and precise management are important for minimizing economic losses and sustainable disease management. Current methods, such as manual scouting and conventional imaging, are inadequate for pecan orchards due to the trees' height and their inability to capture temporal changes or disease transmission patterns. Spatio-temporal modeling is a useful technique that enables tracking disease spread across time and location, identifying hotspots and transmission patterns to prioritize areas needing urgent intervention. This study aimed to develop a spatio-temporal model to visualize and evaluate the progression of bacterial leaf scorch disease in pecan orchards. High-resolution multispectral images of pecan trees were collected using a drone- mounted multispectral camera. A 3D point cloud was generated using Pix4D to create a reference NIR point cloud, and other vegetation indices point clouds were then aligned to provide sufficient data for model training. Ten vegetation indices, including the Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Normalized Difference Red Edge Index (NDRE), Modified Red Edge Simple Ratio (MRESR), Enhanced Vegetation Index (EVI), Soil-Adjusted Vegetation Index (SAVI), Optimized Soil-Adjusted Vegetation Index (OSAVI), Atmospherically Resistant Vegetation Index (ARVI), Chlorophyll Index - Red Edge (CI_RE), and Simple Ratio Index (SR), were used to evaluate disease sensitivity. Individual tree canopies were segmented using the 3D DBSCAN algorithm for each index. A point transformer deep learning model was trained with 3D vegetation indices of each tree with the ground truth to develop the prediction ability of the model for classifying individual each tree disease severity level. The early results indicate that the model can classify disease severity in the 3D point clouds, capturing the disease stress in the individual tree. Additionally, integrating a temporal embedding layer into the trained model enables the transformer block to track changes in vegetation indices and quantify disease progression over time. The findings of this study facilitate the monitoring of disease progression and support site-specific management decisions, thereby enhancing the sustainability of pecan production.
Keywords: Artificial intelligence, Spatio-temporal modeling, Multispectral imaging, Spectral analysis, Drone-based Scouting.

Speakers

Shah Md Abul Hasan

University of Georgia

Co-authors

Md Sultan Mahmud

University of Georgia

Wednesday July 30, 2025 11:15am - 11:30am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv
Funding Source Advisor

11:30am CDT

CITR 2 - Boosting Canopy Health: Micronutrient and Antioxidant Strategies for HLB-Affected Citrus

Wednesday July 30, 2025 11:30am - 11:45am CDT

Foster 1

Huanglongbing (HLB), a.k.a. citrus greening, is an endemic disease significantly impacting Florida and Texas citrus production. HLB-affected trees are compromised in the canopy and root health, often found with heavy loss of root mass that impairs water and nutrient uptake, leading to nutrient deficiencies. The prevalent presence of the suspected causal organism of HLB, Candidatus Liberibacter asiaticus (CLas) bacterium, in the citrus phloem leads to a cascade of active defense responses triggered by plant-pathogen interactions. One of the crucial outcomes of the interactions is the production of reactive oxygen species, leading to excessive oxidative stress that, over time, weakens tree health. Therefore, this research investigated the therapeutic strategies to mitigate nutrient deficiencies and HLB symptoms, attenuate reactive oxygen species load, and improve the production of premium grapefruits in trees affected by HLB by combining an integrated approach of micronutrient applications with antioxidants. The experiment design consisted of the foliar application of micronutrients, zinc (Zn), iron (Fe), and manganese (Mn) varied in two rates: 2 quarts/acre (control) and 3 quarts/acre that were conducted alone or in combination with gamma-aminobutyric acid (GABA), uric acid, and gibberellic acid (GA). The micronutrients, GABA, and uric acid applications were conducted at an interval of three months, while GA sprays were limited between blooming to the pre-harvest period in the HLB-affected mature grapefruit grove with a tree density of 104 trees/acre in the Lower Rio Grande Valley of Texas. The results demonstrated that merely increasing micronutrient application to 3 quarts/acre improved canopy health, with healthy (non-HLB-symptomatic) canopy quadrants reaching an average of 30% compared to 16.7% in the control treatment. Moreover, the standalone 3-quarts/acre significantly improved the yield of premium-size grapefruit to 25% compared to 6.2% in 2-quarts/acre only. The combination of GA (10 Fl.Oz/acre) and GABA (8 gm/tree) with control micronutrient treatment enhanced healthy canopy quadrants to 33% and 38%, respectively, compared to 19% in the micronutrient-only control. In 3 quarts/acre, GA and GABA showed synergistic effects in improving the canopy health by alleviating HLB severity. This applied research provides a practical framework for translating laboratory findings into field applications for managing HLB-affected trees. The integrated approach of combining enhanced micronutrient applications with antioxidants and phytohormones shows promise in mitigating HLB symptoms and improving fruit yield, particularly in the premium size category.

Speakers

Ajith Babburu

Texas A

Co-authors

Aditi Satpute

Texas A

Jong-Won Park

Texas A

Madhurababu Kunta

Texas A

Mamoudou Setamou

Texas A

Wednesday July 30, 2025 11:30am - 11:45am CDT
Foster 1

Oral presentation, Citrus Crops 2

Subject Citrus Crops
Funding Source USDA NIFA ECDRE Federal Award No. 2022-70029-38471
Funding Option SCRI funded all or part of the research associated with this abstract

11:30am CDT

FRBR 1 - Evaluation of diverse papaya germplasm for resistance to papaya ringspot virus under controlled conditions

Wednesday July 30, 2025 11:30am - 11:45am CDT

Strand 12A

Papaya ringspot disease caused by papaya ringspot virus P (PRSV-P), is restricting the commercial cultivation of papaya worldwide. Several measures have been taken to control the disease, including the application of aphicides, identifying host plant resistance, and transgenics. However, only genetically engineered papayas carrying the viral coat protein have been found to effectively control the disease. Transgenic papayas are not cultivated worldwide due to ethical regulations. Assessing the diverse papaya germplasm for resistance to PRSV could be a suitable alternative. Therefore, the present study was undertaken to assess PRSV resistance in 96 accessions, including 36 commercial accessions and 57 wild accessions. To identify novel resistant sources, the accessions were mechanically inoculated with PRSV under controlled conditions. The inoculated plants were continuously monitored for the appearance of PRSV-like symptoms and scored for disease severity, ranging from 0-5. Among all the accessions tested, only two accessions, HCAR 46 (Vasconcellea pubescens) and HCAR 177 (V. stipulate), did not show any symptoms. To further assure that no virus is present in these plants, an RT-qPCR was performed with PRSV coat protein-specific primers. The accession HCAR 46 showed the presence of a faint amplicon of 950 bp. However, no PSRV-specific amplicon was observed in HCAR 177. To further confirm the presence of PRSV, the amplified products were sequenced and showed over 95% sequence similarity with PRSV. The PRSV-resistant genotype identified in the present study could be used to breed PRSV-resistant cultivars.

Speakers

Sumit Jangra

University of Flroida

Co-authors

Jugpreet Singh

University of Florida

Wednesday July 30, 2025 11:30am - 11:45am CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding
Poster # csv

11:30am CDT

PH 2 - “Correlation Between Boron Leaf Damage and Fresh Yield in Saline-Sodic Soils”

Wednesday July 30, 2025 11:30am - 11:45am CDT

Strand 12B

Most of the world's pistachios are grown in saline-sodic soils with soil boron (B) levels over the 2 ppm suggested for most trees. As a resulting symmetrical leaf edge necrosis produced by B accumulation, “B toxicity”, is common and regarded as damaging to leaf photosynthetic capacity. This study was carried out in a 8-year-old pistachio orchard with field-budded Pistacia vera cv. ‘Golden Hills’ on cloned P. atlantica x P. integerrima, UCBI rootstocks, spaced at 18 x 20 feet, 121 trees per acre. The soil was a silty clay loam saline-sodic Cerrini complex with salinity ranging from 3 to 15dS/m, pH 7.5 to 8.2, boron levels of 3 to 12 ppm and soil sodium levels ranging from 16 to 130 meq/l (370 to 3000 ppm). High soil and water B levels will produce increasingly higher scion leaflet B leaf symptoms ranging from a slender marginal necrosis to almost complete necrosis. We analyzed the relationships among soil B, leaf B, percentage of damaged leaf surface and marketable yield. Our results a demonstrated a strong negative correlation of yield as a function of soil B. As soil B levels increased yield decreased; r = - 0.705, p < 0.001. However, both leaf B levels and % leaf damage had had weak, insignificant relationships with soil B levels. As soil B increased leaf B levels and the percentage of damaged leaf areas did not increase. However, there was a moderately positive relationship between leaf boron levels and leaf damage; r = 0.50, P

Speakers

MARTA INES SALUDES ZANFANO

Subs. Professor, Universidad de Salamanca

Marta I. Saludes Zanfaño, a passionate biologist who’s revolutionizing sustainable farming with a special knack for pistachio cultivation and organic weed control. Based at the University of Salamanca, Spain, as a graduate member of the Chemical Sciences and Technology group, she... Read More →

Co-authors

Blake L Mccullough-Sanden

University of California

CLAY BECK

MARICOPA ORCHADS

DONALD WILLIAMS

UNIVERSITY OF FRESNO

Giulia Marino

UC Davis

JOSEPH COELHO

Maricopa Orchards

Louise Ferguson

UC DAVIS

MAE CULUMBER

University of California

Mukesh Mehata

University of California, Davis

Wednesday July 30, 2025 11:30am - 11:45am CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv
Funding Source California Pistachio Research Board
Funding Option OREl or ORG funded all or part of the research associated with this abstract

11:30am CDT

TCHG 1 - The Impact of Indoor Plants on Student Well-being and Academic Performance in University Classrooms

Wednesday July 30, 2025 11:30am - 11:45am CDT

Strand 11B

Previous research has indicated that exposure to indoor plants can reduce stress, improve air quality, and enhance cognitive function. This study builds upon this foundation by specifically examining the classroom environment. In the spring of 2024, the study was conducted to investigate the effects of indoor plants on student well-being and academic performance in university classrooms. Two similar classrooms were used: Room 101 (experimental group, with plants) and Room 105 (control group, without plants). A total of 105 students took a survey at the beginning of the study (Feb 2024) and 91 took the end survey (Apr 2024) with a 78.1% completion at the beginning and 86.8% completion at the end. Demographics presented an unbalanced distribution of gender (66% female, 34% male) and majority of academic year falling into freshman classification (54%). Most participants were aged 18-24 years. Students completed surveys of self-reported depression, anxiety and stress levels using the DASS-21 4-pt Likert scale, and classroom satisfaction. Data set reliability showed a 0.81 Cronbach’s alpha score. After Wilcoxon/Kruskall Wallis analysis, results displayed students in Room 101 reported lower overall DASS scores (p < 0.05) with significantly decreased stress levels (p = 0.025) compared to Room 105. A statistical analysis using Spearman's ρ correlation coefficient revealed no significant relationship between depression and anxiety scores in relation to room types. However, a significant correlation was found between stress scores and room types (p = 0.0498). Common factors in student satisfaction were the lab instructors and the green wall in room 101. These results have important implications for classroom design and educational policy, suggesting that the simple addition of indoor plants and artificial greenery could significantly enhance the learning environment and student outcomes in higher education settings.

Speakers

Alicia Thomas

Assistant Professor of Practice, Texas Tech University

Co-authors

Catherine Simpson

Texas Tech University

Vikram Baliga

Texas Tech University

Wednesday July 30, 2025 11:30am - 11:45am CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

11:30am CDT

TECH - Preliminary Analysis of Computer Vision for Blackberry Flower Quantification

Wednesday July 30, 2025 11:30am - 11:45am CDT

Strand 11A

Precise and accurate quantification of blackberry flowers are essential for yield forecasting, phenotypic assessment, and enhancing management techniques in precision agriculture. Threshold segmentation of images for blackberry feature quantification could be challenging due to shadows and background variability, while manual flower estimation is subjective and time-consuming. The objective of this research was to apply artificial intelligence and computer vision to identify and quantify blackberry flowers from Unmanned Aerial Vehicle (UAV) remote sensing. A computer vision algorithm You Only Look Once (YOLO) was trained with 1142 image datasets of blackberry flowers to develop an image processing workflow to quantify UAV captured images. A performance analysis was conducted with YOLO variants (YOLOv8s–YOLO12s) for quantifying blackberry flowers. YOLOv10s achieved the best performance with a mAP@0.5 of 58%, precision of 60%, and recall of 58%. Input resolution had a notable impact, performing better at 1024×1024 pixels (mAP@0.5 = 55%) than at 640×640 (mAP@0.5 = 30%). Increasing the training dataset from 250 to 1,142 images progressively improved detection accuracy, highlighting the value of data volume for model generalization. Additionally, flower counts predicted by YOLOv10s showed a strong correlation with flower-to-vegetation ratio (FVR; r = 0.71, p < .001), supporting FVR as a practical proxy for estimating floral density in the field. A contribution to computer assisted agriculture integration in the blackberry industry has been made by investigating the performance of computer vision algorithms on blackberry flower detection. Challenges such as small and uneven sized flowers, overlapping occlusion, and plot-wise analysis must be further investigated. Keywords. UAV, automation, blackberry, phenotyping, artificial intelligence.

Speakers

Akwasi Tagoe

University o Arkansas

Co-authors

Aurelie Poncet

University of Arkansas

Cengiz Koparan

University of Arkansas

Donald M Johnson

University of Arkansas

Dongyi Wang

University of Arkansas

Margaret Worthington

University of Arkansas

Ramesh Bahadur Bist

University of Arkansas

Wednesday July 30, 2025 11:30am - 11:45am CDT
Strand 11A

Oral presentation, Technology Applications in Horticulture

Subject Technology Applications in Horticulture
Poster # csv
Funding Source This research was partially funded by the Hatch Project ARK02846

11:45am CDT

CITR 2 - Fruit growth responses of Rio Red grapefruit to annual N granular fertilization

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Foster 1

Nitrogen (N) is an essential nutrient required to support citrus yield and fruit quality. Its bioavailability to the tree must be continuous to support adequate biomass production, especially at key phenological stages such as vegetative flush and fruit setting. However, most commercial nutrition programs in southern Texas deliver synthetic fertilizer on average twice per year when not drip-irrigated. Although adoption of fertigation strategies continues to gain ground, the rate of transition is of low velocity, and a percentage of orchards is still flood-irrigated. In these systems, trees rely on the soil storage capacity to meet permanent nutrient demand. This field study investigated the effects of traditional N management practices on two orchards with different rootstock * scion combinations. We evaluated the effects of different N fertilization rates on fruit growth and postharvest traits such as brix, and size-class distribution. Our preliminary data indicates that despite trees growing in similar soil properties, they exhibited differences in fruit growth rate, and size-class distribution of fruits. Moreover, certain rootstocks * scion combinations exhibited superior fruit yield and quality. Continue refinement of nutrient management practices, especially N application is imperative to support tree long-term productivity under the constant pressure of pathogens in commercial settings.

Speakers

Joel Reyes-Cabrera

Texas A

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Foster 1

Oral presentation, Citrus Crops 2

Subject Citrus Crops
Poster # csv

11:45am CDT

FRBR 1 - Verifying Parentage of Offspring from Crosses of the Pawpaw (Asimina triloba) Cultivar ‘Sunflower’ and the Cultivars ‘Susquehanna’ and ‘KSU-Chappell’ using Simple Sequence Repeat (SSR) Markers

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Strand 12A

Verifying Parentage of Offspring from Crosses of the Pawpaw (Asimina triloba) Cultivar ‘Sunflower’ and the Cultivars ‘Susquehanna’ and ‘KSU-Chappell’ using Simple Sequence Repeat (SSR) Markers Nabin K. Adhikari, Dr. Kirk W. Pomper, Jeremy Lowe, Dr. Srijana Thapa Magar, and Sheri Crabtree College of Agriculture, Health and Natural Resources, Kentucky State University Pawpaw (Asimina triloba), a North American tree fruit in the early stages of commercialization, is typically found in clonal patches in forest understories. Cultivated pawpaws exhibit superior size, flavor, and appearance compared to their wild counterparts. Pawpaw is generally considered self-incompatible due to its protogynous flowers, though anecdotal evidence suggests self-compatibility in the ‘Sunflower’ variety. Previous research at Kentucky State University used simple sequence repeat (SSR) markers, a class of co-dominant genetic markers that target hypervariable regions of the genome, to confirm that ‘Sunflower’ is capable of self-pollination. However, there is little information on optimal pollinizer relationships and which cultivars serve to promote fruit set in cross-pollinations. This study aims to verify the parentage of offspring from crosses between ‘Sunflower’ and the cultivars ‘Susquehanna’ and ‘KSU-Chappell’, as well as the advanced selection 7-90 using simple sequence repeat markers. Leaves of parent trees and offspring were collected for DNA extraction. Young leaves were collected and were frozen (-15 ºC) until DNA extraction. DNA extraction was carried out using a DNAMITE Plant Kit (Microzone Ltd. Haywards Heath, West Sussex, UK). PCR was performed using SSR markers developed by Pomper et al., 2010. PCR products will be separated using a SeqStudio (Applied Biosystems, Foster City, CA) capillary electrophoresis system, and genotyping will be performed with GeneMapper software (Applied Biosystems, Foster City, CA). Parentage verification will be determined by looking for the presence or absence of alleles from the purported parents in the offspring. Offspring were categorized as self-pollinated if only alleles from the pollen recipient parent were present in the offspring, expected cross-pollinated if alleles from both parents were present, or unexpected if unknown alleles were detected.

Speakers

Nabin Adhikari

Kentucky State University

Co-authors

Kirk Pomper

Kentucky State University

Dr. Kirk W. Pomper is the Professor of Horticulture in the College of Agriculture, Community, and the Sciences at Kentucky State University in Frankfort, Kentucky. As Horticulture Research Leader, his program is focused on research and Extension efforts toward developing pawpaw as... Read More →

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Strand 12A

Oral presentation, Fruit Breeding 1

Subject Fruit Breeding

11:45am CDT

PH 2 - Optimizing Mechanical Harvesting of Vidalia Onions Using Impact Sensing Technology to Minimize Bruise Damage

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Strand 12B

Short-day onions such as Vidalia are vital in warmer climates, but their delicate skins make them prone to an average of 8% bruise damage during mechanical harvesting. As a result, manual hand harvesting remains the preferred method despite its high cost of $3,951/hectare for labor, according to the 2019 Onion Irrigated Budget (University of Georgia). Addressing issues of mechanical harvesting could offer a more cost-effective alternative while solving the labor shortage problem. This study aimed to evaluate the bruise tolerance of five Vidalia varieties (Vidora, Sweet Magnolia, Sapelo, Red Maiden, and Monjablanca) under different impact conditions and identify the specific sections of mechanical harvesters that contribute to bruising. Identifying the most bruise-tolerant varieties can guide growers in selecting onions better suited for mechanical harvesting, reducing labor costs and postharvest losses and by understanding which sections of the harvester cause the most damage, modifications can be made to reduce bruising. Controlled pendulum tests were conducted to simulate onion-to-surface impacts, using onions embedded with Impact Recording Devices (IRDs) to measure impact forces at two maturity stages (80% tops down and one week after 80% tops down) and two drying durations (0 and 7 days). Drop heights were selected based on bruise damage results for Vidora, with two levels for each surface type: 10 cm and 30 cm for flat surfaces, and 30 cm and 55 cm for padded surfaces. A total of 320 impacts were recorded. To identify the most bruise-prone sections of the harvester, 23 field trials were conducted using a Top Air Harvester, with IRDs embedded within onions and placed on field, to capture real-time impact data. The Top Air Harvester, consisting of a collecting belt, elevator, sorting belt, and conveyor, transferred onions to the bulb collection truck within 36 seconds. Early results for Vidora variety indicate that bruising severity increases with higher drop heights, on flat surfaces, while padded surfaces significantly reduce damage. Testing all five varieties will provide a comprehensive profile of bruise tolerance, helping growers select varieties better suited for mechanical harvesting, potentially reducing labor costs. Initial analysis of field trials revealed that the conveyor-to-bin transition generated the highest impact forces, significantly contributing to bruising. These preliminary results indicate the need for design improvements in this section to reduce impact damage and enhance mechanical harvesting efficiency. Further testing will validate these findings and guide the development of improved mechanical harvesting practices.

Speakers

Aleena Rayamajhi

University of Georgia

Co-authors

MD Sulton Mahmud

University of Georgia

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Strand 12B

Oral presentation, Postharvest 2

Subject Postharvest
Poster # csv
Funding Source USDA NIFA
Funding Option SCRI funded all or part of the research associated with this abstract

11:45am CDT

TCHG 1 - Making Learning Matter in Greenhouse Management: Assessment of a Design Project to Improve Student Learning and Engagement

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Strand 11B

Greenhouse Management (HORT 310) at Colorado State University equips students with the skills and knowledge necessary to manage a greenhouse production facility, which 88% of students reported is their career plan (n=156). However, based on historic grades, students struggle with heating and cooling principles, which involve calculations of standard heating and cooling needs given a particular structure and climate. In Spring 2023, a Design Project (DP) was implemented as a learning opportunity to apply the principles and skills gained in the class in a context that matters to students. Over the course of the semester, students research and write about a greenhouse operation that they are designing, detailing their production strategies and citing current research. According to Social Practice Theory, learning is intimately intertwined with context, meaning that one’s identity, with which they are emotionally attached, guides participation. Thus, having the agency to choose relevant locations and crops suggests that they would have greater investment and engagement with the DP because the learning matters, or is meaningfully connected, to their own lives. A DP pre- and post-assessment was administered in Spring 2024 (n=36) to better understand if students’ relationships with the DP improved confidence and learning of fundamental HORT 310 principles, specifically greenhouse heating and cooling. In the post-assessment, 98% of respondents felt the DP assisted in their learning, and of respondents that included a free response (n=20), 20% indicated that they enjoyed the DP. Additionally, pre- and post-assessments revealed improved participant performance on questions pertaining to cooling principles following DP implementation, while performance on heating principles was unchanged. Together, these results support the use of Social Practice Theory as a framework for the development of assignments, such as the DP, that foster student learning and engagement by connecting content to student motivations and interests.

Speakers

Joshua Craver

Colorado State University

Co-authors

Samantha P. Rosado

Colorado State University

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

11:45am CDT

UG 1 - Is ‘Arbequina’ Still the Best Option for California? An Evaluation of Established and Novel Varietals in a Super High Density Hedgerow System in the Sacramento Valley

Wednesday July 30, 2025 11:45am - 12:00pm CDT

Foster 2

Global olive oil production tripled over the past six decades to 2.76 million tons in the 2022/23 year. California is the largest producer of olive oil in the United States, and its planting is increasing at an estimated rate of 3000 acres per year. Most of the new plantings for oil in California are in hedgerows under intensive management either in a super high (SHD) or medium (MD) density systems. Of these plantings, an estimated ~80% is ‘Arbequina’, ~15% ‘Arbosana’, and ~5% ‘Koroneiki’. As expected, the industry is continuously searching for novel cultivars that can improve field and oil productivity, EVOO quality, as well as increase economic returns for their operation. With industry support, a trial was planted at the Wolfskill Experimental Orchard in Winters, CA in 2019. Four acres were planted at a density of 620 trees per acre, at 5 feet between trees and 14 feet between rows. ‘Arbequina’, ‘Arbosana’, and ‘Koroneiki’ were planted alongside two new cultivars, ‘Lecciana’ and ‘Sikitita’, and one numbered selection, Agromillora ‘9805-01’. The orchard was planted with five complete replicates of the six cultivars, each cultivar row was randomized within each replicate, with the exception of ‘Lecciana’ which was planted one year later in 2020. Seasonal and cumulative yield were measured from the 2021 through the 2024 growing seasons; while fruit weight, oil content, basal shoot prevalence, and maturity index were measured over the 2023 and 2024 growing seasons. The entire orchard was managed following industry agronomic practices for all replicates. During the four years ‘Koroneiki’ had the greatest cumulative yield on average, followed by ‘Arbequina’ and ‘Arbosana’, ‘Lecciana’, ‘9805-01’, and ‘Sikitita’ (16.60, 13.38, 13.37, 10.61, 8.17 and 7.76 tons per acre respectively). Alternate bearing behavior was more prevalent for ‘9805-01’ and ‘Sikitita’ and ‘Sikitita’ took an additional year to come into production. The results, including seasonal yield, oil content, basal shoot prevalence, and fruit weight, show why ‘Arbequina’, ‘Arbosana’, and ‘Koroneiki’ are still the prevalent cultivars grown in California for SHD plantings. In our trial, ‘Arbosana’ and ‘Koroneiki’ performed as well or better than ‘Arbequina’, but growers in California have planted less of those two cultivars due to concerns with disease resistance and vigor management over time across the different climatic conditions of the state. Our research shows that further evaluation of novel cultivars is essential for a growing industry.

Speakers

Craig Marquis

UC Davis

Co-authors

Adele Amico Roxas

College Of Agricultural And Environmental Sciences-Olive Center, University of California, Davis

Javier Fernandez-Salvador

College Of Agricultural And Environmental Sciences-Olive Center, University of California, Davis

Raeva Johnson

College Of Agricultural And Environmental Sciences, University Of California, Davis

Wednesday July 30, 2025 11:45am - 12:00pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Audience Undergraduate Students
Subject Undergraduate Student
Funding Source California Olive Oil Industry

12:00pm CDT

CITR 2 - Impacts of Biochar on Citrus Root System Architecture, Soil Moisture, and Nutrient Contents Under Greenhouse Conditions

Wednesday July 30, 2025 12:00pm - 12:15pm CDT

Foster 1

Soil organic matter (SOM) is a key determinant of soil health, directly influencing structure, moisture retention, nutrient availability, and microbial activity. Among soil amendments, biochar has gained attention for its potential to enhance soil fertility and support plant productivity. However, its influence on citrus root system architecture and nutrient uptake across different rootstocks remains underexplored. This study evaluated the effects of four biochar concentrations (0%, 10%, 20%, and 30% v/v) mixed with native field soil on four citrus rootstocks: ‘Sour Orange’, ‘Swingle’, ‘US-802’, and ‘US-942’. Plants were grown under controlled greenhouse conditions for 16 weeks. Root system architecture traits: total root length, surface area, root volume, and number of forks, were quantified using WinRHIZO™ analysis. Soil parameters, including pH, cation exchange capacity (CEC), moisture content, and SOM, were assessed post-harvest, alongside plant tissue nutrient concentrations (P, K, Ca, Mg, Mn). The 20% biochar treatment significantly enhanced root morphological traits across all rootstocks, with increases of up to 35% in total root length and 40% in surface area compared to the control. Plant tissue analysis revealed elevated macro- and micronutrient concentrations in the 20% treatment, particularly for P, K, Ca, and Mg. Soil analysis showed progressive improvements in pH, SOM, CEC, and moisture content with increasing biochar concentration, with the highest values recorded at 30%. While higher biochar rates improved soil physicochemical properties, the 20% concentration provided the most balanced benefits, optimizing both root development and nutrient uptake. These findings suggest biochar, particularly at moderate rates, may be an effective amendment for improving soil fertility and citrus root system performance in nutrient-limited soils.

Speakers

Khalid Hussain

University of Florida

Co-authors

John-Paul Fox

University of Florida

Lorenzo Rossi

Texas A

Dr. Rossi’s research program focuses on understanding the responses of horticultural crops to environmental stresses, with the goal of developing environmentally sound and effective management strategies. He is a horticulturist with expertise in plant stress physiology, plant biology... Read More →

Lukas Hallman

University of Florida

Wednesday July 30, 2025 12:00pm - 12:15pm CDT
Foster 1

Oral presentation, Citrus Crops 2

Subject Citrus Crops
Funding Source UF/IFAS Citrus Initiative

12:00pm CDT

TCHG 1 - Student Perceptions of Learning – Use of Quizzes or Authentic Assessment

Wednesday July 30, 2025 12:00pm - 12:15pm CDT

Strand 11B

The objective of this study was to survey student perceptions of mastery of learning outcomes in the 100% online asynchronous course Nutritional Management taught at the University of Florida. There are many ways to perceive if students have mastered learning outcomes in a course. Quizzes are one way to measure if students understand concepts and terminology. However, in online courses there is the concern that students may ‘cheat’ and a quiz is not an effective measure of student achievement. Online instructors need to look for other assessments, like assignments that ask students to apply what they have learned to solve a problem. This is easy to measure in-person classrooms and laboratories but more challenging online. This study conducted a mid-term survey to students in the spring 2025 offering of Nutritional Management. The survey asked students about their perceived learning and mastery of course learning outcomes based on two quizzes and two authentic challenge assignments. This study was deemed IRB exempt.

Speakers

Kimberly Moore

University of Florida

Wednesday July 30, 2025 12:00pm - 12:15pm CDT
Strand 11B

Oral presentation, Teaching Methods 1

Subject Teaching Methods
Poster # csv

12:00pm CDT

UG 1 - No Evidence for Polystyrene Nanoplastic Uptake by Lettuce Grown in Nutrient Film Technique Hydroponics Systems

Wednesday July 30, 2025 12:00pm - 12:15pm CDT

Foster 2

As nanoplastics become an increasing environmental and human health concern, greater understanding of their absorption by crop plants is vital. Many plant species, including lettuce, have been reported to transport nanoplastics from roots to leaves, but most research has not been conducted with crops grown in commercial production systems to harvestable size. Across two greenhouse experiments, we compared ‘Winter Density’ romaine lettuce grown with and without the addition of 10 mg.liter-1 yellow-green fluorescent-labeled 0.2 µm and 0.05 µm polystyrene nanoplastics (PSNP) added to municipal irrigation water in commercial-style hydroponic Nutrient Film Technique (NFT) systems. No difference was observed between lettuce grown with or without PSNPs based on plant width; shoot and root fresh and dry weights; number of true leaves; or chlorophyll content. Stomatal resistance of plants in both treatments was also not different and indicated very high transpiration rates that would support PSNP translocation to shoots. Fluorescence of shoots and roots from each treatment was evaluated via confocal microscopy. No PSNPs were found in the shoot tissue. In the roots, we observed PSNPs aggregated on the surface and possibly penetrated a maximum of 10 to 25 microns deep within outer root tissue. In root samples processed with acetone washes, no PSNPs were observed on or in root tissue by either TEM or confocal microscopy. As such, we found no evidence that 0.2 µm or 0.05 µm PSNPs are absorbed into the vascular system of hydroponically-grown lettuce plants and thus are not translocated to shoot tissue. These findings emphasize problems with current literature and the need for further research to investigate PSNP uptake by plants in realistic production systems.

Speakers

Allison Cloyd

Kansas State University

Co-authors

Daniel Boyle

Kansas State University

Kimberly Williams

Kansas State University

MB Kirkham

Kansas State University

Wednesday July 30, 2025 12:00pm - 12:15pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Source USDA NIFA Hatch-Multistate project 7005973

12:15pm CDT

UG 1 - Growth and Physiological Responses of ‘Little Gem’ and ‘Salad Bowl’ (Lactuca sativa) Lettuce Varieties to Cut-and-Come-Again and Cut-and-Sow Harvest Techniques

Wednesday July 30, 2025 12:15pm - 12:30pm CDT

Foster 2

The "cut-and-come-again" (P

Speakers

Brianna Drew

University of Wyoming

Co-authors

David Claypool

University of Wyoming

Elizabeth Moore

University of Wyoming

Gioia Massa

NASA Kennedy Space Center

Ji-Jhong Chen

University of Wyoming

Jill Keith

University of Wyoming

Nintya Avriantari

University of Wyoming

Shawna McBride

University of Wyoming

Wednesday July 30, 2025 12:15pm - 12:30pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Source Wyoming Space Grant Consortium Undergraduate Student Fellowship (Grant#: 1004680A) and Faculty Research Initiation Grant (Grant#: 1004680B), NASA EPSCoR Rapid Response Research (R3) Grant#: WY-80NSSC24M0162, University of Wyoming College of Agriculture, Life Sciences, & Natural Resources, Office of Research and Economic Development Designated, Department of Plant Sciences. United States Department of Agriculture National Institute of Food and Agriculture (NIFA) Plant Sciences Hatch Funds (WYO-631-22)

12:30pm CDT

UG 1 - Investigating Silicon Supplementation for Lettuce Grown with Food Waste-Based Anaerobic Digestate

Wednesday July 30, 2025 12:30pm - 12:45pm CDT

Foster 2

Food waste liquid anaerobic digestate (FWLAD) contains higher salt concentrations than synthetic fertilizers at comparable nutrient levels. As a result, plants may experience salt stress at optimal nutrient concentrations or nutrient deficiencies when electrical conductivity (EC) is reduced. Silicon (Si) has been shown to alleviate salt stress and promote plant growth under nutrient-limited conditions. This study investigated whether Si supplementation can mitigate salt stress under high EC and enhance growth under low EC when FWLAD is used to fertilize lettuce (Lactuca sativa ‘Muir’) transplants. Lettuce seeds were sown in either rockwool plugs or a 128-cell plug tray filled with a peat-based growing medium. One week after sowing, seedlings were sub-irrigated with one of nine nutrient solutions prepared from FWLAD. These solutions were adjusted to one of three target EC levels (1, 2, or 3 dS·m⁻¹) and amended with one of three Si treatments: (1) no Si (control, supplemented with 1.5 mM potassium sulfate to match potassium levels), (2) 1.5 mM lab-grade potassium silicate (prepared from silicic acid and potassium hydroxide), or (3) 1.5 mM commercial-grade potassium silicate (AGSIL16H, a commercially available product). Seedlings were grown indoors at 22 °C, with a photosynthetic photon flux density of 200 µmol·m⁻²·s⁻¹ and an 18-hour photoperiod, for a total of three weeks after sowing. For the control treatment without Si, leaf number, total leaf area, and shoot fresh mass were highest at EC 2, indicating that moderate EC promoted optimal growth. Compared to the control, supplementation with lab-grade potassium silicate increased leaf number, total leaf area, and shoot fresh mass by 16%, 63%, and 56% at EC 2, and by 69%, 423%, and 255% at EC 3 in rockwool, and by 10%, 10%, and 11% at EC 2, and by 19%, 42%, and 63% at EC 3 in growing medium. At EC 1, lab-grade potassium silicate had little to no effect on leaf area and shoot fresh mass in either substrate. Commercial-grade potassium silicate did not affect leaf number, leaf area, or shoot fresh mass at any EC. These results suggest that Si supplementation using lab-grade potassium silicate can improve lettuce seedling growth under high-EC conditions when fertilized with FWLAD, with more pronounced effects observed in rockwool compared to the growing medium.

Speakers

Trevor Maxwell

Arizona State University

Co-authors

Estevan Felix

Arizona State University

Jennifer Boldt

United States Department of Agriculture

Yujin Park

Arizona State University

Wednesday July 30, 2025 12:30pm - 12:45pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Source Foundation for Food & Agriculture Research

12:45pm CDT

UG 1 - Carbon Dioxide Enrichment Increases Yield Without Negatively Affecting Fruit Quality of Everbearing Strawberries Produce

Wednesday July 30, 2025 12:45pm - 1:00pm CDT

Foster 2

Strawberries are the top consumed and produced berry in the United States. Demand for local and off-season availability has increased the production of strawberries in controlled environment agriculture (CEA). While production protocols exist for many leafy greens, limited information is available for emerging CEA crops such as strawberry. Optimizing carbon dioxide (CO2) concentrations for CEA strawberry production is of interest, given that previous research has shown increased yields and enhanced organoleptic properties of strawberries with CO2 enrichment. However, strawberry chemical composition varies depending on cultural practices, environmental conditions, and cultivar. Therefore, the objective of this research was to evaluate the impacts of CO2 enrichment on yield and fruit quality of everbearing strawberries in a controlled environment. Two strawberry cultivars (Fragaria ×ananassa ‘Albion’ and ‘Ozark Beauty’) were propagated from vegetative runners and grown in 2.7-L pots for eight weeks in walk-in growth chambers under either an ambient (450 μmol·mol–1) or enriched (900 μmol·mol–1) CO2 concentration. Temperature and relative humidity setpoints were 20/12 °C and 55/65% (day/night), respectively, with a photosynthetic photon flux density target of 348 µmol∙m–2∙s–1 (18-h photoperiod; daily light integral of 21 mol∙m–2∙d–1). Fruit mass, width, and count were collected weekly on all ripe berries and a USDA grade was assigned based on width and presence of damage. During the final harvest, fruit firmness and Brix:acid were measured to further assess fruit quality and samples were collected for a sensory evaluation. Total yield (grams/plant) of both cultivars was highest under CO2 enrichment. Specifically, total yield increased by 22% and 37% under CO2 enrichment compared to ambient for ‘Albion’ and ‘Ozark Beauty’, respectively. No quality differences (e.g., fruit firmness and Brix:acid) were observed between CO2 concentration treatments for either cultivar. These results were similar to sensory evaluations for rate-all-that-apply (RATA) and affective (9-point hedonic scale) tests (n=84), with little difference observed between CO2 concentration treatments for either cultivar. Participants rated ‘Albion’ higher in overall appearance and overall liking compared to ‘Ozark Beauty’, regardless of CO2 treatment. ‘Ozark Beauty’ consistently rated higher in fermented flavor. In summary, CO2 enrichment increased everbearing strawberry fruit production without negatively impacting berry flavor for these two cultivars. Outreach efforts have sought to disseminate these results and, through program evaluation, identify interest and potential barriers to crop diversification and adoption of CEA strawberry production in Denver, CO.

Speakers

Yamilex Romero

Colorado State University

Co-authors

Gabriel Sanchez

Colorado State University

Jake Holley

Colorado State University

Jennifer Boldt

United States Department of Agriculture

Joshua Craver

Colorado State University

Kale Harbick

United States Department of Agriculture

Martha Calvert

Colorado State University

Samantha P. Rosado

Colorado State University

Wednesday July 30, 2025 12:45pm - 1:00pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Source USDA-NIFA Project #2023-38640-39571 through the WSARE program under Project #GW24-001

1:00pm CDT

UG 1 - Unravelling the rootstock-scion interaction in grafted watermelon plants

Wednesday July 30, 2025 1:00pm - 1:15pm CDT

Foster 2

As the adoption of grafting technology is increasing among growers to manage soilborne diseases in watermelon production and new rootstocks are being developed, more research is needed to test different combinations of rootstocks and scions to identify growth differences that may be influenced by rootstock-scion interactions. In this greenhouse pot study, we examined the impact of the interspecific hybrid squash rootstock ‘Camelforce’ (Cucurbita maxima × C. moschata) and the wild watermelon rootstock ‘Carolina Strongback’ (Citrullus amarus) on the growth and development performance of two seedless watermelon scion cultivars with contrasting fruit maturity characteristics. Two weeks after seeding, early-maturing ‘Citation’ and late-maturing ‘Miramonte’ seedless watermelon plants were grafted onto each rootstock, respectively, with non-grafted scions and rootstocks as controls. The plants were arranged in a randomized complete block design with five replications and three plants per experimental unit. Non-grafted ‘Camelforce’ showed the longest primary vine, while ‘Miramonte’/‘Camelforce’ displayed significantly higher total vine length than other treatments. Non-grafted ‘Carolina Strongback’ exhibited significantly more leaves, followed by ‘Miramonte’/‘Camelforce’ and non-grafted ‘Miramonte’. ‘Camelforce’ also exhibited significantly greater above and below-ground dry weights, followed by ‘Miramonte’/‘Camel force’, although it did not differ from non-grafted ‘Miramonte’. The dry weights of ‘Citation’/‘Camelforce’ were significantly higher than non-grafted ‘Citation’. The above-ground dry weight of ‘Citation’/‘Carolina Strongback’ was significantly lower than all groups, except for non-grafted ‘Carolina Strongback’. Similarly, the below-ground dry weight of ‘Citation’/‘Carolina Strongback’ was significantly lower than treatments, except for ‘Miramonte’/‘Carolina Strongback’ and non-grafted ‘Carolina Strongback’. All treatments showed male and female flowers by week 3 after transplanting. Both non-grafted rootstocks showed more female flowers than non-grafted and grafted scions. At week 4 ‘Miramonte’/‘Carolina Strongback’ had more female flowers than all other treatments, while non-grafted ‘Camelforce’ exhibited the lowest. No difference in female flowers between the grafted and non-grafted scion groups was observed. Non-grafted scions exhibited more male flowers than the respective grafted plants by week 3. No differences were observed in male flowers except ‘Citation’/‘Carolina Strongback’ with fewer than grafted and non-grafted scions by week 4. Week 3 female flowers results suggest that grafting can significantly affect plant growth, but has a limited impact on flowering. The ‘Miramonte’/ ‘Camelforce’ group exhibited vigorous growth without significantly affecting flowering. Further research is necessary to explore how different types of rootstocks may impact fruit development of watermelon scions of varying fruit development characteristics in commercial production.

Speakers

Kendall Lindsay

University of Florida

Co-authors

Xin Zhao

University of Florida

Wednesday July 30, 2025 1:00pm - 1:15pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Source Florida Specialty Crop Block Grant

1:15pm CDT

UG 1 - Accelerated Composting Of Spent Coffee Grounds For Horticultural Soil Amendments

Wednesday July 30, 2025 1:15pm - 1:30pm CDT

Foster 2

Coffee grounds are generated by home residents daily. The objective of this study is to use an accelerated home food scrap composter to encourage residents to reduce waste volume and weight and provide garden compost to produce garden produce and flowers. Two accelerated composters (Lomi and Vego) were evaluated both for their compost soil health, physical and chemical properties after processing the spent coffee grounds. Lomi processed food for 24h only and the Vego composter for 1, 5, and 10 days. Compost volume and weight increased as days of composting increased. Compost health, nutrients, pH, C/N Ratio were suitable for a horticultural growing amendment. Physical components were within normal parameters for a soil substrate. Finer particles were increased with greater days of composting as expected. Plant growth differences were measured. Compost incorporated at 10 % v/v increased petunia biomass. Accelerated composters reduced volume and weight of food scrapes while providing essential plant nutrients.

Speakers

Claire Bradley

LSU

Co-authors

Alessandro Holzapfel

Louisiana State University Agricultural Center

Edward Bush

LSU AgCenter

William Dunford

Louisiana State University

Wednesday July 30, 2025 1:15pm - 1:30pm CDT
Foster 2

Oral presentation, Undergraduate Student 1

Poster # csv
Funding Option SCRI funded all or part of the research associated with this abstract

1:44pm CDT

EcoPhys 1 - Oral Session

Wednesday July 30, 2025 1:44pm - 1:45pm CDT

Strand 11A

Presiding/Moderator

Al Kovaleski

University of Wisconsin-Madison

Wednesday July 30, 2025 1:44pm - 1:45pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology

1:44pm CDT

FLOR 1 - Oral Session

Wednesday July 30, 2025 1:44pm - 1:45pm CDT

Strand 12B

Presiding/Moderator

Alvaro Pantoja-Benavides

University of Connecticut

Wednesday July 30, 2025 1:44pm - 1:45pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

1:44pm CDT

MKEC - Oral Session

Wednesday July 30, 2025 1:44pm - 1:45pm CDT

Strand 12A

Presiding/Moderator

Ben Campbell

University of Georgia

Wednesday July 30, 2025 1:44pm - 1:45pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics

1:44pm CDT

VCM 3 - Oral Session

Wednesday July 30, 2025 1:44pm - 1:45pm CDT

Strand 11B

Presiding/Moderator

Laura Schulz

Graduate Research Assistant, Washington State University

I am a PhD student at Washington State University working with Carol Miles on introducing sweetpotato as a new crop in western Washington.

Wednesday July 30, 2025 1:44pm - 1:45pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management

1:44pm CDT

WUM 2 - Oral Session

Wednesday July 30, 2025 1:44pm - 1:45pm CDT

Foster 2

Presiding/Moderator

Andre Biscaro

UC Davis

Wednesday July 30, 2025 1:44pm - 1:45pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management

1:45pm CDT

EcoPhys 1 - Hydrogen cyanamide advances budbreak in grapevine by increasing rate of cold hardiness loss

Wednesday July 30, 2025 1:45pm - 2:00pm CDT

Strand 11A

The mechanism controlling dormancy in buds of woody perennial plants remains largely unknown. However, it is known that exposure to cold temperatures (chilling) promotes the transition from a non-responsive to a responsive status to growth-conducive temperatures (i.e., endo- to ecodormancy transition). In horticulture, hydrogen cyanamide (HC) has been used for decades to overcome chilling accumulation deficiencies for temperate fruit crops grown in subtropical climates. Given the connection between cold hardiness loss and budbreak, we hypothesized that HC would increase the rate of cold hardiness loss (deacclimation rate). To test this, we collected grapevine (Vitis hybrid ‘Petite Pearl’) cuttings from field conditions in Madison, WI in approximately bi-weekly intervals from December to April. Single node cuttings were prepared and randomly separated into two treatments: a control group [0.5% surfactant (Regulaid®, KALO, Inc.)], and an HC group [5% hydrogen cyanamide (Dormex®, Alzchem Group AG) and 0.5% surfactant]. Both groups were treated by submersion for 10s. Cuttings were then placed in cups of water, and under forcing conditions. The forcing conditions used for all collections were 22ºC and 16h light. In later collections, two additional forcing temperatures were used: 8ºC and 16ºC. Cold hardiness was measured using differential thermal analysis on the day of treatment application, from field collected buds (n>10), and in semi-regular intervals from cuttings under forcing conditions, with interval length depending on temperature [e.g., quasi-daily at 22ºC (T0 1d, T0 2d, …); about every two days for 16ºC (T0 2d, T0 4d, …), about every five days for 8ºC]. At each collection time and for each temperature and treatment, 10 cuttings were set apart to observe time to budbreak. As expected, budbreak occurred earlier in HC treated buds compared to control. Using measurements of cold hardiness over time under forcing, we determined deacclimation rates as the slope of linear regressions. The rate of deacclimation in the control group increased progressively with each collection, as chilling accumulated in the field (1.0ºC/d in December to 1.4ºC/d in March). However, the deacclimation rate of the HC-treated group was always greater than the control (1.6ºC/d in December and 1.7ºC/d in March). In March, at 16ºC, there was also a difference between control and HC group in deacclimation rate (1.2ºC/d and 1.4ºC/d), while there were no differences at 8ºC. HC increases the rate of deacclimation in grapevines. We anticipate that understanding the interplay between cold hardiness, deacclimation, and budbreak will be helpful in uncovering the dormancy mechanism.

Speakers

Al Kovaleski

University of Wisconsin-Madison

Co-authors

Erica Kirchhof

University of Wisconsin-Madison

Francisco Campos-Arguedas

University of Wisconsin-Madison

Michael North

University of Wisconsin-Madison

Nadia Arias

Universidad Nacional de la Patagonia San Juan Bosco / University of Wisconsin-Madison

Wednesday July 30, 2025 1:45pm - 2:00pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Funding Source Fulbright

1:45pm CDT

FLOR 1 - Chitosan Effect on Petunia Plants Growing Under Different Deficit Irrigation Regimes.

Wednesday July 30, 2025 1:45pm - 2:00pm CDT

Strand 12B

Increasing the efficiency of irrigation practices is necessary to conserve water resources. However, extreme reductions in irrigation may lead to stunted growth. In this project, we aimed to evaluate if chitosan applied as a substrate amendment influenced plant growth, physiology, and marketable parameters of container-grown ornamental crops cultivated at different container capacities. The experiment was a full-factorial design with two factors: container capacity (100%, 70%, and 40%) and chitosan application timing (No application, Week 1, Week 3). The plants were kept in the greenhouse for six weeks and then in growth chambers set at 30°C or 40°C for two weeks to simulate post-production conditions. Plant growth and stomatal conductance were measured weekly and flower area after the sixth week. Significant differences were observed between the treatments. Plant growth was lowest at 70% and 40% CC when chitosan was applied at week 3. The stomatal conductance of plants under 70% and 40% CC was higher than 100% CC with no chitosan, but plants with chitosan at 40% CC had higher stomatal conductance. Flower coverage did not differ at the end of the crop cycle and in the first week at the two post-production temperatures (30°C and 40°C), but in the second week, the flower coverage decreased drastically in all the treatments, with the lowest values observed at 100% CC in both environmental temperatures. Deficit irrigation in petunia plants could be a strategy to produce marketable plants while reducing the volume of water. Chitosan applied in the first week of production seems to be the best application timing under deficit irrigation to see an amelioration effect from lowering container capacity.

Speakers

Alvaro Pantoja-Benavides

University of Connecticut

Co-authors

Rosa Raudales

University of Connecticut

Wednesday July 30, 2025 1:45pm - 2:00pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Poster # csv

1:45pm CDT

MKEC - Optimizing Asparagus Marketability: The Economic Impact of Controlled-Atmosphere Storage for Michigan Growers

Wednesday July 30, 2025 1:45pm - 2:00pm CDT

Strand 12A

Despite an increase in asparagus production in Michigan, which has surpassed California since 2015, national production has declined by 75% since 2000, while imports have surged from 159 million pounds to 580 million pounds. This shift has placed increasing pressure on domestic production, with Michigan growers facing challenges from high labor costs and import competition. By 2022, only 6% of the fresh asparagus supply in the U.S. came from domestic production, with imports accounting for the remaining 94%. As a result, Michigan's asparagus growers are vulnerable to price fluctuations caused by import competition, compounded by a very short six-week harvest season. Consumer demand remains high after the harvest season, driving market prices up by as much as 28% post-harvest, yet growers are unable to capitalize on this price increase. To address these challenges, this study explores the potential of extending the storage life of asparagus, particularly through controlled-atmosphere (CA) storage. This method could help mitigate the impact of price fluctuations on growers' revenues by enabling producers to allocate surplus produce to the market based on demand, while reducing produce losses. A comprehensive bioeconomic model was developed to simulate the economic impact of extending storage. This model integrates yield capacity and annual average costs per acre for Michigan growers, with data derived from interviews and focus groups with local asparagus producers. The model analyzes production costs and yield capacities over a 14-year lifecycle, with peak yields of 5,500 pounds per acre occurring between years 5 and 12. Despite high initial costs, positive net returns are anticipated from years 4 through 12 of the production cycle. The study evaluates four scenarios with varying post-harvest storage durations (i.e., immediate marketing, one-week storage, two-week storage, and three-week storage) and demonstrates that extending storage can capitalize on post-season price increases, thereby enhancing annual revenue, particularly during peak harvesting years. The results suggest that Michigan growers can improve profitability by adopting CA storage for two weeks, aligning storage strategies with market price fluctuations to optimize revenue.

Speakers

Simone Valle de Souza

Assistant Professor, MICHIGAN STATE UNIVERSITY - EAST LANSING,MI,USA

Co-authors

Benjamin Werling

MICHIGAN STATE UNIVERSITY - EAST LANSING,MI,USA

John Bakker

Michigan Asparagus Association

Philip Engelgau

MICHIGAN STATE UNIVERSITY - EAST LANSING,MI,USA

Randolph Beaudry

Michigan State University

Wednesday July 30, 2025 1:45pm - 2:00pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics
Poster # csv

1:45pm CDT

VCM 3 - Role of On-station and On-farm Trials to Test and Introduce New Crops

Wednesday July 30, 2025 1:45pm - 2:00pm CDT

Strand 11B

Many direct-market farmers in western Washington are interested in sweetpotatoes (Ipomoea batatas) for crop rotations, to increase farm sales, offer a culturally relevant crop to consumers, and adapt to climate change. We conducted research station and on-farm trials in 2023, 2024, and 2025 with the goal of testing cultivars, developing production guidelines, and introducing sweetpotato as a new crop for the region. The trials were a partnership between WSU researchers, who led the research station trials, and WSU Extension, who led the on-farm trials. Research station trials provided yield and wireworm resistance data for nine cultivars and breeding lines, and on-farm trials introduced sweetpotato to farmers in the region. On-farm trial participants were provided with slips or roots of three sweetpotato cultivars and a production guide. In 2023, 20 farmers across three counties signed up to participate, 15 farmers planted trials (75% of signups), 11 farmers returned surveys with some data (73% of planted trials), and 5 farmers provided complete data (33% of planted trials). Due to varying management practices and incomplete responses, 2023 on-farm trial data were largely unusable for evaluating yield or wireworm resistance. In 2024, 33 farmers across nine counties signed up to participate, 29 farmers planted trials (88% of signups), 25 farmers returned surveys and/or had data collected by a WSU Extension Field Assistant (89% of planted trials), and 20 farmers provided complete data (71% of planted trials). Hiring a part-time field assistant in 2024 who visited farms and collected data increased farmer response rate and data completeness. Yet, on-farm trial yield and wireworm resistance data still were not fully usable due to inconsistencies in how data were collected, and lack of adherence to production guidelines. In 2025, we redesigned on-farm trial data surveys to focus on farmers’ perceptions regarding suitability of sweetpotato production and marketability for their farm. Participating farmers are uniquely well-suited to answer these qualitative questions, which will assess if sweetpotato has been successfully introduced in the region. In all years of the project, online growing classes, in-person field days, and farm walks proved useful for introducing sweetpotato to new farmers in the region. Visits to on-farm trial locations proved an important avenue of offering support to farmers experimenting with sweetpotato. Completed surveys and conversations with on-farm trial participants provided valuable feedback that was incorporated into our sweetpotato production guide, and expanded and improved our on-line resources including several short production videos.

Speakers

Laura Schulz

Graduate Research Assistant, Washington State University

I am a PhD student at Washington State University working with Carol Miles on introducing sweetpotato as a new crop in western Washington.

Co-authors

Carol Miles

Washington State University

Jordan White

Washington State University

Laurel Moulton

Washington State University

Samantha Grieger

Washington State University

Wednesday July 30, 2025 1:45pm - 2:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management

1:45pm CDT

WUM 2 - Partitioning Evapotranspiration in a Young Pistachio Orchard Using the Conditional Eddy Covariance (CEC) Method in the Mesilla Valley, NM

Wednesday July 30, 2025 1:45pm - 2:00pm CDT

Foster 2

Understanding the partitioning of evapotranspiration (ET) into soil evaporation and plant transpiration is critical for improving irrigation management in young orchards with limited canopy cover. This study focuses on partitioning ET in a 4-year-old drip irrigated pistachio orchard located in the Mesilla Valley, Southern New Mexico, using the Conditional Eddy Covariance (CEC) method. The orchard is equipped with a high-frequency eddy covariance system along with sensors to make meteorological measurements. The CEC approach was applied to identify and isolate flux contributions under specific atmospheric conditions, thereby separating transpiration-driven and evaporation-driven fluxes. The CEC separates fluxes using conditional sampling based on the hypothesis that when transpiration is dominant, CO₂ and H₂O fluxes should be highly correlated. Preliminary results show that the total ET values measured from June to August varied between 1.5 and 4.5 mm/day, with about 20% contributed through transpiration from the plants in the year 2024.

Speakers

Uduwarage Perera

New Mexico State University

Co-authors

A. Salim Bawazir

New Mexico State University

Alexander Fernald

New Mexico State University

Chris Chavez

New Mexico State University

Richard Heerema

New Mexico State University

Wednesday July 30, 2025 1:45pm - 2:00pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Funding Source SWF: USDA NIFA Award No. 2021-69012-35916, USDA-NIFA-SCRI-2022-51181-38327

2:00pm CDT

EcoPhys 1 - Evaluating Cold Hardiness Dynamics and Time to Budbreak of Dormant Grapevines Across the Continental US

Wednesday July 30, 2025 2:00pm - 2:15pm CDT

Strand 11A

Dormancy remains a poorly understood process in temperate woody perennial plants. These plants require cumulative exposure to low temperatures (chilling accumulation) during winter to respond to warm temperatures in spring (forcing) and properly break bud. For successful establishment of temperate woody perennial fruit crops, it is important to understand chilling accumulation and dormancy requirements of species and cultivars. Our recent work indicates cold hardiness is an important co-variate in the analyses related to timing of budbreak, and thus chilling accumulation models and dormancy progression studies. Here we set out to understand aspects of chilling accumulation in different conditions by evaluating two measures of dormancy progression, (i) a classic forcing assay, where time to budbreak is evaluated; and (ii) a newer phenotyping of cold hardiness deacclimation rates using grapevine (Vitis spp.). For a comprehensive analysis, we used grapevine canes from V. vinifera cvs. Cabernet Sauvignon and Riesling, and V. hybrid cvs. Concord, Frontenac, Itasca, Marquette, and Petite Pearl. Canes were collected in several states across the continental United States (CO, IA, MN, NY, PA, SD, TX, WI), and in two locations for two states (NY, WI), representing approximately eight different USDA Cold Hardiness Zones (4a-7b), over the course of two winter seasons (2023-2025). Collections occurred in December, January, February, and March of each season. Upon collection or receipt of shipments, initial cold hardiness of buds was measured using differential thermal analysis (DTA). Following, canes were prepared into single node cuttings, and placed in cups of water and in a growth chamber for forcing (22ºC, 16h day/8h night). A subsample of 15 cuttings was used to evaluate time to budbreak, while the remaining cuttings were used for cold hardiness measurements in semi-regular intervals. We used simple linear regression with cold hardiness measurements to determine deacclimation rates (loss of cold hardiness over time; ºC/day). In general, buds from warmer locations (IA, TX, and Long Island, NY) had less initial cold hardiness (field cold hardiness) than colder locations. Dormancy progression was faster in colder locations than warmer locations, observed in both budbreak assays and evaluation of deacclimation rates. Based on our data, time to budbreak is a function of initial cold hardiness and deacclimation rate. Future work will examine the response of deacclimation rates to chilling accumulation models to determine chilling models that best describe dormancy responses across climates, which will then be incorporated into models that predict field cold hardiness and field budbreak.

Speakers

Al Kovaleski

University of Wisconsin-Madison

Co-authors

Ali Didevarasl

University of Wisconsin-Madison

Amaya Atucha

University of Wisconsin Madison

Jason Londo

Cornell University

Michael North

University of Wisconsin-Madison

Wednesday July 30, 2025 2:00pm - 2:15pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Funding Source USDA National Institute of Food and Agriculture, Award No. 2023-68008-39274.

2:00pm CDT

FLOR 1 - Substrate Water Status and Fertilizer Formulation Affect Growth and Tissue Nutrient Content of Petunia and Calibrachoa

Wednesday July 30, 2025 2:00pm - 2:15pm CDT

Strand 12B

Overwatered spring crops are subject to a range of biotic and abiotic disorders including hypoxia, nutrient deficiencies, and increased susceptibility to root rot diseases. Defining parameters associated with under- and overwatering would demonstrate how watering practices influence growth and abiotic disorders that develop during greenhouse production. Growth and nutrient content of petunia ‘Cascadias Indian Summer’ (IS) and ‘Headliner Strawberry Sky’ (SS; Expt. 1) and calibrachoa ‘Aloha Kona Midnight Blue’ (MB; Expt. 2) plants were grown under three different watering regimes of overwatered (rewatered when weight of sentinel pots dropped to 90 to 95 5% of container capacity, CC), optimally watered (60 5% of CC), and underwatered (35 to 45 5% of CC) and two different fertilizer sources of Jack’s Professional General Purpose and Jack’s Classic Petunia Feed. Across both plant species, the optimal watering regime generally yielded the largest plants based on width, fresh and dry weights. SPAD readings of youngest foliage were different based on fertilizer source. While IS petunia did not develop yellowing of youngest foliage in any treatment, SS petunia developed distinctive symptoms of interveinal chlorosis in youngest foliage of overwatered plants fertilized with general purpose fertilizer. However, tissue analysis of SS petunia revealed no difference in Fe between watering regimes or fertilizer formulations. Differences did occur across watering regimes in tissue P, K, Ca, Mg, S, and Mn and between fertilizer formulations in P, Mg, and S. Overwatering induced visual symptomology of chlorotic young foliage in SS petunia and MB calibrachoa, but not IS petunia, which suggests a genetic component to the disorder. Symptomology is effectively mitigated by using petunia feed. Tissue nutrient content is affected by overwatering, but Fe is not significantly different. Future work will explore a mechanism associated with substrate microbial activity that explains these results.

Speakers

Kimberly Williams

Kansas State University

Co-authors

Elise Girard

Kansas State University

Pierce Hayden

Kansas State University

Wednesday July 30, 2025 2:00pm - 2:15pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Funding Source The Gloeckner Foundation

2:00pm CDT

MKEC - The Impact of Consumer Awareness and Treatment Information on Purchasing Decisions for Container-Grown Plants Amid the Jumping Worm Infestation

Wednesday July 30, 2025 2:00pm - 2:15pm CDT

Strand 12A

Jumping worms (Amynthas spp.), an emergent invasive species native to East-central Asia, threaten the health of temperate ecosystems and the vitality of the plant production industry in the United States. Aptly named due to their characteristic and distinctive ability to thrash, these invasive annelids contribute substantial alterations to soil structure, texture, and nutrient dynamics in temperate forests and with potted plants. Their impact on the physical and chemical properties of native soils result in plant health decline and lead to biodiversity loss of flora and fauna. An unintentional, yet predominant, vector of the spread of jumping worms throughout the U.S. is through horticultural materials such as mulch, potting media, compost, and potted plants. While controlling the spread of these invasive worms is a forefront goal of producers and regulatory authorities in the green industry, there is surprisingly little knowledge about consumer awareness of the worms and their willingness to purchase horticultural products infested with, or treated for, jumping worms, which may help inform green industry production management. The objectives of this study were to examine how purchasing decisions are impacted by consumer awareness and jumping worm treatment information. To achieve this, an online survey was conducted with a diverse sample of consumers in the U.S. to gauge their awareness and knowledge of jumping worms, gardening habits, and demographic information. How jumping worm treatment impacts consumers' value for potted plants in different US regions are also explored. The results revealed a notable decrease in willingness to buy and value for untreated potted plants after participants were informed about the negative effects of jumping worms. Further, consumer willingness to buy treated potted plants increased when participants were informed about potential jumping worm treatment options. The findings highlight the influence of consumer education and transparent communication from plant producers and retailers in shaping consumer decisions regarding potted plant purchases. The results of consumer valuation of treated plants have important implications for pricing strategies of jumping worm treated potted plants. These insights are essential for formulating effective communication and treatment strategies to mitigate the impact of jumping worms on ecosystems and the green industry.

Speakers

Jenna Simon

Research Assistant, University of Minnesota

Jenna Simon studies invasive jumping worms (Amynthas spp.) with a focus on containerized production. She has a strong passion for the nursery profession and strives to bridge the gap between horticulture and ecology. She believes that ecology should be viewed from many different lenses... Read More →

Co-authors

Brandon Miller

University of Minnesota

Chengyan Yue

University of Minnesota-Twin Cities (Minneapolis, MN)

Yang Wang

University of Minnesota

Wednesday July 30, 2025 2:00pm - 2:15pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics
Poster # csv
Funding Source Minnesota Department of Agriculture (Specialty Crop Block Grant Fund)

2:00pm CDT

VCM 3 - Impact of Native Wildflowers on the Yield of Three Sisters Crops On Green Roofs

Wednesday July 30, 2025 2:00pm - 2:15pm CDT

Strand 11B

Urban areas are expanding throughout the world, increasing infrastructure and impermeable surfaces and concurrently decreasing quantity and quality of natural landscapes. With a decrease in green spaces, human communities experience an increase in food scarcity. Ecological communities experience a decrease in biodiversity and suitable habitat. Here, we aim to utilize native wildflowers, vegetable crops and urban infrastructure to provide healthy food as well as biodiversity options to urban areas. In this study we examine (a) how the presence of native perennial Colorado wildflowers may influence the yield of crop plants, specifically the three sister’s guild of maize, beans and squash, plus sunchokes and sunflowers and (b) to evaluate how the crop yields may differ between sites in full sun and partial shade landscapes. To do so, we utilize green roofs and ground plots at Colorado State University in Fort Collins, Colorado to evaluate the yield differences. We hypothesize that the crops with wildflowers nearby will produce a higher crop yield than the crops grown without wildflowers. Additionally, we expect that shade treatments will reduce yield compared to the full sun treatments. Thus far with preliminary data analysis, we find crops grown on the green roof with native wildflowers nearby had a higher average leaf number (as a proxy for the size of the plant). The yield of the squash crop was the highest on the green roof with the native wildflowers while the yield of the pole bean crop was highest at grade with native wildflowers nearby. This shows the proximity to wildflowers may have a significant effect and there may be an effect of shade for the yield of pole beans. With this research, we hope to provide notable insight to continue working towards the most efficient crop growth on green roofs in urban environments.

Speakers

Isabella Rodelius

Colorado State University

Wednesday July 30, 2025 2:00pm - 2:15pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management

2:00pm CDT

WUM 2 - Evaluating OpenET against field scale surface renewal ET in walnuts

Wednesday July 30, 2025 2:00pm - 2:15pm CDT

Foster 2

Walnut is currently grown on over 400 thousand acres in California with the majority of production in the Northern San Joaquin Valley (NSJV). The recurring droughts and climate change in California will likely increase the uncertainty in water supply to walnuts and other specialty crops. Site-specific irrigation is critical to cope with these challenges. Knowing the water use of walnuts is crucial in optimizing irrigation management since it affects nut quality, and productivity. Unlike traditional methods, which are often limited by spatial coverage, high costs, and less precise crop coefficient values, satellite remote sensing offers a cost-effective, widely accessible solution. It enables large-scale evapotranspiration (ET) estimation with increasing adoption in irrigated agriculture, providing a valuable tool for water management. This study compares OpenET models, an open-source database providing ET estimates, against commercial in-situ surface renewal ET sensor. Utilizing OpenET platform provides a good opportunity for growers to improve water use efficiency. Such improvements could lead to the adoption of publicly available irrigation management tools and ensure healthier tree development, better resource utilization, and more resilient orchards in the face of climate change. Based on the data of 2024 season, the Satellite Irrigation Management Support (SIMS) model had the highest accuracy in estimating actual ET when compared to measurements from a commercial in-situ surface renewal system in the orchard, with a mean percent error (MPE) of -18.45%, and R² and mean absolute error (MAE) values of 0.88 and 0.03 inches/d⁻¹, respectively, followed by the Ensemble model. In contrast, the SSEBop model showed the lowest correlation with ETa, with an R² of 0.77 and a relatively high MAE of 0.06 inches, indicating a higher level of uncertainty in its estimates which could potentially lead to over-irrigation if adopted without correction. Based on these findings, growers can confidently incorporate the OpenET SIMS model into their irrigation scheduling, ultimately enhancing water use efficiency. However, further validation through replication over a second year and across multiple sites is essential to substantiate these findings.

Speakers

Abdelmoneim Mohamed

Irrigation and Soils Advisor, University of California ANR

Wednesday July 30, 2025 2:00pm - 2:15pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Poster # csv

2:15pm CDT

EcoPhys 1 - Cellular Mechanism of Freeze-Injury Viewed Through Ionic Analysis of the Leachate from Spinach Leaves Injured at Varying Durations of Freezing

Wednesday July 30, 2025 2:15pm - 2:30pm CDT

Strand 11A

Freeze-desiccation due to exosmosis to extracellular ice is considered as the major stress during equilibrium freezing. This causes structural / functional perturbations in the plasma membrane which leads to leakage of cellular contents. To gain further insight into the cellular mechanism of freeze-thaw injury, four cations (K , Ca2 , Mg2 , Fe2 ), known for their critical roles in plant growth and development, were measured in the leachate from injured spinach (Spinacia oleracea L. ‘Reflect’) leaves exposed to four freezing-durations (FDs) (0.5, 3.0, 5.5, 10.5 h) at a fixed temperature. In general, leakage of K , Ca2 , Mg2 increased incrementally at longer FDs and leaves sustained greater water-soaking after prolonged freezing. Data indicated a higher abundance of reactive oxygen species (O2− and H2O2) in leaves with greater injury at longer FDs. PSII efficiency was incrementally compromised at longer FDs as determined by chlorophyll fluorescence (Fv/Fm). Total electrolyte leakage from tissues right-after-thaw versus those allowed to recover for 6-d revealed that injury at 0.5 or 3 h FDs was recoverable, but leaves were irreparably injured at 5.5 or 10.5 h FDs. K was the most abundant cation in leachate. Data suggests that K -leakage can be used as proxy for total electrolyte-leakage in determining LT50 and can serve as an ionic marker to delineate moderate (recoverable) versus severe (non-recoverable) freeze-injury. Ca2 - and K -leakage data, together, are compatible with an earlier conjecture that leaked K ions replace membrane-associated Ca2 during post-thaw. It is proposed that thus structurally weakened plasma membrane, together with inhibited active transport functions of plasma membrane (noted in previous studies) lead to enhanced K -leakage from more severely freeze-injured leaves. Unlike other cations, Fe2 -leakage was indeed lower in the injured (0.5 FD) leaves compared to unfrozen control. Moreover, Fe2 was undetectable in the leachate at longer FDs. It is hypothesized that such lack of Fe2 in the leachate could result from Fenton reaction in injured tissues which converts soluble Fe2 into insoluble Fe3 . Enhanced Mg2 -leakage at greater freeze-injury suggests structural/functional impairment of chlorophyll / chloroplast complex, resulting in reduced quantum yield of PSII.

Speakers

Rajeev Arora

Iowa State University

Wednesday July 30, 2025 2:15pm - 2:30pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Poster # csv

2:15pm CDT

FLOR 1 - Evaluating Sugarcane Bagasse Amended Substrates to Reduce Phosphorus Fertilizer Use in Petunia

Wednesday July 30, 2025 2:15pm - 2:30pm CDT

Strand 12B

Sugarcane bagasse (SCB), a byproduct from the refinement of sugar, is an abundantly available material in tropical and semi-tropical regions. The use of SCB as a component in soilless substrates and other horticulture applications has gained attention due to its regional availability, use as a peat alternative in floriculture production, and as a phosphorus-rich material. Phosphorus (P) is an essential element for the growth of plants; however, P leaching losses from excessive fertilizer applications can pose environmental concerns. This study evaluated using SCB as a soilless substrate amendment in the production of Petunia ‘E3 Easy Wave Coral’, where two particle sizes of SCB (hammermilled at 4 mm and 6 mm) were blended with a peat moss/perlite (7:3 by vol.) floriculture media at rates of 15% and 30% by volume. Two fertilizer rates were investigated, one applying P at 100 mg L-1 and one applying P at a reduced rate of 30 mg L-1. Plant growth and vigor was assessed through measuring growth index (average of plant height and two widths) and chlorophyll content (SPAD). Leachate collected from containers following the “Pour-Through” method was assessed for pH and electrical conductivity (EC), with subsamples collected and analyzed for nutrient content. Plants appeared to grow larger in the control (peat moss/perlite media only) and 15% SCB amended soilless substrates compared to the 30% SCB substrates, regardless of SCB size or fertilizer rate. Substrates amended with SCB at 30% resulted in less vigorous growth than either the control or the 15% SCB amended substrates; however, the differences were less visible in the 30% SCB media when provided the higher P fertilizer rate. Given the important role of P in plant growth and the environmental concerns associated with fertilizer applications, evaluating P availability in sugarcane bagasse and its potential contribution to plant nutrition could provide a more sustainable alternative for soilless substrate systems in floriculture production.

Speakers

Martha Vilchez

Louisiana State University Agricultural Center

Co-authors

Damon Abdi

Louisiana State University Agricultural Center

Jeb Fields

University of Florida

M.P. Hayes

Louisiana State University

Mysha Ahmed

Louisiana State University

Wednesday July 30, 2025 2:15pm - 2:30pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Funding Source Floriculture Nursery Research Initiative

2:15pm CDT

MKEC - Willingness to Pay for Wildlife-Friendly Plants: Insights from Discrete Choice Experiment

Wednesday July 30, 2025 2:15pm - 2:30pm CDT

Strand 12A

Native plants are defined as species present in North America before European settlement which have coevolved with local flora and fauna. Demand and popularity of native plants in landscaping have increased in the U.S. partially due to a rise in awareness of their ecological benefits. Various factors such as income, education, native labeling, and perceptions of wildlife welfare have been linked to consumer willingness to pay (WTP) for native plants. However, fewer studies have explored how different types of wildlife influence these preferences. In this study, we conducted an online survey of 2,011 U.S. consumers. Mixed logit models were used to estimate willingness-to-pay for different wildlife benefits and customer segments were identified using Latent Class Analysis (LCA). Overall, consumers were generally willing to pay a premium for native plants over exotic species, particularly when the plants attracted birds or pollinators. In contrast, plants associated with deer or offering no wildlife benefit required a discount to be considered. Four customer classes were identified with varying levels of interest in attracting songbirds, pollinators and deer. Marketing implications will be discussed based on class membership.

Speakers

Nama Bhusal

University of Tennessee

Co-authors

Alicia L Rihn

University of Tennessee

Ariana Torres

Purdue University

Bridget Behe

Michigan State University

Sue Barton

University of Delaware

Wednesday July 30, 2025 2:15pm - 2:30pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics
Poster # csv
Funding Source Horticulture Research Institute

2:15pm CDT

VCM 3 - Evaluating Impact of Rooftop Agrivoltaics (RAV) on Chile Pepper (Capsicum annuum L.) Production and Growth

Wednesday July 30, 2025 2:15pm - 2:30pm CDT

Strand 11B

Climate change progression has created many challenges for our current agriculture system such as the degradation of arable land and more intense weather patterns. Rates of food insecurity and population growth are simultaneously increasing in urban areas, so reimagining food production and land management is vital for the future of agriculture. Rooftop agrivoltaics (RAV), growing crops under solar panels on a green roof, may be an effective way to produce clean energy and high yields of specialty crops in underutilized spaces. Chile peppers hold economic and cultural significance to the southwest region of the US. Previous studies show chile peppers perform better under 35% shade than in full sun due to heat stress reduction. This study focused on three cultivars of chile peppers: ‘Hatch’, ‘Mosco’, and an unnamed CSU experimental. Individuals of each cultivar were planted in four on the green roof (under opaque photovoltaics (PV), under bifacial PV, under 40% shade cloth, and full sun) and in one at-grade plot. The 40% shade cloth was used to simulate semi-transparent solar panels. Plants were evaluated by yield (fruit production), water efficiency (stomatal conductance), and plant growth index (average of two widths and height). Analysis shows yield was significantly higher in the full sun and shade cloth plots than all other plots, possibly due to the bifacial and opaque plots providing too much shade for optimized fruit production. Stomatal conductance was reduced in the shade cloth, bifacial, and opaque plots in the first part of the growing season and varied by cultivar and treatment at other times. Plant growth index was highest for plants grown in the shade cloth plot at most time points, but significance varied by cultivar across treatments. Growing chile peppers in RAV systems utilizing semi-transparent solar panels can reduce plant water use while producing more fruit than traditional at-grade growing. Sensory evaluation using a just-about-right (JAR) test and was conducted to assess consumer acceptance of sensory attributes of roasted ‘Hatch’ and ‘Mosco’ chile peppers grown in full sun on a green roof and at grade. A standard 9-point hedonic scale was used to assess overall liking. There was no significant difference in JAR ratings for each of the 7 attributes assessed and no significant difference in overall liking. Growing ‘Hatch’ and ‘Mosco’ chile peppers on green roofs does not significantly impact consumer acceptance. This provides urban farmers with more confidence to grow chile peppers on green roofs.

Speakers

Maria Chavez

New Mexico State University

Co-authors

Jennifer Bousselot

Colorado State University

Wednesday July 30, 2025 2:15pm - 2:30pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management

2:15pm CDT

WUM 2 - Evaluation of the Effects of Treated Wastewater on the Growth of Rose-Scented Geranium and English Lavender

Wednesday July 30, 2025 2:15pm - 2:30pm CDT

Foster 2

Water scarcity is one of the major challenges facing the agricultural industry, necessitating the use of treated wastewater for irrigation purposes. However, not all crops can effectively utilize this water, as it may have negative effects on plant growth, including disruptions in nutrient uptake and photosynthesis. This study aimed to evaluate the effects of treated wastewater on the growth of rose-scented geranium (Pelargonium graveolens) and English lavender (Lavandula angustifolia). The experiment was conducted between 2022 and 2023 at the University of Fort Hare, Dikeni, South Africa. Two harvests were carried out in May 2023 (Harvest 1) and October 2023 (Harvest 2). Five irrigation treatments were applied to both geranium and lavender plants, consisting of treated wastewater from Dikeni town mixed with tap water at varying proportions: 0%, 25%, 50%, 75%, and 100% (v/v). Water and soil used were tested for nutritional composition. Treatments commenced four weeks after transplanting from cuttings, and the experiment followed a completely randomized block design with four replications across four blocks. The results showed no treatment differences in stem diameter, number of shoots, or plant height across treatments for both plant species during the two harvesting seasons. However, English lavender plants irrigated with 25% wastewater exhibited a slight increase in plant height at week 11, while geranium plants treated with 75% wastewater showed an increased plant height from week 5 until harvest at week 11. Additionally, plants receiving the 25% wastewater treatment produced the highest number of shoots from week 8 to week 11. These findings suggest that treated wastewater, both in its diluted and undiluted form, did not adversely affect plant growth. Therefore, it has the potential to serve as an alternative water and nutrients source for geranium and lavender plants, which farmers could utilize in collaboration with local municipalities to mitigate water scarcity challenges. However, further studies, particularly under open-field conditions, are needed to validate these results.

Speakers

Sandile Manzi Ngwenya

University of Fort Hare

Co-authors

Bahlebi Kibreab Eiasu

University of Fort Hare

Yandisa Tokota

University of Fort Hare

Wednesday July 30, 2025 2:15pm - 2:30pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Poster # csv
Funding Source University of Fort Hare Reasearch and Innovation Department

2:30pm CDT

EcoPhys 1 - Characterization of Fulvic acids-mediated Drought Tolerances in Tomatoes using Untargeted Hormonomics and Metabolomics Approaches

Wednesday July 30, 2025 2:30pm - 2:45pm CDT

Strand 11A

Drought stress poses significant environmental challenges to agricultural plants, especially tomatoes, by hindering their growth and reducing yields. Biostimulants like fulvic acids (FA) have emerged promising strategies for mitigating drought effects and enhancing water-use efficiency. However, the regulatory mechanisms of FA-induced drought tolerance are not yet fully understood. This study aimed to characterize FA-induced drought tolerance mechanism in tomatoes. Four-week-old plants were treated with FA at 240 mg per plant, and drought conditions were imposed by withholding 75% of the water supplied to well-watered plants. The plant growth performance and the physiological responses were evaluated. Leaf samples were collected at two stages: the early drought stage (3 days after treatment) and the later stage (7 days after treatment), for untargeted hormonomics and metabolomics analysis using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Under drought conditions, control plants exhibited significant stress symptoms, including reduced height and leaf wilting during the later phase. In contrast, FA-treated plants developed less drought symptoms and improved stomatal conductance. The hormonomics and metabolomics analysis identified 114 hormones and 243 metabolites in ESI . Using orthogonal partial least-squares discriminant analysis (OPLS-DA), we determined that 39 hormones and 162 metabolites (with a VIP score > 1.0) were significant discriminants among the different treatments. Under drought conditions, 2-hydroxy melatonin and abscisic acid (ABA) levels were significantly increased in FA-treated plants, along with higher concentrations of amino acids such as glycine and threonine. These findings suggest that fulvic acids modulate the phytohormones ABA and melatonin to induce drought tolerances, orchestrating a response that enhances drought tolerance by sustaining elevated levels of osmoprotective amino acids.

Speakers

Md Al Mamun

University of Tennessee

Co-authors

Ethan W. Darby

The University of Tennessee

Mahadi Hasan Redoy

University of Tennessee

Tabibul Islam

University of Tennessee, Knoxville

Wednesday July 30, 2025 2:30pm - 2:45pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Poster # csv

2:30pm CDT

FLOR 1 - Temperature Management and Supplemental Lighting Strategy Effects on the Coloration and Morphology of Petunia ×hybrida

Wednesday July 30, 2025 2:30pm - 2:45pm CDT

Strand 12B

In high latitudes (≥40°), commercial greenhouse growers utilize supplemental lighting (SL) and heating to offset low solar radiation, air average daily temperature (ADT), and root-zone temperature (RZT) during peak young-plant production. Growers have historically used high-pressure sodium (HPS) lamps to deliver SL but are transitioning to light-emitting diode (LED) fixtures, mostly because of their improved energy efficacy. However, many growers report changes in crop morphology and undesirable purple leaf pigmentation when cuttings of some species, especially petunia (Petunia ×hybrida), were grown under LEDs. The objectives of this study were to 1) quantify how light intensity during callusing, ADT, RZT, and SL sources influence the morphology, rooting, leaf pigmentation, and quality of petunia and to 2) develop strategies to mitigate the purpling of leaves. Shoot-tip cuttings of petunia SureShot ‘Dark Blue’ and ‘White’ were inserted into 72-cell trays and propagated inside a greenhouse at an air ADT of 21 or 23 °C and with an RZT of 21 or 25 °C. Cuttings were grown under SL delivered by HPS lamps or LED fixtures proving different light qualities (low blue or moderate blue) at a photosynthetic photon flux density of 60 or 120 µmol·m–2·s–1 for the first 6 d, then 120 µmol·m–2·s–1 for the remaining 16 d. Cuttings of both cultivars grown at an air ADT of 23 °C often had greater stem lengths and shoot dry masses than cuttings grown at 21 °C, as well as lower concentrations of anthocyanins. Cuttings of both cultivars grown with an RZT of 25 °C typically had longer stems than those grown with an RZT of 21 °C. Overall, cuttings of both cultivars propagated under LEDs were of greater quality (shorter stems, greater root dry mass) than those grown under HPS lamps. The color of cuttings grown under LEDs were more red and blue than those grown under HPS lamps, especially at low ADT and RZT. Additionally, the anthocyanin content of ‘Dark Blue’ cuttings grown under LEDs was greater than those grown under HPS lamps. Little differences were observed between cuttings grown under either LED fixture. These results indicate that growers using LEDs may have to adjust other environmental parameters, such as light intensity, ADT, and RZT, to produce cuttings of similar morphology and quality to those grown under HPS lamps.

Speakers

Charles Smith

Michigan State University

Co-authors

Erik Runkle

Michigan State University

Nathan Jahnke

Ball Horticultural Company

Roberto Lopez

Michigan State University

Wednesday July 30, 2025 2:30pm - 2:45pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Funding Source Project GREEEN, Michigan Department of Agriculture and Rural Development Specialty Crop Block Grant, Ball Horticultural Company

2:30pm CDT

MKEC - Consumer preferences and willingness to pay for Lettuce and bell peppers grown under different supplemental lighting sources

Wednesday July 30, 2025 2:30pm - 2:45pm CDT

Strand 12A

As sustainable agricultural practices become increasingly important, the use of supplemental lighting technologies—particularly light-emitting diodes (LEDs)—is gaining momentum in greenhouse and indoor farming systems. While LEDs offer advantages in terms of energy efficiency and plant growth potential, consumer perceptions of crops grown under artificial lighting remain uncertain. This study explores how consumers respond to vegetables—specifically lettuce and bell peppers—produced using different lighting sources, including LED, high-pressure sodium (HPS), and natural sunlight, along with other product attributes such as production origin, organic certification, price, and point of purchase. A nationwide online survey was conducted to assess consumer awareness, preferences, and willingness to pay for produce grown under various lighting and production conditions. Participants were randomly assigned to different informational treatments that presented either positive, negative, or no information about LED lighting. A choice experiment was used to simulate real-world purchasing scenarios, allowing researchers to examine how these informational messages influenced consumer decision-making. The findings indicate that both production methods and the way information is communicated can significantly impact consumer preferences. Lighting source, in particular, emerged as a key factor, but its influence varied depending on the context in which it was presented. These insights underscore the need for thoughtful messaging and education strategies when introducing new agricultural technologies to the market. Understanding consumer attitudes toward lighting and other production attributes is essential for supporting the broader adoption of sustainable practices in modern food systems.

Speakers

Andres Mauricio Mayorga-Gomez

The University of Georgia

Co-authors

Ben Campbell

University of Georgia

Julie Campbell

University of Georgia

Wednesday July 30, 2025 2:30pm - 2:45pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics
Poster # csv

2:30pm CDT

VCM 3 - Effect of intercropping asparagus with King Stropharia mushroom in woodchip mulch at three depths

Wednesday July 30, 2025 2:30pm - 2:45pm CDT

Strand 11B

Intercropping mushrooms with field-grown vegetables may provide farmers additional revenue without sacrificing bed space or investing in indoor production facilities. The King Stropharia mushroom (Stropharia rugosoannulata), also called wine cap, can colonize organic material, like woodchips or straw mulch, making it a good candidate for intercropping with vegetables that can be grown on organic mulches. However, no research has evaluated the impact of this strategy on the vegetable yield. This project seeks to evaluate the compatibility of intercropping wine-cap mushrooms with asparagus in woodchip mulch. A randomized complete block experimental design (RCBD) experiment was initiated in 2021, and data was collected during the 2022 and 2023 growing seasons. The trial evaluated two factors: intercropping – inoculated vs. non-inoculated and mulch depth – 0 in (control), 4 in, 8 in, and 12 in. Wine-cap mushrooms were successfully established in the inoculated plots. The woodchip mulch depth had no effect on the timing or overall yield and marketability of the mushrooms, although 4 in mulch produced a smaller proportion of small-medium, Grade 1 mushrooms resulting in higher average weight fruiting bodies compared to deeper mulch treatments. During the first spring harvest, wine-cap mushrooms were also observed on the edges of non-inoculated plots; therefore, we were unable to evaluate the effects of mushroom on asparagus growth. Woodchip mulch did not affect the date of first harvest or harvest duration in either year, except at 12 in depth, which delayed harvest and shortened the production season. Relative to bare ground, woodchip mulch only affected asparagus yield (by number or weight) at 12 in depth, which decreased the number and weight of harvested asparagus. In 2023, asparagus spears grown with 8 in non-inoculated woodchips weighed 80 % more, on average, than spears grown in 4 in and 12 in inoculated plots. While the experiment provides a proof of concept for intercropping wine-cap mushrooms with asparagus, further research is needed to determine whether intercropped mushrooms directly impact asparagus production.

Speakers

Olalekan Sipasi

Post Doc, Dept. of Plant Pathology, Kansas State University

Sipasi Olalekan Ayodele is a Ph.D. Candidate at the Department of Horticulture and Natural Recourses at Kansas State University, ONE Champion 2017, Fellow Thinking School Africa, 2016 Winner of the African Youth Award in Agriculture, a seasoned NYSC SDGs Facilitator, The Future Award... Read More →

Co-authors

Jeremy Cowan

Kansas State University

Wednesday July 30, 2025 2:30pm - 2:45pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management

2:30pm CDT

WUM 2 - Evaluating Nutrient Remediation and Growth of Hibiscus moscheutos ‘Luna Pink Swirl’ in Modified Raingarden Medias

Wednesday July 30, 2025 2:30pm - 2:45pm CDT

Foster 2

Runoff containing excess nitrogen (N) and phosphorus (P) is detrimental to environmental and human health. Bioreactors are biological treatment systems that can be used to combat these problems, which often consist of a lined trench filled with a carbon-rich media (often woodchips) to promote biological remediation through denitrification and other processes. Various carbon-rich organic materials, such as woodchips and sugarcane bagasse (a byproduct of sugarcane production), can be used to fuel biological processes, whereas inorganic materials, such as expanded shale, can provide binding sites for P adsorption as well as physical stability within medias. Raingarden installations utilize similar concepts for trapping runoff water and remediating contaminants; however, the inclusion of ornamental plants provides aesthetic appeal, an important consideration in urban and suburban areas. Seven unique medias were evaluated to determine potential to a.) remediate N and P from runoff and b.) support plant life. An aged pine bark/sand media commonly used for landscape beds (bed mix; BM) served as the control. Organic carbon sources (woodchips (WC) and sugarcane bagasse (SB) to support bacterial communities) and several inorganic materials (including expanded shale (S) and activated aluminum (AA) to bind P) were blended with BM to provide potential enhancement of nutrient removal capabilities. Media blends were homogenized by hand before being transferred into media containers (MC; 2.36 L of substrate per container), wherein Hibiscus moscheutos ‘Luna Pink Swirl’ seedlings were transplanted. Pots were placed within plastic containers (leachate containers (LC)), which served as a collection receptacle for leachate. Simulated runoff water containing N and P was prepared and applied to each replicate, after which leachate was analyzed and collected as sub-samples. Simulated runoff applications were limited in the initial phase of the study (one application per week; three total) and intensified in the final phase (three applications per week; nine total), with all leachate volumes collected between applications. Health and growth of Hibiscus was assessed via SPAD readings, growth index, and destructive harvest at the termination of the study. While the growth of all Hibiscus replicates was generally equivalent between treatments, it was observed that BM amended with SB produced more shoot biomass. Additionally, leachate nutrient content and water chemistry dynamics were influenced by several of the investigated amendments.

Speakers

Brianna Slade

Louisiana State University Agricultural Center

Co-authors

Damon Abdi

Louisiana State University Agricultural Center

Jeb Fields

University of Florida

Jeff Kuehny

Louisiana State University Agricultural Center

Jeffrey Beasley

University of North Carolina - Pembroke

John Pardue

Louisiana State University

M.P. Hayes

Louisiana State University

Mysha Ahmed

Louisiana State University

Wednesday July 30, 2025 2:30pm - 2:45pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Funding Source Environmental Protection Agency

2:45pm CDT

EcoPhys 1 - New Methods to Assess Drought Resistance in Turfgrass

Wednesday July 30, 2025 2:45pm - 3:00pm CDT

Strand 11A

The irrigation of grasses dominates domestic water use across the globe, and a better understanding of water use and drought resistance in grasses is of undeniable importance for water conservation. Drought resistance is a complex trait composed of three distinct, but complementary, strategies: escape, avoidance, and tolerance. In grasses, drought escape is commonly displayed via summer dormancy, and drought avoidance and tolerance are displayed by grasses experiencing dehydration. Breeding programs have released cultivars with improved drought resistance, but the underlying mechanisms remain unknown. In this study, we used a number of plant physiology methods to characterize the mechanisms driving drought resistance in four zoysiagrass cultivars reported to exhibit contrasting levels of drought resistance. They were Lobo, Zeon, Empire, and Meyer. A dry-down was performed through deficit irrigation until 70% decline in evapotranspiration. No drought escape mechanism was identified in this project. Drought avoidance was characterized by the rate of dehydration over time, and drought tolerance was characterized by the decline in functional traits with increasing dehydration. Through this approach, we were able to separate avoidance from tolerance and demonstrate that drought tolerance governs drought resistance in commercial cultivars of zoysiagrass. Interestingly, we also demonstrated that canopy mortality during drought can only be reliably assessed using image analyses shortly after rehydration. This is because severe leaf rolling occurs during drought, confounding leaf rolling with actual leaf mortality. This study advances our understanding of i) drought resistance across commercial cultivars of zoysiagrass and ii) potential methods to select drought-resistant cultivars in turfgrass breeding programs.

Speakers

Amanda Cardoso

North Carolina State University

Wednesday July 30, 2025 2:45pm - 3:00pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Funding Source This work was supported by the Research Capacity Fund (HATCH), project award no. 7003279, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture and the Center for Turfgrass Environmental Research and Education Board at NC State University.

2:45pm CDT

FLOR 1 - Evaluate the effects of photoselective shade nets on physiology and morphology of Zinnia (Zinnia elegans ‘Cherry Queen’)

Wednesday July 30, 2025 2:45pm - 3:00pm CDT

Strand 12B

Photo-selective shade nets substantially benefit ornamental plant production by mitigating excessive radiation, enhancing light diffusion, and promoting adequate ventilation. These nets establish favorable microclimates that optimize water utilization, thereby reducing plant water demand through physiological and environmental adjustments. Shade nets of different colors vary notably in their spectral distribution and light transmission characteristics, directly impacting plant morphology, physiology, and development. This study aimed to evaluate how different colored photo-selective shade nets influence physiological, morphological, and floral characteristics, as well as water usage, in Zinnia elegans ‘Cherry Queen’. We used four distinct shade net colors: blue, red, white, and black with 30% shade factor as treatments. The 107 cm x 61 cm shade structure was prepared using the PVC pipes with different colored shade nets wrapped around it. Seeds of zinnia were sown in a commercial substrate, Metro-Mix® 820, and kept on a misting bench. Following germination, the plugs were transplanted in a 3.6 L pot filled with the same commercial substrate and kept under four distinct color shade nets. Substrate moisture content was consistently maintained at 35% volumetric water content using an automated irrigation system using capacitance-based soil moisture sensor, ECH20 10HS from Meter Group. Black shade nets transmitted the least radiation across all wavelengths. Blue shade nets increased transmission in blue and green wavelengths while reducing red and far-red light transmission. Red shade nets enhanced red and far-red wavelength transmission, whereas white nets provided the highest overall radiation across all wavelengths. Morphologically, plants grown under red and white shade nets exhibited similar growth and floral characteristics to those under blue nets, and all showed improved growth compared to plants under black nets. Physiological responses, including photosynthetic assimilation rate, stomatal conductance, chlorophyll fluorescence (Fv/Fm), Soil Plant Analysis Development (SPAD), Normalized Difference Vegetation Index (NDVI), and anthocyanin content measured via leaf spectrometry remained similar across all treatments. Water use per plant was highest under white shade nets, significantly exceeding usage under black nets but comparable to blue and red nets. Growers may prefer red or white shade nets for optimal growth and water efficiency, blue for balanced spectral quality, or black for reduced radiation needs.

Speakers

Anju Chaudhary

Utah State University

Co-authors

Shital Poudyal

Utah State University

Wednesday July 30, 2025 2:45pm - 3:00pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Poster # csv

2:45pm CDT

MKEC - Living Near A Greenhouse: Proximity and Perception

Wednesday July 30, 2025 2:45pm - 3:00pm CDT

Strand 12A

Perceptions of production agriculture vary from unconcerned to concerned. These positive and negative perceptions can be greater for green industry firms given many firms locate near urban areas. Using a nationally representative survey of 4,000 U.S. residents, this study examines respondent concern level for living near a food and plant producing greenhouse. Furthermore, we examine the role distance a respondent lives from a greenhouse plays in their concern level. We then breakdown concern levels for different production practices (e.g., water usage, energy use, noise pollution, light pollution, etc.) by distance a respondent lives from a greenhouse. Results indicate that distance lived plays a role in greenhouse concern level. Demographics also play a role in concern level. Greenhouse producers can use these results to better understand how their "neighbors" view their operations and what types of educational efforts may be needed when interacting with their community.

Speakers

Ben Campbell

University of Georgia

Wednesday July 30, 2025 2:45pm - 3:00pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Poster # csv

2:45pm CDT

VCM 3 - Evaluating New Broccoli Cultivars: Effect of Planting Time on Growth and Yield in North Dakota

Wednesday July 30, 2025 2:45pm - 3:00pm CDT

Strand 11B

Small-scale growers face challenges in optimizing the quantity and quality of new broccoli cultivars due to shifting weather patterns and the prevalence of heat-sensitive cultivars. This study aims to identify high-performing cultivars and optimal planting dates for late spring to enhance the competitiveness of cool-season specialty crop growers in North Dakota. The research took place at the NDSU Horticulture Research Farm, near Absaraka, ND, to examine how planting time impacts cultivar performance through field experiments on four planting dates: May 1st, May 15th, June 1st, and June 15th. Early planting of broccoli, particularly in May, resulted in higher yields and better quality across all cultivars. Some cultivars outperformed others. 'Jacaranda' yielded significantly more than any other cultivar, which is a noteworthy. Conversely, 'Gypsy' and 'Monty' had yields similar to the standard cultivar 'Green Magic', while 'Purple Peacock' yielded less across all planting dates, indicating poor adaptation. Early planting benefited all broccoli cultivars, with later dates bringing higher temperatures that negatively impacted head formation and curd size across all cultivars. These elevated temperatures alter key physiological parameters, such as increased transpiration and vapor pressure deficit, while potentially reducing photosynthetic efficiency and stomatal conductance. The physiological changes induced by higher temperatures ultimately lead to accelerated maturation, smaller heads, and reduced overall yields. Notably, early planted broccoli potentially achieved up to 35% higher yields than late-planted crops. The findings provide valuable insights into the relationships between planting dates, temperature effects, and cultivar-specific responses, emphasizing the importance of these factors in maximizing yield and quality for cool-season specialty crop growers in the region.

Speakers

Ajay Dhukuchhu

Graduate Research Assistant, NORTH DAKOTA STATE UNIVERSITY

I have developed a great interest in sustainable management practices improving the resiliency of agriculture and ecosystem services to sustain the food production system and ecosystem worldwide, which have long term support in sustainable development. And, I believe maintaining economic... Read More →

Co-authors

Harlene HattermanValenti

NDSU

Wednesday July 30, 2025 2:45pm - 3:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management
Poster # csv

2:45pm CDT

WUM 2 - Evaluating Colorado Native Plants for Green Infrastructure: Survivability and Performance in Semi-Arid Bioretention and Green Roof Systems

Wednesday July 30, 2025 2:45pm - 3:00pm CDT

Foster 2

Green infrastructures, when implemented, need to consider the specifics of the local area and climate. The semi-arid climate along Colorado’s front range creates a challenge for plants in green infrastructure systems such as bioretention facilities and green roofs. These plants experience inundation and fast infiltration during rain events and long periods of hot and dry conditions between storms. To accommodate these periods of inundation and drought, Colorado native plants were evaluated due to their adaptation to the challenging conditions that occur in green infrastructure. The experiments in this study are intended to build upon existing work performed by our collaborators and funders Mile High Flood District, the City and County of Denver, and Colorado State University. We aim to improve green infrastructure facility design by using new bioretention media mixes, amended native soils with 5% compost (SSC) and amended native soils with biochar and zeolite (SBZ), green roof components/systems, new plant growth and establishment strategies, and lower irrigation regimes. In 2023 and 2024, data on plant survivability were collected from the bioretention facilities and the green roofs using 100 containerized and bare-root plants. The five native Colorado species selected were Agastache rupestris, Liatris ligulistylis, Amorpha canescens, Ratibida pinnata, and Schizachyrium scoparium. L. ligulistylis, in container, had a higher survival rate after one year on the green roof, on the other hand, it had a low survival rate after a year in the bioretention facilities. The bare-root L. ligulistylis had a higher survival rate, especially in the SSC media. A. canescens, bare-root, had a higher survival rate in the SSC media, while only 25% survived in the SBZ media. All other species overwintered and grew larger the second year on the green roof and bioretention facilities. The Colorado native plants tolerated challenging conditions better than the nonnative plants in the surrounding area.

Speakers

Amanda Salerno

Colorado State University

Wednesday July 30, 2025 2:45pm - 3:00pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Poster # csv

3:00pm CDT

EcoPhys 1 - From Classic to Cutting-Edge: Optimizing Salinity Tolerance Detection in Brassica juncea

Wednesday July 30, 2025 3:00pm - 3:15pm CDT

Strand 11A

Salinity stress is a growing concern in agriculture, particularly as climate change accelerates soil salinization and limits freshwater availability. Here, we evaluated the effectiveness of classic (low-throughput) versus high-throughput physiological phenotyping methods in detecting early salinity tolerance in Brassica juncea cultivars (‘Carolina Broadleaf’ and ‘Southern Giant Curl’). Traditional phenotyping relies on point measurements such as shoot biomass and leaf gas exchange, which, while valuable, are time-intensive, offer limited temporal resolution, and can be destructive. In contrast, high-throughput phenotyping enables continuous, real-time monitoring of plant physiological responses, providing a dynamic and detailed understanding of stress adaptation mechanisms. We conducted a 42-day experiment in a controlled greenhouse environment, exposing mustard green cultivars to three salinity treatments: control (0.397 dS/m), moderate salinity (10.81 dS/m, ~20% of seawater), and high salinity (24.93 dS/m, ~50% of seawater). The high-throughput PlantArray system was used to measure key physiological parameters, transpiration rates, and net plant weight gain, while traditional phenotyping involved weekly surveys of including stomatal conductance, chlorophyll fluorescence, and biomass accumulation. We found that high-throughput phenotyping allows for earlier and more precise detection of salinity tolerance. Classic methods confirmed significant reductions in biomass, with shoot fresh weight decreasing by up to 80% in high-salinity treatments, but these differences were only detectable at harvest and not before. In contrast, high-throughput phenotyping revealed early signs of osmotic adjustment within the first 20 days, as plants initially maintained transpiration before exhibiting a decline due to ion accumulation. ‘Carolina Broadleaf’ resist moderate salinity, maintaining growth comparable to the control for the first 20 days, suggesting that early harvesting could mitigate yield losses. Overall, this study underscores the advantages of high-throughput phenotyping in improving the precision and efficiency of breeding programs. By integrating continuous physiological measurements, this approach enables earlier and more informed selection of salt-tolerant cultivars, reducing time needed for tolerance screening. Future research should focus on expanding these methods to operational conditions and integrating genomic data to enhance genotype-environment modeling for stress adaptation.

Speakers

Raiza Castillo

University of Florida

Co-authors

Cross Heintzelman

University of Florida

Elias Bassil

University of Cyprus

Gerard Sapes

University of Florida

Laura Torres

University of Floridaa

Marylou Mantova

University of Florida

Melanie Correll

University of Florida

Neus Alcon Bou

University of Florida

William Hammond

University of Florida

Wednesday July 30, 2025 3:00pm - 3:15pm CDT
Strand 11A

Oral presentation, Ecological Physiology 1

Subject Ecological Physiology
Funding Source USDA SAS CEA: 2506-207-2015906
Funding Option SCRI funded all or part of the research associated with this abstract

3:00pm CDT

FLOR 1 - Growing Opportunity: Enhancing Dahlia Production for Maryland's Small-Scale Farmers

Wednesday July 30, 2025 3:00pm - 3:15pm CDT

Strand 12B

Maryland’s cut flower industry represents an expanding sector within the broader U.S. horticultural market, currently valued at $6.69 billion with Maryland alone contributing significantly ($139 million in 2018). Recent surveys conducted at the 2025 Bay Area Fruit School and University of Maryland Eastern Shore, Small Farm Conference-2024 provided critical insights into the demographic diversity, interests, and barriers faced by Maryland cut flower growers. Survey results indicated a diverse population, with participants spanning various ages, experience levels, and farming backgrounds. The largest demographic segment (25%) ranged between 35-44 years, suggesting an active, economically productive age group interested in cut flower production. Notably, the survey underscored a strong existing interest, with half of the respondents expressing a high level of enthusiasm toward cultivating cut flowers. Despite this enthusiasm, significant barriers impede growth and expansion. Key limitations identified included a lack of expertise and technical knowledge (41.7%), limited availability of relevant workshops and training (33.3%), and restricted market access (37.5%). Other reported challenges comprised high production costs (29.2%), pest and disease management issues (25%), limited labor availability (20.8%), and environmental factors such as weather variability and soil conditions. Dahlias emerged from these findings as a particularly promising crop, offering distinct advantages for Maryland farmers, especially those with constrained resources. Due to their delicate blooms and brief vase life, dahlia imports into the U.S. are minimal, primarily limited to pompon varieties. This creates a substantial market gap and an opportunity for local growers to supply diverse, premium-quality blooms tailored to consumer preferences. Consumers increasingly favor locally grown, sustainably produced flowers, especially when sourced directly from local farms, enhancing market potential for dahlias. To enhance dahlia production in Maryland, growers should consider collaborative research trials and evaluations of variety selection, sustainable cultural practices, and integrated pest management strategies under varying conditions, including open fields and protected cultivation such as high tunnels. Developing specialized extension materials, hands-on workshops, and practical demonstrations can also significantly address existing knowledge gaps. Such focused, region-specific guidance and facilitation of access to lucrative markets would empower Maryland's small-scale growers to capitalize fully on the growing demand for locally produced specialty flowers, significantly enhancing their productivity, profitability, and long-term sustainability.

Speakers

Naveen Dixit

University of MD Eastern Shore

Wednesday July 30, 2025 3:00pm - 3:15pm CDT
Strand 12B

Oral presentation, Floriculture Floriculture 1

Subject Floriculture
Funding Source USDA-EIP

3:00pm CDT

MKEC - Identifying Boundaries of Profitability in Horticultural Production: Economic

Wednesday July 30, 2025 3:00pm - 3:15pm CDT

Strand 12A

As the human population grows in number and in urban locations, global food production will need scale to demand while concurrently minimizing its environmental impact. One possible answer for sustainably meeting future food demand is the adoption of controlled environment agriculture (CEA) systems. CEA includes indoor, greenhouse, and other types of growing systems that allow for the control of light intensity and duration, temperature, and humidity. As a horticultural approach, CEA has the ability to reduce water use by 95% while occupying 90% less land than traditional field agriculture. CEA also improves growers’ control over crop quality, which contributes to premium prices, while improving yield and reducing waste. Despite this promise, the emergent CEA industry faces a critical challenge: achieving economic feasibility while improving its systemic environmental sustainability; a problem underscored by the energy-intensive nature of the controlled environment. Our study integrates production efficiency with economic and environmental evaluation using a combination of a bioeconomic modeling approach followed by a strategic profitability analysis as well as a life cycle analysis (LCA). A case study was used to develop the spatiotemporal model, integrating three modules: production, labor and economic performance. The model employs a mathematical framework to represent interactions between biological systems, technological settings, and the economic systems that exploit them, which allow for the identification of relationships and production patterns amongst variables. The model’s economic output was then evaluated using the DuPont equations: measures of asset turnover (return on assets [ROA]), leverage (return on equity [ROE]), and profitability (net income/sales). These key performance indicators framed our analysis of the sample farm’s financial health. Finally, the LCA evaluated the farm's externalities across environmental impact multiple categories. The LCA evaluates CEA’s built environment as well as production resource use. The analysis focused on 4 different varieties: romaine, pak choi, red radish and basil. Results show that economically, labor is the most significant operating expense (41%) and environmentally, the crop production stage is the most significant contributor environmentally (due to lighting and HVAC energy use). These results conclude that deployment of automation could improve the financial viability of CEA farms; while investing in energy efficient lighting could reduce CEA’s environmental impact.

Speakers

Megan Burritt

MSU

Co-authors

Liping Wang

University of Wyoming

Simone Valle de Souza

MICHIGAN STATE UNIVERSITY - EAST LANSING,MI,USA

Sujit Dahal

University of Wyoming

Wednesday July 30, 2025 3:00pm - 3:15pm CDT
Strand 12A

Oral presentation, Marketing and Economics

Subject Marketing and Economics
Poster # csv
Funding Source USDA National Institute of Food and Agriculture - Specialty Crop Research Initiative [grant no. 2019-51181-300]

3:00pm CDT

VCM 3 - Rhizome Growth Dynamics of High Tunnel Ginger in Virginia

Wednesday July 30, 2025 3:00pm - 3:15pm CDT

Strand 11B

As a tropical crop, ginger (Zingiber officinale) rhizomes will not fully mature inside high tunnels in Virginia. The objective of this study was to monitor the growth and development of ginger rhizomes throughout the season, as reflected in the fresh and dry weights. The ultimate goal was to determine the harvest time of rhizomes for profitable fresh and dry ginger. Ginger cultivars Bird, Blue Ring, Buffalo Gung, Chinese, Indian, Peruvian Yellow, Red, and Yellow were pre-sprouted in a greenhouse in mid-March of 2024. Sprouted ginger rhizomes were transplanted into raised beds in a 26’ x 150’ high tunnel on May 16, 2024, on Randolph Farm of Virginia State University. The in-row spacing was 1 ft. Monthly destructive samples of 3 plants/cultivar (one in each of the 3 replications) were conducted for fresh and dry weights. Cultivars differed in the rhizome fresh and dry weight over time. Fresh rhizome weight of cultivar Bird, Chinese, Indian, Peruvian Yellow and Yellow reached 0.5 lb/plant 3 months after transplanting (MAT). “Red” had significantly higher percentages of dry weight (> 8%) than other cultivars (< 6%) until 5 MAT, when other cultivars began to catch up. Pooling data from all cultivars, we found that ginger rhizomes will reach 0.5 lb/plant, which is a profitable yield, around 3 MAT. The percentage of dry weight remained low (5.3-5.7%) until 4 MAT, but the number spiked quickly to 8.3 % at 5 MAT and 13.4 at 6 MAT. Our results suggest that young ginger harvest can happen as early as 3 MAT. However, to harvest rhizome for dry ginger, 5 MATs are needed and harvest should occur at the end of season for maximal yield. “Red” is a unique cultivar. It has the lowest yield (1.3 lb/plant), but its percentage of dry weight remained high (8.2-8.8%) for 5 months, compared to all other cultivars (4.4-6.4%).

Speakers

Sanjun Gu

Virginia State University

Co-authors

Peter Coffey

Virginia State University

Wednesday July 30, 2025 3:00pm - 3:15pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 3

Subject Vegetable Crops Management
Poster # csv

3:00pm CDT

WUM 2 - Seasonal Water Use and Yield Productivity: Comparing Organic vs. Conventional Iceberg Lettuce with Different Irrigation Scheduling Strategies under Surface Drip Irrigation in Yuma, Arizona

Wednesday July 30, 2025 3:00pm - 3:15pm CDT

Foster 2

Lettuce (Lactuca sativa) is a key winter vegetable with significant consumptive water use in the Lower Colorado River Basin, especially in Yuma, AZ. Generally, lettuce requires about 300 – 400 mm to produce a desirable crop, which can vary significantly depending on irrigation method, soil type, field slope, temperatures, and planting window. However, the magnitude of the quantified differences in seasonal evapotranspiration and crop water productivity among different irrigation scheduling strategies under the subsurface drip irrigation method for organic vs. conventional iceberg lettuce production systems has not been sufficiently investigated. Field experiments were conducted in the fall 2024 growing season at the Valley Research Center at the University of Arizona Yuma Agricultural Center, Yuma, Arizona. This project was conducted in a one-acre field (half-acre organic field and the other half conventional field) under the subsurface drip irrigation method with two irrigation scheduling strategies (sensor-based irrigation (SI) and traditional irrigation (TI) based on growers' standard decision basis that is common in the Yuma area. The field was planted with the iceberg lettuce variety SVLD0023 on October 29th, 2024, on Gadsden clay loam soil. The fertilizer treatments imposed included (1) organic fertilizer, (2) combined biostimulant and organic fertilizer in an organic lettuce field, (3) nitrogen, and (4) combined biostimulant and nitrogen in a conventional lettuce field. Each treatment was replicated three times within each experimental block. Each experimental unit had three beds, and each bed was approximately 120 feet long and 3.5 feet wide, with a randomized complete block design. The objectives of this project include: (1) quantify and compare the seasonal iceberg lettuce evapotranspiration between organic and conventional iceberg lettuce production systems, (2) measure and compare the crop water productivity, and irrigation water use efficiency between two irrigation scheduling strategies for organic and conventional iceberg lettuce production systems, and (3) quantify and compare improvements in soil water retention under the combined application of biostimulant and organic fertilizers in organic lettuce versus the combined application of biostimulant and nitrogen in conventional lettuce. Data collection is currently in progress and will be analyzed in a manner consistent with the experimental design and the objectives of the study. Results will be presented with preliminary conclusions and directions for further research.

Speakers

Ali Mohammed

University of Arizona/Yuma Ag Center

Wednesday July 30, 2025 3:00pm - 3:15pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Poster # csv

3:15pm CDT

WUM 2 - Assessing Drip Irrigation as an Alternative to Micro-sprinklers During Strawberry Establishment in Southern California – 2nd Season

Wednesday July 30, 2025 3:15pm - 3:30pm CDT

Foster 2

While approximately 80 to 90% of the sprinkler-applied water to a strawberry crop is lost through runoff, deep percolation and evaporation, all the strawberry fields in Ventura County are still irrigated with overhead sprinklers during crop establishment. Even though water use-efficiency for the in-season irrigation is on average high, the escalating regulatory pressure to achieve sustainable groundwater use in California, and therefore limiting water availability, will demand further efficiency. This study quantified differences in water use, yield, canopy coverage and root depth between drip tape (DT) and micro-sprinkler (MS) irrigation during crop establishment at a commercial field located in Oxnard, CA during the 2023-2024 and 2024-2025 growing seasons. This abstract shares the results of the second season. The treatments were applied during the first 42 days after planting, after which drip tape became the only irrigation method. The irrigation scheduling of the MS treatment was defined by the irrigator (grower standard), while the DT irrigation was guided by tensiometers and field observations. All other production practices remained the same. Each treatment was replicated four times in a randomized complete block design, with an area of 0.15 acre per plot (7 beds of 175ft long). Total water use during establishment was 74.4% greater for the MS treatment compared to DT (5.8 and 3.4 acre-in, respectively). Marketable yield up to March 31 was very similar between treatments (19,268 and 19,420 lb/acre for DT and MS, respectively) and not statistically significant (p-value = 0.9517). Although not statistically significant, canopy cover MS was 9 and 11% greater at 1 month and 3 months after planting, respectively. Root depth measured at 1 month after planting was very similar and not statistically different (p-value = 0.9496).

Speakers

Andre Biscaro

UC Davis

Co-authors

Gina Ferrari

UC Cooperative Extension

Oleg Daugovish

University of California Cooperative Extension

Raul Coronado

Good Farms

Wednesday July 30, 2025 3:15pm - 3:30pm CDT
Foster 2

Oral presentation, Water Utilization and Management 2

Subject Water Utilization and Management
Poster # csv

3:59pm CDT

CE 4 - Oral Session

Wednesday July 30, 2025 3:59pm - 4:00pm CDT

Strand 12B

Presiding/Moderator

Neil Mattson

Cornell University

Wednesday July 30, 2025 3:59pm - 4:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments

3:59pm CDT

HIH - Oral Session

Wednesday July 30, 2025 3:59pm - 4:00pm CDT

Strand 11A

Presiding/Moderator

Elizabeth Diehl

Director of Therapeutic Horticulture, University of Florida

Wednesday July 30, 2025 3:59pm - 4:00pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

Subject Human Issues in Horticulture

3:59pm CDT

OPB - Oral Session

Wednesday July 30, 2025 3:59pm - 4:00pm CDT

Strand 12A

Presiding/Moderator

Navdeep Kaur

Texas A&M University

Wednesday July 30, 2025 3:59pm - 4:00pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding

3:59pm CDT

PBIG 2 - Oral Session

Wednesday July 30, 2025 3:59pm - 4:00pm CDT

Foster 1

Presiding/Moderator

Guo-qing Song

Michigan State University

Wednesday July 30, 2025 3:59pm - 4:00pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology

3:59pm CDT

WCPM 2 - Oral Session

Wednesday July 30, 2025 3:59pm - 4:00pm CDT

Foster 2

Presiding/Moderator

Chris Marble

University of Florida/IFAS

Wednesday July 30, 2025 3:59pm - 4:00pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management

4:00pm CDT

CE 4 - Multimodal Deep Learning for Lettuce Growth Forecasting to Enhance Resource Use Efficiency in CEA

Wednesday July 30, 2025 4:00pm - 4:15pm CDT

Strand 12B

Regulating the microclimate to achieve the desired crop quality and yield demands substantial resource consumption, making it essential to optimize resource use. AI models can be used to forecast future plant development based on microclimate conditions, allowing controllers to preemptively adjust climate settings to optimize growth and resource consumption. However, the current paradigm of microclimate controller lacks AI-assisted feedback to predict how crops respond to dynamic climate conditions (crop × environment interactions). Thus, there is an urgent need to develop an AI-assisted predictive analytics system that can support decision-making processes. This study presents a multimodal deep learning approach for forecasting lettuce growth in CEA using both microclimate (aerial and rootzone) and early-stage plant image data. We employed Long Short-Term Memory (LSTM) networks to model the temporal dependencies of microclimate variables such as temperature, humidity, and light intensity. Further, we integrated image and microclimate data into the multimodal growth predictor to enhance T-days ahead prediction accuracy by capturing visual and temporal cues of plant growth and development. The model effectively predicted the lettuce growth trend using multimodal data, achieving high accuracy in its forecasts for the next few days. The combined use of LSTM and image data provides an efficient framework for forecasting lettuce growth, offering valuable insights for optimizing resource use in CEA.

Speakers

Azlan Zahid

Assistant Professor, Texas A&M University

AI and Robotics for CEA

Wednesday July 30, 2025 4:00pm - 4:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Poster # csv

4:00pm CDT

HIH - Using Nearby Nature to Increase Health

Wednesday July 30, 2025 4:00pm - 4:15pm CDT

Strand 11A

The role of nature in improving health is being explored in a growing number of healthcare fields. At the University of Florida, programs using nature-based interventions include physical medicine and rehabilitation, oncology, addiction recovery, Parkinson’s Disease, mental health, and autism, among others. These expanding program opportunities are slowly but steadily moving nature into the domain of public health. Some of the more recognizable examples of this trend are therapeutic gardens and nature prescriptions but there are many other ways to use nature to boost health in cities around the world. Spending time in green spaces (plant-dominated) and blue spaces (water-dominated) is linked to improved life satisfaction, reduced anxiety, and increased happiness. Nature exists on a spectrum and whether experiencing ‘big’ nature or ‘micro’ nature, high quality contact generates an increase in positive emotions and feelings of vitality, a decrease in negative emotions, relief from mental fatigue, and an improvement in our attention span. This presentation will explore research that highlights the health benefits of nature interaction, the primary components of high-quality nature experiences, and the key factors in connecting people and nature.

Speakers

Elizabeth Diehl

Director of Therapeutic Horticulture, University of Florida

Wednesday July 30, 2025 4:00pm - 4:15pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

Subject Human Issues in Horticulture

4:00pm CDT

OPB - Loropetalum Genome Size Survey

Wednesday July 30, 2025 4:00pm - 4:15pm CDT

Strand 12A

Loropetalum chinense, is a popular ornamental shrub known for its distinctive flowers and foliage color. Due to its aesthetic appeal and adaptability, Loropetalum is widely used in landscaping and has become an important crop for U.S. nurseries. However, limited understanding of genetic diversity among cultivars presents challenges for breeding efforts, as genome size and ploidy levels play a crucial role in hybridization success and in determining phenotypic traits such as flower size, color, and plant vigor. This study aimed to measure the ploidy levels and relative genome sizes of a wide range of Loropetalum cultivars in the U.S. to inform future breeding strategies. Flow cytometry was used to determine genome size and estimated ploidy, and chromosome countings were performed to validate the ploidy data. A total of 33 accessions were inspected, with 32 found to be diploids and one triploid. The 1Cx genome size ranged from 2.42 to 3.06 pg across cultivars. These results provide a foundational knowledge on ploidy and genome size variation in the Loropetalum germplasm that would benefit future Loropetalum breeding decisions.

Speakers

Rick Shih

North Carolina State University

Co-authors

Hsuan Chen

North Carolina State University

Wednesday July 30, 2025 4:00pm - 4:15pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding
Poster # csv

4:00pm CDT

PBIG 2 - Agrobacterium-mediated transformation of the cultivated strawberry (Fragaria × anannassa duch.) with GFP visual selection

Wednesday July 30, 2025 4:00pm - 4:15pm CDT

Foster 1

The origin of the cultivated strawberry traces to the 1700s, when representatives of the octoploids F. chiloensis and F. virginiana – previously brought to Europe from South and North America, respectively – were grown in proximity in European horticultural gardens. Cross-pollination produced hybrids that were quickly recognized for their unique and desirable combinations of morphological and fruit characteristics and were brought into cultivation and breeding (Hancock 1999). Traditional breeding objectives are the following (Rosati 1993): a production of relatively large berry size in order to limit the cost of harvest, a firmer fruit with regular shape and long shelf life, which is easy to harvest, an increase in the total yield, an improvement in fruit appearance (color, shape, brightness), and disease resistances. The recent origin makes F. ananassa one of the youngest of contemporary crop species. Bottle neck existing in strawberry traditional breeding is that it is difficult to manipulate single genes to control strawberry characteristics, modern genetic transformation and genome editing technology provide promising ways for single gene control in strawberry. Diploid strawberry transformation has been reported, limited report was available for transformation of octoploid cultivated strawberry. We report an efficient Agrobacterium mediated strawberry transformation system with the aid of GFP visual selection. First three open leaves from 4 weeks old in vitro plants were harvested, and leaflets were separated from each other and inoculated with Agrobacterium tumefaciens GAV3101 contains a binary vector with GFP and hygromycin resistance genes. Transgenic callus and shoots obtained with GFP visual selection with high efficiency. PCR double check proved transgenes in transgenic plants. Transgenic plants are phenotyping in the greenhouse.

Speakers

Kedong Ka

North Carolina State University

Director of plant transformation lab at North Carolina State University

Co-authors

Anna Nelson

North Carolina State University

debao huang

NCSU

Huani Leng

North Carolina State University

Seth Cockman

North Carolina State University

Sydney McLennan

North Carolina State University

Tianbao Yang

USDA-ARS

Wusheng Liu

North Carolina State University

Wednesday July 30, 2025 4:00pm - 4:15pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv
Funding Source USDA-ARS
Funding Option SCRI funded all or part of the research associated with this abstract

4:00pm CDT

WCPM 2 - Effect of seed placement on the efficacy of rice hulls for control of 5 common nursery weed species

Wednesday July 30, 2025 4:00pm - 4:15pm CDT

Foster 2

Many types of mulch have been shown to reduce weed growth in container crops. In the past, mulch use in nurseries was not as feasible due to its high cost, but as costs of hand weeding increase, labor shortages become more severe, and environmental awareness rises, utilization of mulch has become more popular in recent years. Parboiled rice hulls are a waste product of the rice industry and are dry rice husks removed from rice grains. They are light weight, hydrophobic and make for an ideal mulch choice in container nursery production and have been previously evaluated for use as a weed management tool in container nurseries. However, research was typically conducted on a limited number of species and studies were performed in greenhouses or other protected structures. The objective of this research was to evaluate rice hulls for control of five common nursery species in an outdoor environment in Florida during the summer season. Nursery pots (1.7 L) were filled with a standard pinebark based potting soil and amended with standard control release fertilizers via incorporation. Upon filling, pots received one of three levels of rice hulls, 0 cm or the non-treated control, 1.3 cm, or 2.5 cm. To test efficacy, approximately 30 seeds of crabgrass (Digitaria sanguinalis), doveweed (Murdannia nudiflora), longstalk Phyllanthus (Phyllanthus tenellus), spotted spurge (Euphorbia maculata), or eclipta (Eclipta prostrata) were sown either above or below the rice hull mulch layers mentioned above. Data collected included weed coverage ratings (0 to 100%) at 4, 6, 8, 10, and 12 weeks after planting (WAP) and shoot dry weights at 12 WAP. Few differences were observed among the different depths of mulch when seeds were placed below. For seeds placed on top of the mulch, the higher 2.5 cm depth generally provided greater control. For all 5 weed species, control significantly increased when seeds were placed on top of the mulch compared to seeds beneath the mulch layer. Control, as measured by a percent reduction in shoot weight compared to the non-mulched control, ranged from 80 to 100% for seeds placed on top compared with decreases of 0 to 40% when seeds were placed below mulch. Overall, data suggest that because rice hulls are more effective on weed seeds placed on top of the mulch layer, growers would likely see increased efficacy when mulching as soon as possible after potting.

Speakers

Chris Marble

University of Florida/IFAS

Co-authors

Yuvraj Khamare

The University of Florida

Wednesday July 30, 2025 4:00pm - 4:15pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Funding Source Horticulture Research Institute

4:15pm CDT

CE 4 - Comparison of AI-driven and conventional climate control strategies for greenhouse tomato production

Wednesday July 30, 2025 4:15pm - 4:30pm CDT

Strand 12B

Greenhouse tomato production with high-wire system and indeterminate tomato cultivars facilitates year-round production with high quality and productivity. However, maintaining optimal climate conditions in greenhouse is expensive due to high operational costs. Optimizing climate control strategies requires in-depth understanding of controlling systems, outdoor climate, and plant physiology. But skilled and experienced growers may not always be available. Artificial intelligent-driven climate control (AI) has been emerged as a potential solution. Yet, few trials have conducted, which may not be at an equivalent scale as the industry and following the industry standard. To address this gap, we compared AI and conventional climate control strategies (human decision-based; CV) for greenhouse tomato production in two identical high-tech greenhouse compartments (namely, AI and CV each with 481.7 m²) over 145 days after the final transplanting with management practices established by commercial growers. Each compartment had 420 plants of the indeterminant cultivar Maxxiany at a planting density of 3 plants m⁻². The AI algorithms were developed using datasets from commercial growers and a digital twin via physiology-informed neural network (photosynthesis and transpiration modules). Leaf pruning in AI was determined based on weekly light integral below canopy (Kim and Kubota, 2025), while CV followed conventional pruning based on harvesting trusses. To evaluate the performance of AI, parameters for crop development, yield, and fruit quality were collected in addition to environmental conditions and resource usage for lighting, cooling, heating, and fertigation. AI maintained relatively higher day and night temperature with high heating pipes temperature and keeping windows closed. AI also resulted in more leaves within canopy from fewer leaf pruning compared to CV. Those contributed to increase in cumulative irrigation volume (936 vs. 785 l m⁻² for AI and CV) and thus total fertilizer use (878 vs. 639 g m⁻²). AI used more natural gas for heating (190 vs.79 MJ m⁻²) and more electricity for supplemental lighting (91.4 vs. 80.4 kWh m⁻²). However, AI had higher cumulative yield (9.3 ± 0.3 vs. 8.5 ± 0.3 kg m⁻²) and greater PAR-based productivity (grams of fruits per PAR mol; 4.1 vs 3.6 g mol⁻¹). These findings suggest that AI increased resources use (water, fertilizer, natural gas, and electricity) but also resulted in higher yields as a trade-off. Further optimization of AI’s algorithms regarding fertigation and heating strategies may improve economic feasibility of AI application in greenhouse tomato production.

Speakers

Changhyeon Kim

University of Connecticut

Co-authors

Chieri Kubota

The Ohio State University

Kenneth Tran

Koidra Inc.

Wednesday July 30, 2025 4:15pm - 4:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Funding Source This project is supported by the Specialty Crop Research Initiative (grant no. 2022-51181-38324, Project ADVANCEA) from the US Department of Agriculture National Institute of Food and Agriculture.
Funding Option SCRI funded all or part of the research associated with this abstract

4:15pm CDT

HIH - Indigenous Perceptions Of Agrivoltaics In The Navajo Nation: Insights From A Community-Based Assessment

Wednesday July 30, 2025 4:15pm - 4:30pm CDT

Strand 11A

The dissemination of agrivoltaic technology within Indigenous communities remains insufficiently understood, posing significant challenges to its successful implementation. As agrivoltaic systems continue to expand across the United States, it is imperative to examine how different social groups perceive and accept this technology. The Navajo Nation, the largest Indigenous tribe in the U.S., spans the Four Corners region, with the San Juan River Valley serving as a critical agricultural hub. To evaluate the feasibility of agrivoltaic adoption within this context, a sub-study was conducted as part of a broader Indigenous farmers’ needs assessment, focusing specifically on Navajo farmers in the San Juan River Valley. This study employed a qualitative survey consisting of eight binary-response questions to assess participants' knowledge of and interest in agrivoltaics. Results indicate that only 6% (n=126) of respondents were previously familiar with agrivoltaics, yet 88% expressed interest in learning more about the technology upon receiving an explanation. Furthermore, 73% of respondents were interested in exploring the use of photovoltaic systems to support their farms’ energy needs, although only 12% had prior experience with solar energy systems, underscoring key barriers to adoption. These findings suggest that agrivoltaic systems hold promise as a strategy for enhancing both local support for renewable energy development and food security within the Navajo Nation. However, significant knowledge gaps and limited technical expertise present obstacles to widespread implementation. The results emphasize the necessity of targeted educational and training programs to facilitate the successful integration of agrivoltaic systems. Without such efforts, adoption may remain limited due to a lack of familiarity and technical proficiency. Ultimately, this research underscores the potential for agrivoltaics to contribute to sustainable agricultural practices and renewable energy expansion within the Navajo Nation, highlighting the critical role of knowledge transfer and capacity-building initiatives in ensuring long-term success.

Speakers

Emiliano McLane

New Mexico State University

Emiliano McLane (Newe) is from the Tosawihi clan of the Te-Moak Tribe of Western Shoshone and was primarily raised on the South Fork Indian Reservation near Jiggs, Nevada. He is also a descendant of the Pomo, Wailaki, and Nomlaki tribes and spent part of his upbringing on his father’s... Read More →

Co-authors

Don Edgar

New Mexico State University

Kevin Lombard

New Mexico State University

Kevin Lombard is a Professor of Horticulture and Research Director of the New Mexico State University Agricultural Science Center at Farmington, a 250 acre research farm uniquely located on the Navajo Nation. His research encompasses specialty crop evaluations including grapes, fruit... Read More →

Olga Lavrova

New Mexico State University

Shannon Norris Parish

New Mexico State University

Wednesday July 30, 2025 4:15pm - 4:30pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

Subject Human Issues in Horticulture

4:15pm CDT

OPB - Bridging Breeding and Design: An Innovative Model for Anthurium Cut Flower Varietal Development

Wednesday July 30, 2025 4:15pm - 4:30pm CDT

Strand 12A

The University of Hawaii's anthurium breeding program established a partnership with floral design professionals, transitioning from informal collaboration in 2016 to a formalized Professional Advisory Team (PAT) in 2021. This collaboration integrates established phenotypic selection practices with artistic design expertise to enhance new variety development. The PAT, comprising influential floral designers and growers, provides essential feedback on spathe and spadix color, conformation, and size at the early flowering stage, directly influencing breeding decisions, such as advancement to cloning and field evaluation, thereby ensuring market relevance. By incorporating designer insights from the seedling stage through advanced testing, the program prioritizes selection based on perceived market demands. Grower feedback during field testing focuses on plant vigor, pest and disease resistance, ease of shipping and customer acceptance. The breeding program released three new cultivars developed with the model, at national floral design events, including the AIFD symposium and Fresh Floral Expo; social media and trade publications covered the varietal release events. Integrating grower feedback, a long-standing practice, with the new design-focused evaluations strengthens the breeding program’s ability to produce new varieties which meet the needs of growers, designers, and consumers.

Speakers

Teresita Amore

University of Hawaii

Wednesday July 30, 2025 4:15pm - 4:30pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding
Poster # csv

4:15pm CDT

PBIG 2 - Functional analysis of blueberry TFL1 and FD using RNAi

Wednesday July 30, 2025 4:15pm - 4:30pm CDT

Foster 1

Flowering plays a crucial role in blueberry production since fruits develop from flowers. In plants, FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1), which interact with the bZIP transcription factor FD, are central regulators of flowering. This study investigates the roles of their homologs in blueberries, VcTFL1 and VcFD, using RNA interference (RNAi) to silence these genes. Two RNAi constructs, VcFD-RNAi and VcTFL1-RNAi, were introduced into the northern highbush blueberry (Vaccinium corymbosum) cultivar ‘Aurora’ via Agrobacterium tumefaciens-mediated transformation. Phenotypic analysis of first-generation (T0) transgenic plants accessed flowering time, architecture, fruit and leaf bud development, plant height, and branching. Preliminary results revealed that VcFD-RNAi plants produced fewer shoots, while VcTFL1-RNAi plants exhibited reduced branching per shoot compared to nontransgenic ‘Aurora’ controls. Significant differences in leaf bud number were also observed between nontransgenic and transgenic lines. VcFD-RNAi plants were smaller than nontransgenic ‘Aurora’ plants, whereas no significant size difference was detected between VcTFL1-RNAi and wild-type plants. Transcriptomic comparisons between nontransgenic ‘Aurora’ and transgenic lines revealed differentially expressed genes (DEGs). The VcFD-RNAi vs. nontransgenic ‘Aurora’ identified 2,108 DEGs, including 49 flowering-related genes, 116 genes hormone pathway genes, and 57 sugar metabolism genes. Similarly, the VcTFL1-RNAi vs. nontransgenic ‘Aurora’ uncovered 2,030 DEGs, with 52 flowering-related, 111 hormone-related, and 55 sugar-metabolism-associated genes. Ongoing analyses of these DEGs aim to elucidate the molecular mechanism underlying VcFD- and VcTFL1-mediated flowering regulation of flowering and development in blueberry. This study will reveal the functional roles of VcFD and VcTFL1, offering potential targets for genetic improvement of blueberry architecture and yield.

Speakers

Jirapa Jaikham

Michigan State University

Co-authors

Guo-qing Song

Michigan State University

Wednesday July 30, 2025 4:15pm - 4:30pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv

4:15pm CDT

WCPM 2 - Comparison of Postemergence Herbicide Efficacies Under Elevated and Normal Temperature for Controlling Large Crabgrass in Ornamental Production

Wednesday July 30, 2025 4:15pm - 4:30pm CDT

Foster 2

Elevated temperatures can intensify weed issues by accelerating weed growth and germination, especially for C4 species, due to their heat tolerance and efficient carbon fixations, making their control more challenging. Temperature also influences herbicide absorption, translocation, and metabolism. Large crabgrass (Digitaria sanguinalis), a highly problematic C4 weed, poses a significant threat to nursery and field-grown ornamentals under these conditions. This study aims to evaluate the efficacy of postemergence herbicides at different rates (0.5X, 1X, 2X) under normal and elevated temperatures for managing large crabgrass in ornamental production. Experiments were conducted in summer and fall 2024 using a growth chamber and an open hoop house setup. Large crabgrass seeds were sown in pots filled with standard substrate, irrigated, and placed in separate growth chambers where temperatures were maintained at normal (22–28°C) and at 2-5°C above the species’ optimum range (28-34°C). Once weeds reached the 3–6 leaf stage, they were transferred to an open hoop house for herbicide application. Postemergence herbicides such as topramezone and glyphosate were applied at 0.5X, 1X, and 2X rates using a CO₂ backpack sprayer. After the restricted entry interval, treated weeds were placed back to their respective growth chambers and maintained there for four weeks. A control treatment without herbicide application was maintained in both growth chambers. Weed control ratings were visually assessed at 1, 2, 3, and 4 weeks after treatment (WAT) using a 0–10 scale, where 0 = no control (green foliage, upright growth, no damage) and 10 = complete plant death (dark brown foliage, no green tissue, collapsed structure)). At 4 WAT, all weeds were harvested, and dry weight of aboveground parts of weed was recorded. The experiment followed a completely randomized design with eight replications per treatment and was repeated twice. Data were analyzed using ANOVA in SAS 9.4, and treatment means were separated using Fisher’s LSD test. The results showed that at 4 WAT glyphosate weed control efficacy at normal temperature was 88% which reduced to 73% under elevated temperature condition. Whereas the high temperature increased topramezone efficacy by 10%. The lowest amount of weed dry weight was observed at 2X rates in high temperature conditions, but no difference was observed among rates at normal temperature. Hence it can be concluded that with an increase in temperature, higher rates of the tested herbicides will be required for effective weed management in ornamentals.

Speakers

Supti Saha Mou

Michigan State University

Co-authors

Debalina Saha

Michigan State University

Wednesday July 30, 2025 4:15pm - 4:30pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Poster # csv

4:30pm CDT

CE 4 - Forecasting Plant Growth Patterns Dynamics in Controlled Environment Agriculture through Vision-Based Phenotyping and Time-Series Modeling

Wednesday July 30, 2025 4:30pm - 4:45pm CDT

Strand 12B

In controlled environment agriculture (CEA), accurate yield forecasting remains challenging due to reliance on environmental sensor data, which fails to capture plants’ dynamic morphological responses to growth conditions. This study bridges the gap by establishing a vision-based framework to forecast plant growth dynamics through automated phenotyping and time-series modeling. A plant phenotype monitoring framework was implemented using commercially available cameras and off-the-shelf deep learning-based models (YOLO). The robustness of the YOLO and time-series models was evaluated under various treatment conditions, including salt stress and variations in root architecture, in hydroponic greenhouse trials across two seasons. Top-view images of the plants were collected using GoPro and Raspberry Pi cameras, and different YOLOv8 instance segmentation model variants were trained on four image datasets to extraction of morphological traits such as area, major, and minor axes. Results indicated that YOLOv8 generalized well, achieving mAP50 for bounding boxes and masks in the range of 0.897 – 0.952 and 0.896 – 0.947, respectively. Plants with split root systems exhibited superior growth under the highest salt stress levels compared to single-root systems. Comparisons between physical measurements and image-derived parameters such as major and minor axes yielded high R² values of 0.85 and 0.92 for single-root systems, and 0.90 and 0.84 for split root systems. Additionally, the area parameter obtained from images showed an R² of 0.882 when compared with plant fresh weight. Area parameters were forecasted using an ARIMA model over 2-, 4-, and 8-day windows, evaluated using MAPE. The lowest MAPE values (3.99 in the fall and 1.70 in the spring) were attained by single-root plants under salt stress when projected for two days. The forecasted area values demonstrated R² values of 0.623, 0.671, and 0.75 for the 2-, 4-, and 8-day forecast windows respectively when compared with fresh weight, indicating that the area parameter is a reliable predictor of yield. These findings confirm that morphological changes capture environmental influences and can be reliably forecasted, introducing a scalable, data-driven method to predict yield in CEA while helping growers optimize resource usage and reduce productivity risks.

Speakers

Md Hasibur Rahman

Auburn University

Co-authors

Tanzeel Rehman

AUBURN UNIVERSITY

Wednesday July 30, 2025 4:30pm - 4:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Poster # csv

4:30pm CDT

HIH - The effect of a school gardening program on horticultural career interest, environmental locus of control, and climate anxiety among elementary-aged students

Wednesday July 30, 2025 4:30pm - 4:45pm CDT

Strand 11A

Climate anxiety among children is on the rise and research shows that discussing the issues and empowering youth are some ways to approach the issue. Historically, school gardens were used to teach children many subjects while addressing environmental issues and while fostering a love of plants and ecosystems. The objective of this study was to examine the influence of a 10-week outdoor, after-school youth gardening education program for first through third-grade students, specifically evaluating the effects on horticulture interest, environmental locus of control, and climate anxiety before and after participation in the program. The treatment group participated in an outdoor gardening program that involved hands-on learning related to growing plants and providing sustainable habitats while working through measures to create a National Wildlife Schoolyard Habitat as well as a recognized San Marcos Certified Habitat Stewardship Program landscape. The control group participated in the pre- and post-survey only and was not a part of the outdoor gardening or wildlife certification program, but was involved in other after-school activities offered at the elementary school. The survey questions were adopted from pre-determined, reliable, and valid instruments as well as adjusted for reading levels. Surveys utilized 5-point Likert scale questions with answer options employing emoticons that ranged from happy to sad. Pre- and post-survey data was analyzed through The Wilcoxon Signed-Rank tests and descriptive statistics. Data from this study determined the potential for school programs to increase horticultural interest in schools while empowering youth to make positive environmental action.

Speakers

Mackenzie Bark

Texas State University

Co-authors

Tina Waliczek Cade

Texas State University

Wednesday July 30, 2025 4:30pm - 4:45pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

4:30pm CDT

OPB - Genomics and phenomics variation of dwarf gladiolus for the potted plant market

Wednesday July 30, 2025 4:30pm - 4:45pm CDT

Strand 12A

Gladiolus(-i), Gladiolus ×hybridus (Iridaceae), is a tetraploid, asexually-propagated, herbaceous perennial floricultural crop. Gladiolus is in the top five cut flower crops in the world for use in floral design. Despite their ability to widely intercross with dwarf stature wild type species, gladiolus have not been developed for the potted plant market. The objective of this analysis is to identify potential genetic marker(s) related to dwarfism to direct future breeding efforts towards the gladiolus potted plant market. In this study we examine 2,662 unique gladiolus cultivars and numbered selections using DNA marker-based analysis. Samples were collected from the public (University of Minnesota) and private (Meyer, Otto) sector gladiolus breeding programs in Minnesota and elsewhere in Europe. A total of 194 dwarfs (90cm) genotypes were identified in our analysis. Dwarfs were defined as being less than 90cm in height of the entire plant including inflorescence at first bloom. Population genetic diversity was analyzed using 17,556 single nucleotide polymorphism (SNP) low-density markers using DArTseq technology. After filtering call rates at the 95% level a total of 2,026 SNPs remained, separating genotypes into 177 dwarfs and 2,235 standard individuals. No private alleles were found when comparing dwarfs to standards. When we narrowed the definition of dwarf to those

Speakers

Marie Abbey

University of Minnesota

Marie Abbey is a researcher at the University of Minnesota Horticultural Science department. She has studied perceptions of biotechnology, invasive plant species, and aquaponics. Her current research is in flower breeding and molecular genetics.

Wednesday July 30, 2025 4:30pm - 4:45pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding
Poster # csv
Funding Source MN Agricultural Experiment Station

4:30pm CDT

PBIG 2 - Chitosan-dsRNA Nanocomplex: A Stable and Effective sprayable RNAi-based Solution for Fungicides Resistant B. cinerea Management

Wednesday July 30, 2025 4:30pm - 4:45pm CDT

Foster 1

Botrytis cinerea is the second most economically important fungal phytopathogen causing gray mold disease. Multiple fungicide-resistant B. cinerea strains have also been reported, especially in strawberries, raspberries, grapes, and tomatoes. RNA interference (RNAi) is a post-transcriptional gene silencing mechanism in all known eukaryotes. The exogenous application of dsRNAs to knock down the target organism's essential genes is called spray-induced gene silencing (SIGS). This non-transgenic SIGS-based approach has emerged as an appealing alternative biofungicide. Despite the great potential of sprayable RNAi-based pesticides, this innovative technology encountered challenges. The low stability and the limited uptake efficiency of dsRNA are significant challenges facing SIGS. Nanomaterials-based delivery systems and structured modification of dsRNA molecules could be innovative SIGS approaches for improving its stability, uptake efficiency, and biofungicidal efficacy. This study aims to develop sprayable RNAi (SIGS) solutions by modifying dsRNA structure and using chitosan-based nanoparticles to control fungicide-resistant B. cinerea. Chitosan nanoparticles (CNPs) were generated using ionic gelation, and different forms of double-stranded RNA (dsRNA), either linear or secondary-structured, were loaded into them. The positive charges from the amine groups present in chitosan facilitated the self-assembly of the CNPs-dsRNA complex through electrostatic attraction. The stability of CNPs-dsRNAs complexes was evaluated ex-vivo by incubating naked-dsRNAs and complex-dsRNAs with the RNase A. Gel retardation assay revealed that CNPs-dsRNA complex of either linear or secondary structured-dsRNAs exhibited substantial protection of dsRNA from RNase A degradation for up to 72 hours, suggesting its potential for improving stability and long-lasting efficacy. The CNPs-dsRNAs significantly reduced the mycelial growth of wild-type and fungicide-resistant B. cinerea isolates. The results from this study indicated that chitosan-based polymer could be an effective delivery technology for both linear and secondary-structured dsRNA and hold great promise for the management of gray mold diseases.

Speakers

Md Al Mamun

University of Tennessee

Co-authors

Tabibul Islam

University of Tennessee, Knoxville

Wednesday July 30, 2025 4:30pm - 4:45pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv

4:30pm CDT

WCPM 2 - Implementing Anaerobic Soil Disinfestation On-farm for the Management of Soilborne Pests and Pathogens in High Tunnel Production Systems

Wednesday July 30, 2025 4:30pm - 4:45pm CDT

Foster 2

Intensive cultivation in high tunnel production systems is leading to the emergence of soilborne pest and pathogen issues which over time can compromise crop productivity and profitability. Growers facing such challenges are in search of sustainable and effective solutions capable of suppressing soilborne pests and pathogens while preserving soil health. Anaerobic soil disinfestation (ASD) is a broad-spectrum pre-planting biological approach proposed for the management of soilborne issues affecting high-value specialty crops. ASD is applied by incorporating in the soil readily labile organic amendments as a carbon (C) source, tarping the soil with an impermeable film, and irrigating the soil to saturation. Although ASD already proved to be effective against a range of soilborne pests and pathogens across different US regions, crops, and production systems, its adoption at commercial scale remains relatively limited. Factors hindering the adoption of ASD include application cost, complexity of microbial driven processes, and lack of knowledge of the method, its implementation steps, and its efficacy and benefits. Capitalizing on over six years of research aimed at optimizing the ASD application method and its integration in high tunnel production systems in Pennsylvania, a series of on-farm ASD applications were conducted over the 2023 and 2024 growing season with the purpose of demonstrating the technology and let growers evaluate first-hand its viability and efficacy. The on-farm trials were conducted on selected farms growing vegetables and small-berries in high tunnels and employing both conventional and organic production methods. Raised-bed and broadcast application were tested along with the use of clear and black film. Wheat middlings alone or in combination with feed-grade sugarcane molasses were tested as C sources testing different soil incorporation equipment and methods. Depending on the specific crop system, and the grower planting schedule, ASD was applied between the end of the Spring (before a late high tunnel crop planting) and mid-October (after an early high tunnel crop). Parameters measured included soil redox potential, temperature, pH, electrical conductivity and mineral nitrogen. The level of anaerobiosis achieved varied depending on the amount of labile carbon applied, the type of tarp used, and the temperature levels achieved. High levels of cumulative soil redox potential were achieved and the use of clear film allowed to achieve relatively higher soil temperatures and cumulative redox potential levels in most on-farm applications. Additional demonstration efforts are needed to facilitate the adoption of ASD and demonstrate its efficacy.

Speakers

Francesco Di Gioia

Pennsylvania State University

Co-authors

Beth Gugino

Pennsylvania State University

Caterina Roman

Pennsylvania State University

Claudia Schmidt

Pennsylvania State University

Erin Rosskopf

USDA-ARS U.S. Horticultural Research Laboratory

Joe Ono-Raphel

Pennsylvania State University

Kathy Demchak

Pennsylvania State University

Leah Fronk

Penn State Extension

Mihail Kantor

Pennsylvania State University

Wednesday July 30, 2025 4:30pm - 4:45pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Funding Source USDA-NIFA, Organic Research and Extension Initiative Grant # 2021-51300-34914, the USDA NIFA Crop Protection and Pest Management Grant #2021-70006-3531, and the USDA-NIFA Organic Transition Program Grant #2024-51106-43166.

4:45pm CDT

CE 4 - Chlorophyll Fluorescence Estimation Using Machine Learning for Dynamic Supplemental LED Control

Wednesday July 30, 2025 4:45pm - 5:00pm CDT

Strand 12B

Efficient supplemental lighting control is crucial for optimizing crop productivity and energy use in controlled environment agriculture (CEA). While environmental factors such as temperature and carbon dioxide (CO2) concentration significantly influence photosynthesis, current lighting control strategies rely solely on ambient sunlight levels. To address this limitation, a chlorophyll fluorescence (CF)-based biofeedback system has been proposed to dynamically adjust LED light intensities based on real-time photosynthetic responses. However, frequent CF measurements using pulse-amplitude modulated (PAM) fluorometers can induce severe photoinhibition due to repetitive saturating light pulses, limiting long-term application. This study explores an alternative approach by developing a machine learning model to estimate the quantum yield of photosystem II (ΦPSII) from environmental parameters, eliminating the need for the fluorometer and continuous physical measurements. Four-week-old green and red lettuce (Lactuca sativa) cultivars (‘Casey’ and ‘Cherokee’) were grown in a greenhouse for a month, where ΦPSII was measured every 15 minutes using a fluorometer (Monitoring-PAM; Heinz Walz, Effeltrich, Germany) alongside environmental data, including extended photosynthetically active radiation, temperature, CO₂ concentration, and vapor pressure deficit. A linear regression model was developed to estimate ΦPSII, generating cultivar-specific equations that were integrated into the biofeedback system for LED control. The estimated ΦPSII values exhibited a strong correlation with the measured data, allowing the biofeedback system to optimize lighting without the risk of photoinhibition associated with frequent PAM fluorometer measurements. This approach enabled dynamic light adjustment based on environmental conditions and lettuce cultivar, with the regulated light levels closely aligning with direct measurements. These findings highlight the potential of integrating predictive models into the biofeedback-controlled lighting systems, offering a cost-effective and non-invasive alternative to direct CF measurements for precision lighting management in CEA.

Speakers

Suyun Nam

University of Georgia

Co-authors

Leo Bastos

University of Georgia

Rhuanito S. Ferrarezi

University of Georgia

Wednesday July 30, 2025 4:45pm - 5:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Poster # csv

4:45pm CDT

HIH - Enhancing Foot Health and Safety in Farmers and Horticultural Professionals through Extension Education

Wednesday July 30, 2025 4:45pm - 5:00pm CDT

Strand 11A

Foot health in the workplace, particularly among farmers and agricultural professionals, is often neglected, despite its significant impact on overall health and well-being. In Florida, environmental conditions frequently lead to hot, damp feet, exacerbated by improper footwear, which contributes to poor foot health. Due to a reluctance to seek medical intervention, foot issues often progress to more severe complications. This commercial horticulture extension program aimed to improve foot health awareness, increase learning gains, and promote healthy behavior changes in agriculture and horticulture workers. Objectives: The primary objectives were: (1) to improve knowledge and skills related to foot health, and (2) to encourage the adoption of healthy foot care behaviors. Methods: A total of 238 clients were pre-surveyed from 2020 - 2024 to assess their foot health and identify areas of need. Participants were then invited to attend an extension program in-person or via webinar. Four classes were presented over the four-year span, focusing on foot health and safety, addressing issues like foot or leg pain, diseases, and deformities. Practical solutions were provided, including individual diagnostic assessments by a podiatrist/surgeon who demonstrated exercises and discussed the use of orthotics for improving foot health. Participants were encouraged to rate their foot health and report discomfort. A post-intervention survey was conducted three months later to evaluate changes in knowledge, behavior, and foot health status. Outcomes and Results: The pre-survey revealed that 69% of participants reported foot issues, with an average self-assessed foot health grade of 6.85 out of 10. After attending the educational session and implementing recommended practices, 98% of participants (n=25) reported significant relief from foot discomfort. Moreover, 95% committed to behavior changes, such as performing leg exercises, using orthotics, and changing footwear. The average foot health grade improved to 8.0 out of 10, representing an 11.5% improvement. Additionally, 96% (n=9) of participants shared their knowledge with 35 others, expanding the intervention's impact. Conclusion: This study shows that educational interventions focused on foot health can lead to significant improvements in knowledge and foot health outcomes among agricultural workers. The adoption of behaviors like using orthotics, performing exercises or consulting with a podiatrist resulted in measurable improvements. The widespread sharing of information indicates that the intervention had a positive ripple effect. Continued efforts to promote foot health in high-risk occupations are essential to prevent long-term complications and improve quality of life.

Speakers

Karen Stauderman

Commercial Horticulture Agent III, UF/IFAS Extension Volusia County

Wednesday July 30, 2025 4:45pm - 5:00pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

Subject Human Issues in Horticulture
Poster # csv

4:45pm CDT

OPB - Genetic Mapping of Black Spot and Cercospora Leaf Spot Resistance in Autotetraploid Roses Using Three Biparental Populations

Wednesday July 30, 2025 4:45pm - 5:00pm CDT

Strand 12A

Roses are among the most important ornamental crops globally. Major fungal diseases affecting this crop in East-Central Texas are Cercospora leaf spot (Rosisphaerella rosicola Pass.) and black spot (Diplocarpon rosae F.A. Wolf). This study aims to uncover the genetic basis of resistance to these diseases using three biparental F1 autotetraploid rose populations derived from the following crosses: ‘Miracle on the Hudson’ × ‘Morden Blush’ (MoHxMB, N=196), ‘Miracle on the Hudson’ × ‘Morden Fireglow’ (MoHxMF, N=180), and ‘Morden Blush’ × ‘Brite Eyes’ (MBxBE, N=182). The populations, planted in a randomized complete block design with two replications, were scored for disease severity monthly from May to November over two years (2023 and 2024) at the Texas A

Speakers

Navdeep Kaur

Texas A&M University

Co-authors

David Byrne

Texas A and M University

Ivan Perez

Texas A and M University

Jeekin Lau

USDA

Oscar Riera-Lizarazu

Texas A and M University

Patricia E. Klein

Texas A and M University

Tessa Hochhaus

Texas A

Wednesday July 30, 2025 4:45pm - 5:00pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding
Poster # csv

4:45pm CDT

PBIG 2 - Identification of the interacting protein of a tomato bacterial wilt resistance gene

Wednesday July 30, 2025 4:45pm - 5:00pm CDT

Foster 1

Bacterial wilt (BW), caused by the soil-borne vascular bacterium Ralstonia solanacearum (Rs) species complex (RSSC), is one of the most devastating diseases affecting tomato and many other economically important crops. Rs infection leads to quick wilting and eventually plant death. Unfortunately, tomato bacterial wilt resistance genes have not been identified yet. Our previous study identified a candidate resistance gene from Hawaii 7996, a highly resistant tomato cultivar, that appears to be associated with qualitative resistance to bacterial wilt. Overexpression of the allele from Hawaii 7996 resulted in enhanced resistance in Heinz 1706, a model bacterial wilt susceptible cultivar. Gene editing-assisted gene knockout of the allele in Hawaii reduced bacterial wilt resistance. Yeast two-hybrid assay revealed a potential kinase that interacts with this resistance gene. The identification of the resistance gene and its interacting partner provide a better understanding of the resistance mechanisms and can be used for tomato bacterial wilt resistance breeding.

Speakers

Debao Huang

NCSU

Co-authors

Frank Louws

North Carolina State University

James Duduit

North Carolina State University

Tika Adhikari

North Carolina State University

Wusheng Liu

North Carolina State University

Wednesday July 30, 2025 4:45pm - 5:00pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv

4:45pm CDT

WCPM 2 - Pest Management Using Insect Netting in Organic Chinese Cabbage Production

Wednesday July 30, 2025 4:45pm - 5:00pm CDT

Foster 2

Organic farming with its reliance on natural fertilizers, cover cropping, and crop rotation, presents a sustainable approach to food production. However, a significant challenge in organic production is insect and disease management. Organic insecticides often have limited efficacy, are expensive, and require repeated applications. Mesotunnels, medium-sized (36-40 inches tall) tunnels covered with insect netting, have emerged as a pest management tool for organic vegetable growers. This study evaluated the effectiveness of mesotunnel and low tunnel systems for pest management and season extension in organic Chinese cabbage (cultivar ‘Minuet’) production. The first season of this two-year study was conducted in Fall 2024 on certified organic land at Iowa State University Horticulture Research Station, Ames, IA. The experiment was set up as a randomized complete block design with four replications and following treatments: i) 85 g ExcludeNet insect netting, ii) 0.55 oz Agribon row cover, iii) 85 g ExcludeNet insect netting + OMRI-listed insecticide iv) OMRI-listed insecticide, and v) an untreated control, uncovered with no insecticide. Weekly pest surveillance focused on Brassica insect pests such as aphids, loopers, harlequin bugs, flea beetles, and their damage was recorded. Hobo data loggers recorded variations in light intensity, air and soil temperature, and relative humidity to observe microclimate variations in each treatment. At harvest, yield data was categorized as marketable or nonmarketable and graded according to USDA commercial standards. Among all treatments, the highest marketable produce was recorded in ExcludeNet + OMRI-listed insecticide treatment (42%), followed by Agribon row cover (31%) and the lowest in OMRI-listed insecticide (15%) during the first harvest. The earlier maturity in these treatments was likely due to warmer temperatures and improved humidity regulation under the tunnels. The insect abundance and their damage on leaves was significantly lower in ExcludeNet & ExcludeNet + OMRI-listed insecticide treatment. Integrating netting and row covers with limited use of organic insecticides provided the highest pest suppression, suggesting that physical barriers can effectively optimize pest management and enhance marketability in organic vegetable production systems. Findings from this study will inform growers and the research community about the feasibility of insect nettings as a sustainable pest management tool in organic specialty crop systems.

Speakers

Smriti Chaudhary

Iowa State University

Co-authors

Ajay Nair

Iowa State University

Wednesday July 30, 2025 4:45pm - 5:00pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Poster # csv

5:00pm CDT

CE 4 - Quantum Dot Greenhouse Glass as a Light-Management Strategy for Improved Lettuce Growth

Wednesday July 30, 2025 5:00pm - 5:15pm CDT

Strand 12B

Using luminescent quantum dot (QD) films as greenhouse coverings offers a novel approach to enhancing plant growth by modifying the light spectrum. This study evaluates the effects of novel QD glass on the growth, morphology, and yield of butterhead lettuce (Lactuca sativa cv. butterhead) in a greenhouse setting. Two identical greenhouses were employed: one fitted with a QD film and the other with conventional glass, serving as a control. Lettuce seedlings were cultivated in a deep-water culture hydroponic system, with continuous monitoring of key environmental parameters—including temperature, relative humidity, CO₂ concentration, and light spectrum. After four weeks of growth, various morphological traits were assessed, such as canopy diameter, leaf count, total leaf area, and fresh and dry biomass. Results indicated that lettuce grown under the QD glass displayed enhanced leaf development and significantly higher biomass accumulation, with a 37% increase in fresh weight and a 27% rise in dry weight compared to the control. The spectral modifications induced by the QD film, especially the conversion of blue photons to red wavelengths, likely contributed to these improvements in plant morphology and productivity. These findings highlight the potential of QD glass to boost greenhouse lettuce production by increasing radiation capture and biomass accumulation.

Speakers

MD SHAMIM AHAMED

University of California, Davis

Co-authors

Amrit Kumar Thakur

University of California, Davis

Damon Hebert

UbiQD

Laura Cammarisano Cammarisano

University of California, Davis

Nazmin Akter

University of California, Davis

Wednesday July 30, 2025 5:00pm - 5:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Funding Source USDA SBIR

5:00pm CDT

HIH - Comparison of United States Professional Florists’ Perceptions of Environmentalism and their Use of Sustainable Floral Design Practices Based on Geographical Regions

Wednesday July 30, 2025 5:00pm - 5:15pm CDT

Strand 11A

As environmental sustainability becomes increasingly important to consumers of fresh cut flowers, the educators of floral design should consider adding topics covering sustainability within the floral industry into their curriculums. Perceptions of sustainability can vary depending on the US region in which a person lives and works. The main purpose of this study was to compare the perceptions of environmentalism and the use of sustainable floral design practices currently being implemented by professional florists based on the geographical area in which they live within the US. By investigating florists' attitudes toward sustainability and their current practices based on the US region in which they live, this study sought to shed light on the current sustainable practices being implemented within the floral design industry so that educators can make informed decisions when modifying their curriculums depending on where they are located within the US. A majority of respondents from each region in the study indicated they were personally aware of sustainable products (75.4% overall) and mechanics (80.5% overall) in floral design. Differences were found in the sustainable practices being implemented by professional florists based on the US region in which they live. Overall respondents from the West indicated they used fair-trade products, sustainable and/or compostable containers, sustainable and/or compostable floral foams, recycled carboard, composted flower waste, and is attempting to eliminate plastic at a higher rate than other US regions. Based on what professional florists are currently implementing into their own business models and what consumers have indicated as being important sustainable considerations to them when making floral purchases in past research studies, topics that focus on sourcing locally grown fresh cut flowers, post-harvest care for specialty cut flowers, growing specialty cut flowers within limited space, methods for composting fresh cut flower waste, sustainable design techniques that can be incorporated into multiple design styles an occasions, and current sustainable floral products on the market for use in floral design are all example of sustainable topics that could be incorporated into a floral design curriculum.

Speakers

Lauren Baskins

Mississippi State University

Co-authors

Cole Etheredge

Mississippi State University

James DelPrince

Mississippi State University

Tina Waliczek Cade

Texas State University

Wednesday July 30, 2025 5:00pm - 5:15pm CDT
Strand 11A

Oral presentation, Human Issues in Horticulture

Funding Source This study was facilitated and funded by the Floral Marketing Fund (FMF), in cooperation with the American Floral Endowment (AFE), and co-sponsored by BloomNet® and Syndicate Sales.

5:00pm CDT

OPB - Flowering and vegetative phenology was consistent across a ploidy series in Acer ginnala

Wednesday July 30, 2025 5:00pm - 5:15pm CDT

Strand 12A

Amur maple (Acer ginnala) is a medium sized street tree grown for its durability in challenging environments. Unfortunately, it has escaped cultivation from prolific seed production and is banned in multiple regions. To breed for reduced fertility, a ploidy series was developed including 3x, 4x, and 5x genotypes. As part of the evaluation for fertility, phenology of field plants including the range from diploid to pentaploid were evaluated between 2020 and 2023. Reproductive traits included first flower, 50% flowering, full flower, seed set, seed abortion, and seed ripening. Vegetative traits included first leaf, full leaf, first fall color, full fall color, and leaf drop. There were no differences in phenology of any reproductive or vegetative traits relative to ploidy, and across all genotypes there was a high degree of consistency in timing of all observed traits. Confirming simultaneous flowering of all genotypes will provide confidence in future data collected on relative fertility of accessions to facilitate cultivar release. Additionally, this study confirmed that ploidy does not alter early or late season events that may expose plants to more damage from frost events during these periods.

Speakers

Ryan Contreras

Oregon State University

Wednesday July 30, 2025 5:00pm - 5:15pm CDT
Strand 12A

Oral presentation, Ornamental Plant Breeding

Subject Ornamental Plant Breeding
Poster # csv

5:00pm CDT

PBIG 2 - Constitutive Expression of Full-length or Partial of SOC1 genes for Yield Enhancement in Tomato

Wednesday July 30, 2025 5:00pm - 5:15pm CDT

Foster 1

Manipulating the expression of flowering pathway genes holds potential for regulating tomato fruit productivity. SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) is a MADS-box gene that serves as a key integrator in the flowering pathway. In this study, two full-length SOC1 genes cloned from maize (ZmSOC1) and soybean (GmSOC1), along with a partial SOC1 gene from blueberry (VcSOC1K, containing the K-domain), were individually transformed into tomato for constitutive expression. Phenotypically, the expression of VcSOC1K and ZmSOC1, but not GmSOC1, led to early flowering. Most transgenic lines for all three constructs exhibited a significant increase in fruit number per plant. More importantly, compared to non-transgenic plants, all three constructs resulted in varying degrees of increased fruit production per plant, primarily through enhanced branching. At the transcriptomic level, comparative analysis of GmSOC1 revealed the broader impact of the transformed genes. The increased expression of CLF and EZA1 appears to explain the unchanged flowering time of the GmSOC1 transgenic plants, while the repressed expression of DWARF genes likely contributes to enhanced branching. Additionally, numerous genes associated with biotic and abiotic stress tolerance displayed differential expression. These findings demonstrate that constitutive expression of either full-length or partial SOC1 has the potential to enhance tomato fruit production.

Speakers

Guo-qing Song

Michigan State University

Co-authors

Gharbia H. Danial

University of Duhok

Jirapa Jaikham

Michigan State University

Wednesday July 30, 2025 5:00pm - 5:15pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv

5:00pm CDT

WCPM 2 - Do Bicultures of Sunn Hemp with Sorghum Sudangrass Decrease Its Weed and Plant-Parasitic Nematode Suppression Efficacy?

Wednesday July 30, 2025 5:00pm - 5:15pm CDT

Foster 2

Sunn hemp (SH, Crotalaria juncea L.) is used in Florida strawberry production as an off-season summer legume cover crop to provide agroecosystem services such as weed and plant-parasitic nematode (PPN) suppression. Bicultures of SH with sorghum-sudangrass (SS) (Sorghum bicolor Moench × S. sudanense [Piper] Stapf) are of interest to reduce the cost of SH use. Our study objective was to determine whether bicultures retain the weed and PPN suppression benefits provided by SH grown in monoculture. A replacement series experiment was conducted in summer 2022 and repeated in 2023 in north-central Florida in a PPN-infested field. A factorial treatment arrangement of five SH:SS biculture proportions (100:0, 75:25, 50:50, 25:75, and 0:100) and three seeding rates (20, 40, and 60 lb/acre) were evaluated in a randomized complete block design with four replications. A no-cover crop, weedy control was also included in each block. Data were collected on cover crop biomass and carbon: nitrogen ratio (C:N), weed density, weed biomass, and PPN populations at eight weeks after planting. Bicultures consistently produced higher total cover crop biomass than the SH monoculture. Bicultures were as effective as the SH monoculture in reducing total weed density and resulted in either lower or equivalent total weed biomass. Averaged over year, only the 60 lb/acre seeding rate had a lower total weed density than the 20 lb/acre rate. In 2022, both the 40 and 60 lb/acre seeding rates resulted in lower weed biomass than the 20 lb/acre rate, while seeding rate had no significant effect on total weed biomass in 2023. Root-knot nematode populations in both years and sting nematode populations in 2022 were detected at levels too low for analysis. However, in 2023, the lowest and highest sting nematode populations occurred with the SH and SS monocultures, respectively; and sting nematode populations increased as the proportion of SS in the bicultures increased. Bicultures with ≤50% SS had significantly higher sting nematode populations than the weedy control. An increase in C:N was observed as SS proportion in bicultures increased. Thus, we conclude that SH/SS bicultures maintain the weed biomass suppression benefits of SH monocultures while increasing cover crop biomass. However, bicultures may lead to higher sting nematode populations, which will be of concern in organic strawberry production where soil fumigation is not permitted. Growers will also need to consider the effects of the higher C:N ratio of biculture residue on nitrogen fertilizer immobilization.

Speakers

Jean-Maude Louizias

University of Florida

Co-authors

Carlene Chase

University of Florida

Gabriel Maltais-Landry

University of Florida

Johan Desaeger

University of Florda

Nathan Boyd

University of Florida

Rosalie Koenig

University of Florida

Wednesday July 30, 2025 5:00pm - 5:15pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Poster # csv

5:15pm CDT

CE 4 - Right on the Dot? Validation of a Lettuce Growth Model Under a Mock Silicon Quantum Dot Spectrum

Wednesday July 30, 2025 5:15pm - 5:30pm CDT

Strand 12B

Incorporation of quantum dots within greenhouse films has the potential to enhance local food production with a reduced carbon footprint, without compromising yield or quality. Silicon quantum dots in particular hold advantages over other photoluminescent nanoparticles in that they have low toxicity and are highly tunable. The down-shifting of photons observed under silicon quantum dot films can enhance vegetative productivity of plant commodities, but due to a relatively low photon emission efficiency of the films, the transmitted light to crop canopies below is reduced. A growth model has been used to predict the performance of lettuce grown under a silicon quantum dot spectrum, but no studies have been conducted to validate these predictions. Our study aimed to evaluate the yield and physiological performance of Lactuca sativa cv. ‘Rex’ grown in controlled environment growth chambers fit with tunable 11-channel LEDs which were used to match the color fraction of a solar spectrum transmitted through glass greenhouse glazing or a solar spectrum transmitted through a silicon quantum dot film. Light intensity levels of 500 and 350 µmol m−2 s−1 were also tested to simulate the expected 33% loss of light transmission through the silicon quantum dot film at a density of 5 wt%. The spectrum and light intensity treatments were tested in a factorial design for a total of four treatments, with each treatment replicated five times. Fresh biomass results from the growth chambers showed that growth model predictions underestimate the performance of ‘Rex’ under the mock silicon quantum dot spectrum. The elimination of UV-A photons and enrichment of red and far red photons in the mock silicon quantum dot treatment increased leaf area and growth at their respective light intensities compared to the mock solar spectrum; however, the yield of the 350 µmol m−2 s−1 mock silicon quantum dot spectrum did not surpass that of the 500 µmol m−2 s−1 mock solar spectrum. This research highlights the importance of coupling solar cells with silicon quantum dot films to increase their economic feasibility and further illuminates the effects of down-shifted spectra on lettuce physiology.

Speakers

Christopher Nieters

University of Minnesota

Co-authors

Bryan Runck

University of Minnesota

Nathan Eylands

University of Minnesota

Walid Sadok

University of Minnesota

Wednesday July 30, 2025 5:15pm - 5:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Poster # csv

5:15pm CDT

HIST - Evolution of ASHS Conferences: 60 Consecutive Years' Attendance

Wednesday July 30, 2025 5:15pm - 5:30pm CDT

Strand 11A

ASHS Annual Meetings (now conferences) have evolved over the 60 years of my attendance. From the 1965 Annual Meeting in Urbana Illinois where I stayed in a tent on the University quadrangle, to the most recent conference in Honolulu, they have been professionally stimulating, exciting and memorable. The dogwood pin given to attendees of the 1966 meeting with ISHS in Maryland, the long drive from St. Paul to College Station, Texas in 1967 and the ISHS/ASHS meeting in Davis stimulated my involvement and commitment to attending these important conferences. Involvement with the ASHS infrastructure began when I became a Board member representing the Great Plains Section when attending the meeting in Manhattan Kansas. I was immersed into the ASHS system further as the Chair of Local Arrangements for the 1972 meeting in St Paul (remember the chicken fiasco?) The Guelph meeting in 1974 was memorable because I attended "on the way" to sabbatical at the University of Nottingham and was "on the way back" to the 1975 meeting in Honolulu (September meeting). It was an easier drive from St. Paul to Ames in 1982 where I took my grad students in a van to save them money (I have always encouraged my students to become ASHS members by paying for their first year's memberships). Past President Dermot Coyne sponsored me for ASHS Fellow, awarded at the meeting in East Lansing in 1988. My second meeting in Honolulu was of note because following inducements of pineapples, luau and more, I purchased a timeshare to make sure that I'd take a "real" vacation in addition to my usual tacking on a few days to ASHS conferences. Among the important changes with which I had the privilege to assist was the creation of the ASHS Endowment Fund, and now the "$125 for Five" campaign that will continue to help deserving students. Of course I am humbled to say that one of my greatest honors was election as President of ASHS. Following the devastation wrought by Hurricane Katrina, I was inundated with "where can we meet", "when can we meet" emails and calls. I was proud to respond that we will help New Orleans by following through with our commitment to meet there. I will mention many more important ASHS changes and insights as part of my presentation this year as we return to the site of my Presidential Address in the "Big Easy".

Speakers

Paul Read

University of Nebraska

Wednesday July 30, 2025 5:15pm - 5:30pm CDT
Strand 11A

Oral presentation, History of Horticultural Science

Subject History of Horticulture
Poster # csv

5:15pm CDT

PBIG 2 - Testing Different Plant Growth Regulators for Germination and Conversion of Cornus florida Somatic Embryos

Wednesday July 30, 2025 5:15pm - 5:30pm CDT

Foster 1

Flowering dogwood (Cornus florida) is a native tree species to the Eastern US that is susceptible to powdery mildew fungus. Genetic transformation of somatic embryogenic tissue in conjunction with gene editing are molecular methods used to breed pathogen-resistant cultivars. This research investigates the most effective germination treatment in regenerating plantlets from genetically transformed somatic embryos of flowering dogwood. From somatic embryogenic callus cultures containing the reporter transgene ß-glucuronidase (GUS), we grew tissue in liquid suspension and size fractioned using sterile metal sieves of different pore sizes. We collected pro-embryogenic masses (PEMs) from the small mesh size sieve, plated PEMS onto nylon supports using vacuum, and placed the nylon supports to semi-solid maturation media for embryo development. We chose somatic embryos elongating beyond the torpedo stage with the best quality and appearance and placed them across the four germination treatments. The germination experiments evaluated four different treatment concentrations of four different plant growth regulators (PGRs), gibberellic acid (GA3), abscisic acid (ABA), 6-benzylaminopurine (BAP), and melatonin. The environmental conditions for the first experiment included fluorescent lighting (10 μmol/m²/sec), temperature at 23 ºC (±1), and a photoperiod of 16h light:8h dark. Somatic embryos growing in germination media supplemented with GA3 (1, 2mg/L) had a higher percentage of embryos showing emergence of the apical shoot meristem between the cotyledons. The next highest percentage of somatic embryos with emerging apical meristems occurred using BAP at the concentrations 0.5 and1mg/L. The second germination experiment assessed the same treatments above except used early- stage torpedo somatic embryos and the light intensity increased to 35 μmol/m²/sec. BAP at 0.5 and 1mg/L showed the highest percentage of greening cotyledons and rooting rates. However, in 60 days, all the somatic embryos died in the GA3, ABA, melatonin, and BAP germination treatments. Although we successfully developed healthy transgenic somatic embryos, converting them into plants was a major challenge. The furthest germination stage we reached was the emerging of apical shoots, where the meristem elongates and continues to primary leaf formation. The difficulty in obtaining complete conversion to plants from these transgenic somatic embryos suggests there may be unintended impacts on growth or germination based on the location of the GUS transgene in the genome. Additionally, the original transgenic embryogenic culture was eight years old prior to the germination experiments, which could have influenced embryo conversion to plants.

Speakers

Heather Gladfelter

University of Georgia

Co-authors

Dayton Wilde

University of Georgia

Will Johnson

University of Georgia

Wednesday July 30, 2025 5:15pm - 5:30pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv
Funding Source University of Georgia CURO and CAES Undergraduate Research Grants

5:15pm CDT

WCPM 2 - Bed Architecture and Fumigation Strategies for Strawberries in Eastern NC

Wednesday July 30, 2025 5:15pm - 5:30pm CDT

Foster 2

Management of plant parasitic nematodes (PPNs), soil-borne diseases, and weeds in the strawberry industry is fundamental for every North Carolina grower, to achieve a successful production season. The prohibition of methyl bromide (MBr) in 2005 caused significant challenges for growers leading to the search for new and efficient strategies to suppress and control the impact of pests and diseases that affect strawberry growers. Hence, the objective of this project was to evaluate alternative fumigation strategies combined with new bed architectures for the control of soil-borne pests in strawberry production. Two experiments were conducted in North Carolina where, compact beds (24 inches wide by 12 inches tall) were compared to traditional North Carolina strawberry beds (30 inches wide by 6 inches tall). Both bed architecture designs were fumigated with either shank or drip-applied fumigants (Pic-Clor 60 and Pic-Clor 60 EC, respectively), with and without the inclusion of a soil surfactant for the drip fumigation treatments. In both studies, we measured strawberry plant biomass, volumetric water content in multiple points of the planting beds, plant parasitic nematodes (PPNs) and weed pressure before and after fumigation, plant reflectance indexes, bed compaction, and crop yield. Post-treatment results demonstrated that compact beds with both shank and drip-applied fumigants achieved comparable control of weeds and PPNs to traditional beds with shank fumigation. Bed compaction measures indicated that compact bed treatments present less compaction at 4-, 8- and 12-inch depths compared to the higher compaction observed in North Carolina’s traditional strawberry beds.

Speakers

Josue Alarcon Mendoza

North Carolina State University, Horticultural Science

Co-authors

Emmanuel Torres Quezada

North Carolina State University

Wednesday July 30, 2025 5:15pm - 5:30pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Poster # csv

5:30pm CDT

CE 4 - Advancing Energy Efficiency: Insights from the New York State Greenhouse Energy Benchmark Project

Wednesday July 30, 2025 5:30pm - 5:45pm CDT

Strand 12B

Energy costs are typically the second largest operational cost for greenhouses behind labor and these costs are increasing over time. Energy use varies greatly between operations based on their geographic location, type of technology, months of operation, and type of crops grown. Energy benchmarking is a process used for many commercial buildings whereby energy performance of facilities are quantified. The information can be used by operations to better understand their energy use relative to their peers and can help identify opportunities for energy efficiency improvements and cost savings. The Greenhouse Lighting and Systems Engineering (GLASE) consortium leads a project with a goal of benchmarking energy use in 40 greenhouse operations in New York State. The process began with implementing a database tool with EnSave’s FEAT (farm energy audit tool) specific to greenhouse operations. The tool allows energy efficiency contractors to enter information from farm site visits on: building dimensions and properties, equipment usage (including HVAC and lighting), past utility bills, crops grown and months of the year they are grown. The database tool outputs a benchmarking report to give operations a clear understanding of energy use (total energy, energy use intensity and on a per square foot production space and per crop unit basis). Through New York State Energy Research and Development Authority (NYSERDA), funding was made available for up to 80 greenhouses in New York State to participate. More than 40 operations have now enrolled in the project. Findings will be presented on the initial results. Challenges in reporting include the diversity of types of operations (with different types of products produced) and in many diversified farms there are not specific energy meters relative to greenhouses vs. other diversified farm activities. Nevertheless the results provide a baseline of energy use intensity in New York State greenhouses.

Speakers

Neil Mattson

Cornell University

Co-authors

Gretchen Schimelpfenig

Cornell University

Kyle Clark

EnSave Inc.

Matthew Del Buono

Cornell University

Timothy Shelford

Cornell University

Wednesday July 30, 2025 5:30pm - 5:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments

5:30pm CDT

HIST - Gardening During the World Wars – Horticulture Efforts to Feed the US and the War Effort

Wednesday July 30, 2025 5:30pm - 5:45pm CDT

Strand 11A

The United States during the national crises of the First and Second World Wars developed gardening and food production programs in order to support the war effort and to supply food for the troops and those at home. The National War Garden Commission, a private organization, was created in 1917 one month before the US entry in World War 1. The role of the commission was to encourage US citizens to cultivate in all available space, offering free seeds and plants and to “Sow the Seeds of Victory!” President Woodrow Wilson in 1917 indicated “everyone who creates or cultivates a garden helps,” and tasked government agencies with aiding the effort to conserve food and other supplies for soldiers. The civilian garden program was supported by the commission who gave away free booklets on gardening, canning, and food preservation. These gardens, termed “war gardens” were grown throughout the country on vacant land, parks, backyards, and schools; there was call for schools to join the United States School Garden Army. There were many war gardens in the USA and around the world. There were more than 5.2 million war gardens in the USA by 1918. Towards the end of World War 1 the effort shifted to victory gardens with the goal of feeding the hungry, and prevention of starvation. With the advent of World War 2 the victory gardens were mobilized to provide resources to fight the war and support the US allies. Almost 20 million Americans planted gardens – in backyards, vacant lots, athletic fields, schools, roof tops. Produce from their gardens would help to lower the price of vegetables needed by the US War Department to feed the troops, thus saving money that could be spent elsewhere on the military. An estimated 40 % of the nation’s fresh vegetables were produced in victory gardens. The federal government, via the USDA provided resources such as seeds, production guides, and guidance in order to support victory gardens. The guides were intended to provide information to novice gardeners on growing food as well as proper canning and preservation techniques. The current farm to school movement and the People’s Garden program have their roots in the previous wartime efforts in order to support a more diverse resilient food system and address issues such as food access and climate change.

Speakers

Carl Motsenbocker

Professor, Executive Director Louisiana Farm to School Program, Louisiana State University

Wednesday July 30, 2025 5:30pm - 5:45pm CDT
Strand 11A

Oral presentation, History of Horticultural Science

Subject History of Horticulture
Poster # csv

5:30pm CDT

PBIG 2 - Hormonomics-Guided Bloom Regulation: Enhancing Climate Resilience in Peach

Wednesday July 30, 2025 5:30pm - 5:45pm CDT

Foster 1

Spring frost is a major environmental stressor caused by sub-zero temperatures (≤ 0 °C), often accompanied by freezing dew points, and poses a substantial economic threat to fruit crops. While the frequency of spring frost events may be influenced by climate change, the severity of damage has increased in recent years. This is largely due to elevated early spring temperatures that induce precocious bloom, making developing flower buds more vulnerable to subsequent frost events. Although no bloom-delay plant growth regulator (PGR) has been fully established to date, the use of PGRs to postpone flowering and mitigate frost risk remains a highly sought-after strategy in horticultural production. Our previous research demonstrated that fall applications of ethephon can delay bloom by 3–6 days in peach (Prunus persica). However, this treatment has also been associated with severe gummosis, necrosis, and branch damage. In the present study, we employed a plant hormonomics approach to investigate the relative abundance of endogenous hormones in flower buds of ethephon-treated versus untreated peach trees. Our analysis revealed dynamic profiles of abscisic acid (ABA), auxins (e.g., indole-3-acetic acid, indole-3-acetamide, 2-oxo-indole-3-acetic acid), brassinosteroids (e.g., 28-norcastasterone), cytokinins (e.g., zeatin, kinetin, N6-isopentenyladenosine), jasmonate-related compounds (e.g., cis-12-oxo-phytodienoic acid, dinor-12-oxo-phytodienoic acid, jasmonic acid [JA], JA-phenylalanine), salicylic acid, gibberellins (e.g., GA1, GA3, GA4, GA6), and strigolactones, with distinct accumulation patterns related to chilling and heat accumulation during dormancy and in response to ethephon treatment. Among these, jasmonates exhibited a unique pattern: levels remained low during dormancy and spiked sharply near bud break, but this spike was significantly suppressed in ethephon-treated trees. Based on this observation, we hypothesized that JA biosynthetic inhibitors could serve as effective bloom-delay agents. Indeed, over two consecutive seasons (2023 and 2024), we tested two JA inhibitors—propyl gallate and antipyrine—in two peach cultivars, ‘Sunhigh’ and ‘Redhaven’. Both compounds significantly delayed bloom progression compared to untreated controls. Furthermore, in 2025, antipyrine treatment resulted in a marked reduction in flower mortality following a killing freeze, which caused 100% damage in untreated trees versus approximately 90% in antipyrine-treated trees. To the best of our knowledge, this study represents the first hormonomics-driven translational approach aimed at regulating bloom time in perennial fruit trees to enhance their resilience to climate-related frost events.

Speakers

khalil Jahed

Virginia Tech

Co-authors

Amolpreet Kaur Saini

Virginia Tech

Lauren Erland

University of Fraser Vally

Mohammad Monirul Hasan Tipu

Virginia Tech

Sherif Sherif

Virginia Tech

Dr. Sherif M. Sherif is an Associate Professor at Virginia Tech, where he channels his fervent zeal for life sciences and educational outreach into his specialization in tree fruit physiology and molecular biology. His career is defined by a dedication to overcoming the biological... Read More →

Wednesday July 30, 2025 5:30pm - 5:45pm CDT
Foster 1

Oral presentation, Plant Biotechnology 2

Subject Plant Biotechnology
Poster # csv

5:30pm CDT

WCPM 2 - Residual herbicide degradation on nursery trees following drift events

Wednesday July 30, 2025 5:30pm - 5:45pm CDT

Foster 2

Minnesota (MN) in the US ranks 2nd for corn silage production and 3rd for soybean production. Studies have shown that off-target movement (drift) from an unshielded sprayer, in row crops, can range from 1 to 16% of the target dose; however, boom height and wind can double or triple these doses. Pre-study 37 pesticide residue tests were conducted in five Minnesota nurseries in 2018. Nine different herbicides were detected in the 37 tests. Glyphosate (sold as Roundup Power Max 32% glyphosate) became the focus of 2019 studies, conducted at concentrations of 0, 6, 18 and 54% for glyphosate as drift events. Relating ppm’s disclosed in laboratory analyte foliar residue samples collected by various state agriculture departments after drift events to injury symptom, development, and growth reduction or time after application have ever been conducted for nursery crops. From personal communication with nursery owners experiencing neighbor’s drift event (MD; KY, OH, MI, FL) the average time from the drift event to recognizing problems, and sample collection is six weeks (6 weeks after drift event) (6 WADE). Slower metabolism of glyphosate at higher residues, explained our finding that the largest residues were detected in all, but one species/ treatments used with glyphosate, versus three other herbicides examined or in combinations. Higher residues meaning higher injury, does not occur with glyphosate. Potentially high residues mean slow metabolism for glyphosate, and thus less injury. In five cases glyphosate applied alone had no impact on growth measured as caliper over the season, even though glyphosate had the highest residue in three of the five. In only one case was caliper growth reduction highest with glyphosate (Syringa 18%) over the entire study. In terms of phytotoxicity rating, glyphosate caused no commercially unacceptable injury in four cases. Residues increased with all rates on the three species evaluated between 3 DADE and 6 WADE. With Acer freemanii and Tilia cordata residue levels declined slightly between 6 WADE to 14 WADE with all rates. Only, Syringa reticulata showed an increase in foliar residues between 6 WADE to 14 WADE. Since carry over injury the next year (or three) is a concern with all glyphosate applications to perennial plants, all trees were observed in 2020. None were commercially acceptable and in severe decline (regardless of rate) in spring 2020, only 6% glyphosate on Syringa survived to the fall , and by spring 2021 were dead.

Speakers

Hannah Mathers

Mathers Environmental Science Services, LLC

Owner of Mathers Environmental Science Services, established 2010, active since 2015 resigning from Ohio State University, as Full Professor/ State Extension Nursery/ Landscape Extension Specialist 2000 to 2015. Previous to OH State University was Assistant Professor and Regional... Read More →

Co-authors

James Beaver

Mathers Environmental Science Services, LLC

Wednesday July 30, 2025 5:30pm - 5:45pm CDT
Foster 2

Oral presentation, Weed Control and Pest Management 2

Subject Weed Control and Pest Management
Funding Source Specilaty Crop Block Grant/ MDARD/MNLA

5:45pm CDT

CE 4 - An Argument in Favor of Creating a United American Society for Greenhouse and Controlled Environment Growers to Build a Connected, Collaborative Grower Network for More Efficient Technology Transfer and Production

Wednesday July 30, 2025 5:45pm - 6:00pm CDT

Strand 12B

While Controlled Environment Agriculture (CEA) continues to expand rapidly across North America, the U.S. lacks a unified national organization to represent, support, and connect greenhouse growers. In contrast to Canada and the Netherlands, which benefit from strong national-level grower associations, American growers remain fragmented across states, commodity groups, or scale-specific networks. The existing groups tend to be state-specific, crop-specific, or focused on suppliers and hobbyists—leaving a major gap for commercial growers who need actionable support and a unified voice. This fragmentation further limits access to shared knowledge, economic leverage, and consistent representation in research and policy. To address this, we propose the creation of the United Greenhouse Growers Association (UGGA), a national, grower-led association designed to support collaboration, knowledge-sharing, and improved market efficiency. Initial development will begin in Kentucky, where the University of Kentucky has already mapped CEA activity across the state, providing a strong foundation for data-driven outreach, pilot engagement, and program testing. What distinguishes this initiative is its emphasis on practicality, inclusion, and tangible value. Rather than serving as a passive affiliation, the UGGA will offer direct support through group purchasing programs, collective marketing strategies, access to shared services, and the translation of academic research into usable tools. There will be the opportunity for the UGGA to set training and certification standards for professional growers which will give guidance to trade schools and colleges. Membership will be kept affordable and low-barrier, intentionally structured to welcome small and mid-sized growers alongside larger operations. Most critically, the organization will be led by growers themselves—not just vendors or researchers—ensuring the priorities reflect real operational challenges and opportunities. The society will address national gaps that existing groups often overlook: the need for peer-to-peer knowledge on transitions from soil to substrate, crop management under protected/controlled environments, strategies for reducing the isolation of growers in low-density CEA states, and creating a network that supports national-scale coordination without losing local relevance. The UGGA structure would also allow for cross-state collaboration and integration with USDA priorities around regional supply chain resilience and U.S. producer support. This abstract proposes launching an organizing committee to begin outreach, host stakeholder roundtables in Kentucky and beyond, define founding principles, and formalize UGGA’s nonprofit framework in preparation for national rollout.

Speakers

Melanie Yelton

GrowBig Consulting

Melanie Yelton, Dr. Yelton leverages over 25 years of plant science leadership to guide controlled agriculture entities towards climatically resilient food systems. Via her consultancy company, GrowBig, she advises controlled environment agriculture farms, lighting partners and R... Read More →

Co-authors

Derek Smith

Resource Innovation Institute

Qinglu Ying

University of Kentucky

Sam Chronert

GrowBig Consulting

Trevor Terry

Kentucky Horticulture Council

Wednesday July 30, 2025 5:45pm - 6:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 4

Subject Growth Chambers and Controlled Environments
Poster # csv

7:59am CDT

FLOR 2 - Oral Session

Thursday July 31, 2025 7:59am - 8:00am CDT

Strand 11B

Presiding/Moderator

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 7:59am - 8:00am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture

7:59am CDT

PNM 3 - Oral Session

Thursday July 31, 2025 7:59am - 8:00am CDT

Foster 2

Presiding/Moderator

Elena Maximo

University of Florida

Thursday July 31, 2025 7:59am - 8:00am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management

7:59am CDT

TCHG 2 - Oral Session

Thursday July 31, 2025 7:59am - 8:00am CDT

Strand 11A

Presiding/Moderator

Cynthia Domenghini

Kansas State University

Thursday July 31, 2025 7:59am - 8:00am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods

7:59am CDT

VGBR 2 - Oral Session

Thursday July 31, 2025 7:59am - 8:00am CDT

Strand 12B

Presiding/Moderator

Amol Nankar

University of Georgia (UGA)

Thursday July 31, 2025 7:59am - 8:00am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding

7:59am CDT

VSF 2 - Oral Session

Thursday July 31, 2025 7:59am - 8:00am CDT

Foster 1

Presiding/Moderator

Pedro Rojas-Barros

Washington State University

Thursday July 31, 2025 7:59am - 8:00am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits

8:00am CDT

FLOR 2 - Municipal Reclaimed Water to Irrigate Field-grown Ranunculus in Southern California

Thursday July 31, 2025 8:00am - 8:15am CDT

Strand 11B

Ranunculus are sensitive to high soil salinity and to high chloride concentrations. A trial was set up in fall 2024 at the Flower Fields in Carlsbad, CA to evaluate the yield and quality parameters of field-grown ranunculus under three irrigation water treatments and corresponding increasing levels of water salinity. The treatments were 1) Municipal water, currently used at the Flower Fields to grow ranunculus and other crops; 2) a 50:50 blend of municipal water and reclaimed municipal water; 3) 100% reclaimed water (called hereafter “recycled”). The objective of the study was to investigate if a blend of municipal and reclaimed water or 100% reclaimed water can be used in the future to grow ranunculus at the flower fields. The expected salinity levels in the water, measured as electrical conductivity before fertilizer injection were

Speakers

Gerry Spinelli

University of California Cooperative Extension

Irrigation management in nurseries and greenhouses

Co-authors

Jess Williams

Mellano

Mike Anthony Mellano

Mellano

Thursday July 31, 2025 8:00am - 8:15am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Funding Source Kee Kitayama Foundation

8:00am CDT

PNM 3 - Evaluating impact of organic amendments on broccoli transplant production

Thursday July 31, 2025 8:00am - 8:15am CDT

Foster 2

Transplants provide an early start and help with better establishment and enhanced yield and quality in vegetable crops. For production of healthy and high-quality transplants, nutrient management is critical. There are several organic amendments available that can be directly added to the transplant growing media to provide essential nutrients for transplant growth and development. Some of the commonly used amendments include blood meal, bone meal, feather meal, fish emulsion, alfalfa meal, crab meal, shrimp meal, bat guano, etc., These organic amendments are obtained from dried animal blood or bone products which are rich in nutrients like Nitrogen, Phosphorus, and Potassium. Even though these amendments are available, there is lack of information on their efficacy and impact in organic transplant production. This greenhouse study conducted at Iowa State University, investigated the use of several amendments in broccoli transplant production. Treatments included: blood meal, bone meal, feather meal, fish emulsion, compost, conventional fertilizer, compost, and a no-fertilizer control. Plant height, stem diameter, SPAD (Soil Plant Analysis Development), dry biomass, and root length are the parameters we analyzed to determine the transplant growth. The findings show that the conventional fertilizer treatment had the tallest plant, with a mean height of 8.54 cm, followed by the blood meal with a height of 8.15 cm. No significant difference was observed between the conventional fertilizer and blood meal treatment. The highest mean stem diameter was found in the blood meal treatment, measuring 4.2 mm, followed by the feather meal treatment, which had a mean stem diameter of 3.65 mm. Blood meal and feather meal treatments were significantly different from each other. The plant biomass was high in the blood meal treatment at 3.36g. The blood and feather meal treatments differed significantly from the bone meal, compost, fish emulsion, and control treatments. Results from this study show that organic amendments can be successfully used to improve the transplant growth with a single application, potentially saving labor and cost. Keywords: transplants, organic amendments, SPAD, nutrients, blood meal, bone meal, feather meal.

Speakers

Akshaya Thinakaran

Iowa State University

Co-authors

Ajay Nair

Iowa State University

Thursday July 31, 2025 8:00am - 8:15am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv

8:00am CDT

TCHG 2 - Creating a Course to Target Self-Efficacy and Interest in Horticulture among Non-Horticulture Majors

Thursday July 31, 2025 8:00am - 8:15am CDT

Strand 11A

The Department of Horticulture and Natural Resources at Kansas State University offers a horticulture course for non-horticulture majors introducing students to an overview of the subject matter. This in-person, 16-week course provides hands-on learning and may be a tool to increase awareness of the horticulture industry while recruiting students to enroll in additional horticulture courses. Enrolled students were surveyed at the beginning of the semester and again at the end to evaluate changes in their self-efficacy and interest in horticulture as a future career and/or hobby after participation in the course. Twenty-nine students participated in both surveys over the two semesters data was collected. Survey responses required participants to indicate on a scale of one through five how strongly they agreed (5) to disagreed (1) with each statement in relation to the course. The data from the two semesters was compiled to create one dataset. Responses for each question were averaged and the differences between pre and post surveys were calculated to evaluate change. Results indicate positive change from pre- to post-survey in each area, though the differences were most notable in three categories. Student interest in pursuing horticulture as a hobby and as a career increased by one and two scale values respectively shifting from neutral or disagree to agree in both areas. Another area that showed this level of change was the prompt “I plan to recommend this course to others”. The difference from pre to post was one scale value shifting from neutral to agree. These results, along with the other positive results suggest the course may provide opportunities to increase student interest in horticulture and recruitment of new students to the program. Future students will be surveyed as the course is offered to add to the dataset informing the efficacy of this course as a recruitment tool.

Speakers

Cynthia Domenghini

Kansas State University

Thursday July 31, 2025 8:00am - 8:15am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods

8:00am CDT

VGBR 2 - Genome Wide Association Analysis of Free Sugars in the Storage Roots of a Diverse Collection of Carrot (Daucus carota L.)

Thursday July 31, 2025 8:00am - 8:15am CDT

Strand 12B

Carrots are one of the most popular vegetables, valued for both their culinary uses and health benefits. While carrot breeders have primarily focused on enhancing appearance to meet consumer expectations, flavor is also an important factor. Sugars, which are key to carrot flavor, are the focus of this project. Carrots accumulate two main types of free sugar-reducing sugars (glucose and fructose) and non-reducing sugars (sucrose). Carrots with high percentage of reducing sugar tend to have sweeter, less harsh and more preferred flavor. The balance between sucrose and reducing sugars is controlled by a dominant gene called Rs, where heterozygous plants have a higher proportion of reducing sugars. In this study, we conducted a genome-wide association study (GWAS) using a diverse set of carrot accessions grown over five years to identify SNP markers linked to sugar composition in carrots. The enzyme acid-soluble invertase isozyme II, which breaks down sucrose into glucose and fructose, was identified as the most significant candidate gene. To further validate this gene’s involvement in the Rs locus, we are using genome editing techniques. Details of this genome editing work will be presented.

Speakers

Gunay Yildiz

University of Wisconsin-Madison

Co-authors

Erin Lalor-King

US Department of Agriculture (USDA)–Agricultural Research Service, Vegetable Crops Research Unit, Madison, Wisconsin, USA

Julie Dawson

Department of Plant and Agroecosystem Sciences, University of Wisconsin–Madison, Wisconsin, USA

Michael Paulsmeyer

Agricultural Research Service, Midwest Area

Patrick Krysan

Department of Plant and Agroecosystem Sciences, University of Wisconsin–Madison, Wisconsin, USA

Philipp Simon

US Department of Agriculture (USDA)–Agricultural Research Service, Vegetable Crops Research Unit, Madison, Wisconsin, USA

Rajesh Yarra

Department of Plant and Agroecosystem Sciences, University of Wisconsin–Madison, Wisconsin, USA

Shelby Ellison

Department of Plant and Agroecosystem Sciences, University of Wisconsin–Madison, Wisconsin, USA

William Rolling

Department of Plant and Agroecosystem Sciences, University of Wisconsin–Madison, Wisconsin, USA

Thursday July 31, 2025 8:00am - 8:15am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv

8:00am CDT

VSF 2 - Protecting Raspberries from Extreme Heat: Evaluating Physiological and Yield Responses to Cooling Strategies

Thursday July 31, 2025 8:00am - 8:15am CDT

Foster 1

Extreme heat events threaten raspberry (Rubus ideaus) production in the U.S. Pacific Northwest. The aim of this study was to evaluate strategies for reducing heat stress at a field site located in Prosser, Washington. Treatments were arranged in a split-plot design with four replicates and included three heat mitigation treatments (evaporative cooling with micro-sprinklers, shade cloth, and an untreated control) as main plots and four genotypes (‘Meeker’, ‘WakeField’, WSU 2188, and ORUS 4715-2) as subplots. Across the genotypes, evaporative cooling and shade cloth enhanced photosynthesis and chlorophyll fluorescence and increased yield compared to untreated controls. Shade cloth also resulted in higher stem water potentials than the other mitigation treatments, indicating improved hydration in each genotype. Preliminary economic analyses indicate that shade cloth is more expensive to install than micro-sprinklers for cooling and may interfere with mechanical operations. Evaporative cooling, on the other hand, increases weed pressure, which requires additional management. It also increased postharvest pathogens on the fruit after two weeks of cold storage in ORUS 4715-2. In each case, cooling was run continuously whenever ambient air temperature was > 30°C. Next, we will evaluate whether cooling for 15 minutes every hour is effective and results in fewer weeds and pathogens than continuous cooling.

Speakers

Makonya Givemore Munashe

Washington State University

Co-authors

David Bryla

USDA

Karina Gallardo

Washington State University

Lisa Wasko DeVetter

Washington State University

Lisa Wasko DeVetter joined Washington State University in 2014 and leads the small fruit horticulture program at the Northwestern Washington Research and Extension Center in Mount Vernon, Washington. She has developed a diverse research and extension program with an emphasis on maximizing... Read More →

Michael Hardigan

USDA

Suzette Galinato

Washington State University

Troy Peters

Washington State University

Wendy Hoashi-Erhardt

Washington State University

Thursday July 31, 2025 8:00am - 8:15am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Poster # csv

8:15am CDT

FLOR 2 - From Farm to Florist: Carbon Footprints in Local Cut Flower Supply Chains in the United States

Thursday July 31, 2025 8:15am - 8:30am CDT

Strand 11B

Floriculture supply chains are undergoing a shift toward sustainability, driven by consumer demand and industry initiatives to reduce environmental impacts. While previous research has explored the carbon footprint of some ornamental horticultural products, domestic U.S. cut flower production and distribution remains largely understudied. Understanding the emissions associated with different supply chain models can guide sustainable practices in the domestic floriculture industry. This study examines the carbon emissions from the production and transportation of one representative cut flower species – snapdragon. Two primary distribution models were compared: point-to-point delivery where individual growers supply retailers directly and the hub-and-spoke system where wholesale hubs consolidate and distribute flowers. By evaluating data collected from 188 growers, 330 retailers, and six regional wholesale hubs, the research quantifies carbon emissions at each stage of the supply chain. The life cycle analysis uses openLCA software to standardize emissions data to an "emissions per stem" metric, aligning with horticulture footprinting standards. The results highlight the importance of optimizing supply chain logistics to reduce emissions. Furthermore, applying the social cost of carbon ($185 per metric ton of CO2) provides an economic perspective on the environmental impact of floral supply chains. As businesses move toward more climate-conscious operations, these insights can guide decisions that align with both financial and sustainability business goals.

Speakers

Amanda Solliday

PhD student, North Carolina State University

Hi, I'm a PhD student at NC State University conducting climate and sustainability research in cut flowers.

Co-authors

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 8:15am - 8:30am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Funding Source Association of Specialty Cut Flower Growers (ASCFG)

8:15am CDT

PNM 3 - Effect of Planting Dates and Nitrogen Rates on Broccoli in North Carolina

Thursday July 31, 2025 8:15am - 8:30am CDT

Foster 2

Shifts in regional precipitation patterns and rising temperatures due to climate change have increased uncertainty surrounding optimal planting windows and nitrogen (N) management strategies for broccoli production in North Carolina (NC). In particular, growers face challenges in aligning planting schedules with ideal environmental conditions and adjusting N application rates to match crop demands under variable temperature regimes. Given that both air and soil temperatures directly influence crop nutrient uptake and development, this study aimed to evaluate the combined effects of planting date, nitrogen rate, and application timing on the growth and productivity of two commercially important broccoli cultivars: 'Eastern Crown' and 'Emerald Crown.' Field experiments were conducted at the Horticultural Crops Research Station of North Carolina State University in Clinton, NC. The first trial included four planting dates—early March, late March, early April, and late April—combined with three fertigation N rates of 120, 100, and 80 lb/acre. The second trial focused on two planting dates, late March and late April, combined with four pre-plant N application rates: 0%, 20%, 40%, and 60% of total recommended N. Across both trials, plant performance was assessed through measurements of canopy volume, aboveground biomass, leaf greenness via Normalized Difference Vegetation Index (NDVI), tissue nutrient content, and marketable yield. Results show that early planting dates were associated with lower accumulation of Growing Degree Days (GDD), which may have limited early crop development. In contrast, later planting dates generally experienced higher GDD accumulation, improving crop rate of growth. Higher N application rates were positively correlated with increased NDVI values, biomass, and yield. Reduced NDVI readings under lower N rates indicate a possible decline in plant vigor and photosynthetic activity. Additionally, strategic pre-plant N applications showed potential benefits in improving early plant establishment and nutrient status, particularly under later planting dates. Overall, our findings show the importance of optimizing both planting timing and N management strategies to improve broccoli productivity in NC. Tailoring N rates based on planting date and anticipated thermal conditions may contribute to more resilient production systems under changing climate conditions.

Speakers

Tomas Quezada Baez

North Carolina State University

Thursday July 31, 2025 8:15am - 8:30am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv

8:15am CDT

TCHG 2 - Developing a University Campus Tree Inventory as a Tool for Sustainability, Student and Community Education

Thursday July 31, 2025 8:15am - 8:30am CDT

Strand 11A

University campus trees provide valuable ecosystem services to the surrounding community while directly and indirectly supporting numerous United Nations Sustainable Development Goals. The purpose of this project was to develop a GIS-supported tree inventory, in conjunction with a service-learning course, to support Tree Campus USA initiatives and maintain a collection of woody plant materials on the Texas State University campus. Horticulture students in a Woody Plants course applied their expertise through use of the ArcGIS FieldMaps mobile app to record the tree inventory on campus. GPS functionality allowed students to digitally map tree location points that contained identification, size, health and maintenance recommendations for each tree. The data were made accessible for select specimen through mounted QR codes on the trees. While the benefits of urban vegetation have been widely studied, tree inventories can provide guidance to facility crews for appropriate planting and maintenance based on the needs of the local environment. Furthermore, the data obtained through a campus tree inventory provided a tool to support campus sustainability initiatives and information demonstrating the economic and environmental values campus trees provided.

Speakers

Tina Waliczek Cade

Texas State University

Co-authors

Alberto Giordano

Texas State University

Jasmin Cruz

Texas State University

Thursday July 31, 2025 8:15am - 8:30am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods

8:15am CDT

VGBR 2 - Mapping anthocyanin content and pubescence in a unique F2 purple carrot population

Thursday July 31, 2025 8:15am - 8:30am CDT

Strand 12B

Purple carrots (Daucus carota L.) are becoming increasingly popular as a fresh market novelty food and as sources of natural pigments in foods and beverages. Anthocyanins are associated with many health benefits, such as reduced cardiovascular disease risk, fewer types of cancers, and reduced inflammation. Increasing anthocyanin content in purple carrots is therefore worthwhile for plant breeders and consumers. An interesting trait in carrots is heavy pubescence in the highest anthocyanin-producing breeding lines. Pubescence has been shown to be linked to anthocyanin content and abiotic stress resistance in other plant species. An F2 mapping population was created between two purple breeding lines developed from two separate Turkish accessions. The population contrasted in the level of pubescence and anthocyanin content in petioles and roots. Anthocyanin content was determined in the taproots and the level of pubescence was scored visually and through image analysis. Pubescence mapped to two loci that may be related with transcriptional regulation of trichome density and length. Anthocyanin content appears to be inhibited by a single locus that is unlinked with pubescence in this population. Epigenetic silencing was also observed in the purple carrot population and has implications on the development of high anthocyanin content varieties. Information from this study will provide genetic markers for increasing anthocyanin content in purple carrot breeding populations and developing pubescent varieties with abiotic stress resistances.

Speakers

Michael Paulsmeyer

Postdoc, USDA-ARS

Co-authors

Philipp Simon

USDA-ARS

Thursday July 31, 2025 8:15am - 8:30am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv
Funding Source 2016-51181-25400

8:15am CDT

VSF 2 - Dormancy and Cold Hardiness of Two Blackberry Cultivars in the Pacific Northwest

Thursday July 31, 2025 8:15am - 8:30am CDT

Foster 1

The blackberry (Rubus spp.) industry in the Pacific Northwest (PNW) has rapidly expanded in recent years due to growers and major berry companies’ capacity to produce high-value fruit for fresh and processing markets. The expansion of the blackberry industry has been further supported by increases in fresh and frozen blackberry consumption. However, revenues and crop expansion in northwest Washington (WA) are limited by freeze events during the winter period that affect fruit production. Freezing temperatures below critical thresholds irreparably damage primary bud meristems. However, little is known about the conditions resulting in freeze damage, as well as the duration of dormancy and time to bud break among key blackberry cultivars. The objective of this study was to evaluate dormancy and cold hardiness of ‘Victoria’ and ‘Celestial’ blackberry floral buds in the PNW. Samples were collected weekly from 15 Oct 2024 to 7 March 2025 from two commercial farms in Skagit County, WA. Sampled laterals were cut into smaller cuttings, each containing one single floral bud, and subjected to either dormancy or cold hardiness evaluations. Samples for the dormancy evaluation were placed in suitable growing conditions (22 C°, 16 h light), and time to bud break was quantified. In parallel, samples for the cold hardiness evaluation were placed into a glycol-bath exposed to 10 freezing temperatures ranging from -4 C° to -20 C°, and a lethal temperature in which 50% of the floral buds were damaged (LT50) was determined through a visual evaluation of damage to the primary meristem. In ‘Victoria’, the maximum bud break rate was observed once canes accumulated over 900 chilling hours (threshold between 0 and 7.2 C°), while ‘Celestial’ required an additional 300 chill units to exhibit similar rates. Regarding cold hardiness, in ‘Victoria’, the LT50 was between -14 and -16 C° through most of the winter season, while the LT50 for ‘Celestial’ fluctuated between -14 and -16 C° during the fall, then between -18 C° and -20 C° during the winter. The higher cold hardiness observed in ‘Celestial’ is attributed to its genetic traits as a semi-erect cultivar rather than environmental factors. The information from this study will be used to develop a decision-support tool for blackberry growers to reduce loss associated with damage from freezing temperatures in the PNW.

Speakers

Pedro Rojas-Barros

Washington State University

Co-authors

Clark Kogan

Washington State University

Heather Pedroza

Washington State University

Lisa Wasko DeVetter

Washington State University

Thursday July 31, 2025 8:15am - 8:30am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Funding Source WSDA Specialty Crop Block Grant (Agreement K5598)

8:30am CDT

FLOR 2 - Assessing Caladium Plant Growth and Tuber Production after Kaolin Treatments

Thursday July 31, 2025 8:30am - 8:45am CDT

Strand 11B

Caladiums (Caladium x hortulanum) are popular ornamental plants prized for their vibrant foliage and unique patterns. The great majority of caladium tubers used by the U.S. and the world are produced in Florida. The tuber production process typically begins in March, with harvesting taking place between November and February. During this period, plants are exposed to high temperatures, high radiation, high relative humidity, heavy rainfall, and tropical storms, resulting in multiple stresses on the plants. Research in other crops has demonstrated the effectiveness of clay-based products in reducing leaf temperatures and protecting plants from environmental and/or biological stresses. This study aimed to assess the plant growth, quality, and tuber production of five caladium cultivars ('Tapestry', 'Lava Glow', 'Wonderland', 'Pink Panther', and 'Summer Pink') under different kaolin clay treatments. Field-grown plants were sprayed throughout the season with either kaolin, kaolin with red dye, or left untreated (control) to assess their response. An adjuvant was added to prevent excessive washout from rainfall. Data collected over two seasons included plant height, canopy coverage, and volume (per plot) extracted from multispectral images captured by a small uncrewed aerial system, leaf temperature using an infrared thermometer, chlorophyll content using a SPAD meter, and subjective ratings for plant color display, leaf health, and plant fullness using a scale from 1 to 5. At harvest, tuber production was evaluated through fresh weight, dry weight, and production index. Results showed that the growth curves for plant height, canopy coverage, and volume exhibited a bell-shaped curve, with an initial linear growth and a maximum peak in early to mid-September for most cultivars, except 'Summer Pink', which peaked later. Treatment differences were not statistically significant, with cultivar variations being the primary factor. However, kaolin and kaolin red treatments effectively reduced leaf temperatures during the 2023 production season, with kaolin red also receiving a higher rating for color display. Plants under kaolin treatments displayed lower chlorophyll content compared to untreated plants. Tuber production was unaffected by the treatments but showed differences among the cultivars, with 'Tapestry' producing the highest tuber dry weight. The production index, which accounts for tuber grading, number, and relative economic values, revealed that 'Summer Pink' had the highest value compared to 'Tapestry'. This study provides valuable insights into the growth behavior of caladium cultivars and the potential benefits of using kaolin treatments as a crop protection strategy.

Speakers

Gasselle Cordova

University of Florida

Co-authors

Zhanao Deng

University of Florida

Thursday July 31, 2025 8:30am - 8:45am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Funding Source USDA Hatch Project FLA-GCC-006190

8:30am CDT

PNM 3 - Evaluating the effect of SAFEROCK micronized for nutrient use efficiency, growth, and yield in tomato and sweet corn

Thursday July 31, 2025 8:30am - 8:45am CDT

Foster 2

SafeRock micronized is a 100% natural mineral soil enhancer and fertilizer booster mined from unique sandstone deposits in United Kingdom and contains a balanced blend of over 70 nutrients and clay minerals. A field experiment was conducted at Blackville SC to evaluate the ability of SafeRock micronized to improve nutrient use efficiency, growth and yield of tomato and sweet corn. The experiment comprised of seven treatments [normal farming practices (NFP), NFP SafeRock soil mix (50 and 75 kg/ha.), NFP SafeRock fertigation (50 and 75 kg/ha.), 80% N

Speakers

Bhupinder Jatana

Assistant Professor -Horticulture, Clemson University

Co-authors

Tom Sanders III

Clemson University

Thursday July 31, 2025 8:30am - 8:45am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv
Funding Source National Watermelon Association

8:30am CDT

TCHG 2 - Incorporating a “Food Waste as Fertilizer” Module into Instruction of Horticulture Courses

Thursday July 31, 2025 8:30am - 8:45am CDT

Strand 11A

Up to 40% of the food supply in the United States is wasted, but much of it could be repurposed as fertilizer. Learning modules were developed to introduce undergraduate students to the concepts surrounding food waste and extreme weather, the potential for a future circular bioeconomy that integrates the food-energy-water-waste-nutrient nexus, and the use of organic fertilizers in hydroponic systems that such processes will require. “Food Waste as Fertilizer” learning modules were integrated into the instruction of undergraduate coursework in horticulture at Kansas State University (KSU; HORT 705 Hydroponic Food Production) during Spring 2024 and Arizona State University (ASU; ABS 314 Applied Plant Physiology and ABS 464 Desert Horticulture) during Fall 2024. Impact of the modules on changing student perceptions and knowledge were evaluated with pre- and post-surveys administered just before and after the module intervention. Matched pairs were analyzed using the Wilcoxon Signed Rank Test for the ordinal data. At KSU (n=17), the learning module resulted in a positive shift in perception of students in response to 1) their interest in using organic fertilizer during hydroponic production, and 2) reporting that using organic fertilizers would be standard practice in the future. Other knowledge and perception survey items were not different between the pre- and post-tests. At ASU (n=15), students showed 1) a greater interest in applying organic fertilizers and 2) increased confidence in their ability to successfully grow hydroponic crops using organic fertilizers. Additionally, students recognized that optimizing processing methods and growing conditions could enhance the quality and performance of organic fertilizers. These findings suggest that "Food Waste as Fertilizer" learning modules successfully enhanced students’ understanding and confidence in using organic fertilizers in hydroponic systems. The positive shifts in perception at both KSU and ASU demonstrate the potential of such educational interventions to promote sustainable horticultural practices. Additionally, students recognized the importance of optimizing fertilizer processing and growing conditions, highlighting the role of innovation in improving fertilizer performance for future horticultural practices.

Speakers

Kimberly Williams

Kansas State University

Co-authors

Yujin Park

Arizona State University

Thursday July 31, 2025 8:30am - 8:45am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods

8:30am CDT

VGBR 2 - Carotenoid Diversity of New Mexican Chile Peppers (Capsicum annuum L.): Variability in Health-related Compounds and Implications for Molecular Breeding and Genetic Improvement

Thursday July 31, 2025 8:30am - 8:45am CDT

Strand 12B

Chile peppers (Capsicum annuum L.) hold a vital position in global agriculture and diets, valued for their unique flavor, diverse uses, and nutritional benefits. Among their bioactive compounds, carotenoids play a significant role, acting as antioxidants and precursors to vitamin A, with immense implications for human health. This study aims to identify carotenoid diversity and determine the genetic control of carotenoid production in a diverse population of 127 chile pepper genotypes. Fruits grown in Las Cruces, NM, were harvested in the 2024 growing season. High-performance liquid chromatography (HPLC) will be employed to profile individual carotenoids such as β-carotene, lutein, capsanthin, capsorubin, zeaxanthin, and violaxanthin. To optimize carotenoid extraction and minimize degradation, three different saponification methods were tested, varying in incubation time and temperature: 30 minutes at 50°C, 30 minutes at room temperature, and 60 minutes at room temperature. The best results were obtained with 30 minutes of incubation at room temperature. After getting HPLC results for the whole pannel this data will be integrated with genome-wide association studies (GWAS) to identify key genetic loci and candidate genes associated with carotenoid content. The study aims to provide a foundation for marker-assisted selection to improve the nutritional quality of chile peppers. The findings have direct implications for breeding programs, enabling the development of biofortified chile pepper varieties.

Speakers

Muhammad Ibrar Khan

New Mexico State University

Co-authors

Dennis Nicuh Lozada

New Mexico State University

Ehtisham S. Khokhar

New Mexico State University (NMSU)

Ivette Guzman

New Mexico State University

Jerlie Mhay Matres

New Mexico State University

Shahab Nourbakhsh

New Mexico State University

Thursday July 31, 2025 8:30am - 8:45am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv
Funding Source NIFA grant project

8:30am CDT

VSF 2 - Effect of Freezing Temperatures on Re-growth and Photosynthetic Mechanisms in ‘Victoria’ Blackberry.

Thursday July 31, 2025 8:30am - 8:45am CDT

Foster 1

Freezing temperatures limit blackberry (Rubus spp.) growers from meeting their full yield potential in the Pacific Northwest (PNW). Damage from freezing winter temperatures spans a gradient and ranges from complete mortality to partial damage of floral buds and supporting vascular and structural tissues. Partial damage can permit resumption of plant growth but is poorly characterized. Moreover, understanding the mechanisms contributing to this gradient of damage could lead to novel practices focused on mitigation and recovery. The objective of this study was to investigate the relationship between freeze damage and floral bud re-growth. Once chill unit accumulation was sufficient, floricane samples of ‘Victoria’ blackberry were collected for five consecutive weeks during late winter from a commercial farm in Skagit County, Washington. Sampled canes were cut into smaller cuttings, each containing one single floral bud, and exposed to freezing temperatures (-4 C°, -6 C°, -8 C°, -10 C°, and -12 C°) in a glycol bath. The freezing temperature treatments were based on historical freezing temperatures in the area over the past decade during the sample collection period. Treated samples were then placed in suitable growing conditions (22 C°, 16 h light), and shoot growth, chlorophyll fluorescence (Fv/Fm), and gas exchange were measured after three weeks. Shoot growth was delayed from buds exposed to -8 C°, -10 C°, and -12 C° compared to the untreated control. The delay in re-growth is likely explained by limitations in water transportation to the leaves rather than carbohydrate depletion, considering leaf transpiration and stomatal conductance were significantly lower in treated canes compared to the untreated control, while Fv/Fm and carbon assimilation remained unaffected. Findings from this study demonstrate partial re-growth from freeze-damaged blackberry canes and floral buds, and damage to the xylem is likely responsible for reductions in re-growth.

Speakers

Pedro Rojas-Barros

Washington State University

Co-authors

Ashley Fincham

Washington State University

Clark Kogan

Washington State University

Lisa Wasko DeVetter

Washington State University

Thursday July 31, 2025 8:30am - 8:45am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Funding Source WSDA Specialty Crop Block Grant

8:45am CDT

FLOR 2 - Strategic Stratification of Sugarcane Bagasse Biochar Improves Nutrient Retention in Peat-based Greenhouse Substrates

Thursday July 31, 2025 8:45am - 9:00am CDT

Strand 11B

Peatmoss, a commonly used substrate component, is facing numerous challenges to remain a sustainable option for horticultural production. Due to mounting factors such as weather-limited harvesting, increasing transport costs, waning public acceptance, and now potential international tariffs, many are searching for alternative materials to replace some of the peatmoss in their operations. Biochar is one such alternative that may present numerous benefits as a peat alternative in container production. Biochar is the product of the pyrolysis of biomass (commonly agricultural residues) in an oxygen limited environment, resulting in a product that has increased porosity, increased water and nutrient retention, and can be produced regionally from a number of sources. Incorporating biochar into container production can reduce peat use and improve nutrient retention. However holistically blending can prove costly and alter the substrate physical properties, requiring major changes to production practices, an obstacle that can be considered a barrier. The use of stratification has been shown to successfully reduce peat use while maintaining highly productive growing conditions. With stratification, growers can incorporate alternative materials strategically in the container while limiting the associated costs. Therefore, this study was designed to evaluate the effect of sugarcane bagasse biochar on nutrient retention in both stratified and non-stratified peat-based container systems. Nine peat-based substrate treatments were utilized in this study, with either the entire container filled with peat-based substrate or stratified above a pine bark or hammermilled wood fiber. Within each substrate, sugarcane bagasse biochar was amended at 0 (control) or 10% of the container volume, by either blending throughout the container or blending at 20% upper strata only (equivalent to 10% by vol. overall). Petunia plugs were planted into 3.8 L containers filled with each of these different substrate treatments. The plants were placed on two different fertilizer regimes, with plants receiving either 100 ppm or 300 ppm fertilizer once a week. Leachate was collected biweekly to assess the impact on nutrient retention. Plant growth and nutrition were assessed. The incorporation of biochar has not significantly impacted plant growth; however, it has improved nutrient retention. Biochar improved nutrient retention in the plants stratified with wood fiber in both the high and low fertilizer regimes, while improving nutrient retention in stratified bark in the high fertilizer regime. The results indicate that strategic inclusion of biochar may reduce fertilizer application frequency.

Speakers

Megan Gibb

University of Florida

Co-authors

Damon Abdi

Louisiana State University Agricultural Center

Jeb Fields

University of Florida

Thursday July 31, 2025 8:45am - 9:00am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Poster # csv

8:45am CDT

PNM 3 - Evaluation of Critical Nitrogen Requirements for Commercial Tomato Production in MS

Thursday July 31, 2025 8:45am - 9:00am CDT

Foster 2

Ensuring nitrogen applications targeting the optimum rate is critical in tomato production. This is because nitrogen (N) requirements in tomato production may vary depending on the soil type, location, climate, and cultivation practices. Despite tomato being a major vegetable crop in MS, information on the N requirements for commercial production in the state is limited. Therefore, this study was conducted in an open field to determine the critical nitrogen rate for commercial tomato production under the northeast growing conditions of MS. The study evaluated six N application rates (0, 67, 101, 135, 202, and 269 kg ha-1) arranged in a randomized complete block design with four replicates per treatment. Red Duce variety of tomato was planted, and nitrogen was applied at 50% pre-plant (33-0-0) and 50% fertigation (15.5-0-0). Both potassium and phosphorus were the same for all treatments and applied at 100% pre-plant using 0-0-60 and 0-46-0 respectively. Preliminary results indicate that higher N application rates significantly increased total fruit yield, total marketable yield, fruit sizes, and total biomass. The highest total fruit yield (93.79 t ha-1), total marketable yield (71.58 t ha-1), large fruit yield (10.40 t ha-1), and total biomass (6.96 t ha-1) were observed at 269 kg N ha-1. Increasing N application rates significantly increased tissue N concentration. Therefore, the greater yield observed at higher N application rates was attributed to the consistently higher tissue N concentration from leaf samples collected at different weeks during the growing season. Based on the results obtained, the critical N application rate for open-field fresh-market tomato production in northeast MS could be up to 269 kg ha-1. However, follow-up studies are currently being conducted to validate these preliminary results.

Speakers

Prakash Khanal

Mississippi State University

Co-authors

Ibukun Ayankojo

Mississippi State University

Thursday July 31, 2025 8:45am - 9:00am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv

8:45am CDT

TCHG 2 - Keep It Simple: Bilingual Booklet Boosts Landscape Best Practices

Thursday July 31, 2025 8:45am - 9:00am CDT

Strand 11A

Florida’s massive environmental horticulture industry generates over $10 billion annually and employs over 100,000 individuals, with 33% identifying as Hispanic/Latino. The landscaping sector plays a crucial role in this industry, yet many positions lack formal certification, leaving training dependent on in-house instruction that varies in quality. Teaching Best Management Practices (BMPs) and Integrated Pest Management (IPM) practices to landscape professionals often involves navigating language barriers, varying levels of formal education, and limited training time. To address these challenges, a team of UF/IFAS Extension agents secured a USDA-NIFA IPM Extension grant in 2021 and developed a bilingual (English/Spanish) landscape reference booklet rooted in the principles of cognitive load theory and adult learning. Grounded in the KISS (Keep It Simple, Stupid) model, the booklet emphasizes clarity, brevity, and relevance—hallmarks of effective educational design for working adults. The tool features simple language, annotated photographs, and minimal text to reduce extraneous cognitive load and enhance information retention. Visual cues and side-by-side translations support dual coding and help bridge comprehension gaps. Finally, the booklet is pocket-sized and waterproof allowing for in-field deployment. Since its April 2024 publication, the booklet has reached a wide audience, with 366 copies distributed through Extension outreach of which 216 were distributed after a 1 – 2-hour class in English or Spanish on the topic. Its impact became evident as 164 individuals completed Qualtrics post-class surveys, with 99% (162) planning to use the information in their home landscapes and 63% (103) intending to apply practices on the job—44% (72) of whom believed the booklet would directly support BMP adoption among multilingual teams. Post-class surveys reported 80% (131) increased BMP knowledge. A 3–6-month follow-up survey confirmed sustained impact, as 85% of respondents (41 of 48) reported applying the information, and at least 83% (40) implemented one or more BMPs. Beyond its educational success, the booklet has gained traction within the industry. The UF/IFAS Bookstore sold 100 copies, generating $1,600 in revenue, while Extension Agents and industry trainers have formally adopted it as a standardized training tool. By starting with the basics and addressing language barriers, this initiative is empowering Florida’s landscaping workforce, fostering sustainability, and synergizing resilience. This project demonstrates how applying the science of simplicity can increase the effectiveness of Extension materials, particularly for linguistically diverse audiences. The format is easily replicable, adaptable to other horticulture topics, and well-suited for Extension’s fast-paced, field-based educational environments.

Speakers

HANNAH WOOTEN

UF/IFAS

Co-authors

Morgan Pinkerton

UF/IFAS Extension Seminole County

Tatiana Sanchez-Jones

UF/IFAS

Tina McIntyre

UF/IFAS Extension

Tina McIntyre is the Florida-Friendly Landscaping™ Agent at the UF/IFAS Extension in Seminole County. She specializes in surface water quality and quantity, best management practices related to landscape management, and restoration of urban green spaces. Tina came to Extension after... Read More →

Thursday July 31, 2025 8:45am - 9:00am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods
Poster # csv
Funding Source USDA-NIFA

8:45am CDT

VGBR 2 - Association Mapping Integrated with High-throughput Phenotyping Identifies Candidate Genes Regulating Fruit Development in New Mexican Chile Pepper (Capsicum annum L.)

Thursday July 31, 2025 8:45am - 9:00am CDT

Strand 12B

Fruit morphology has a significant impact on the agronomic performance of chile peppers, influencing both yield potential and mechanical harvest efficiency. Through the integration of genome-wide association studies (GWAS) with Tomato Analyzer, an image-based phenomics tool, we aim to identify single nucleotide polymorphism (SNP) markers associated with fruit architecture and morphology. A Capsicum association mapping panel (CAMP) consisting of 128 genotypes with three checks evaluated in Las Cruces, NM under an augmented design for the 2024 growing season. The design consisted of ten blocks, each with a different number of test genotypes whereas checks were replicated in each block. Ten green and ten red fruits (N=20) for each genotype were scanned using a flatbed scanner and images were processed using Tomato Analyzer software to record fruit architecture. Best linear unbiased predictions (BLUPs) were calculated for maximum fruit height (MAXH; cm), maximum fruit width (MAXW; cm), curved fruit height (CURH; cm), width mid-height (WMH; cm), area (ARA; cm2), and perimeter (PER; cm). High narrow sense heritability (h2) ranging between 0.80 and 0.98 was observed. A medium to high Pearson correlation (r=0.56–1.00) was observed for all traits except WHM. After filtration and imputation, 40,709 genotyping-by-sequencing (GBS) SNP markers were used to perform multi-locus GWAS. A total of 129 SNP markers associated with seven basic fruit measurements across 10 chromosomes were identified. The SNP marker SCM002812.1_10016804 on chromosome 1 at 10.02 Mb was found to be associated with the potential candidate gene YABBY4, which can regulate fruit developmental processes. Other candidate genes identified included Gibberellin receptor GID1B, Cyclin-L1-1, and U6 small nuclear RNA (adenine-(43)-N(6))-methyltransferase), regulating plant growth hormones, cell division, and methylation, respectively. The findings of this study will be relevant for the development of molecular markers for marker-assisted selection and studying expression levels of genes regulating fruit development in a comparative analysis using chile pepper genotypes with contrasting fruit morphology.

Speakers

Ehtisham S. Khokhar

Graduate Teaching Assistant, New Mexico State University

I am a Ph.D. candidate specializing in Plant Breeding and Genetics with a background in genomics analyses, phenomics applications, statistical proficiency, and seed systems. My expertise lies in translating complex genomics and phenomics data into meaningful insights that drive evidence-based... Read More →

Co-authors

Dennis Nicuh Lozada

New Mexico State University

Muhammad Ibrar Khan

New Mexico State University

Shahab Nourbakhsh

New Mexico State University

Thursday July 31, 2025 8:45am - 9:00am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv

8:45am CDT

VSF 2 - Evaluation of Calcium Fertilization on Yield and Fruit Quality in Three Raspberry Cultivars in the U.S. Pacific Northwest

Thursday July 31, 2025 8:45am - 9:00am CDT

Foster 1

Calcium (Ca) is an important macronutrient for plant health and fruit quality. Insufficient Ca in fruit tissues can lead to physiological disorders that reduce crop quality. To prevent this, Ca fertilizers are frequently applied to soil or plant canopies to increase Ca concentrations in fruits. However, the role of Ca fertilizers in promoting fruit quality and overall yields is poorly understood in raspberry (Rubus idaeus). The objective of this study was to evaluate methods to increase Ca concentrations in raspberry fruits and leaves and assess impacts on yield and fruit quality. Replicated field trials were conducted in 2023 and 2024 using floricane-fruiting raspberry ‘WakeHaven’ ‘Meeker’, and ‘Kulshan’ in Whatcom County, Washington. Treatments included: 1) soil application of Ca fertilizer (gypsum) applied before budbreak, 2) foliar application of Ca fertilizer (calcium hydroxide) applied weekly during immature green to white fruit stage, and 3) an untreated control with no calcium fertilizer. Neither method of Ca application affected yield, fruit quality, soil Ca levels, or Ca concentrations within primocane leaves and raspberry fruits across cultivars. However, in ripe fruit, the concentration of Ca in the receptacles was more than ten times higher than in the drupelets of each cultivar. Cultivars with higher fruit Ca concentration also had higher Ca concentrations in the receptacle (Adjusted R2 = 0.58). These findings demonstrate the important role of cultivar genetics when it comes to explaining variations in fruit Ca concentrations. Moreover, results from this study show that standard fertilizer practices have no impact on fruit Ca concentrations or other important yield and fruit quality variables. A physiological barrier limiting Ca movement from receptacles to fruits was identified, and future studies should further explore what these barriers are, when they develop, and whether they can be adjusted to increase Ca transport to raspberry fruits.

Speakers

Pedro Rojas-Barros

Washington State University

Co-authors

Brian Maupin

Washington State University - NWREC

David Bryla

USDA

Lisa Wasko DeVetter

Washington State University

Michael Hardigan

REE-ARS

Scott Orr

REE - ARS

Thursday July 31, 2025 8:45am - 9:00am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Funding Source Washington Red Raspberry Commission

9:00am CDT

FLOR 2 - Regulating Growth and Promoting Branching in ‘Dragon Wing® Red’ Begonia with Benzyladenine and Ethephon Foliar Sprays

Thursday July 31, 2025 9:00am - 9:15am CDT

Strand 11B

Our objective was to evaluate the efficacy of benzyladenine or ethephon foliar spray applications to control growth and improve branching of ‘Dragon Wing® Red’ begonia (Begonia interspecific). On 10 Sep 2024, a 288-cell plug tray of ‘Dragon Wing® Red’ begonia was received from a commercial propagator. Plugs were transplanted into 15.2-cm-diameter containers filled with a commercially available soilless peat-based substrate. Plants were grown in a glass-glazed greenhouse under supplemental and day-extension lighting provided by 780-W light-emitting diode lamps from 0600 to 2200 HR (16-h photoperiod) with an air temperature set point of 20 °C. At 7 d after transplant, 10 single-plant replicates were treated with a solution containing benzyladenine or ethephon and a surfactant. Plants received a foliar spray (vol. 0.2 L·m–2) containing deionized water (0 mg·L–1; untreated) or 10, 30, 50, 70, or 90 mg·L–1 benzyladenine or 125, 250, 500, 750, 1,000, or 2,000 mg·L–1 ethephon. Benzyladenine and ethephon foliar spray applications influenced begonia growth and development differently. Benzyladenine concentrations increasing from 10 to 90 mg·L–1 suppressed growth index, an integrated measurement of height and diameter, by 1% to 3%, respectively, compared to untreated plants. Branch number increased by 32% to 64% (3 to 5 branches) as concentrations increased from 30 to 90 mg·L–1 benzyladenine compared to untreated plants. Shoot dry weight (SDW) decreased as benzyladenine concentrations increased, but time to flower (TTF) was unaffected. Ethephon concentrations increasing from 125 to 2,000 mg·L–1 influenced plant height, plant diameter, growth index, branch number, SDW, and TTF. Growth index was suppressed as ethephon concentrations increased from 125 to 2,000 mg·L–1, resulting in plants that were 11% to 30% smaller than untreated plants. Compared to untreated plants, ethephon concentrations increasing from 125 to 1,000 mg·L–1 improve branching with 1 to 2 more branches developed per plant. Ethephon concentrations of 125 to 2,000 mg·L–1 limited SDW by 23% to 49% compared to untreated plants. Time to flower was delayed by 3 to 10 d as concentrations increased from 125 to 2,000 mg·L–1 ethephon. Begonia plants sprayed with ≥750 mg·L–1 ethephon developed phytotoxicity and had reduced ornamental quality. Our results indicate that growers can attain growth control and enhance branching with foliar spray applications of 30 to 90 mg·L–1 benzyladenine or 125 to 500 mg·L–1 ethephon, but these should be used as an initial range for trials during greenhouse production.

Speakers

Garrett Owen

Extension Specialist and Assistant Professor of Sustainable Greenhouse & Nursery Systems, The Ohio State University

Dr. W. Garrett Owen is Assistant Professor and Extension Specialist of Sustainable Greenhouse and Nursery Production Systems with primary responsibilities in teaching (20%), research (30%), and Extension (50%) in the Department of Horticulture and Crop Science at The Ohio State University... Read More →

Co-authors

Layne Speckert

The Ohio State University

Thursday July 31, 2025 9:00am - 9:15am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Poster # csv
Funding Source We thank Fine Americas, Inc. for the plant growth regulator and financial support; Sun Gro Horticulture for soilless substrate; and J.R. Peters, Inc. for fertilizer.

9:00am CDT

PNM 3 - Determining the Phosphorus Fertilizer Application Threshold for Potato (Solanum tuberosum L.) Based on Nutritional Requirement in Subtropical Spodosol of Northeast Florida

Thursday July 31, 2025 9:00am - 9:15am CDT

Foster 2

Phosphorus (P) is a macronutrient essential for plant growth and yield; however, its availability in spodosols is often limited due to high acidity, low organic matter, and strong adsorption to soil minerals, particularly iron (Fe) and aluminum (Al) in tropic Spodosol in Northeast Florida. Efficient P management is essential for optimizing crop productivity while minimizing environmental risks. This study investigated the effects of different P fertilizer rates on Potato (Solanum tuberosum, L.) growth, yield, and nutrient dynamics at the UF/IFAS Hastings Agricultural Extension Center, Northeast Florida over two consecutive growing seasons (Spring 2022 and Sprin 2023). A randomized complete block design was employed, with five P rates of 0, 90, 135, 180, and 225 kg ha-1 of phosphorus pentoxide (P2O5) as triple superphosphate (TSP). The changes in plant growth, nutrient uptake, yield, as well as soil properties were determined to evaluate the effectiveness of P fertilization as plant growth performance and tuber yield. The results showed that P application significantly increased potato tuber yield compared to the control, with the highest yield observed at 225 kg ha-1 P2O5. Pearson correlation analysis indicated strong associations between plant growth, tuber yield, and nutrient accumulation. Principal component analysis (PCA) highlighted notable seasonal differences in tuber yield and soil characteristics. The study highlights the importance of site-specific P recommendation to synchronize nutrient availability with crop demand, particularly in nutrient-poor spodosols in Northeast Florida. These findings provide a scientific basis for establishing P fertilizer thresholds that balance crop productivity with environmental sustainability in agricultural systems.

Speakers

Md Jahidul Islam Shohag

University of Florida

Co-authors

Guodong Liu

University of Florida

Thursday July 31, 2025 9:00am - 9:15am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv
Funding Source Florida Department of Agriculture and Consumer Services
Funding Option OREl or ORG funded all or part of the research associated with this abstract

9:00am CDT

TCHG 2 - Efficacy of podcasting as an extension format

Thursday July 31, 2025 9:00am - 9:15am CDT

Strand 11A

Podcasting is an underutilized extension format, and little information exists as to its efficacy as a teaching tool. One extension podcast is Growing the Valley (GtV), which focuses on tree fruit and nut production in California’s Central Valley. Topics cover research updates, best management practices, and discussions of current events. Irrigation and nitrogen management episodes were made available for an online, on-demand continuing education credits for a certification program in California focused on reducing nitrogen losses from agricultural fields. A optional short survey was embedded in the credit program to gauge user’s knowledge of topics discussed in the episodes before and after listening. Results indicate that GtV listeners showed significant gains in knowledge, suggesting that this format is an effective educational tool for extension personnel.

Speakers

Phoebe Gordon

University of California

Co-authors

Luke Milliron

University of California Agriculture Natural Resources

Rachel Shellabarger

University of California, Agriculture and Natural Resources

Thursday July 31, 2025 9:00am - 9:15am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods
Poster # csv

9:00am CDT

VGBR 2 - Implementation of PlexSeq SNP markers for molecular breeding of agronomic traits in chile peppers

Thursday July 31, 2025 9:00am - 9:15am CDT

Strand 12B

Marker-assisted selection is important to facilitate the process of genetic improvement in vegetable breeding programs. A set of 192 trait-associated single nucleotide polymorphism (SNP) markers identified from previous genome-wide mapping studies has been developed at the New Mexico State University (NMSU) Chile Pepper Breeding and Genetics Program (NMSU-192) through the PlexSeq Genotyping Technology of AgriPlex Genomics (https://www.agriplexgenomics.com/plexseq-technology). The NMSU-192 SNP array consists of SNPs associated with easy destemming (14 SNPs), plant architecture and morphology (76), yield and yield components (78), and Phytophthora capsici resistance (24). Genetic diversity analysis using the NMSU-192 demonstrated the feasibility of the SNP array to characterize 188 Capsicum spp. genotypes based on fruit architecture and morphology. Together with parental and reference genotypes, F2:3, F3:4, and F4:5 segregating families of chile pepper breeding lines will be genotyped using the NMSU-192 for marker-assisted breeding and selection at the NMSU Chile Pepper Breeding and Genetics Program. The NMSU-192 will be a valuable component of the breeding toolbox for the genetic improvement of traits relevant to the chile pepper industry in New Mexico and in the pepper genetics community.

Speakers

Dennis Nicuh Lozada

Co-authors

Ehtisham S. Khokhar

New Mexico State University (NMSU)

Muhammad Ibrar Khan

New Mexico State University

Thursday July 31, 2025 9:00am - 9:15am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv
Funding Source New Mexico Chile Association

9:00am CDT

VSF 2 - Investigating fruit-surface lenticel development using muscadine (Muscadinia rotundifolia) as a model species

Thursday July 31, 2025 9:00am - 9:15am CDT

Foster 1

The plant epidermis, despite being a single-cell layer, serves diverse roles in regulating organ growth, responding to environmental cues, and mediating gas exchange and water loss. While extensive research has focused on epidermal differentiation in leaves, where stomata and trichomes play critical roles in overall plant physiology, much less is known about epidermal cell fate on fruit surfaces. Many developing fruits initially contain stomata, but as the fruit rapidly expands, these structures face mechanical strain and often rupture. In several species, this process leads to the formation of lenticels, small, permanently open pores that enable continued gas exchange. While lenticels are essential for gas exchange in certain fruit, their presence and morphologies vary widely across species, and the underlying genetic and developmental mechanisms involved in their formation remain poorly understood. Muscadine, a grape species native to the southeastern U.S., serves as a valuable model for studying lenticel development due to its prominent lenticel formation. In this study, we investigated the cellular transition from stomata to lenticels in muscadine fruit using light and electron microscopy, revealing key stages in epidermal restructuring. Transcriptomic analysis of one muscadine cultivar across four developmental stages of lenticel formation identified candidate genes that may regulate this process. These findings provide insight into the genetic regulation of lenticel development that can help explain natural variation in lenticel traits observed across different muscadine cultivars and fruit species. Further, by drawing comparisons to periderm formation in woody tissues and wound responses in other fruit, this study highlights potential conserved genetic pathways underlying lenticel development. Understanding these processes can provide insights into the role of lenticels in postharvest physiology and contribute to targeted breeding strategies for improving fruit storability.

Speakers

Alana Brinley

University of Florida

Co-authors

Ali Sarkhosh

University of Florida

Tie Liu

University of Florida

Thursday July 31, 2025 9:00am - 9:15am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Poster # csv

9:15am CDT

FLOR 2 - Ethephon Substrate Drench Efficacy is Influenced by Application Timing

Thursday July 31, 2025 9:15am - 9:30am CDT

Strand 11B

Ethephon substrate drenches have been shown to effectively control growth of annual bedding plants and herbaceous perennials. However, research has shown the efficacy of ethephon substrate drenches is impacted by the time of application. Therefore, the objective of our research was to evaluate how ethephon substrate drenches impact growth when applied at varying times post-transplant. Young plants of lobed tickseed (Coreopsis ×hybrida Big BangTM ‘Mercury Rising’) and coleus [Coleus scutellarioides (L.) Benth. ‘Main StreetTM Bourbon Street’] were transplanted into 12.7-cm containers filled with a soilless peat-based substrate. At 3, 7, 10, 14, 17, or 21 d after transplant, 8 single-plant replicates received a single substrate drench of 90 mL aliquots of a solution containing 0, 25, 50, 100, or 200 mg·L–1 ethephon. Plants were grown in a glass-glazed greenhouse for 5 to 7 weeks after initial drench application before growth and morphological data including plant height, plant diameter, shoot dry weight (SDW), and root dry weight (RDW) were determined. In general, increasing concentrations of ethephon influenced plant height, plant diameter, SDW, and RDW of coleus and lobed tickseed. In Expt. 1, plant size (height and diameter) and biomass accumulation (SDW and RDW) of coleus was significantly influenced by increasing concentrations of ethephon, with the effects diminishing as application time was delayed. For example, as concentrations increased from 0 to 200 mg·L–1 ethephon, coleus treated at 3 days after transplant (DAT) were 33% (5.3 cm) shorter, while those treated at 17 DAT were 21% (3.6 cm) shorter. Shoot dry weight of coleus drenched with 200 mg·L–1 ethephon at 3 or 21 DAT were 50% (2.0 g) and 23% (1.0 g) lower, respectively, compared to untreated plants. Compared to untreated plants, RDW of plants drenched with 200 mg·L–1 ethephon 3 or 14 DAT was 65% (2.8 g) and 50% (2.6 g) smaller, respectively. In Expt. 2, plant height was unaffected by increasing concentrations of ethephon, but plant diameter and biomass accumulation of lobed tickseed was significantly affected. For example, as concentrations of ethephon increased from 0 to 200 mg·L–1, lobed tickseed treated 3 and 21 DAT were 8% (2.4 cm) and 9% (2.8 cm) narrower, respectively, compared to untreated plants. Overall, the magnitude of control diminished as application time increased and negative phytotoxic effects were seen in early applications (≤7 d). Therefore, we suggest applying ethephon substrate drenches 7 to 14 d after transplanting.

Speakers

William Rich

The Ohio State University

Co-authors

Garrett Owen

The Ohio State University

Thursday July 31, 2025 9:15am - 9:30am CDT
Strand 11B

Oral presentation, Floriculture Floriculture 2

Subject Floriculture
Poster # csv

9:15am CDT

PNM 3 - Effectiveness of Hydrogel Polymer Combined with Phosphorus on Snap Bean (Phaseolus vulgaris) Growth and Yield.

Thursday July 31, 2025 9:15am - 9:30am CDT

Foster 2

Phosphorus is well known for being a nutrient vital for plants, influencing key stages of plant cycle. However, its efficiency can be reduced by nutrient fixation processes or leaching, with challenging strategies to enhance phosphorus availability. Hydrogel polymers have been proposed as soil amendments to improve moisture retention and nutrient uptake. This study evaluates the impact of hydrogel polymer combined with different phosphorus rates on the growth and yield of Snap Bean (Phaseolus vulgaris). The experiment consists of six phosphorus rates of 0, 100, 150, 200, 250, and 300 lbs/A P2O5, and a hydrogel rate of 30 lbs/A. Treatments were arranged in a randomized complete block design with 4 replications per treatment, and 4 rows per replication. Growth parameters such as Plant Height, Leaf chlorophyll content, weekly tissue sampling. Yield parameters such as number of pods per plant, pod weight, pod yield were also assessed. Data analysis is performed using one-way ANOVA in R Studio, with post-hoc comparisons using Tukey’s HSD test at P

Speakers

Elena Maximo

University of Florida

Co-authors

Guodong Liu

University of Florida

Md Jahidul Islam Shohag

University of Florida

Thursday July 31, 2025 9:15am - 9:30am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv
Funding Source FDACS P03050303

9:15am CDT

TCHG 2 - A Review of Introductory Horticulture and Plant Science Classes In US Colleges and Universities: A national survey of co

Thursday July 31, 2025 9:15am - 9:30am CDT

Strand 11A

A survey of the structure and contents of introductory horticulture and/or plant science classes was developed to understand common content, laboratories, and resources used across the U.S. The survey was distributed by email to 267 universities and colleges comprised of 1864 and 1890 Land Grant institutions, public state universities, colleges, technical schools, tribal colleges, and private institutions. Responses were received from 104 institutions, a 39% response rate of which 30 responses did not complete sufficient information to be included. The majority of responses came from Carnegie R-1 or R-2 institutions (51%) which had research programs along with undergraduate programs. Of the respondents, 42% were from designated horticulture departments or units, 26% from combined plant science units, 17% agriculture departments, and 14% responded “other.” Of the respondents, 47% offered degrees in horticulture, 21% a degree in plant sciences, 11% a degree in agriculture, and 21% “other.” Faculty instructing an introductory horticulture or plant science course were most commonly tenure track (64%) or nontenure track (35%) instructors. Full professors were the most common faculty instructors (45%), followed by assistant professors (20%). For 87% of the respondents, the course served as a degree requirement, was required for upper-level courses within the program (78%) and was commonly a university general education accepted course (59%). Two thirds of the courses had a required textbook while the remaining course had an optional textbook or had no textbook. The mode of learning was face-to-face (53%) or hybrid and asynchronous on-line (14%). The majority of courses (68%) were lecture-based delivery. The approach to the course was science based (55%) or a balance of science and practical technology (45%). The ranked topics covered in the course (from most frequent to least frequent) were plant growth and development, environmental effects, plant anatomy, plant nutrition and fertility, plant physiology, plant classification and nomenclature, plant chemistry, plant genetics and breeding, and history of horticulture. The rank of disciplines taught or emphasized in the courses were greenhouse operations and management, ornamental and nursery production and operation, landscape management, vegetable production and management, fruit production and management, arboriculture, and turf production and management. These results, and others presented, will help instructors in introductory horticulture and plant science courses develop course content that is commonly used across the U.S. and could be used to establish standards for learning outcomes.

Speakers

Curt Rom

University Professor. And Associate Director, University of Arkansas and ASHS

Co-authors

David Kopsell

Illinois State University

Michelle M. Wisdom

University of Arkansas

Thursday July 31, 2025 9:15am - 9:30am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods
Poster # csv

9:15am CDT

VGBR 2 - Pepper Breeding for Southeast US and Beyond: From Concept Mapping to Comprehensive Trait Characterization of Capsicum Ge

Thursday July 31, 2025 9:15am - 9:30am CDT

Strand 12B

Establishing a successful breeding program requires careful planning across multiple dimensions, including crop prioritization, stakeholder engagement, infrastructure development, germplasm acquisition, and definition of breeding goals. With these priorities in mind, we are developing a comprehensive vegetable breeding program focused on pepper (Capsicum spp.), anchored by both statewide and national stakeholder surveys and concept mapping exercises. These efforts have informed infrastructure development, germplasm sourcing, and trait prioritization aligned with end-user needs. As a foundational step, we assembled the UGA-CAPSI-CORE collection, a curated panel of over 450 diverse pepper accessions, including breeding lines, improved landraces, and ex-PVPs. This collection is currently being evaluated for key horticultural traits through conventional field-based assessment and high-throughput phenotyping. In parallel, a preliminary experimental subset is undergoing targeted screening for major biotic stresses, including Phytophthora capsici (Phytophthora blight), Colletotrichum spp. (Anthracnose), Meloidogyne incognita (Root-knot nematode), and insect pests such as pepper weevil (Anthonomus eugenii), green peach aphid (Myzus persicae), and whitefly (Bemisia argentifolii). Fruit quality parameters, including firmness, color, total soluble solids, and vitamin A and C content, are also being evaluated in the same subset. To complement phenotypic evaluation, we have screened the UGA-CAPSI-CORE collection for Phytophthora resistance using publicly available SSR markers, with allele binning conducted via TANDEM software. Whole genome resequencing (WGRS) of the full collection is currently underway to provide a high-resolution view of genetic diversity and trait architecture. Looking ahead, we are expanding the program to include transcriptomics and metabolomics analyses in response to P. capsici infection, enabling a systems-level understanding of host-pathogen interaction. The integration of phenotypic, genotypic, transcriptomic, and metabolic data will accelerate discovery of candidate genes and molecular markers for use in genomics-assisted breeding. This multipronged strategy positions the UGA vegetable breeding program to deliver pest- and disease-resistant, and nutritionally enhanced pepper cultivars for Georgia and beyond.

Speakers

Amol Nankar

University of Georgia (UGA)

Co-authors

Angelos Deltsidis

University of Georgia

Bhabesh Dutta

University of Georgia

Deepa Jaganathan

University of Georgia

Post Doc at University of Georgia with over 15 years of experience in molecular breeding and gene editing in crops. Research expertise spans drought tolerance in chickpea, TYLCV resistance in tomato, salinity tolerance in rice, genetic mapping in banana, and currently focused on disease... Read More →

Intiaz Chowdhury

University of Georgia

Jessica Gibbs

University of Georgia

Luan Oliveira

University of Georgia

Miaoying Tian

University of Georgia

Noel Thomas

University of Georgia

Saumik Basu

University of Georgia

Ted McAvoy

University of Georgia

Thursday July 31, 2025 9:15am - 9:30am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv
Funding Source Georgia Department of Agriculture (GDA) Specialty Crop Block Grant Program (SCBGP) - RGDAG000188920A

9:15am CDT

VSF 2 - Assessment of Genetic Diversity among Vitis shuttleworthii Populations

Thursday July 31, 2025 9:15am - 9:30am CDT

Foster 1

Vitis shuttleworthii, commonly referred to as callose grape, is a wild grape species endemic to Central and South Florida and serves as a valuable genetic resource for the development of subtropical and tropical scion and rootstock cultivars. V. shuttleworthii can thrive in a humid environment and grows readily in nutrient deficient soils. This species is also resistant to anthracnose, downy mildew, Pierce’s disease and root knot nematodes. This study explores the genetic diversity and phylogenetic relationships among V. shuttleworthii populations sampled from diverse regions across Florida. The overarching objective of the current study is to characterize the extent of natural genetic variation within and among populations and to identify promising genetic sources for resistance to key grapevine diseases. DNA obtained from 72 V. shuttleworthii individuals, along with 25 reference grape accessions, were sequenced using the Illumina platform (2 X 150 bp configuration). We identified over 64 million SNPs from the 97 accessions and 376,753 high-quality SNPs were retained for downstream analysis. Phylogenetic and principal component analyses revealed geographically structured clustering among V. shuttleworthii populations, indicating patterns of local adaptation and evolutionary divergence. The phylogenetic tree delineated clear genetic separation between wild Florida populations and cultivated Vitis species or breeding lines. Principal Component 1 accounted for 61.65% of the variance, while Principal Component 2 explained 9.86% of the variance. This spatial genetic structure suggests significant genetic diversity and restricted gene flow across regions. This study highlights the natural genetic variation present within the V. shuttleworthii population and provides a valuable resource for grape breeding programs.

Speakers

Sheetal Ramekar

University of Florida

Co-authors

Dylan Hacker

University of Florida

Manjul Dutt

University of Florida

Sadanand Dhekney

University of Maryland Eastern Shore

Thursday July 31, 2025 9:15am - 9:30am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Poster # csv

9:30am CDT

PNM 3 - Enhancing Snap Bean (Phaseolus vulgaris L.) Growth and Yield through Liquid Oxygen and Phosphorus Fertigation Under Fiel

Thursday July 31, 2025 9:30am - 9:45am CDT

Foster 2

Snap bean (Phaseolus vulgaris L.) is a vital crop in Florida, but it is highly vulnerable to low-oxygen (O₂) stress in soil and phosphorus (P) deficiency, particularly in regions utilizing deep well irrigation. The objective of this study was to evaluate the effects of liquid O₂ and P fertigation on plant growth, pod yield, and nutrient uptake under field conditions. A Randomized Complete Block Design (RCBD) with four replications was employed, testing two rates of liquid O₂ (0 and 45 kg ha⁻¹ as hydrogen peroxide, H₂O₂) and five levels (0, 90, 135, 180, and 225 kg ha⁻¹) of liquid P as 0-54-0 phosphoric acid (H₃PO₄). Key variables assessed included plant growth, P uptake, pod yield, and soil properties to evaluate the effectiveness of fertigation in promoting plant performance and nutrient uptake. The results indicated that both liquid O₂ and P applications enhanced plant growth and pod yield, with the highest pod yield achieved from the combination of 45 kg ha⁻¹ of liquid O₂ and 225 kg ha⁻¹ of liquid P. Pearson correlation analysis revealed strong associations between plant growth, pod yield, and nutrient uptake. Principal component analysis (PCA) confirmed the significant effects of liquid O₂ and P fertigation on growth parameters and pod yield. This study concludes that liquid O₂ fertigation alleviates soil hypoxia, improves P use efficiency, and boosts crop productivity, offering a promising and cost-effective solution for optimizing snap bean cultivation.

Speakers

Md Jahidul Islam Shohag

University of Florida

Co-authors

Elena Maximo

University of Florida

Guodong Liu

University of Florida

Thursday July 31, 2025 9:30am - 9:45am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv
Funding Source Florida Department of Agriculture and Consumer Services
Funding Option OREl or ORG funded all or part of the research associated with this abstract

9:30am CDT

TCHG 2 - Teaching Research Methods by Developing Production Recommendations for Various Philodendron Cultivars Grown in a Central

Thursday July 31, 2025 9:30am - 9:45am CDT

Strand 11A

Plugs of various Philodendron cultivars, such as ‘Moonlight’, ‘Green Princess’, ‘Birkin’ and ‘Imperial Green’ are readily available to Florida commercial foliage growers. Although older generalized recommendations for producing philodendrons exist, specific production guidelines are not available for many newer cultivars. Growing a crop of foliage plants like philodendrons to completion not only provides for development of grower guidelines but also provides excellent research method learning experiences for undergraduate students. Each year, in September, tissue-cultured plugs of various philodendrons are potted up in 15.24cm standard pots using conventional peat/perlite soilless mixes amended with dolomite, STEM, and several different rates of various controlled-release fertilizers (CRF). The pots are placed on greenhouse benches in randomized blocks within a split-plot design under two different shade levels. The controlled-release fertilizers (CRF) should release evenly at soilless medium temperatures up to 30°C. Throughout the production schedule (usually September to March), medium temperatures are measured using Onset HOBO MX2202 Bluetooth data loggers buried in several pots; light level, temperature and humidity at plant height are also measured. All pots receive the same irrigation treatment. Non-destructive plant growth parameters, such as plant height and number of leaves, are collected frequently. Leaf chlorophyll content is measured several times using various different chlorophyll meters. Leaf color is measured with various color meters. Electrical conductivity (EC) and pH for all pots are measured using the standard pour-through method to evaluate the overall fertilizer levels available; these leachate sample solutions are collected and evaluated in the lab for nitrate, phosphate, potassium, calcium, and magnesium concentrations in the leachate solutions using different types of meters. At the end of the six-month growing period, plants are moved to another location, randomized, and then evaluated by student buyers not involved in the production of the crop. This marketing survey allows us to check for differences between treatments that might impact consumer acceptance. Destructive measurements, such as leaf chlorophyll content and/or leaf chemical content can also be measured after the marketing survey. Statistical analysis is also performed on the collected data. Since the data types are varied, students are introduced to several different statistical techniques from standard deviation to variance to correlation to regression. After completion of the production study, student participants often publish manuscripts and give presentations at conferences. Grower production recommendations are also offered.

Speakers

John L Griffis Jr

Florida Gulf Coast University

Co-authors

Krystin Perry

Florida Gulf Coast University

MADELEINE TENNY

Florida Gulf Coast University

Malcolm Manners

Florida Southern College

Rory Dunn

Florida Gulf Coast University

Senthil Balaji Girimurugan

Florida Gulf Coast University

Thursday July 31, 2025 9:30am - 9:45am CDT
Strand 11A

Oral presentation, Teaching Methods 2

Subject Teaching Methods
Poster # csv

9:30am CDT

VGBR 2 - Harnessing Aerial Imagery and AI for Efficient Yield Assessment in Sweetpotato Breeding

Thursday July 31, 2025 9:30am - 9:45am CDT

Strand 12B

Modern sweetpotato breeding programs evaluate hundreds of genotypes across successive generations to identify lines with superior storage root quality traits. However, traditional phenotyping methods rely on manual storage root evaluation, limiting both the scale and speed of selection. Small Unmanned Aircraft System (sUAS)-based high-throughput phenotyping offers scalable, image-based alternatives that enable breeders to collect highly detailed data with reduced bias, facilitating genomic selection. By linking image-derived phenotypes to genotypic data, these approaches could shorten the breeding cycle by supporting earlier or more optimal selection decisions. In this study, we developed an image-based yield estimation pipeline for early generation and advanced sweetpotato breeding lines using sUAS-based RGB (0.17 cm pixel⁻¹) and multispectral imagery. The pipeline leveraged a previously developed Mask R-CNN segmentation model for sweetpotato storage root detection that was pre-trained using mobile RGB images and fine-tuned using annotated aerial images to optimize performance for sUAS applications. Imagery was acquired in 2024 from two research fields immediately after harvest. Ground truth plot-level root yield was collected using mechanical singulation in an optical sorter (Exeter Engineering). The Mask R-CNN model generated instance masks of individual storage roots directly from plot-level RGB imagery, with root metrics such as length, diameter, and volume estimated using multiple geometrical methods. The model demonstrated strong predictive performance across both locations. Combined-location analysis yielded a correlation coefficient of 0.94 for storage root weight estimation (0.88 and 0.97 for individual locations) with a root mean squared error (RMSE) of 1.24 kg plot⁻¹. Root count estimation achieved a correlation coefficient of 0.78 (0.73 and 0.92 independently) with an RMSE of 11 roots plot⁻¹. These results indicate robust yield estimation across diverse genotypes and field conditions. Furthermore, these findings highlight the potential of combining aerial imagery and deep learning to streamline yield assessment in sweetpotato breeding programs. Future work will focus on enhancing model accuracy by incorporating root feature analysis, quality classifications, and expanded datasets to further support breeding decisions and accelerate selection pipelines.

Speakers

Alexis Suero

North Carolina State University

Co-authors

Craig Yencho

North Carolina State University

Jerome Maleski

North Carolina State University

Jing Zhang

North Carolina State University

Ken Pecota

North Carolina State University

Michael Kudenov

North Carolina State University

Russell Mierop

North Carolina State University

Simon Fraher

North Carolina State University

Thursday July 31, 2025 9:30am - 9:45am CDT
Strand 12B

Oral presentation, Vegetable Breeding 2

Subject vegetable Breeding
Poster # csv

9:30am CDT

VSF 2 - Vineyard Groundcover and Nitrogen Fertility Changes on Plant-Parasitic Nematode Populations and Soil Nutrient Cycling

Thursday July 31, 2025 9:30am - 9:45am CDT

Foster 1

Plant-parasitic nematodes (PPNs) are common in perennial cropping systems, particularly where traditional fertility and floor management practices biologically disturb soil ecosystems. Four vineyard floor management treatments were applied to mature ‘Norton’ vines—(1) grower control (mown tall fescue in the aisle with herbicide-treated bare driplines), (2) red fescue (creeping red fescue established throughout aisle and dripline), (3) successional cover crops (annual rotation of cereal rye, oats, and sorghum-sudangrass using no-till planting), and (4) compost (a mix of hardwood mulch and composted winery pomace applied across aisle and dripline)—in combination with two nitrogen fertility regimes: no nitrogen (0 lb N/ac) and N fertilization (20 lb N/ac applied at budbreak, bloom, and veraison (60 lb N/ac total)). The study was conducted on a Hosmer silty-clay loam in southern Illinois, arranged in a randomized complete block design with four replications. Soil samples were analyzed for populations of plant-parasitic nematode genera—including Pratylenchus, Helicotylenchus, Xiphinema, and Longidorus—alongside soil nutrient metrics such as water-extractable potassium (WEK), phosphorus (WEP), and organic carbon (WEOC), as well as percent organic matter (OM), carbon-to-nitrogen ratio (C:N), and soil respiration (CO₂). Results showed that red fescue may act as a host for Pratylenchus, particularly when supported by nitrogen fertilization (236/100cc) in the vineyard dripline, compared to 156/100cc under compost, 204/100cc under successional cover, and 164/100cc in the grower control during the same period. The increase may be attributed to red fescue’s weak, fibrous root system, which lacks the structural defenses of deeper-rooted species and may act as an attractant. Although Pratylenchus have higher damage thresholds, these population densities have the potential to affect grapevine health. In contrast, compost and successional cover treatments suppressed multiple PPN genera while significantly improving nutrient availability. Populations of Xiphinema and Longidorus were reduced by 57–92% under compost and successional treatments with no nitrogen, compared to the control. These treatments also increased WEK by up to 249%, raised WEP, and elevated OM to 2.6%, compared to 2.1% in the control. Soil respiration reached 68.4 kg/ha, and estimated nitrogen release was as high as 62.8 kg/ha, while maintaining stable C:N ratios (~12.5), indicating enhanced nutrient cycling and organic matter mineralization. These findings suggest that biologically diverse vineyard floor management can suppress plant-parasitic nematodes while simultaneously improving soil nutrient relationships. Integrating organic amendments and dynamic cover cropping into vineyard systems offers a strategy to reduce pest pressure, enhance nutrient cycling, and build soil health.

Speakers

Amanda Weidhuner

Southern Illinois University Carbondale

Co-authors

Bradley Taylor

Southern Illinois University Carbondale

Thursday July 31, 2025 9:30am - 9:45am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Poster # csv

9:45am CDT

PNM 3 - Nutrient Solubility in Response to Root Zone pH for Soilless Plant Culture

Thursday July 31, 2025 9:45am - 10:00am CDT

Foster 2

The pH of the root zone plays a crucial role in influencing the solubility of nutrients within a soilless substrate or hydroponic solution, affecting their uptake into plant tissue. Our objective was to re-evaluate and update the understanding of how root zone pH affects nutrient solubility in soilless substrates and hydroponic systems using chemical equilibria software, laboratory testing, and a literature review. The aim was to provide horticulture practitioners with an understanding of the trends that should be considered when managing substrates and fertilization. Calcium and magnesium have decreasing solubility with increasing pH. However, dolomitic limestone added for neutralization of acidic substrates such as bark and peat increase Ca and Mg under alkaline conditions. Because potassium salts are usually the liming sources in hydroponics, Ca and Mg levels decrease at high pH. Phosphorus availability is limited primarily because of reactions with Ca at high pH. Results demonstrated substantial differences in micronutrient solubility between sulfate-based and chelated micronutrients. In hydroponic simulations (GEOCHEM-EZ), sulfate-based micronutrients rapidly became insoluble at higher pH (>6.0), whereas chelates, particularly Fe-EDDHA (ethylenediamine-N,N-bis(2-hydroxyphenylacetic acid), maintained solubility even under alkaline conditions (up to pH 10.0). Visual MINTEQ simulations highlighted the role of DOM in stabilizing micronutrient availability in soilless substrates through the formation of metal-organic complexes, especially for metal micronutrients Fe, Cu, and Zn. Laboratory measurements were consistent with chemical equilibrium simulations, demonstrating higher water-extractable micronutrient solubility with EDTA (ethylenediaminetetraacetic acid) chelates compared with sulfate forms, particularly at elevated pH. Fe and Mn solubility sharply declined with increasing substrate pH, whereas Zn and Cu solubility peaked at intermediate pH levels (5.5 to 6.5). Boron availability decreased as substrate pH increased, whereas Mo solubility increased under alkaline conditions. A review of trends in plant tissue micronutrient concentration at different pH levels in hydroponics and soilless substrates emphasized that translating micronutrient solubility to plant availability is complex. For example, absorption of cations by roots at very low pH may be impeded in soilless substrates hydroponics by a combination of growth inhibition, nutrient disorders, and direct pH effects of H concentration. Plant uptake involves numerous biological processes, including root exudation, microbial interactions, nutrient competition, redox conditions, and plant-specific nutrient strategies. Updated pH solubility charts were developed to help visualize micronutrient solubility and plant uptake under different scenarios that have practical implications for horticulture fertilizer management.

Speakers

Paul Fisher

University of Florida

Co-authors

Jinsheng Huang

University of Florida

Thursday July 31, 2025 9:45am - 10:00am CDT
Foster 2

Oral presentation, Plant Nutrient Management 3

Subject Plant Nutrient Management
Poster # csv
Funding Source Floriculture Research Alliance, USDA-ARS Floriculture and Nursery Research Initiative #58-3607-8-725, USDA NIFA multi-state NC1186, and HATCH FLA-ENH-005918

9:45am CDT

VSF 2 - Mode of action of a new Seaweed Extract and Amino Acid Based Biostimulant for Abiotic Stress Tolerance

Thursday July 31, 2025 9:45am - 10:00am CDT

Foster 1

A new biostimulant formulation (APH-1035; alkaline Ascophyllum nodosum seaweed extract and amino acid, L-phenylalanine) was evaluated in mode of actions studies to understand the contribution of each active ingredient to the effect of the biostimulant. Previous controlled environment studies showed under salinity and drought stress, plants treated with this new biostimulant had an increase in shoot weight and leaf area, and improvements in photosynthetic parameters, showing statistical synergy between the active ingredients. Field trials had similar results with treated plants having an increase foliar and root fresh and dry weight, and yield under drought and salinity stress. An increase in flowers and fruit set was also seen. Controlled environment studies evaluated the potential mode of action of APH-1035 on strawberry under drought stress. Treatments consisted of a non-stressed control, a stressed control, APH -1035, and the individual active ingredients in APH-1035 (seaweed extract, and phenylalanine) at the equivalent concentrations in APH-1035. Leaf tissue samples were collected pre-stress, and two time points post stress, frozen, and RNA extracted, followed by RNASeq, and subsequent data analysis. Plants treated with APH-1035 showed a transcriptional profile more similar to the non-stressed plants than stressed control plants. The individual active profiles were more similar to the stressed control. Transcript abundance increased over time and did not change after prolonged drought stress. In contrast, stressed control plants, showed down regulation of this gene cluster. Correlation analysis resulted in 221 genes whose expression correlated significantly with treatments. Some of these genes are related to photosynthesis and starch metabolism, which can be linked to drought resistance. These results suggest that the novel biostimulant, with the combination of seaweed extract and an amino acid (phenylalanine) influences gene expression within plants to reduce abiotic stress and promote growth and metabolism under stress, and that this response is greater than the individual actives alone.

Speakers

Holly Little

Director, research and development, Acadian Plant Health

Thursday July 31, 2025 9:45am - 10:00am CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 2

Subject Viticulture and Small Fruits
Poster # csv

10:14am CDT

CE 5 - Oral Session

Thursday July 31, 2025 10:14am - 10:15am CDT

Strand 12B

Presiding/Moderator

Abishkar Regmi

Graduate Research Assistant, Texas Tech University

Thursday July 31, 2025 10:14am - 10:15am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments

10:14am CDT

CHMG 1 - Oral Session

Thursday July 31, 2025 10:14am - 10:15am CDT

Strand 11A

Presiding/Moderator

Amy Bruzzichesi

NC State University

Amy Bruzzichesi, MSW, HTR is a therapeutic horticulturist, horticultural therapist, and career social worker with a background in elder care, medical social work, and the nonprofit world. Amy is part of NC Cooperative Extension as the Therapeutic Horticulture Program Manager, sustaining... Read More →

Thursday July 31, 2025 10:14am - 10:15am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener

10:14am CDT

PGR - Oral Session

Thursday July 31, 2025 10:14am - 10:15am CDT

Foster 2

Presiding/Moderator

Haramrit Gill

University of California Agriculture and Natural Resources

Thursday July 31, 2025 10:14am - 10:15am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation

10:14am CDT

POM 2 - Oral Session

Thursday July 31, 2025 10:14am - 10:15am CDT

Foster 1

Presiding/Moderator

Ashley Sorrow

University of Georgia

Thursday July 31, 2025 10:14am - 10:15am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology

10:14am CDT

VCM 4 - Oral Session

Thursday July 31, 2025 10:14am - 10:15am CDT

Strand 11B

Presiding/Moderator

Marisa Thompson

New Mexico State University

Thursday July 31, 2025 10:14am - 10:15am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management

10:15am CDT

CE 5 - A Chemical Biostimulant Enhances Growth of Greenhouse Lettuce, but not Other Leafy Greens, in Aerated Hydroponics

Thursday July 31, 2025 10:15am - 10:30am CDT

Strand 12B

A calcium-mobilizing chemical biostimulant has been developed to improve crop growth and quality by promoting calcium uptake and mobilization. Although designed to be applied as a foliar spray, it can potentially be added to the nutrient solution in controlled-environment hydroponic systems. Although it has been shown to mitigate calcium deficiency-induced tipburn while maintaining biomass in hydroponic lettuce (Lactuca sativa), its efficacy in other emerging hydroponic leafy greens remains unclear. The objective of this study was to determine the influence of this biostimulant, when added to the nutrient solution, on the growth traits of four hydroponic leafy greens: arugula (Eruca sativa) ‘Astro’, kale (Brassica oleracea var. sabellica) ‘Starbor’, lettuce ‘Rex’, and pac choi (Brassica rapa var. chinensis) ‘Win-Win Choi’. After 11 days of germination and seedling propagation under indoor sole-source lighting, we transplanted seedlings of all crops into actively aerated deep-water-culture trays in a summer greenhouse environment. The trays had the same nutrient solution without and without the added biostimulant at a concentration of 0.25 mL⋅L−1 in three blocks of a randomized complete block design. Plant data were collected 21 and 28 days after transplanting (DAT). At 21 DAT, the added biostimulant decreased shoot fresh and dry mass of arugula, kale, and pac choi by 21% to 31% but increased that of lettuce by 23% to 25%. At 28 DAT, the added biostimulant also increased shoot fresh and dry mass of lettuce by 24% to 29%, did not influence shoot fresh mass of the other crops, and decreased shoot dry mass of kale and pac choi by 14% to 21%. Tipburn incidence was minimal without or with the added biostimulant at 21 and 28 DAT, although tipburn reduction was observed in arugula and pac choi with the added biostimulant. Chlorophyll concentration index was generally unaffected by the added biostimulant, except for an 11% increase in lettuce with the added biostimulant at 28 DAT. Extension growth of all crops except lettuce had a 9% to 15% reduction with the added biostimulant at 21 DAT but was unaffected by the added biostimulant at 28 DAT. We conclude that the added biostimulant boosted the growth of lettuce, but not the other leafy greens tested, in summer greenhouse aerated hydroponics.

Speakers

Qingwu Meng

University of Delaware

Co-authors

Yoko Suzuki

University of Delaware

Thursday July 31, 2025 10:15am - 10:30am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Funding Source University of Delaware College of Agriculture and Natural Resources Envision Program, which was funded by the USDA National Institute of Food and Agriculture Award #2020–67037–31077

10:15am CDT

CHMG 1 - Citi-Sci: A Multi-state Gardening Project to Evaluate Plant Preferences and Knowledge Gained from Extension Education

Thursday July 31, 2025 10:15am - 10:30am CDT

Strand 11A

A citizen-science gardening project was conducted in 2024 with 205 participants from Indiana, Iowa, North Carolina, and Tennessee. Participants grew two cultivars of strawberry (Fragaria × ananassa): ‘Elan’, a vigorous white-flowered plant, and ‘Tristan’, a pink-flowered plant with ornamental appeal. The study used a 15-question pre- and posttest format to assess changes in participant confidence related to pest management, personal nutrition, and mental health care. Participants also reported cultivar and plant-type preferences in the post-test. Monthly virtual educational sessions on the assessed topics were delivered by Extension faculty. Only 110 participants completed both the pre- and posttests, enabling evaluation of knowledge gain. An increase in mean scores was measured for 13 questions, suggesting that participants benefited from the educational Extension programming. The greatest improvements were measured in pest management knowledge, with gains ranging from 10% to 19%, whereas questions about methods to reduce stress increased only by 6% to 8%. In the posttest, 76% of participants preferred ‘Tristan’, citing its more attractive appearance, earlier harvest, and better yield compared to ‘Elan’. On average, ‘Tristan’ plants produced their first harvest 49 d after planting, compared to 58 d for ‘Elan’. Notably, willingness-to-pay data indicated that participants valued both cultivars similarly. Our findings demonstrate the positive impact of Extension programming on gardening-related knowledge and highlight the value of collaboration between university researchers, Extension faculty, and stakeholders as citizen scientists.

Speakers

Celina Gomez

Purdue University

Co-authors

Cynthia Haynes

Iowa State University

Karen Mitchell

Purdue University

Melinda Knuth

North Carolina State University

Michael Fidler

Purdue University

Natalie Bumgarner

University of Tennessee

Siria Cardenas

Purdue University

Thursday July 31, 2025 10:15am - 10:30am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Funding Source This activity was funded by Purdue University as part of AgSEED Crossroads funding to support Indiana’s Agriculture and Rural Development.

10:15am CDT

PGR - Overcoming the Pre-Harvest Fruit Drop vs. Fruit Color Trade-off in 'Honeycrisp' Apples Using Combined Plant Growth Regul

Thursday July 31, 2025 10:15am - 10:30am CDT

Foster 2

Pre-harvest fruit drop (PFD) causes significant yield losses in commercially valuable apple cultivars like 'Honeycrisp'. Ethylene, the master regulator of various fruit ripening traits in climacteric fruits, accelerates pre-harvest fruit drop. While ethylene inhibitors such as aminoethoxyvinylglycine (AVG) effectively reduces PFD, it can negatively impact fruit color development, a process also regulated by the plant hormone ethylene. To address this trade-off, we evaluated various plant growth regulators (PGRs), such as Accede (1-aminocyclopropane-1-carboxylic acid (ACC)-10%), Motivate (ethephon-21.7%), ReTain (AVG-15%) and their combinations, in ‘Honeycrisp’ apples over two consecutive years (2023

Speakers

Mohammad Monirul Hasan Tipu

Virginia Tech

Co-authors

khalil Jahed

Virginia Tech

Sherif Sherif

Virginia Tech

Thursday July 31, 2025 10:15am - 10:30am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv

10:15am CDT

POM 2 - Effects of intermittent warm temperature exposure on progression of chill accumulation during peach floral bud dormancy

Thursday July 31, 2025 10:15am - 10:30am CDT

Foster 1

Dormancy is an important strategy in perennial plants such as the tree fruit peach (Prunus persica), to protect them from damage during harsh environmental conditions such as winter weather. As day length and temperature decrease in the fall, floral and vegetative buds enter a state of endodormancy where they remain unresponsive to growth promoting environmental signals (Nilsson, 2022). Exposure to cold temperatures (typically ≤ 7° C) during the winter allows for chill accumulation and upon sufficient such chill accumulation, release from endodormancy occurs. This is followed by exposure to warmer temperatures in the spring leading to the end of eco- dormancy and bud break. In the field, low winter temperatures are often interspersed with periods of substantially warm weather thereby interrupting or negating the progression of chill accumulation and affecting bud break in the spring. Understanding responses of peach buds to intermittent warm temperature exposure is needed to mitigate crop loss due to temperature fluctuations. Experiments were conducted to determine the effects of such intermittent warm temperature exposure on chill accumulation in ‘Contender’ peach. Potted trees were maintained at ambient conditions in the field until around 50% of chill requirements (100 % = 1050 chill hours) were met. Following this, trees were subjected to one of three treatments: Control, Chill break I, and Chill break II, with 4 replicates per treatment. The Control group of peach trees were maintained under ambient conditions to reach their chill requirement. Chill break I and Chill break II were exposed to intermittent warm temperatures of continuous 14 °C in a growth chamber for 7 and 14 days, respectively. Following the treatment, trees were returned to ambient conditions. Peach buds were collected from each treatment at three stages and remaining buds were monitored to track floral bud break progression. Additionally, we determined the metabolite and phytohormone concentrations in ‘Contender’ peach buds that naturally accumulated their chilling requirements. Results indicate that as chilling progression increases, starch concentration increases. Concentration of the phytohormone ABA (abscisic) acid appeared to decrease upon completion of endodormancy. Together, these analyses are expected to help us gain a better understanding of dormancy progression in peach.

Speakers

Ashley Sorrow

University of Georgia

Co-authors

Anish Malladi

University of Georgia

Dario Chavez

University of Georgia

Savithri Nambeesan

University of Georgia

Thursday July 31, 2025 10:15am - 10:30am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology

10:15am CDT

VCM 4 - The Effect of Power System on Potato Production for Small Farms

Thursday July 31, 2025 10:15am - 10:30am CDT

Strand 11B

Despite not well studied within the sustainable agriculture research community, there is evidence that animal traction could be a regenerative power option for small farms. Animals cause minimal compaction, appreciate, and can regenerate. Fuel can be grown on farm, some animals are multi-purpose, and there is social benefit for those that interact with them. However, opportunities for aspiring teamsters to gain knowledge are limited. Extension materials and programming from public Universities are also not widely available. A side-by-side tractor animal traction comparison was established at the Meigs Horticulture Facility in Lafayette IN (Meigs). There were two treatments potato production with animal traction (AT) and potato production with small tractor traction (TT). During the study all field activities related to potato production were performed with animal power or tractor power in the two treatments, respectively. Data collection included: cost of equipment, time for each field, potato yield, and comprehensive soil health assessment including penetration resistance. Potato yield did not differ between AT and TT (P = 0.79213). Yields were 15,266.3 ± 7,523.6 and 12,981.0 ± 9,175.0 lb. 1-acre for AT and TT, respectively. Overall cost of capital equipment used in thus study were 17,050 and 42,147.30 for AT and TT, respectively. Total time in the field for major field events was 4 hours for AT compared to TT. Preliminary results reveal that similar yields to tractor power can be achieved when using animal power. Time in the field may be greater in animal traction, but capital equipment costs can be lower.

Speakers

Moriah Bilenky

Purdue University

Thursday July 31, 2025 10:15am - 10:30am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Funding Source North Central SARE

10:30am CDT

CE 5 - Optimizing Hydroponic Lettuce Production in Mississippi Through Cultivar Selection, System Comparison, and Biostimulant

Thursday July 31, 2025 10:30am - 10:45am CDT

Strand 12B

The southeastern U.S. struggles with horticultural production due to a harsh climate that exacerbates issues such as severe weed, soil-borne pests, and diseases. Hydroponic cultivation offers a promising solution by reducing pesticide use and facilitating year-round production. However, there is a lack of regionally research-based guidance on hydroponic cultivation in Mississippi. This study aimed to screen the lettuce cultivars that are suitable for hydroponic cultivation in Mississippi and to evaluate the effects of different hydroponic systems and biostimulants on plant growth. Six lettuce cultivars (Buttercrunch, Adriana, Rex, Rouxai, Oscarde, and Skyphos) were grown in two hydroponic systems (vertical tower and deep-water culture), and subjected to three biostimulant treatments (control, kelp and microbial biostimulant) to assess their impacts on growth parameters. Results indicated that lettuce cultivar significantly affected hydroponic lettuce growth. Adriana showed the highest leaf area and plant biomass while Buttercrunch displayed the highest relative chlorophyll content (SPAD) and shoot fresh weight. Rouxai accumulated the least biomass. Biostimulants demonstrated positive effects on lettuce plant growth; however, their efficacy was specific to both the hydroponic system and lettuce cultivar. Kelp was found to be more effective than microbial biostimulants in enhancing growth parameters. Overall, lettuce plants grown in the deep-water culture system exhibited faster growth compared to those in the vertical tower system. In conclusion, this study demonstrated that hydroponic cultivation is a viable solution for lettuce production in Mississippi, with deep-water culture system and kelp biostimulant significantly enhancing growth parameters.

Speakers

Gaosheng Wu

Mississippi State University

Co-authors

Jingyi Wu

Mississippi State University

Qianwen Zhang

Truck Crops Branch Experiment Station

Tongyin Li

Mississippi State University

Thursday July 31, 2025 10:30am - 10:45am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Funding Source USDA National Institute of Food and Agriculture (NIFA) Hatch Project MIS-300011

10:30am CDT

CHMG 1 - East Texas Master Gardener Characteristics, Volunteer Choices, and Willingness to Answer Questions from the Public

Thursday July 31, 2025 10:30am - 10:45am CDT

Strand 11A

East Texas Master Gardener volunteers were asked to participate in an exploratory Qualtrics survey during the fall of 2023. This study examined the demographic characteristics, volunteer engagement choices, and challenges of Master Gardener volunteers in Texas A

Speakers

Jared Barnes

SFASU

Co-authors

Candis Scallan

Stephen F Austin State University

Greg Grant

Stephen F Austin State University

Pat Stephens-Williams

Stephen F Austin State University

Ray Darville

Stephen F. Austin State University

Thursday July 31, 2025 10:30am - 10:45am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Poster # csv

10:30am CDT

PGR - Testing of 1-Aminocyclopropane-1-Carboxylic Acid (ACC) for Chemical Removal of Flowers of Young Orchard Trees Aiming at

Thursday July 31, 2025 10:30am - 10:45am CDT

Foster 2

Approximately 3-5% of perennial orchard trees are replanted annually. Bearing fruit on newly planted orchard trees is undesirable because fruits are strong carbohydrate sinks and compete with shoot growth, and thus limit early growth of orchard trees to fill their space. Therefore, manual removal of flowers and fruitlets from newly planted trees has been practiced. In almond, leaving nuts on young trees cannot just limit vegetative growth but also serve as harboring site for navel orange worm. Therefore, removal of flowers and fruitlets/nutlets via spray application of chemical thinners would be highly desirable to aim tree growth and reduce manual labor cost for tree defruiting. In a series of experiments in nectarines, almonds and walnuts in California, we investigated the effects of the application of ACC alone or in combination with S-abscisic acid (S-ABA), 6-benzyladenine (6-BA) on flower and fruitlet/nutlet removal. Results indicated that ACC by itself at 450-600 mg/L or in combination with 300 mg/L S-ABA or 400 mg/L 6-BA can effectively defruit young orchard trees and reduce manual labor cost. No phytotoxicity was observed in any of the trials.

Speakers

Jozsef Racsko

Valent USA

Co-authors

Poliana Francescatto

Valent BioSciences

Thursday July 31, 2025 10:30am - 10:45am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv

10:30am CDT

POM 2 - Comparative evaluation of phytochemicals in low-chill peach, nectarine, and plum cultivars grown in Florida

Thursday July 31, 2025 10:30am - 10:45am CDT

Foster 1

Peaches, nectarines, and plums are among the most popular and valuable stone fruits from the Rosaceae family. Their fruit are rich in bioactive compounds, including flavonoids, anthocyanins, carotenoids, phenolic compounds, vitamins, and antioxidants. In this study, the chemical attributes, bioactive compound content, and antioxidant activity of 18 peach cultivars (‘UFOne’, ‘UFGlo’, ‘UFBeauty’, ‘UFSun’, ‘Flordaprince’, ‘Gulfcrismon’, ‘UFBlaze’, ‘TropicSnow’, ‘TropicBeauty’, ‘UFGem’, ‘UFBest’, ‘Flordaglo’, ‘Flordabest’, ‘UFO’, ‘Flordaking’, ‘Flordacrest’, ‘UFSharp’, and ‘Flordabelle’), four nectarine cultivars(‘UFRoyal’, ‘Sunraycer’, ‘Sunmist’, and ‘Sunbest’), and four plum cultivars (‘Gulfrose’, ‘Gulfgold’, ‘Gulfblaze’, and ‘Scarlet Beauty’) were evaluated. Total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, and juice pH presented significant variations among cultivars. The highest TSS content was recorded in ‘Sunmist’ nectarine, while plum cultivars had the highest TA levels, particularly ‘Scarlet Beauty’. The TSS/TA ratio was highest in ‘UFSun’ peach. ‘Gulfrose’ plum showed the highest total anthocyanin concentration (TAC) level. Total phenolic content (TPC) varied significantly, with plum cultivars, particularly ‘Scarlet Beauty’, having the highest amount. Similarly, total antioxidant activity (TAA) was highest in ‘Scarlet Beauty’ and ‘Gulfrose’ plums, while ‘TropicSnow’ peach and ‘SunBest’ nectarine had the lowest TAA. Multivariate statistical analyses revealed clear separations among cultivars based on chemical and bioactive parameters. These findings provide valuable insights into the biochemical diversity of peach, nectarine, and plum cultivars, emphasizing the superior bioactive and antioxidant properties of plum cultivars.

Speakers

Fariborz Habibi

University of Florida

Co-authors

Ali Sarkhosh

University of Florida

Jeffrey Brecht

University of Florida

Jose Chaparro

University of Florida

Thursday July 31, 2025 10:30am - 10:45am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology

10:30am CDT

VCM 4 - Field Evaluation of Edamame Varieties During Two Planting Seasons in a Subtropical Region

Thursday July 31, 2025 10:30am - 10:45am CDT

Strand 11B

Edamame, a vegetable soybean harvested at the immature stage with green pods, has gained popularity in the United States due to its high nutritional value and appealing taste, resulting in growing consumer demand. However, over 70% of the edamame consumed in the U.S. is currently imported from East Asia. To support domestic production and reduce reliance on imports, identifying suitable varieties and production windows is essential—especially in regions like Florida, where subtropical conditions allow for multi-season cropping. This study aimed to evaluate the performance of sixteen commercial edamame varieties (maturity groups 0–V) across South Florida’s two primary bean production seasons: spring (early February to mid-May) and fall (early October to mid-December). The objectives were to (a) identify varieties best suited to South Florida’s subtropical climate, and (b) determine the optimal growing season for each variety. Growth parameters (emergence rate, plant height, canopy diameter, leaf area, and nodes per plant) and agronomic traits (fresh pod yield and 10-pod weight) were measured to assess adaptation and productivity. In the spring, ‘UA-Kirksey’ achieved the highest yield at 5.0 t/ha, while ‘Midori Giant’ had the lowest at 0.8 t/ha. In the fall, ‘Chiba Green’ produced the highest yield at 3.2 t/ha, and ‘Karikachi #3’ the lowest at 0.5 t/ha. Six varieties, i.e., ‘KAS 355-11’, ‘Kahala’, ‘Karikachi #3’, ‘Shirofumi’, ‘UA-Kirksey’, and ‘Young Soybean’ yielded significantly higher (p ≤ 0.05) in spring compared to fall, while no significant seasonal differences were observed for the other varieties. These findings demonstrate the importance of selecting season-appropriate varieties to maximize yield potential and production efficiency in subtropical regions like South Florida, offering a promising strategy to support local edamame cultivation.

Speakers

Xiaoying Li

University of Florida, IFAS

Co-authors

Vander Rocha Lacerda

University of Florida Tropical Research and Education Center

You's Kertye Myrtil

University of Florida

Thursday July 31, 2025 10:30am - 10:45am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Poster # csv

10:45am CDT

CE 5 - Tylosin in Hydroponic Systems: Assessing Growth and Antibiotic Residue in Lettuce Cultivation

Thursday July 31, 2025 10:45am - 11:00am CDT

Strand 12B

Antibiotic persistence in the environment, including water sources, is a significant concern due to the increasing prevalence of antibiotic-resistant bacteria. Tylosin is a common macrolide antibiotic used as a growth promoter in cattle, with 71% of feedlots administering it. Antibiotics such as tylosin, can persist as residual contaminants in surface water, groundwater, and wastewater. This poses a risk when these contaminated waters are used for irrigation. Such practice can result in the uptake of antibiotics by plants, which in turn may contribute to the development of antibiotic resistance in both human and living organisms. To determine the antibiotic uptake and its effects on crops, we spiked the nutrient solution with 2 levels of tylosin and grew lettuce (Lactuca sativa) in a nutrient film technique (NFT) hydroponics system. Two replicated experiments utilized the NFT hydroponic systems and included tylosin at concentrations of 5 mg/L and 10 mg/L, with reverse osmosis (RO) water as the control. Growth parameters were measured after 4 weeks at harvest, including aerial weight, head diameter, plant height, root weight, and root length. The results indicated that tylosin treatments had a negative impact with decreased root weight and length in the first experiment, whereas aerial measurements did not differ between treatments. The 10 mg/L tylosin treatment in the second experiment resulted in significantly wider head diameters and longer roots. Tylosin concentrations in lettuce leaf tissue were higher in both treatments compared to the control, although the 5 mg/L and 10 mg/L treatments showed similar responses. Water analyses throughout the experiments showed a decrease in tylosin concentration in the treated water over time, with no tylosin detected in the control treatment at any time. Multivariate correlation analysis revealed negative correlations between tylosin concentration and all growth parameters. These findings highlight the potential effects of tylosin on hydroponically grown lettuce and raise important considerations for using recycled or alternative water sources in hydroponic agriculture, particularly concerning food safety and crop productivity.

Speakers

Dario Rueda Kunz

Texas Tech University

Co-authors

Catherine Simpson

Texas Tech University

Haydee Laza

Texas Tech University

Jyotsna Sharma

Texas Tech University

Marcos Sanchez

Texas Tech University

Thursday July 31, 2025 10:45am - 11:00am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Poster # csv

10:45am CDT

CHMG 1 - Free Farmers' Markets for Salt Lake County Seniors

Thursday July 31, 2025 10:45am - 11:00am CDT

Strand 11A

The Utah Commission on Aging defines food insecurity as lack of reliable access to sufficient amounts of affordable and nutritious foods. Seniors experiencing food insecurity are disproportionately low-income and often suffer from chronic health conditions (Hartline-Grafton, 2019) and food insecure older adults with chronic conditions have higher health care costs than their non-food insecure counterparts (Garcia et al., 2018). Food insecurity among low-income seniors is a complex issue because impacted individuals may experience limited mobility and not reside near food stores. Additionally, many low-income seniors must choose between feeding themselves, paying medical bills, and affording household expenses (Utah Food Bank, 2019). The Utah Food Bank reports that about 12% of Utah seniors struggle with hunger (up 45% since 2001) and the number is expected to climb to 8 million by 2050 as the aging population doubles. Salt Lake County (SLCo) Adult and Aging Services published a 2023 Community Needs Assessment which identified the top three of needs of local seniors were healthcare, transportation, and nutrition. The study highlighted government providers must “achieve greater impact through partnerships and innovation”. The free farmers’ markets at senior centers program demonstrates an innovative partnership that couples County government providers with Utah State University Extension (USU Extension) to address food insecurity experienced by low-income seniors. USU Extension utilizes public volunteers to grow and disseminate locally grown produce to urban dwelling seniors through the farmers’ market program. USU Extension Master Gardener (MG) volunteers provide service hours in exchange for horticulture training. In Salt Lake County, MGs are encouraged to grow and donate homegrown produce for distribution at markets. Since 2017, 20 tons of produce has been distributed with an approximate market value of $80,000. 7,500 seniors were served during 135 markets. Benefitting seniors reported that: 97% saved money, 100% increased access to fresh produce, and 100% increased consumption of fresh produce.

Speakers

Katie Wagner

Utah State University

Thursday July 31, 2025 10:45am - 11:00am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Poster # csv

10:45am CDT

PGR - The effect of preharvest ethylene regulator treatments on ‘Ambrosia’ fruit drop and crack, maturity, quality and related

Thursday July 31, 2025 10:45am - 11:00am CDT

Foster 2

‘Ambrosia’ is an emerging apple cultivar recently introduced from British Columbia and knowledge of ripening and preharvest physiology is limited in the mid-Atlantic region. ‘Ambrosia’ must meet minimum quality and color marketability standards in the US though it requires a high temperature differential for full color development and has a short harvest period. Plant growth regulators, such as aminoethoxyvinylglicine (AVG) and 1-methylcyclopropene (1-MCP), can alter preharvest fruit drop, maturity and quality by hindering ethylene biosynthesis and perception, respectively. AVG has historically been used at several rates by mid-Atlantic growers with variable cultivar specific impacts. The objective of this study was to characterize and compare the effects of AVG and 1-MCP on preharvest fruit drop and crack, ethylene production, fruit physicochemical parameters, skin color, and transcript accumulation of ethylene and anthocyanin-related genes in 'Ambrosia' apples throughout on-the-tree ripening over two production seasons. Four treatments were established and applied based on manufacturer’s recommendations: full-rate AVG (Retain), half-rate AVG (Retain), 1-MCP (Harvista) and a control. Fruits were harvested at three maturity stages: 1 week before the anticipated commercial harvest (1WBCH), at the anticipated commercial harvest (CH), and one week after CH (CH 1). Our results showed that both AVG and 1-MCP treatments significantly reduced preharvest fruit drop and crack with respect to control fruit. While full-rate AVG treatment showed the most significant decrease in ethylene production and exhibited the greatest downregulation of ethylene biosynthesis and perception-related gene expression, it also negatively impacted red color and anthocyanin biosynthesis related gene expression and reached minimum 50% skin blush one week later than the other treatments. Half-rate AVG and 1-MCP treatments displayed an intermediate behavior between full-rate AVG and control fruit, delaying fruit maturity and the associated gene expression when compared to control, but without sacrificing skin blush development. This study contributes to understand how preharvest ethylene regulator treatments influence ‘Ambrosia’ apples grown under the mid-Atlantic environmental conditions.

Speakers

Macarena Farcuh

University of Maryland

Co-authors

Emily Johnson

University of Maryland

Thursday July 31, 2025 10:45am - 11:00am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv
Funding Source State Horticultural Association of Pennsylvania and startup funds awarded to M.Farcuh, University of Maryland

10:45am CDT

POM 2 - Identifying Low-Chill Blackberry Cultivars for Optimal Performance in Florida

Thursday July 31, 2025 10:45am - 11:00am CDT

Foster 1

The successful cultivation of blackberries in subtropical regions like Florida depends on selecting low-chill cultivars capable of withstanding high temperatures, disease pressure, and minimal chilling hours. This study evaluates the performance of 17 breeding lines alongside four commercial cultivars ('Freedom', 'Ponca', 'Horizon', and 'Osage') to determine their adaptability to Florida’s climate. The goal is to identify blackberry germplasm with the potential for high yields, good fruit quality, and post-harvest stability under these challenging conditions. Field trials were established in late June 2023 at the Citra Research Center, Central Florida, using three-month-old greenhouse-grown plants successfully transplanted into the field. Data collection focused on key production parameters, including total yield, single berry weight, and marketable fruit percentage. Fruit quality was assessed through pH, Brix, and organic acid composition (tartaric, citric, and malic acid). Subjective evaluations of firmness, flavor, and seed content were also conducted. Additionally, post-harvest performance was analyzed by monitoring decay, leakage, and red druplet reversion after seven days of cold storage at 5°C. Preliminary results indicate considerable variation among the evaluated cultivars. 'BLB', 'BLH', 'BLA', and 'Freedom' exhibited the highest yields, whereas 'BLG', 'BLP', and 'BLI' were among the lowest-yielding selections. Berry size ranged from 8.98 g in 'BLB' to 5.27 g in 'Osage'. Acidity levels varied significantly, with 'BLC' (pH 4.01) and 'BLJ' (pH 3.99) displaying the mildest flavor profiles, while 'BLP' (pH 3.60) and 'BLQ' (pH 3.62) exhibited higher acidity. Beyond fruit evaluations, plant vigor and structural characteristics were documented. Prior to last year’s harvest, primocane count and height were recorded, and this season, plants were rated based on vigor, overall health, and the proportion of green versus brown canes. Ongoing data analysis will further clarify cultivar performance in relation to plant growth and long-term productivity. This research provides valuable insights into selecting blackberry cultivars best suited for Florida’s subtropical environment. The findings will contribute to optimizing cultivar recommendations for growers looking to enhance yield, fruit quality, and marketability in sub-tropical climate production systems like Florida.

Speakers

Nurjahan Sriti

University of Florida

Co-authors

Guodong Liu

University of Florida

Jeffrey Williamson

University of Florida

Steven Sargent

University of Florida/IFAS

Professor and Extension Postharvest Specialist

Zhanao Deng

University of Florida

Thursday July 31, 2025 10:45am - 11:00am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology

10:45am CDT

VCM 4 - Standard Edamame Row Spacing Results in Greatest Yield but Increases Weed Growth

Thursday July 31, 2025 10:45am - 11:00am CDT

Strand 11B

Edamame [Glycine max (L.) Merr.] exhibits a promising opportunity for Indiana farmers. Its high nutritional value and nitrogen-fixing capabilities reduce input costs while benefiting crop rotation systems. The crop’s short duration facilitates sustainable practices like cover cropping. Research on edamame cultivation for Midwest local markets remains limited despite increasing sales and consumption. Therefore, this study aimed to explore potential cultivars suited for the fresh and direct consumer market and identify cultural and cultivation practices that minimize weed-crop competition here in Indiana. A field experiment was established at Meigs Horticulture Research Farm, Lafayette, Indiana, which evaluated three different row spacings (7 inch, 15 inch, and 30 inch) on growth and yield of six edamame cultivars (Chiba Green, Sayamusume, BeSweet 292, Midori Giant, Tohya, and Karikachi). This study was designed as an RCBD split-plot design with 4 replications, with different row spacings as main plots, and variety as the split-plot. Leaf area index (LAI), dry weight of weed, total pod count, pod count, and fresh weight of marketable and non-marketable pods were measured. All data were analyzed with R Studio. We hypothesized a) standard row spacing (30 inch) would improve edamame seed yield and productivity compared to narrow row spacings (7 and 15 inch); b) narrow row spacing would reduce the weed growth and density of common weed species compared to standard row spacing; c) standard row spacing may increase yield of edamame but would increase weed-crop competition. Our results from one year are in agreement with our hypotheses. Standard row spacing resulted in the greatest pod yield, but highest weed dry weight. Specifically, 30 inch row spacing produced significantly greater pod count (27) per plant compared to 7, and 15 inch row spacing (9 and 16 pods per plant, respectively). Also, 30 inch row spacing resulted in the greatest marketable pod count (23) per plant compared to 7 and 15 inch row spacing (6 and 12 pods per plant, respectively). 30 inch row spacing led to significantly greater weed dry weight (4.27 g) compared to 7 and 15 inch row spacing (1.01g and 2.81g, respectively). Lowest weed dry weight (1.01 g) at 7-inch row spacing suggests that narrow row spacing might help suppress weed growth. The greatest LAI was measured at 7-inch row spacing (5.26) compared to others (3.77 and 3 for 15 and 30 inch row spacing). BeSweet 292 performed better in terms of yield parameters compared to other varieties.

Speakers

MD MOYEED HASAN TALUKDER

Purdue University

Co-authors

Moriah Bilenky

Purdue University

Thursday July 31, 2025 10:45am - 11:00am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Poster # csv
Funding Source Bilenky Sustainable Horticulture Lab

11:00am CDT

CE 5 - Biofortification: Method to increase Vitamin C through foliar spray of Ascorbic acid in lettuce under Nutrient film (NFT

Thursday July 31, 2025 11:00am - 11:15am CDT

Strand 12B

Despite adequate caloric intake of food, developed nations are still struggling with the problem of “hidden hunger” due to overconsumption of nutrient-poor foods. Biofortification with vitamins and nutrients offers a solution to mitigate this issue by increasing nutrient and vitamin content in crops through different techniques such as agronomic practices, conventional plant breeding and modern biotechnology. This study investigates agronomic Vitamin C biofortification in lettuce through foliar sprays in two different hydroponics systems: Deep water (DW) and nutrient film technique (NFT). For this, replicated experiments were conducted. Seedlings were first grown to maturity in each system, then two days prior to harvest, foliar sprays of 200 and 400 ppm ascorbic acid (AsA) rate along with a control (DI water) were applied to each system. At harvest, plants were measured for fresh biomass, processed, and then flash frozen in liquid nitrogen prior to lyophilization. Certain samples remained fresh to determine persistence of Vitamin C at room and refrigerated temperatures (4C) at 24, 48, and 72 hrs. after harvest. Ascorbic acid (AsA) and total ascorbic acid (TAsA) content were measured for all samples. Overall, biomass was higher for DW grown lettuce compared to NFT. While biofortification rate did not affect DW grown lettuce, NFT biofortified lettuce treated with 200 ppm AsA had greater AsA and TAsA content. In the shelf-life study, AsA declined over time. Temperatures also affected AsA, where refrigerated lettuce treated with 400 ppm had greater TAsA content. These data show higher variability of AsA among the different hydroponics systems. In conclusion, this study demonstrates the potential of foliar spray of ascorbic acid to enhance the Vitamin C content of lettuce grown in hydroponics system. The observed variability between different systems suggests that system-specific optimization is necessary to achieve the benefits of biofortification.

Speakers

Abishkar Regmi

Graduate Research Assistant, Texas Tech University

Co-authors

Arjun Kafle

Texas Tech University

Carlos Carpio

Texas Tech University

Catherine Simpson

Texas Tech University

Dario Rueda Kunz

Texas Tech University

Leslie Thompson

Texas Tech University

Sukhbir Singh

Texas Tech University

Thursday July 31, 2025 11:00am - 11:15am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Poster # csv

11:00am CDT

CHMG 1 - The Real Truth About Tech Savviness Among Extension Personnel and Volunteers

Thursday July 31, 2025 11:00am - 11:15am CDT

Strand 11A

With an increasing dependence on technology for delivering volunteer training and client programs within Extension, it is essential to assess the tech savviness of both volunteers and paid personnel. Paid personnel often express frustration over volunteers’ lack of technological skill, while volunteer skills can also far surpass that of the personnel’s skill level. These situations can lead to mistrust and missed opportunities for both personnel and volunteers alike. To assess technology skills (tech savviness) among personnel and volunteers, a random sample (n=572) of Extension personnel (agents, staff, AmeriCorps members, and county coordinators) and volunteers (Extension Master Gardeners and 4-H volunteers) were asked to provide subjective assessment of their technology skills as well as that of their counterparts (i.e., volunteers self-assessed their program coordinators, while paid personnel assessed that of their volunteers). Respondents then completed a 10-question technology skills quiz for an objective measure of skills. Questions included keyboard shortcuts, trouble-shooting scenarios, use of computer and social media applications, as well as hardware and basic equipment set-up. Results confirmed that there is a significant difference between actual and perceived volunteer and personnel technology skills, though overall scores reflect a need for continued technology skill-development for both volunteers and personnel.

Speakers

Sheri Dorn

Co-authors

Keri Hobbs

University of Georgia

Thursday July 31, 2025 11:00am - 11:15am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Funding Source Horticultural Research Institute

11:00am CDT

PGR - Ethylene-Generating Compounds for Chemical Thinning: Comparative Evaluation of 1-Aminocyclopropane-1-Carboxylic Acid (AC

Thursday July 31, 2025 11:00am - 11:15am CDT

Foster 2

Ethylene plays a significant role in flower and fruitlet abscission. The use of compounds that generate ethylene for chemical thinning of fruit trees has been in the focus of research for decades. 1-aminocyclopropane-1-carboxylic acid (ACC) is a naturally occurring precursor to ethylene and has recently been registered as a chemical thinner in the US and elsewhere for stone fruit and apple. Ethephon has also been evaluated for chemical thinning of peaches but phytotoxicity and inconsistency in efficacy has hindered its commercial use. With the recent registration of ACC for chemical thinning of peaches, questions arose if similar efficacy can be achieved with the use of ethephon. The objective of the study reported here was to compare thinning efficacy and phytotoxicity of ACC (300 mg/L) and ethephon (428 mg/L; molar equivalent to 300 mg/L ACC) when used in peaches. A field experiment was conducted in Red Top peach variety in Oregon where the two compounds were sprayed to different set of trees every day from pink bud to petal fall to evaluate the effect of daily weather conditions on flower abscission. Phytotoxicty was also recorded in the experiment. ACC and ethephon showed similar thinning pattern throughout the flowering time. While no phytotoxicity was observed for ACC, severe leaf drop and gummosis occurred in the ethephon treatments. The presentation will discuss the potential reasons for the efficacy and difference in level of phytotoxicity between the two compounds.

Speakers

Jozsef Racsko

Valent USA

Co-authors

Poliana Francescatto

Valent BioSciences

Thursday July 31, 2025 11:00am - 11:15am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv

11:00am CDT

POM 2 - Cold Hardiness of Apple Scions and Rootstocks

Thursday July 31, 2025 11:00am - 11:15am CDT

Foster 1

The current understanding of apple stem cold hardiness is very broad- there are certain cultivars generally accepted to be cold hardy or tender. There has been no comprehensive study of cold hardiness of apples at multiple timepoints over multiple years. In this study, cold hardiness was evaluated for 21 rootstock and 23 scion genotypes monthly throughout the dormant season over 4 years. Cold hardiness was measured using the electrolyte leakage method and the temperature at which 25% tissue damage occurs (LT25) was used as the cold hardiness phenotype. The four study winters varied drastically in intensity and had a significant effect on genotype cold hardiness. Contrasting phenotypic responses in cold versus mild winters demonstrated clear environmentally driven differences between inferior and superior genotypes. Another major finding from the study is the rapid deacclimation of rootstocks compared to scions in late winter/early spring- we observed that differences in mean hardiness between groups exceeded 6 °C in some years. Overall, this study represents the largest apple cold hardiness experiment to date in terms of cultivars used and timepoints examined, resulting in both novel implications for how grafted apples navigate cold hardiness during dormancy and which cultivars are best suited for unusual but increasingly common winter conditions.

Speakers

Kenneth Buck

Cornell University

Co-authors

Hanna Martens

Cornell University

Jason Londo

Cornell University

Thursday July 31, 2025 11:00am - 11:15am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology
Poster # csv

11:00am CDT

VCM 4 - Utilizing Biodegradable Mulch Derived from Low-Grade Cotton for Sustainable Jalapeño Pepper Production in Texas

Thursday July 31, 2025 11:00am - 11:15am CDT

Strand 11B

Plastic mulches are widely used in U.S. vegetable production to cut costs and improve efficiency. However, polyethylene, the principal ingredient of plastic mulches, is a poorly degradable material causing significant pollution. Biodegradable mulches, especially those made from local waste materials such as low-grade cotton, offer a sustainable alternative by reducing pollution, enhancing soil health, and supporting circular economy principles. This study aims to evaluate two different types of low-grade cotton mulches in comparison to commercially available plastic and biodegradable plastic mulches in Jalapeño pepper production. Five mulch treatments, including a no-mulch control, were arranged in a randomized complete block design with four replications. The assessment focuses on mulch decomposition, plant biomass, crop yield, and weed suppression.

Speakers

Ethan Carter

Texas Tech University

Co-authors

Rupinder Saini

Texas Tech University

Seshadri Ramkumar

Texas Tech University

Sukhbir Singh

Texas Tech University

Thursday July 31, 2025 11:00am - 11:15am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Poster # csv

11:15am CDT

CE 5 - A Calcium-Mobilizing Biostimulant Prevents Tipburn in Greenhouse Hydroponic Lettuce ‘Rex’ as an Alternative to Vertical

Thursday July 31, 2025 11:15am - 11:30am CDT

Strand 12B

Lettuce (Lactuca sativa) tipburn is a calcium-related physiological disorder that affects enclosed young leaves, leading to browning, necrosis, and curling of leaf margins and reduced marketability. While greenhouse vertical airflow fans (VAFs) have been proven effective at controlling tipburn, they have not been widely adopted due to cumbersome installation, sunlight obstruction, and electricity consumption. Recent research showed that a calcium-mobilizing biostimulant, when added to the nutrient solution, mitigated tipburn in greenhouse hydroponic lettuce by enhancing calcium mobility. However, how it compared to VAFs was unknown. We investigated the effects of this biostimulant and VAFs on lettuce tipburn and growth in a greenhouse hydroponic system during summer. Seedlings of lettuce ‘Rex’ were propagated indoors and, on day 14, transplanted into deep-water-culture trays in a climate-controlled greenhouse. In a split-plot randomized complete block design with two blocks, plants were subject to six treatments per block: three biostimulant concentrations (0, 0.25, and 0.5 mL⋅L–1) with and without VAFs promoting vertical airflow at ≈1 m⋅s–1. Plants were sampled on 14, 21, and 28 days after transplant (DAT). Compared to plants without the biostimulant or VAFs that progressively exhibited severe tipburn, plants with either the biostimulant (at 0.5 mL⋅L–1) or VAFs had similar tipburn reduction and shoot fresh mass on 21 and 28 DAT. Without VAFs, increasing the biostimulant concentration from 0 to 0.5 mL⋅L–1 reduced the tipburn rating and the number of tipburn-affected leaves by 96% and 94%, respectively, on 21 DAT and by 75% and 71%, respectively, on 28 DAT. Compared to no VAFs, VAFs eliminated or minimized tipburn throughout, regardless of the biostimulant. Increasing the biostimulant concentration from 0 to 0.25 mL⋅L–1 did not affect shoot fresh mass, whereas increasing it from 0 to 0.5 mL⋅L–1 decreased it by 26% to 32% on 14 and 21 DAT. Compared to no VAFs, VAFs generally did not affect plant growth, except that they decreased shoot fresh mass and total leaf number by 25% and 11% at the biostimulant concentration of 0.5 mL⋅L–1 on 21 DAT. However, neither the biostimulant at any concentration nor VAFs affected shoot fresh mass on 28 DAT. We conclude that the calcium-mobilizing biostimulant is as effective as VAFs at tipburn control of hydroponic lettuce in summer greenhouse environments where VAFs may be undesirable, and that the biostimulant mitigates tipburn without incurring any yield penalty at final harvest.

Speakers

Moein Moosavi

PhD student, NC State University

Co-authors

Qingwu Meng

University of Delaware

Thursday July 31, 2025 11:15am - 11:30am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Funding Source This work is supported by the Urban, Indoor, and Emerging Agriculture Program (project award no. 2023-70019-39371) from the U.S. Department of Agriculture’s National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.

11:15am CDT

CHMG 1 - What motivates people to become an Extension Master Gardener, and what inspires them to remain?

Thursday July 31, 2025 11:15am - 11:30am CDT

Strand 11A

Why do people pay a significant amount of money to take 50 hours of coursework and give 50 hours of volunteer service to become a certified Extension Master Gardener (EMG)? What is the incentive to remain an EMG? Why do they volunteer for Extension instead of a local hospital or other community organizations? This study answered these questions to enhance Extension educator training on volunteer management and engagement, recruitment, and retention of EMGs. The EMG program director and program manager partnered with a family and consumer science specialist and staff to co-develop the study and collect data. Six focus group interviews with EMGs (n=26) and eight focus group interviews with Extension EMG county coordinators (n=15) were conducted and recorded via Zoom in November 2024. The comments obtained in the focus group sessions were transcribed and coded into themes in each of the combined groups interviewed. Focus group comments revealed information that needed to be and could be addressed immediately. This led to four technical reports containing recommendations for program improvement in recruitment and retention of EMGs directed to Extension administration, the EMG program director and manager, Extension EMG coordinators, and EMGs. In addition, data will be used to formulate questions for a survey to be administered to EMGs in the fall of 2025. In this session, you will learn about the research study, the focus group data collection process, results and recommendations for program improvement, and the necessary steps to continue developing this knowledge.

Speakers

Pam Bennett

State Master Gardener Program Director, Professor, Ohio State University

Co-authors

Anita Armstrong

Ohio State University

James Bates

Ohio State University

Jennifer Andon

Ohio State University

Thursday July 31, 2025 11:15am - 11:30am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Poster # csv

11:15am CDT

PGR - Quantifying the Effects of Prohexadione-calcium Foliar Spray and Substrate Drench Applications on Perennial Ornamental G

Thursday July 31, 2025 11:15am - 11:30am CDT

Foster 2

Our objective was to quantify prohexadione-calcium foliar spray or substrate drench applications to control growth of two perennial ornamental grass taxa. On 6 June 2024, 38-cell liner trays (126-mL individual cell volume) of Andropogon gerardii ‘Red October’ and Miscanthus sinensis ‘Fire Dragon’ were received from a commercial propagator. Liners were transplanted with one plant per 19.7-cm-diameter container (1.7 L volume) filled with a commercially available bark-based substrate comprised of (by vol.) 56.5% aged pine bark, 34.8% Canadian sphagnum peatmoss, and 8.7% perlite, dolomitic limestone, a nutrient starter charge, and a wetting agent. Plants were grown at bench-level in a glass-glazed greenhouse under supplemental and day-extension lighting provided by 1000-W light-emitting diode lamps from 0600 to 2200 HR (16-h photoperiod) with an air temperature set point of 20 °C. At 7 d after transplant, 10 single-plant replicates of each taxa were treated with a solution containing prohexadione-calcium and a water conditioning agent. Plants received either a foliar spray (vol. 0.2 L·m–2) solution containing deionized water (0 mg·L–1; untreated) or 250, 500, 750, 1,000, or 2,000 mg·L–1 prohexadione-calcium or a substrate drench of 296-mL aliquots of solution containing 0, 125, 250, 500, or 1,000 mg·L–1 prohexadione-calcium. At eight weeks after treatment, plant height, plant diameter, and shoot dry weight (SDW) were determined for all plants, and root dry weights (RDW) were determined for a sub-sample (n = 5) of each taxa from each substrate drench treatment. Foliar spray applications of 125 to 2,000 mg·L–1 prohexadione-calcium did not affect growth of either perennial ornamental grass taxa. Substrate drenches were effective in controlling growth of each perennial ornamental grass taxa although the magnitude of response varied among taxa. For example, compared to untreated plants, plant height, plant diameter, SDW, and RDW of ‘Red October’ Andropogon drenched with 125 to 1,000 mg·L–1 prohexadione-calcium decreased by 20% to 57% (19.7 to 55.9 cm), 0% to 43% (7.8 to 33.4 cm), 3.6 to 28.9 g (10% to 81%), and 10.4 to 28.5 g (27% to 74%), respectively. This research demonstrated substrate drench applications of prohexadione-calcium to be effective for controlling growth, while further research is warranted to determine optimal concentrations for foliar spray applications. We suggest substrate drench applications of 125 to 500 mg·L–1 prohexadione-calcium as an initial range for trials to control growth of ornamental perennial grasses.

Speakers

Garrett Owen

Extension Specialist and Assistant Professor of Sustainable Greenhouse & Nursery Systems, The Ohio State University

Co-authors

Lark Wuetcher

The Ohio State University

Thursday July 31, 2025 11:15am - 11:30am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv
Funding Source We thank Fine Americas, Inc. for the plant growth regulator and financial support; Sun Gro Horticulture for soilless substrate; and J.R. Peters, Inc. for fertilizer.

11:15am CDT

POM 2 - ‘King’ Florets of an Apple Cyme Freeze at Higher Temperatures Than Lateral Florets Prior to Visible Changes in Bud Pheno

Thursday July 31, 2025 11:15am - 11:30am CDT

Foster 1

Cold hardiness and dormancy are critical physiological adaptations enabling woody perennials to endure low temperatures in winter and initiate growth in spring. Hardiness in apple (Malus domestica) is genotype dependent, however maximum hardiness level gained by the buds is strongly regulated by environment. Understanding the relationship between dormancy progression and cold hardiness is essential for predicting plant responses to winter and spring freeze events, as well as optimizing breeding efforts for resilience and orchard decisions for frost management. Information on hardiness mechanism is becoming more crucial given the impact of global climate change in apple growing regions where earlier bloom dates have inherently greater risk of crop loss due to episodic spring frost events. The existing lethal temperature chart for apple floral buds is limited to the visible development stages and lacks critical temperature thresholds for the freeze resistance of floral buds during their transition out of ecodormancy. Further, there is no information distinguishing positional effects of individual florets of the apple cyme inflorescence with respect to their hardiness status. Because the ‘King’ floret is developmentally advanced compared to laterals and has the highest fruit growth and economic potential, the development of lethal temperature limits to inform its protection seems prudent. Thus, we evaluated the difference in LT50 between ‘King’ and ‘Lateral’ florets in ‘Gala’ on ‘Bud9’ rootstock during the transition phase from ecodormacy to growth resumption in 2022 and 2023. Our results demonstrated that cold hardiness is lost at early stages of, or transitions out of, ecodormancy; notably, this occurs prior to visible changes in bud phenology. Moreover, the ‘King’ florets are markedly less hardy than the ‘Laterals’ by approximately 6°C. The magnitude of difference in lethal temperatures between ‘King’ and ‘Lateral’ florets differed between years but remained significant. Increasing susceptibility to freeze mortality at higher temperatures was commensurate with an increase in the relative water content (RWC) of the buds and a marked decrease in sorbitol and sucrose concentration. In both years, an RWC of approximately 60% coincided with the visible green stage of bud burst. Our data indicate that decreasing sorbitol concentration can act as a potential biochemical marker for cold hardiness loss and inform protection measures of the ‘King’ fruit. Further study incorporating multiple commercially important apple cultivars will be beneficial in understanding the cold hardiness in apples.

Speakers

Sangeeta Sapkota

Michigan State University

Co-authors

Todd Einhorn

Michigan State University

Thursday July 31, 2025 11:15am - 11:30am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology
Poster # csv
Funding Source Martin and Judith Bukovac Professorship in Tree Fruit Physiology Endowment

11:15am CDT

VCM 4 - Effects of Soil Solarization on Weed Management and Lettuce Yield in Kentucky and Tennessee High Tunnels

Thursday July 31, 2025 11:15am - 11:30am CDT

Strand 11B

High tunnel production is increasingly important on small, diversified farms with more than 1,700 and 700 high tunnels (HTs) in Kentucky and Tennessee, respectively. Weed management in HTs is more challenging than open field production and there are limited options. Soil solarization is one alternative; it heats moist soil to high temperatures by trapping solar radiation under transparent plastic tarps. Heating soil to at least 40°C is beneficial for managing soil-related issues, such as reducing the weed seedbank. Soil solarization was conducted in April, July, and September 2024 in Kentucky and Tennessee in open and closed HTs to assess whether growers could solarize individual beds. The objectives were to evaluate the effect of solarization on soil temperatures, weed biomass and emergence, and lettuce yield. Treatments included 2-week (Sol-2wk) and 4-week (Sol-4wk) solarization and a nonsolarized control (NS). Data loggers recorded soil temperatures hourly. Soil in closed HTs accumulated more hours >40°C versus open HTs. The most hours over 40°C occurred in July, followed by September then April, with more hours in Tennessee than Kentucky. In Kentucky, after April solarization, there was less weed biomass in Sol-4wk compared to NS in the closed HT and less weed emergence in Sol-2wk and Sol-4wk compared to NS. There were no differences in lettuce yield. After July solarization, there was less weed biomass in Sol-2wk and Sol-4wk in the closed HT compared to NS, but no differences among treatments for weed emergence. Lettuce yield was higher in Sol-2wk and Sol-4wk compared to NS regardless of HT. There were no differences in weed biomass or weed emergence in September. Lettuce yield in Sol-4wk was higher than NS regardless of HT. In Tennessee after April solarization, there was less weed emergence in Sol-4wk in the closed HT compared to Sol-2wk and NS. Lettuce yield was higher in Sol-2wk and Sol-4wk compared to NS in the closed HT. In July, there was less weed biomass in Sol-2wk and Sol-4wk in the open HT compared to NS. Lettuce yield in Sol-4wk was higher compared to NS regardless of HT. In July and September, there was less weed emergence in Sol-2wk and Sol-4wk compared to NS regardless of HT. There were no differences in lettuce yield in September. Overall, soil solarization in July in both locations reduced weeds and increased lettuce yields. Results were mixed in April and September. The experiment will be repeated in 2025.

Speakers

Paula Luize Lessmann

University of Kentucky

Co-authors

Annette Wszelaki

University of Tennessee

Brooke Keadle Emery

University of Tennessee

Rachel Rudolph

University of Kentucky

Thursday July 31, 2025 11:15am - 11:30am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Funding Source Southern Sustainable Agriculture Research and Education

11:30am CDT

CE 5 - Beneficial Bacterial Endophytes Promoted Growth of Bok Choy in Hydroponic Systems

Thursday July 31, 2025 11:30am - 11:45am CDT

Strand 12B

Controlled environment agriculture will play an important role in feeding the increasing world population as urbanization is expanding, and arable land is decreasing. Higher yields will help offset the initial high cost for building hydroponic production facilities. Beneficial bacterial endophytes have been receiving more attention in sustainable agriculture practices because they can promote plant growth, enhance nutrient uptake, and inhibit pathogen growth. Bok Choy (Brassica rapa subsp. chinensis) is a cruciferous vegetable that's often used in Asian cooking. It is a nutrient-dense vegetable high in fiber, vitamins A, C, K, calcium and vitamin B6. The entire Bok Choy plant is edible, including the leaves, stalks, and flowers. Initially, seven bacterial endophytes from our bacterial endophyte library were chosen to test plant growth promotion in two Bok Choy cultivars (Wan Wan Qing and White Stem) in pots with clay pebble under controlled environmental conditions. The results showed that bacterial endophytes (IALR1786 and IALR1368) significantly increased shoot fresh weight of cv. White Stem by 26.9% and 20.8%, respectively. Bacterial endophytes (IALR1368, IALR1629, IALR1422 and IALR1786) significantly increased shoot fresh weight of cv. Wan Wan Qing by 44.7%, 34.3%, 26.1%, and 22.0%, respectively. Then, the 3 best bacterial endophytes (IALR1368, IALR1629, and IALR1786) were chosen to further test in pots with clay pebble, as well as in nutrient film technique (NFT) units. In pots with clay pebble, IALR1629 increased shoot fresh weight of cv. White Stem by 13.5% but not significantly. IALR1786 significantly increased root fresh weight of cv. White Stem by 25.9%. Similar results were obtained in cv. Wan Wan Qing. In NFT units, IALR1786 significantly increased shoot fresh weight and root dry weight of cv. White Stem by 23.3% and 33.3%, respectively. All 3 bacterial endophytes significantly increased shoot fresh weight of cv. Wan Wan Qing by from 19.1% to 41.8%. IALR1786 also significantly enhanced root dry weight of cv. Wan Wan Qing by 30.8%. These bacterial endophytes will be identified using 16S sequencing and tested with other cultivars. In Summary, IALR1786 performs best and consistently achieves growth promotion in two different cultivars under different conditions.

Speakers

Chuansheng Mei

Institute for Advanced Learning and Research

Co-authors

Robert Chretien

Institute for Advanced Learning and Research

Scott Lowman

Institute for Advanced Learning and Research

Thursday July 31, 2025 11:30am - 11:45am CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Poster # csv

11:30am CDT

CHMG 1 - Accelerated Composting Of Kitchen Scraps Used In Horticultural Substrates

Thursday July 31, 2025 11:30am - 11:45am CDT

Strand 11A

Residential food scraps accounts as a major landfill product that is responsible for 40% of kitchen waste. Reducing these waste products is a goal of EPA by 2030. The objective of this study is to use an accelerated home food scrap composter to encourage residents to reduce waste volume and weight and provide garden compost to produce garden produce and flowers. Two accelerated composters (Lomi and Vego) were evaluated both for their compost soil health, physical and chemical properties after processing kitchen scraps (apples, bread, chicken, coffee, milk, and Irish potatoes). Lomi processed food for 24h only and the Vego composter for 1, 5, and 10 days. Compost volume and weight increased as days of composting increased. Compost health, nutrients, pH, C/N Ratio were suitable for a horticultural growing amendment. Physical components were within normal parameters for a soil substrate. Finer particles were increased with greater days of composting as expected. Plant growth, SPAD readings showed an increase with 5- and 10-days composting. Compost incorporated at 10 % v/v increased petunia biomass. Accelerated composters reduced volume and weight of food scrapes while providing essential plant nutrients.

Speakers

William Dunford

Louisiana State University

Co-authors

Alessandro Holzapfel

Louisiana State University Agricultural Center

Claire Bradley

LSU

Edward Bush

LSU AgCenter

Thursday July 31, 2025 11:30am - 11:45am CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Funding Source Hatch
Funding Option SCRI funded all or part of the research associated with this abstract

11:30am CDT

PGR - Evaluating the Impact of Foliar Indole-3-butyric Acid on the Adventitious Rooting of Ornamental Woody Nursery Taxa

Thursday July 31, 2025 11:30am - 11:45am CDT

Foster 2

The propagation of ornamental woody nursery liners (young plants) is primarily through stem cuttings to maintain genotypic and phenotypic uniformity. The application of rooting hormones is common practice in stem cutting propagation to hasten, promote uniformity, and enhance the quality of adventitious rooting. Rooting hormones are traditionally applied by dipping cuttings into solutions or powders. However, these methods increase labor costs, cutting stress, and opportunities for contamination. Foliar applications of rooting hormones would improve production efficiency, reduce cutting contamination and stress, and allow for multiple hormone applications after sticking. Thus, there is a critical need to identify the optimal rates of foliar rooting hormones to improve and maximize adventitious rooting in woody nursery taxa. Therefore, this study aimed to quantify the impact of foliar rooting hormones on root growth and development of ornamental woody nursery cuttings. Unrooted stem cuttings of four ornamental nursery taxa were obtained from commercial nurseries and individually inserted into 6.4-cm diameter containers filled with a propagation substrate. Cuttings were placed in a diffused glass-glazed greenhouse under a propagation environment of fixed 4-mil clear construction film. The greenhouse was set at 20 °C air temperature, 80% relative humidity, and ambient daylight supplemented with ≈120 µmol·m–2·s–1 delivered from light-emitting diode arrays from 0600 to 2200 hr. At 1 d after sticking, cuttings were sprayed with a solution containing clear tap water and 0, 500, 1,000, 1,500, 3,000, or 6,000 mg·L–1 20% indole-3-butyric acid (IBA) at a volume of 1.89 L·m–2. After 42 d, data was collected including callusing and rooting percentage, stem length and caliper, leaf area, and shoot and root dry mass. In general, increasing IBA foliar application concentration improved rooting success and uniformity to different magnitudes among species. For example, rooting percentage of Chamaecyparis increased by 67% as foliar IBA concentrations increased from 0 to 6,000 mg·L–1 IBA. The results of this study determined the optimal rates of foliar IBA application across an array of woody taxa to hasten adventitious rooting and improve quality for ornamental woody nursery liner production.

Speakers

Olivia Liebing

The Ohio State University

Co-authors

Garrett Owen

The Ohio State University

Thursday July 31, 2025 11:30am - 11:45am CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv
Funding Source The Ohio State University College of Food, Agricultural, and Environmental Sciences - New Investigators Grant; USDA Agricultural Research Service - Floriculture & Nursery Research Initiative 5082-21000-001105S

11:30am CDT

POM 2 - Dissecting Frost Tolerance in Apple: Rootstock Effects on Gene Networks and Metabolite Profiles

Thursday July 31, 2025 11:30am - 11:45am CDT

Foster 1

Late spring frosts pose a recurrent threat to apple production, particularly under climate change scenarios that promote earlier bloom and heightened exposure to frost events. Recent evidence from our investigations on different apple-rootstock combinations suggested that rootstock genotype may influence scion resilience to frost, yet the underlying molecular mechanisms remain poorly understood. Field trials were conducted from 2021–2023 on 12-year-old ‘Gala’ and ‘Fuji’ trees grafted onto ten rootstocks, including ‘B.9’ and ‘M.26’, representing extremes of frost tolerance. Following three naturally occurring frost events, we have shown that ‘B.9’ rootstock consistently conferred lower bud mortality relative to ‘M.26’, independent of bloom timing. To dissect the molecular and biochemical mechanisms underlying the differential responses of these scion-rootstock combinations to frost, tissue-specific RNA-Seq analysis and untargeted metabolic profiling were conducted on floral buds, scion leaves, and rootstock sucker leaves from ‘Gala’-grafted trees. Samples were collected 12 h before and 6 h after the 2021 frost. Weighted gene co-expression network analysis (WGCNA) was employed to identify frost-responsive modules, and hub genes were validated via qRT-PCR in both ‘Gala’ and ‘Fuji’. Transcriptomic analyses revealed extensive gene regulation following frost exposure, including over 10,000 differentially expressed genes (DEGs). WGCNA identified three frost-correlated gene modules. Key hub genes were implicated in cold acclimation, ABA signaling, and cellular stress tolerance. GO and KEGG enrichment analyses highlighted significant representation of pathways associated with ABA response, cold response, and water deprivation stress. Metabolomic profiling of different tissues and genotypes further supported the transcriptomic findings and provided metabolic signatures associated with the identified gene networks. This work establishes a foundation for integrative omics approaches to dissect physiological cold tolerance mechanisms in apples and guides rootstock selection and germplasm improvement strategies.

Speakers

Sherif M. Sherif

Associate Professor, Virginia Tech

Co-authors

Amolpreet Kaur Saini

Viginia Tech

Clay Wright

Viginia Tech

Khalil Jahed

Virginia Tech

Thursday July 31, 2025 11:30am - 11:45am CDT
Foster 1

Oral presentation, Pomology 2

Subject Pomology
Poster # csv
Funding Source 2022-67013-36293

11:30am CDT

VCM 4 - Evaluating the USDA Tepary bean (Phaseolus acutifolius) diversity panel and its potential as a cover crop in organic pro

Thursday July 31, 2025 11:30am - 11:45am CDT

Strand 11B

Tepary bean (Phaseolus acutifolius) is a short-lived legume native to the deserts and semi-arid regions of Northwestern Mexico and the Southwestern United States. It is resilient and adaptable to high temperatures and drought stress, ideally suited as a low-input organic cover crop in southern Texas. Tepary beans are prized for their nitrogen-fixing potential and high nutritional value. We explored the effectiveness of tepary beans and common summer legume cover crops, such as cowpea and Sunn hemp, on the productivity of subsequent vegetable crops like spinach. Additionally, we evaluated 207 USDA-GRIN undomesticated tepary bean accessions under organic production systems to assess their seed nutritional profiles. Preliminary findings indicated that spinach grown following tepary beans as a cover crop significantly enhanced biomass and exhibited nitrogen use efficiencies comparable to Sunn hemp and cowpeas. The amino acid profiles of the seeds and the total protein content across tepary bean accessions displayed significant variability. We conducted a genome-wide association study (GWAS) of seed nutritional and physiological traits using SNPs obtained through GBS. The candidate genes and loci associated with these traits could advance breeding efforts to enhance nutritional value. The study's outcomes would help affirm the potential of tepary beans as a promising summer cover crop, identifying high-value accessions with superior yield and nutritional qualities to facilitate the development of improved cultivars through introgression breeding.

Speakers

Sri Kiran Reddy Alla

Texas A

Co-authors

Benedict Analin

Texas A

Dalton Thompson

Texas A

Vijay Joshi

Texas A

Thursday July 31, 2025 11:30am - 11:45am CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Funding Source Texas Department of Agriculture (TDA); Specialty Crop Block Grant GSC2023039; Southern Region SARE 2024 Granduate Student Grant

11:45am CDT

CE 5 - Cooling Potential of Ornamental Vines Under Different Irrigation Regimes for Urban Heat Mitigation

Thursday July 31, 2025 11:45am - 12:00pm CDT

Strand 12B

Rising global temperatures are contributing to increased Urban heating affecting human well-being and ecosystems. Vegetation can help mitigate heat by providing shade and evaporative cooling. This study evaluates the cooling potential of two ornamental vines, Vitis × californica × vinifera ‘Rogers Red’ and Lonicera x heckrottii ‘Goldflame’ (goldflame honeysuckle), grown under different volumetric water content (VWC) regimes. The vines were grown on trellises in a greenhouse setting, with substrate VWC maintained at 0.15, 0.25, or 0.35 m³·m⁻³ for two months. A total of 12 vines per species were grown using an automated irrigation system. Canopy and background temperatures were measured using a FLIR thermal camera. Results showed that water stress impaired canopy growth in Rogers Red, whereas no significant effect was observed in the honeysuckle. In Rogers Red, lower VWC (0.15 m³·m⁻³) reduced leaf number, specific leaf area, and dry biomass, while honeysuckle exhibited consistent growth across all treatments. SPAD, NDVI, photosynthetic rate, and net assimilation rate did not differ significantly across treatments for either species. The higher cooling potential of Rogers Red compared to honeysuckle was attributed to its larger leaf size. Both vines demonstrated evaporative cooling potential, as indicated by lower canopy temperatures relative to the background temperature. However, Rogers Red exhibited significantly greater cooling potential at 0.35 m³·m⁻³ VWC, whereas honeysuckle maintained a similar cooling effect across all treatments due to its similar canopy area. These findings suggest that ornamental vines can provide cooling benefits however species selection can make a difference. Incorporating vine covers in urban areas can help in mitigating urban heat as cities continue to warm due to climate change.

Speakers

Saroj Burlakoti

Utah State University

Co-authors

Shital Poudyal

Utah State University

Thursday July 31, 2025 11:45am - 12:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Poster # csv

11:45am CDT

CHMG 1 - Therapeutic Horticulture Learning in Action: An Update from NC State

Thursday July 31, 2025 11:45am - 12:00pm CDT

Strand 11A

The NC State Extension Gardener - North Carolina Botanical Garden Online Therapeutic Horticulture course partnership has demonstrably achieved significant success in expanding access to affordable, comprehensive training in the field. Since its 2020 inception, this collaboration has successfully introduced over 600 students residing in 45 U.S. states and 19 countries to the practice, establishing itself as a pivotal resource for individuals seeking to integrate nature-based interventions into therapeutic practices. The program's curriculum is thoughtfully designed to guide participants along a continuum, fostering growth from initial interest in the benefits of human-plant interaction to the development of practical proficiency in therapeutic horticulture techniques and program management. A key element of the course's success lies in its robust and adaptable online format, which effectively transcends geographical barriers and accommodates diverse learning styles and schedules. The comprehensive training encompasses foundational horticultural knowledge, an in-depth exploration of the theoretical underpinnings of therapeutic horticulture, and practical strategies for designing and implementing effective plant-based activities tailored to various populations and therapeutic goals. Furthermore, the partnership leverages the combined expertise of experienced professionals, ensuring a well-rounded and evidence-based educational experience. The substantial enrollment figures and broad geographical reach underscore the growing recognition of therapeutic horticulture as a valuable intervention within healthcare, education, and community-based settings. By equipping individuals with the necessary knowledge and skills, this online program is actively contributing to the expansion of qualified practitioners and the wider adoption of therapeutic horticulture practices globally. The positive impact is evidenced not only by the number of students served but also by the anecdotal reports of graduates successfully applying their training to enhance well-being and facilitate positive change in their respective communities. The continued growth and influence of this partnership highlight the transformative potential of accessible and high-quality online education in this increasingly vital field.

Speakers

Amy Bruzzichesi

NC State University

Co-authors

Alta Zhang

NC State University

Emilee Weaver

University of North Carolina at Chapel Hill

Joanna Lelekacs

University of North Carolina at Chapel Hill

Lucy Bradley

NC State University

Sally Haskett

University of North Carolina at Chapel Hill

Sarah Tanke

University of North Carolina at Chapel Hill

Thursday July 31, 2025 11:45am - 12:00pm CDT
Strand 11A

Oral presentation, Consumer Horticulture and Master Gardeners 1

Subject Consumer Horticulture and Master Gardener
Funding Source Project is funded through cost-recovery revenue

11:45am CDT

PGR - Night Interruption UV-A Radiation Influences Plant Architecture and Biomass Accumulation of Potted Spearmint and Greek O

Thursday July 31, 2025 11:45am - 12:00pm CDT

Foster 2

A high-quality containerized culinary herb is one that is proportional to its container with a compact growth habit and stems or leaves that are not excessively elongated. However, chemical plant growth regulators (PGRs) used to modify plant growth, increase branching, or reduce stem elongation are not labeled for use on culinary herbs. A novel option for reducing stem elongation could be exposure to night-interruption (NI) ultraviolet (UV) radiation. Therefore, our objectives were to 1) quantify the influence of UV-A radiation on the growth, stem elongation, and relative chlorophyll concentration of containerized spearmint (Mentha spicata) and Greek oregano (Origanum vulgare var. hirtum) and 2) determine the most effective duration and sequence of exposure. Rooted cuttings were transplanted into 15-cm containers and placed in a greenhouse at 23 °C and under a 16-h long-day (LD) provided by LED supplemental lighting (SL) or under a 9-h short-day (SD) and 6-h of NI lighting providing 385 nm of UV-A radiation at an intensity of 20 µmol∙m–2∙s–1 for 4 weeks. The 10 treatments included: LD entire time, LD 2 week-UV 2 weeks, LD 1.5 weeks-UV 2.5 weeks, LD 2 weeks-UV 2 weeks, LD 2 week-UV 1 weeks-LD 1 week, UV entire time, UV 2 weeks-LD 2 weeks, UV 2.5 weeks-LD 1.5 weeks, UV 2 weeks-LD 2 weeks, or UV 2 week-LD 1 week-UV 1 week. Exposure to SD UV-A NI for 4 weeks, resulted in a ≈ 25 and 29% reduction in height of Greek oregano and spearmint, respectively. Furthermore, when LDs were the last treatment spearmint plants received, they had a higher chlorophyll content than those exposed to UV-A. Our results indicate that UV-A NI lighting for spearmint and Greek oregano may be an option for height control in controlled environments.

Speakers

Rose Elbert

Michigan State University

Co-authors

Roberto Lopez

Michigan State University

Thursday July 31, 2025 11:45am - 12:00pm CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv
Funding Source USDA SCRI
Funding Option SCRI funded all or part of the research associated with this abstract

11:45am CDT

VCM 4 - Mitigating Beet Curly Top Virus in Tomatoes Without Compromising Yield or Quality: Effects of Shade Cover and Irrigation

Thursday July 31, 2025 11:45am - 12:00pm CDT

Strand 11B

In this 2023 undercover tomato study conducted at the New Mexico State University Agricultural Science Center in Los Lunas, New Mexico, treatments included two tomato cultivars, ‘Big Beef Plus’ (indeterminate, hybrid) and ‘San Marzano II’ (indeterminate, heirloom), grown under three types of shade cloth: 1) white 15% shade, 2) white 50% shade, and 3) black 60% shade. Unshaded plants of both cultivars served as controls. Two irrigation methods were also evaluated: drip irrigation and furrow flood irrigation, each applied to half of the plots. Dependent variables included mortality rates attributed to confirmed beet curly top virus (BCTV) infection, as well as plant size, yield, and fruit quality indicators such as the percentage of fruit exhibiting blossom end rot. Preliminary data indicate expected cultivar differences in yield and susceptibility to blossom end rot. Shade treatment and irrigation method appeared to influence blossom end rot incidence, although the effects varied between cultivars. The protective effect of shade cover was pronounced. By July, 79% of the surviving, uncovered control plants tested positive for BCTV; assuming that untested deceased plants were also infected, this rate rises to 89%. In contrast, among the shaded treatments (white 15% shade, white 50% shade, and black 60% shade), 25%, 25%, and 9% of the surviving plants tested positive for BCTV, respectively, with only one untested deceased plant. These findings suggest that the shade cover, wrapped around the tomato cages, effectively limited exposure to the only known vector of BCTV. The plot thickens, however, as some shaded plants that tested positive for BCTV in July still produced over 21.9 kg of fruit per plant before the first frost in late October. These preliminary findings underscore the potential of shade structures as a viable cultural practice for mitigating BCTV impact and warrant more comprehensive investigation.

Speakers

Marisa Thompson

New Mexico State University

Thursday July 31, 2025 11:45am - 12:00pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Funding Source “This work is supported by the Crop Protection and Pest Management Program (grant no. 2021-70006-35765) from the National Institute of Food and Agriculture.”

12:00pm CDT

CE 5 - Post-Transplant CO2 Enrichment Increases Lettuce Biomass Irrespective of Pre-Transplant CO2 Enrichment

Thursday July 31, 2025 12:00pm - 12:15pm CDT

Strand 12B

Indoor vertical farms can provide local, fresh, and nutritious food to densely populated urban regions as an alternative approach to food production. They enable growers to precisely adjust cardinal environmental factors, including CO2, per crop requirements to enhance growth and nutritional quality. As the substrate of photosynthesis, CO2 enrichment can enhance crop growth; however, how crops respond to sequential CO2 changes is not yet well understood. In a randomized complete block design, we studied how pre- and/or post-transplant CO2 concentration influenced lettuce growth. Lettuce ‘Rex’ and ‘Rouxai’ were grown from seed in four growth chambers with CO2 concentrations set randomly at 400, 800, 1200, and 1600 µmol·mol−1, under the same photoperiod of 24 h, photosynthetic photon flux density of 180 µmol·m−2·s−1 (blue:green:red = 20:40:120), temperature of 22 °C, and relative humidity of 60%. On day 11, biomass and morphological data on seedlings were collected while three additional uniform seedlings per chamber per cultivar were transplanted in hydroponic units in each of the four growth chambers, creating 16 sequential CO2 treatments. On day 28, biomass and morphological data were collected on mature plants. Preliminary data showed that pre-transplant CO2 enrichment from 400 to 1600 µmol·mol−1 increased seedling shoot fresh and dry mass of ‘Rex’ by 53% and 37%, respectively. In contrast, pre-transplant CO2 enrichment from 400 to 1200 µmol·mol−1 maximally increased shoot fresh and dry mass of ‘Rouxai’ by 81% and 122%, respectively. In mature plants, pre-transplant CO2 enrichment did not influence final ‘Rex’ biomass. In contrast, pre-transplant CO2 enrichment from 400 to 1200 µmol·mol−1 increased final shoot fresh mass of ‘Rouxai’ by 25%, whereas enrichment from 400 to 800 µmol·mol−1 saturated the increase in final shoot dry mass by 22%. Post-transplant CO2 enrichment had greater influence on final biomass of both cultivars than pre-transplant CO2 enrichment. Post-transplant CO2 enrichment from 400 to 1200 µmol·mol−1 saturated the increase in final biomass by 22% to 32% in ‘Rex’ and by 58% to 60% in ‘Rouxai’. Final leaf number, length, and coloration were generally unaffected by pre- or post-transplant CO2 enrichment. In all cases, there was no interaction between pre- and post-transplant CO2 concentration. We conclude that pre- and/or post-transplant CO2 enrichment independently influenced lettuce growth, with no CO2 acclimation. Post-transplant CO2 enrichment determined final biomass, with 1200 µmol·mol−1 being the saturation point. Keywords: carbon dioxide, controlled environment agriculture (CEA), indoor vertical farming, elevated CO2 concentration, growth chamber, whole-plant photosynthesis

Speakers

Harkirat Kaur Mashiana

University of Delaware

Co-authors

Qingwu Meng

University of Delaware

Thursday July 31, 2025 12:00pm - 12:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 5

Subject Growth Chambers and Controlled Environments
Funding Source Foundation for Food and Agriculture Research

12:00pm CDT

PGR - Ethephon Drench Efficacy is Not Affected in Sphagnum Peat-Based Substrates Amended with Perlite, Aged Pine Bark, or Wood

Thursday July 31, 2025 12:00pm - 12:15pm CDT

Foster 2

Greenhouse substrates are soilless mixes formulated by blending organic and inorganic components at varying proportions. Substrate properties are known to influence the efficacy of plant growth regulators applied as a substrate drench. Ethephon is a plant growth regulator used in floriculture production to control stem elongation, increase lateral branching, and manipulate flowering. Ethephon substrate drenches have been shown to control growth in annual bedding plants and herbaceous perennials; however, there is a lack of research examining how substrate composition influences the efficacy of ethephon substrate drenches. Therefore, the objective of this research was to evaluate ethephon drench efficacy in peat-based substrates amended with perlite, aged pine bark, or wood fiber. Lantana (Lantana camara L. ‘BandoleroTM Pink’ and ‘New Gold’) were transplanted into 15.2-cm containers filled with one of six peat-based substrates amended (by vol.) with 20% or 40% perlite, aged pine bark, or wood fiber. After 10 d, eight single-plant replicates received a drench of 150 mL aliquots of solution containing 0, 25, 50, 75, 100, or 200 mg·L–1 ethephon. Plants were grown in a glass-glazed greenhouse for 5 weeks after drench before growth data, including plant height, plant diameter, shoot dry weight (SDW), and root dry weight (RDW) were determined. Increasing concentrations of ethephon decreased plant height, plant diameter, SDW, and RDW of both cultivars of lantana. Substrate components and formulation had varied effects on plant growth. For example, in Expt. 1, plant height was unaffected by formulation but the component × concentration interaction was significant. When substrates were formulated with perlite, aged pine bark, or wood fiber plants were 23% (3.9 cm), 13% (2.0 cm), and 18% (3.1 cm) shorter, respectively, as concentrations increased from 0 to 200 mg·L–1 ethephon, compared to untreated plants. In Expt. 2, neither component or formulation significantly influenced plant height, and when drenched with 200 mg·L–1 ethephon plant diameter was 42% (15.8 cm) less than untreated plants. In Expt. 1, SDW was not influenced by formulation but the component × concentration interaction was significant. For instance, compared to untreated plants, SDW of plants grown in substrates containing perlite, aged pine bark, or wood fiber were 42% (3.8 g), 23% (1.7 g), and 35% (2.7 g) smaller, respectively, as concentrations increased from 0 to 200 mg·L–1 ethephon. Overall, ethephon substrate drench efficacy was not reduced by the incorporation of perlite, pine bark, or wood fiber in peat-based substrates.

Speakers

William Rich

The Ohio State University

Co-authors

Garrett Owen

The Ohio State University

Thursday July 31, 2025 12:00pm - 12:15pm CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv

12:00pm CDT

UG 2 - Exploring Marketing Strategy of Green Industry Firms

Thursday July 31, 2025 12:00pm - 12:15pm CDT

Foster 1

Horticulture producers need to make their business distinctive to consumers to stay competitive. Millions of Americans participate in gardening activities recreationally, composing a market of infrequent but avid horticulture consumers. Attending trade shows, reaching out to green industry publications, and creating websites are typical marketing practices producers utilize to make themselves known to their consumers. Some businesses also create regular newsletters and catalogues to keep consumers updated on and invested in the development of their products. To explore the progression of marketing strategies in the horticulture industry, we surveyed and compared 55 businesses on the marketing strategies they invested in and new-customer inflow to determine what kinds of marketing strategies are preferred by producers today, and how effectively they may grasp the interest of consumers. The results show that producers who primarily advertise using digital methods tend to report a higher proportion of new customers in their sales. This indicates a growing digital advertising influence for showing the value of horticultural products. In the horticulture industry, where consumers do not consciously differentiate goods beyond their type, producers need to keep their products in front of consumers to entice consumers towards favoring their products. As such, the importance of marketing and outreach towards new customers stays vital.

Speakers

Ella Lin

North Carolina State University

Co-authors

Daniel Tregeagle

North Carolina State University

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 12:00pm - 12:15pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv
Funding Source Horticulture Research Institute

12:00pm CDT

VCM 4 - Increasing the number of sweet potato storage roots to increase the yield of sweet potato crops in Hawaii

Thursday July 31, 2025 12:00pm - 12:15pm CDT

Strand 11B

Sweet potato is grown year-round and is planted on all islands of Hawaii. During the 20th century, sweet potato was a profitable export crop for Hawaii, but production and sales have been declining for decades. Environmental conditions, such as continued droughts or precipitations and poor soil nutrients, contribute to low sweet potato yields. Sweet potato yields can be determined by the number of storage roots (tubers) per plant, and the size of each storage root at harvest. To maximize the marketable yields of sweet potato, it is necessary to achieve the greatest possible number of storage roots. In a field trial at the Kula Agricultural Park in the island of Maui, Okinawan sweet potatoes were grown under different irrigation regimes, both with and without fertilizer application. Control plots were irrigated daily regardless of soil moisture, and irrigation treatments were designed to initiate irrigation events based on soil moisture thresholds as follow: high moisture (irrigated to a soil water tension threshold of -60 kPa), medium moisture (irrigated to a soil water tension threshold of -80kPa), low moisture (irrigated to a soil water tension of -100 kPa). Fertilizer (16-16-16 and potassium sulfate) was applied to half of each plot in a split plot design. Marketable yield was evaluated in the different treatments. The fertilizer treatments were only significantly different in the irrigated control and the lowest moisture treatment. Marketable yield was highest in the irrigated control that received no fertilizer, and lowest in the low moisture treatment that received fertilizer. As irrigation was reduced, yield was also reduced, and the number of off-grade small tubers increased. In the irrigated control, adding fertilizer reduced the number and weight of marketable tubers, especially in the AA grade, and increased the number and weight of large, off-grade tubers. In the lowest moisture treatment, high numbers of “pencil roots” were observed due to inadequate moisture during tuber development, and few marketable tubers in both the fertilized and unfertilized treatments.

Speakers

Rosemary Gutierrez-Coarite

University of Hawaii at Manoa

Co-authors

Amjad Ahmad

University of Hawaii at Manoa

Thursday July 31, 2025 12:00pm - 12:15pm CDT
Strand 11B

Oral presentation, Vegetable Crops Management 4

Subject Vegetable Crops Management
Poster # csv

12:15pm CDT

PGR - Evaluating the Effect of PEG-Induced Drought Stress on Seed Germination in Ornamental Plant Species

Thursday July 31, 2025 12:15pm - 12:30pm CDT

Foster 2

Polyethylene glycol (PEG) is widely used to simulate drought stress in plant germination studies due to its ability to induce osmotic stress without being absorbed by plant tissues. This study investigates the effects of PEG-induced drought stress on the seed germination of various ornamental plant species, including Celosia argentea, Petunia hybrida, Rudbeckia hirta, Salvia splendens, and Zinnia elegans. Seeds are treated with different concentrations of PEG-6000 (0%, 5%, 10%, and 15%) to mimic varying levels of water deficit. Germination trials are conducted under controlled environmental conditions using LED lights with a 16/8-hour photoperiod to simulate light/dark conditions, and an optimum temperature of 70-75°F (21-23°C) to support ideal germination and seedling growth. Current seed research trials are underway with aims to evaluate germination-related traits under stress, including germination percentage, mean germination time, germination rate, and seedling vigor. These traits are used to assess the early-stage drought tolerance of ornamental plants. Understanding how different species respond to water stress at the germination stage is crucial for the ornamental plant industry, as it supports the selection and development of more resilient varieties suited for landscapes and markets increasingly affected by water scarcity.

Speakers

Haramrit Gill

University of California Agriculture and Natural Resources

Co-authors

Santosh Bhandari

University of California Agriculture and Natural Resources

Thursday July 31, 2025 12:15pm - 12:30pm CDT
Foster 2

Oral presentation, Plant Growth Regulation

Subject Plant Growth Regulation
Poster # csv
Funding Source UCANR

12:15pm CDT

UG 2 - How Warm Glow and Social Influence Shape Consumer Choices in Sustainability

Thursday July 31, 2025 12:15pm - 12:30pm CDT

Foster 1

Sustainability is becoming a top priority for consumers, businesses, and governments. Warm glow is the positive emotional satisfaction people have after motivating actions such as recycling or purchasing eco-friendly products. Past research shows there is still a significant gap between what people say they want in sustainable products and how they spend their money. Understanding why this occurs is critical to driving meaningful changes in consumer behavior and marketing messaging that can effectively improve sustainable purchasing decisions. However, studies show that emotional satisfaction can occasionally override real impact, people may feel fulfilled simply by voicing pro-sustainability ideas, even if they do not follow through financially. Social pressure also plays a role, as customers may outwardly favor sustainability in order to fit in but then hesitate when faced with actual expenses. This study investigates whether people's perceived (subjective) versus factual (objective) awareness of sustainability affects their purchasing decisions. We conducted a survey that assessed approximately 1,040 participants' knowledge on sustainability and measured their willingness to donate money using an incentive. Post survey, the participants were categorized into four groups based on their knowledge levels: (1) high in both subjective and objective knowledge, (2) high in subjective but low in objective knowledge, (3) low in subjective but high in objective knowledge, and 94) low in both subjective and objective knowledge. The results show that individuals who think they know a lot about sustainability (subjectively) are more likely to declare they love sustainable items, whilst those who actually know (objectively) are more likely to spend on them. These findings indicate that stated preferences do not necessarily translate into action, implying that narrowing the information gap and appealing to inner motivation, rather than societal pressure, could inspire more meaningful sustainability decisions. This study explains consumer behavior and provides recommendations for firms and policymakers attempting to close the gap between sustainability attitudes and real expenditures.

Speakers

Sabeel Zayan

North Carolina State University

Co-authors

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 12:15pm - 12:30pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv

12:30pm CDT

UG 2 - Understanding Barriers to Sustainable Practices of Florists in the U.S.

Thursday July 31, 2025 12:30pm - 12:45pm CDT

Foster 1

Having bloomed into a multi-billion dollar industry, floral industry businesses are striving for sustainable solutions to their environmental, social, and economic impact. However, information regarding how often sustainable practices are being used is largely unknown. There is limited comprehensive data on the current state and future plans of sustainability within the sector. Consequently, the study addresses the need to understand the sustainability practices among florists in the United States. Surveys were distributed via industry groups such as: American Floral Endowment, Society of American Florists, American Specialty Cut Flower Growers, American Hort’s Cultivate; accumulating to a total of 107 respondents. In order to provide a diverse representation of the industry, growers, suppliers, wholesalers, and florists were surveyed. This presentation will focus exclusively on florist results. The results show that while florists exhibit strong personal motivations for sustainability, significant barriers persist. For example, cost remains the top barrier to adoption. These findings emphasize the need for increased educational efforts and resources to support current sustainable practices and adoption of future practices of florists. Ultimately, this research opens the door for any florist thinking about incorporating sustainability into their company by identifying the issues that other florists are currently facing.

Speakers

Allison Langston

North Carolina State University

Co-authors

Amanda Solliday

North Carolina State University

PhD student at NC State University conducting sustainability and climate research in cut flowers and ornamentals.

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 12:30pm - 12:45pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv

12:45pm CDT

UG 2 - Studying the market potential for a dried flower petal confetti produced from floral retailer organic waste

Thursday July 31, 2025 12:45pm - 1:00pm CDT

Foster 1

Vast quantities of organic waste are generated each year at retail floral shops much of which is discarded as municipal waste solids (MSW) by retailers. Plastic party confetti is also produced at a large scale and is used throughout the world for celebrations. Microplastics are increasingly a global environmental threat where they have been detected in not only in the soil and freshwater and ocean systems, but also in the atmosphere and even groundwater. The purpose of the study was to investigate the value, marketability and willingness to pay for a recycled dried flower petal confetti product created from retail floral providers organic waste. Flower petals and foliage pieces for drying were collected from local floral vendors as well as from spent and shattered flowers during the course of multiple semesters of university-level Floral Design course and program flowers. Flower petals and foliage pieces were air-dried in a cool, dark room in thin layers laid out in cardboard boxes and then packaged in 1-2 cup quantities in small paper sacks. They were labeled with printed stickers outlining their recycled nature and source. Students self-selected for the study by volunteering to participate. They were surveyed using a tool posted via Qualtrics that they could access on their cellphone and complete within 5 -7 minutes. Participants were asked if they use confetti and if they plan to purchase confetti for a graduation event. Next, they were asked to consider a sample of the flower petal confetti and how much they would be willing to pay for a bag (1-2 cups) of the flower petal confetti while viewing and touching the product. Results of the study indicated the potential value of this material that is currently mostly landfilled at this time. Recent research found floral consumers are willing to pay more for floral products from florists who implement sustainable practices into their operations, so the practice of drying floral waste could have this value as well.

Speakers

Isabella Dodson

Texas State University

Co-authors

Cole Etheredge

Mississippi State University

Tina Waliczek Cade

Texas State University

Thursday July 31, 2025 12:45pm - 1:00pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv

1:00pm CDT

UG 2 - Marketing Investment: A Study of Growers, Retailers, and Landscapers in the Green Industry

Thursday July 31, 2025 1:00pm - 1:15pm CDT

Foster 1

The green industry is the growth, input, and sale of any plant that is used for ornamental purposes. Businesses with the green industry are growers, landscapers, and retailers. This study presents insights from a national Green Industry survey that examined U.S. industry member responses on the costs of marketing. The survey was distributed digitally, and physical copies were mailed to business addresses. Businesses answered questions consisted of total sales spent on advertising, use of social and traditional media outlets, market outlets, and sales methods. Businesses were organized by size of firm: small ($1M). Results show that 38.5% were small businesses, 18.4% were medium, and 29.2% were large. Social media marketing was most used (84% of businesses surveyed). Additionally, on average 2.55% of sales was spent on marketing per firm. This data can give current and future members of industry a benchmark on marketing expenditures by firm size and type of marketing strategy.

Speakers

Daniel Morales

North Carolina State University

Co-authors

Daniel Tregeagle

North Carolina State University

Melinda Knuth

North Carolina State University

Thursday July 31, 2025 1:00pm - 1:15pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv
Funding Source Horticulture Research Institute

1:15pm CDT

UG 2 - Local Food Needs Local Seed: Increasing production and Use of Locally Adapted Seed with a Farm to Community Network

Thursday July 31, 2025 1:15pm - 1:30pm CDT

Foster 1

Seed saving is an effective strategy for farmers who want to improve farm resilience and biodiversity. Farmers expressed a desire to reduce dependency on national seed suppliers whose cultivars are often poorly adapted for Florida’s subtropical climate and were eager to improve their seed saving skills. This SR-SARE funded education project focused on farmer training and documenting seed saving methods was led by Working Food in collaboration with UF and three established small farm operations in North Central Florida. Activities and deliverables from the project included farmer training, photography, video recording and editing, seed processing demonstrations, farmer interviews, and community workshops. Throughout, farmers provided opinions on the ways that seed saving can or might improve their operation’s management and economic viability, as well as the constraints associated with seed saving such as longer rotations and additional labor for seed harvest and processing. Interviews and video recordings for this project occurred during summer 2024 through spring 2025. Story boards were developed to guide the organization of content and images needed before video recording began. Over 640 hours of recording and editing were completed using editing software programs Premier Pro and Canva. Seven educational materials were created including three farmer interview videos, two dry seed processing videos with Working Foods, and two slide shows that detailed the process of seed saving for cowpea (Vigna unguiculata), pepper (Capsicum annuum), tomato (Solanum lycopersicum), and winter squash (Cucurbita moschata). Growers engaged in tasting panels to provide farmer-informed observations regarding which locally adapted varieties seemed best and ultimately most viable for their farming operations. Farmers expressed positive feedback, noting consumers were enthusiastic about purchasing locally adapted cultivars and often expressed a preference for their flavor. Overall, challenges faced by the farmers included labor and storage constraints, lack of experience growing crops to maturity. Despite these barriers, participants who had prior experience with traditional farming practices or access to community support were more likely to adopt seed-saving practices. Farmers cited reduced production costs and more control of their crop selection as benefits of seed saving. Ultimately, seed saving has the potential to reduce external inputs, increase product diversification and cultivate stewardship for locally adapted and culturally important crops.

Speakers

Noah Allen

University Of Florida

Co-authors

Danielle Treadwell

University of Florida

Melissa DeSa

Working Food

Thursday July 31, 2025 1:15pm - 1:30pm CDT
Foster 1

Oral presentation, Undergraduate Student 2

Poster # csv
Funding Source Southern Region Sustainable Agriculture (SR-SARE) Education Grant #2022-3864037488

1:44pm CDT

CE 6 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Strand 12B

Presiding/Moderator

Eric Stallknecht

Virginia Tech

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments

1:44pm CDT

FLOR 3 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Strand 11A

Presiding/Moderator

Juan Quijia Pillajo

The Ohio State University

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture

1:44pm CDT

GG 2 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Foster 2

Presiding/Moderator

Shengrui Yao

New Mexico State University

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

1:44pm CDT

PH 3 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Strand 11B

Presiding/Moderator

Deepak Kumar Jha

Texas A

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

1:44pm CDT

VSF 3 - Oral Session

Thursday July 31, 2025 1:44pm - 1:45pm CDT

Foster 1

Presiding/Moderator

Haley Williams

Mississippi State University

Thursday July 31, 2025 1:44pm - 1:45pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits

1:45pm CDT

CE 6 - Effects of Light Intensity and Continuous Lighting on Yield and Nutritional Profile of Pea, Radish, and Sunflower Microg

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Strand 12B

Microgreens are increasingly cultivated indoors using artificial lighting, which can be energy-intensive and depending on the species, can have varying effects on yield, commercial quality and nutritional profile. Understanding how light conditions influence plant physiological processes, including growth, phytochemical composition, and nutrient accumulation, is essential for optimizing indoor farming systems. Previous studies indicate that a light intensity of 300 µmol/m²/s enhances growth in microgreens, increasing dry weight and phytochemical content. Extending photoperiods with lower photosynthetic photon flux density (PPFD) has been proposed as a strategy to improve efficiency and plant biomass accumulation under controlled environment. Some photosynthetically active pigments may also be influenced by light manipulation. Carotenoids, a group of pigments that are beneficial to human health, are known to be protective of the photosynthetic system in plants, by regulating the flow of energy and mediating the damage caused by excess light absorption. Continuous lighting can be used to reduce energy costs in microgreen production; however, this may exceed species-specific tolerance thresholds, causing physiological stress. Nevertheless, there is limited information on the effect of continuous lighting on microgreens. To this purpose, a study was conducted in the spring of 2024, at the Penn State greenhouse facilities. We assessed the growth and nutritional responses of pea, radish, and sunflower microgreens under a factorial combination of 16- and 24-hour photoperiods and 150 or 300 µmol/m²/s light intensity. Photoperiod and light intensity impacted all three species of microgreens. Yield was highest under a 24-hour photoperiod at 150 µmol/m²/s. Dry matter content was unaffected by photoperiod but was highest at 300 µmol/m²/s. Regarding phytochemical content, carotenoids increased under continuous lighting and improved at 300 µmol/m²/s. Total antioxidant levels were higher at 300 µmol/m²/s compared to 150 µmol/m²/s. On the other hand, nitrate content increased under shorter photoperiods and lower light intensity, a trend also observed for total nitrogen, and iron concentration at 16-hour photoperiod and 150 µmol/m²/s. These findings indicate that all three microgreen species tested tolerate continuous lighting with positive or no effects on yield and nutritional quality, suggesting that light intensity and continuous lighting can be used in controlled environment systems to enhance the commercial quality and nutritional profile of microgreens.

Speakers

Aline Seffrin

Pennsylvania State University

Co-authors

Francesco Di Gioia

Pennsylvania State University

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source This research was funded by the USDA-NIFA Specialty Crop Block Grants # C940001528 “Advancing the Sustainability of Indoor Urban Agricultural Systems” and # C940001096 “Employing Agronomic Biofortification Techniques for the Production of High-Value Functional Vegetable Crops” and was supported in part by the United States Department of Agriculture (USDA)’s National Institute of Food and Agriculture (NIFA) Federal Appropriations under Project #PEN05002, Accession #7007517.

1:45pm CDT

FLOR 3 - Substrate pH and Inoculant Amendments Modulate Phosphate-Solubilizing Bacteria Efficacy in French Marigold: Impacts on

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Strand 11A

Calcium phosphate [Ca₃(PO₄)₂] is an nonlabile form of phosphorus (P) commonly found in substrates with a basic pH and it is not available for plant uptake. Phosphate solubilizing bacteria (PSB) are plant-associated microorganisms that can solubilize calcium phosphate by secreting organic acids. PSB inoculation alleviates P deficiency symptoms including leaf purpling, and PSB inoculum can be amended with substances that may improve PSB performance (i.e. glucose). Our goal was to evaluate the efficacy of PSB isolated from the rhizosphere of greenhouse ornamentals (Pantoea trifolii C2B11, Pantoea formicae C8D10, Pantoea sp. C2G6 and Enterobacter soli C4A1) in substrate with pH 6.0 or 6.5, and with an inoculum amended with glucose (10 g·L-1), Luria Bertani (LB) broth (111 mL·L-1), or humic and fulvic acids (20 g·L-1). An experiment was conducted using French marigold 'Durango Yellow' (Tagetes patula) fertilized once per week with 200 mg·L-1 N from a 15N-0P-12.5K-2.9Ca-1.2Mg fertilizer. P was supplemented to the fertilizer solution as Ca3(PO4)2 at 10 mg·L-1 P. Bacillus velezensis was included as a positive control. Digital biomass, Normalized Pigment Chlorophyll Ratio Index (NPCI), Plant Senescence Reflectance Index (PSRI) and canopy hue (color) were measured with the TraitFinder, a digital phenotyping workstation. NPCI and PSRI values from healthy foliage are low but increase under stress. At pH 6.0, all marigolds receiving PSB had increased growth regardless of the inoculum amendments. PSB amended with glucose resulted in marigolds with a lower NPCI than non-inoculated plants. Additionally, PSB-treated marigolds had a higher proportion of green canopy, and a lower proportion of red canopy compared to non-inoculated marigolds when the inoculum was amended with glucose or not amended. At pH 6.5, all PSB resulted in increased marigold growth regardless of inoculum amendments. PSB treated marigolds were healthier than non-inoculated plants, as indicated by their lower NPCI and PSRI values, regardless of the inoculum amendments. Accordingly, PSB treated marigolds had a higher proportion of green canopy and a lower proportion of red canopy compared to non-inoculated marigolds. Bacterial effects were more consistent when inoculum was supplemented with LB. A greater benefit was observed in plants grown at pH 6.5. Microbiome analysis of the rhizosphere showed that inoculation with C2B11, C2G6, and C8D10 increased the relative abundance of the genus Pantoea, and C4A1 enriched the genus Enterobacter. Careful determination of optimal inoculum supplements is key to developing efficient inoculants that promote growth in greenhouse ornamentals.

Speakers

Juan Quijia Pillajo

The Ohio State University

Co-authors

James Altland

USDA-ARS

James Owen

USDA ARS

Laura Chapin

The Ohio State University

Michelle Jones

The Ohio State University

Sachin Naik

The Ohio State University

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture
Funding Source NIFA AFRI grant 2022-67013-36489

1:45pm CDT

GG 2 - Jujube germplasm metabolomic study of fruit and seeds in New Mexico and western Texas

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Foster 2

To fully evaluate jujube germplasm, we sampled sour jujubes both from Las Cruces, NM and western Texas to examine their fruit and seed metabolomic profiles to facilitate further employment of those jujube germplasm trees. Samples were taken from the NMSU campus and Tornillo/Fabens, TX which had both the wild type and middle types (cross between wild ones and cultivars). Jujube germplasm fruit metabolomic profile reveals that jujube cultivar samples were similar to germplasm samples from Texas. Sour jujube samples in NM were separated from sour jujube from TX. Sour jujube in TX were mingled together with Cross in TX. So-called Cross and sour jujube were arbitrary classifications. Without cultivars, germplasm was separated by location NM vs TX, not by sour jujube or Cross. For significant compounds, there were only 110 significant different compounds between TX sour jujube vs Cross, while Cross vs NM sour jujube, TX sour jujube vs NM sour jujube or TX vs NM, had over 700. TXS and Cross group overlaid and NM group was totally separated from the other two groups. TX samples had significantly higher contents of large numbers of amino acids and derivatives. More compounds were identified from seed samples and their grouping/PCA results were similar to fruit metabolomic results. Cross samples were mixed together with TX sour jujubes and NM sour jujubes were separated from TX samples. New Mexico samples in Las Crues near graduate student housing area were planted at similar time which could be from one nursery, closed related to each other. Texas germplasm was the result of human selection, not the original sour jujubes but cross between sour jujubes or sour jujube and cultivar-like germplasm. The dominant triterpenes were different between fruit and seeds. In fruit flesh, pomolic acid was the dominant one with Honeyjar as the highest, followed by rutundic acid, Cleanothic acid, 2,3,23-Trihydroxyurs-12-en-28-oic acid, 2,3,23-Trihydroxyolean-12-en-28-oic acid, madasiatic acid, which were higher for NM samples than TX samples. In seeds, the dominant triterpenes were oleanolic acid, mangiferotic acid, momordicoside I aglycone, 3,13,15-trihydroxyolenonane-12-one, jujubogenin, and pomolic acid. The contents of the first three metabolites were equivalent and much higher than the rest, ranging from 0.5X108 to 1.5x108 depending on germplasm. Pomolic acid was much lower in seeds than in fruit. The data contained over 1600 metabolites in fruit and over 2000 for seeds which would be good references for future utilization of those jujube germplasm for horticultural or pharmaceutical purposes.

Speakers

Shengrui Yao

New Mexico State University

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

1:45pm CDT

PH 3 - Priming onion seeds with iron and copper nanoparticles enhances yield, reduces pungency, and improves postharvest qualit

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Strand 11B

Priming seeds with nanoparticles (NPs) has the potential to enhance germination, growth, and resilience against environmental stresses by inducing the biosynthesis of secondary metabolites, which promote plant protection and health. However, the effectiveness of the essential micronutrients iron (Fe) and copper (Cu) as priming agents for crop production and postharvest qualities is largely unexplored. This study examines the impact of seed priming with Fe- and Cu-NPs on the production of onions, a crop of significant economic importance in Texas. NPs were synthesized using a green approach that employs onion juice as a reducing agent. The resulting Fe-NPs and Cu-NPs were characterized, and an optimal dose, determined by the length of root and shoot growth, was employed as a priming agent for two commercial yellow onion varieties (Legends and Pecos) and two Texas A

Speakers

Deepak Kumar Jha

Texas A

Co-authors

Bhimanagouda S. Patil

Texas A

John Jifon

Texas A

Subas Malla

Texas A

Vikas Dadwal

Texas A

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

1:45pm CDT

VSF 3 - Impact of Shade Cloth on Gas Exchange and Yield of Strawberry Cultivars Grown in Lubbock, Texas

Thursday July 31, 2025 1:45pm - 2:00pm CDT

Foster 1

Due to increasing demand for strawberries (Fragaria × ananassa Duch.) and their health associated benefits, strawberry production has expanded within the United States. Within Texas, strawberry cultivation remains a minor crop (currently less than 162 ha dedicated to strawberry production). However, the state's vast geographic size and diverse climatic conditions present significant opportunities for expanding strawberry production into traditionally non-producing regions. Despite potential for expanding strawberry production, Texas strawberry growers are faced with a number of production challenges. This study aimed to evaluate effects of different shade levels upon gas exchange and production of two strawberry cultivars, ‘Camino Real’ and ‘Albion’ in Lubbock, Texas. Bare root strawberries were planted Fall of 2021 under three shade treatments: Full sun (no shade), 70% full sun, and 50% full sun. Each treatment was applied to 16 plants of each cultivar, with three replications of each treatment. During fall, winter, and early spring, all plants were grown within low plastic tunnels. During the spring production season shade treatments maintained lower air and soil temperatures when compared to the full sun treatment. Light levels were reduced under shade treatments leading to greater leaf gas exchange rates under full sun growing conditions. Marketable yield and berry number for each plant were greater for 'Camino Real' compared to 'Albion', with 'Camino Real' producing twice the yield. Among shade treatments, the 70% sunlight treatment resulted in the greatest marketable yield and berry number for each plant. The lowest yield and berry number for each plant was observed under full sun conditions. Results suggest the interaction between plant cultivar and sun exposure plays a crucial role in determining strawberry yield and quality. Findings highlight the importance of selecting appropriate shade levels and cultivars to optimize strawberry production within demanding environmental conditions.

Speakers

Srijana Panta

Graduate Research Assistant, Texas Tech University

Co-authors

Russ Wallace

TAMU AgriLife Extension

Thayne Montague

Texas Tech University

Thursday July 31, 2025 1:45pm - 2:00pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Funding Source Texas Department of Agriculture Specialty Crop Block Grant

2:00pm CDT

CE 6 - Short-Term Cold Treatment Improved Microgreen Nutritional Quality

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Strand 12B

Microgreens are emerging as a culinary novelty ingredient, with rich nutritional content and fresh taste. It can be produced within just a few weeks and is becoming popular among chefs and health-conscious consumers. Cold stress is one of the abiotic stresses, it may induce the accumulation of phytochemical properties in plants. This study investigated the effects of short-term, pre-harvest cold treatment on the nutritional contents of microgreens. Four microgreens including buckwheat, pea, sunflower and watercress, were grown in a growth chamber maintained at a constant temperature of 25°C. The photoperiod was set for a 15-hour light cycle. We treated these four microgreens with a short-term treatment including control and cold treatment at 4°C for 24h before harvesting. The results showed that shoot length, stem diameter, and shoot dry weight in four microgreen species were not affected by cold treatment compared to the control. But cold treatment increased the fresh weight of watercress and the SPAD values in pea and sunflower. Cold treatment significantly affected soluble sugar content. Specifically, it increased fructose, glucose, and sucrose contents in pea microgreen compared to the control. In sunflower microgreen, it improved fructose and glucose content by 65% and 78%, respectively, but had no effect on sucrose levels. Buckwheat microgreen under short-term cold treatment showed increased sucrose content, while fructose and glucose levels remained unchanged. In watercress microgreen, short-term cold treatment increased fructose content by 39% but decreased glucose content by 29%. These findings suggest that buckwheat, pea, sunflower, and watercress microgreens have different responses to a 24h short-term cold treatment regarding plant growth and specific phytochemical contents. While this treatment did not have a negative effect on the yield of the four microgreens, it influenced their flavor by significantly increasing fructose, glucose, and sucrose levels. Given the small space required for a microgreen tray, a short-term 4°C cold treatment is easily achievable in refrigerators. This innovative pre-harvest cold treatment presents an accessible method for enhancing the flavor and nutritional quality of microgreens. Future research will explore the impact of short-term cold treatment on other phytochemicals in microgreens.

Speakers

Jingyi Wu

Mississippi State University

Co-authors

Gaosheng Wu

Mississippi state university

Guihong Bi

Mississippi State University

Qianwen Zhang

Truck Crops Branch Experiment Station

Tongyin Li

Mississippi State University

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source USDA National Institute of Food and Agriculture (NIFA) Hatch Project MIS-300011

2:00pm CDT

FLOR 3 - Siderophore producing bacteria isolated from the rhizosphere of greenhouse plants enhance plant growth under iron-limiti

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Strand 11A

Supplying adequate iron (Fe) to greenhouse crops is challenging, particularly for iron-sensitive plants grown in soilless substrates under alkaline conditions. High pH levels reduce Fe bioavailability by promoting the formation of insoluble iron hydroxide (Fe(OH)₃), which limits plant uptake. Plant growth-promoting bacteria (PGPB) enhance plant growth and stress tolerance through diverse mechanisms, including siderophore production. Siderophores are small molecules that have a high affinity for metal ions like ferric iron (Fe³⁺). Once the siderophore chelates iron, the complex is soluble, and plant roots can readily absorb it. This study identified siderophore producing bacteria (SPB) capable of enhancing plant growth under Fe-limiting conditions. A rhizosphere bacterial collection from greenhouse plants was screened for siderophore production using the chrome azurol S (CAS) assay. Genomic analysis of 12 isolates identified in the CAS assay revealed diverse siderophore-related genes and other plant growth-promoting traits. Five of the isolates (C2G2, C5A12, C6E3, C8G7, and C10A8) were identified as strong candidates based on their siderophore-related genes and Fe uptake pathways. A ferrozine-based assay confirmed Fe solubilization in a modified Hoagland’s solution containing goethite (Fe³⁺O(OH)) as an insoluble Fe source, with bacterial treatments yielding 0.57 mg Fe L⁻¹ versus 0 mg Fe L⁻¹ in controls (no bacteria). Subsequent in planta experiments evaluated the impact of SPB on French marigold ‘Durango Yellow’ (Tagetes patula) growth in hydroponic systems under Fe-limiting conditions. French marigold proved to be a good model plant for this screening system. Digital phenotyping showed that plants inoculated with isolates C5A12, C8G7, or C10A8 had 53.0%, 45.7%, or 50.3% more green leaf tissue, respectively, compared to untreated control plants. Additionally, treated plants had increased root biomass. These findings demonstrate the potential of SPB to enhance Fe availability and plant growth under iron-limiting conditions and offer a novel strategy for improving greenhouse crop production. The incorporation of SPB into greenhouse practices may benefit Fe-sensitive crops or systems where pH fluctuations reduce Fe availability, ultimately improving crop quality and sustainability.

Speakers

Laura Chapin

The Ohio State University

Co-authors

Michelle Jones

The Ohio State University

Sachin Naik

The Ohio State University

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture
Funding Source NIFA Agriculture and Food Research Initiative, 2022-67013-36489

2:00pm CDT

GG 2 - Unraveling the Genetic Architecture of Key Traits for Prunus Crop Improvement

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Foster 2

The accumulated genetic, genomic, and breeding data for Prunus species is often underutilized in breeding applications. This study examines 25 years of curated Prunus data in the Genome Database for Rosaceae (GDR, rosaceae.org) to uncover the genetic architecture of key traits, and provide actionable insights for Prunus breeding. The curated dataset includes 177 genetic maps, primarily for almond, apricot, peach, and sweet cherry, and 28,971 trait-associated loci. Most of the trait associations (72.4%) were from genome-wide association studies (GWAS), 18.7% from quantitative trait loci (QTL), and 8.9% from Mendelian trait loci. We identified 17 potential QTL hotspots for fruit morphology, fruit quality, and disease resistance, as well as 17 syntenic regions among peach, sweet cherry, and almond. These findings provide valuable resources for tool development for Prunus breeding, particularly for complex polyploid genomes and less-studied species.

Speakers

Michael Itam

Clemson University

Co-authors

Chun-Haui Cheng

Washington State University

Dorrie Main

Washington State University

Katheryn Buble

Washington State University

Ksenija Gasic

Clemson University

Ping Zheng

Washington State University

Sook Jung

Washington State University

Taien Lee

Washington State University

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

2:00pm CDT

PH 3 - Storage of ‘Covington’ Sweet Potatoes Under Controlled Atmosphere Conditions: Effects on Quality and Shelf Life

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Strand 11B

Sweet potato is a nutritious root crop, rich in fibers, beta-carotene and vitamin C, especially in highly pigmented varieties. The warm climate of Georgia provides ideal conditions for the cultivation of sweet potatoes. Maintaining postharvest quality during long-term storage remains a challenge for sweet potatoes packers and shippers. This study aimed to evaluate the effects of controlled atmosphere (CA) storage on the postharvest quality and shelf life of ‘Covington’ sweet potatoes. Roots from two farms in South Georgia, Herring Farms (HF) and Bland Farms (BF), were cured at 29 °C and 85–90% relative humidity (RH), for three weeks and one week, respectively. After curing, samples were stored at 13 °C and 85–90% RH for up to six months under different atmosphere compositions: (1) Air 21 kPa O2-Control, (2) 7 kPa O2, (3) 7 kPa O2 2 kPa CO2, and (4) 7 kPa O2 10 kPa CO2, using an Oxystat 200 control atmosphere system, which mixed and regulated O2 and CO2 gases under constant pressure, ensuring gas levels within ± 0.5% of the target concentrations. After cold storage, roots were transferred to ambient conditions (21 °C and 85–90% RH) to simulate market and consumer handling. Quality parameters, including firmness, color, weight loss, decay incidence, sprouting, and respiration rates, were assessed at six time points: one month, one month plus two weeks at ambient conditions (AC), three months, three months plus two weeks at AC, six months, and six months plus two weeks at AC. For each location, 1,260 roots were evaluated, with 315 roots assigned to each atmospheric composition (three replicates of 15 roots per evaluation time point). Results demonstrated that storage under low O2 and moderate CO2 levels (7 kPa O2 2 kPa CO2) reduced weight loss and decay while maintaining higher firmness compared to Control (storage in air). In contrast, higher CO2 levels (10 kPa) resulted in increased weight loss and surface decay. These findings suggest that controlled atmosphere storage with low O2 and moderate CO2 levels can improve postharvest quality and extend the shelf life of sweet potatoes, whereas higher CO2 levels negatively affect postharvest quality of Georgia-grown ‘Covington’ sweet potatoes.

Speakers

Jakeline Zuluaga Acosta

University of Georgia

Co-authors

Angelos Deltsidis

University of Georgia

Wei-Shiang Liao

University of Georgia

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

2:00pm CDT

VSF 3 - Evaluation of Two Day – Neutral Strawberry Cultivars Grown Hydroponically in a Greenhouse

Thursday July 31, 2025 2:00pm - 2:15pm CDT

Foster 1

Strawberry cultivation under a hydroponic system in a protected environment can be the key to enhancing off-season production in the U.S. Yet this type of cropping system remains a challenge. The aim of this study is to evaluate the performance of two day-neutral strawberry cultivars, ‘Albion’ and ‘San Andreas’, grown hydroponically in a greenhouse. Photosynthetic activity, growth and development, fruit yield, and quality have been evaluated for three seasons (2022-2025). The study is conducted at the Plant Science Research Center at Auburn, AL. Environmental conditions are recorded every 15 minutes. So far, the results presented the following: ‘Albion’ and ‘San Andreas’ have shown similarities in photosynthetic response with 15.00 µmol m-2s-1 for ‘Albion’ and 16.03 µmol m-2s-1 for ‘San Andreas’. Growth and development showed that plant height did not differ which is 22.2 cm and 23.9 cm ‘Albion’ and ‘San Andreas’, respectively. Leaf area (cm2) for ‘San Andreas’ is higher, 1679.11, than ‘Albion’, 1091.6. Leaves and stem dry weights (g plant-1) is higher for ‘San Andreas’, 12.89 and 6.63 than for ‘Albion’, 8.77 and 4.25, respectively. Flower and fruit dry weights did not differ for both cultivars. ‘San Andreas’ has a significantly higher yield (g plant-1), 21.80 than ‘Albion’, 17.30. Fruit quality varied between cultivars. ‘Albion’ has a higher brix with 9.15 than ‘San Andreas’ with only 7.85, while ‘San Andreas’ is firmer, 1.13 kg cm-1, than ‘Albion’, 1.03 kg cm-1. ‘San Andreas’ has larger fruits than ‘Albion’, 16.63 cm2 and 14.82 cm2, respectively. Thus, it is feasible to produce strawberries under hydroponic systems in a greenhouse.

Speakers

MAVERICK MARIQUIT

Auburn University

I am currently studying in Horticulture as PhD student and at the same time working as a Graduate Research Assistant in Auburn University. My interest lies on the study of fruit crops with a significant focus on fruit growth and development as well as production and physiology (fruit... Read More →

Co-authors

Brenda Ortiz

Auburn University

Elina Coneva

Auburn University

Melba Ruth Salazar Gutierrez

Auburn University

Paul Bartley

Auburn University

Penelope Perkins-Veazie

NCSU

Thursday July 31, 2025 2:00pm - 2:15pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Poster # csv

2:15pm CDT

CE 6 - Effects of Blue and Red LED Lighting Ratio on Yield and Quality Components of Broccoli and Radish Microgreens

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Strand 12B

With growing consumer interest in health-promoting diets, microgreens have gained importance as nutrient-rich and functional leafy greens. These crops are increasingly grown indoors under LED lighting and the manipulation of light quality has been identified as a critical factor influencing plant growth, yield, and nutritional quality. Blue and red LED are both considered critical for plant growth, have high photon efficiency and can be readily absorbed and utilized by plants. However, each wavelength has different effects on the plant physiology and metabolism and there is a need to understand how their combination in different proportions may affect microgreens yield, morphology and nutritional quality. Therefore, we conducted a study aimed at evaluating the effects of different combinations of blue and red LED light on the yield and nutritional composition of radish and broccoli microgreens. Microgreens were grown in a walk-in growth chamber under a 14-hour photoperiod and six LED treatments (%): 100 white, 100 red, 100 blue, and blue: red ratios of 50:50, 25:75, and 75:25. The average photosynthetic photon flux density was 165 μmol m−2 s−1. Radish and broccoli were harvested after 7 and 8 days, respectively. Microgreens grown under 100% blue, red, and white LED light showed higher shoot height than those grown under mixed blue:red treatments, with 100% blue producing the tallest shoots. Dry biomass accumulation differed among treatments, with 100% blue LED light resulting in the lowest dry biomass. At the phytochemical level, antioxidant activity showed to be highest under 100% blue light, with a 16.3% increase across both species, while 100% red resulted in the lowest levels. The mineral composition was also affected by LED treatments, as microgreens grown under blue: red 50:50, 25:75, and 75:25 treatments resulted in the highest iron concentrations, averaging 10.4% higher compared to monochromatic red and blue light or to broad-spectrum white light. These findings are consistent with previous studies indicating that blue light enhances secondary metabolite accumulation and that combined red and blue light influences mineral uptake, highlighting the importance of light optimization for the commercial quality of microgreens grown in controlled environment.

Speakers

Aline Seffrin

Pennsylvania State University

Co-authors

Francesco Di Gioia

Pennsylvania State University

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source This research was funded by the USDA-NIFA Specialty Crop Block Grants # C940001528 “Advancing the Sustainability of Indoor Urban Agricultural Systems” and # C940001096 “Employing Agronomic Biofortification Techniques for the Production of High-Value Functional Vegetable Crops” and was supported in part by the United States Department of Agriculture (USDA)’s National Institute of Food and Agriculture (NIFA) Federal Appropriations under Project #PEN05002, Accession #7007517.

2:15pm CDT

FLOR 3 - Wood Component Type And Peat Inclusion Rate Impact Pre-Plant Substrate pH Across Four Dolomitic Lime Amendment Rates.

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Strand 11A

Increased interest in peat-alternative substrates has contributed to the development of both regional and global wood substrates. Utilizing different manufacturing equipment to produce wood fiber components allows producers to modify wood fibers/inputs through chipping, milling, heat, pressure, or various combinations, to alter physical properties and yield suitable material for horticulture use. Commercial substrates available for plant production include peat-reduced formulas with various percentages (by volume) of wood fiber. Current lime amendment suggestions to bring substrates into the optimal pH range for plant growth are based on peat as the main component. Wood fiber has variable initial pH across manufactured type and reacts differently to lime amendments compared to peat. To aid in the understanding of lime amendments to wood fiber substrate blends, this study was designed to measure the pre-plant pH response over time of substrates influenced by wood component type, peat inclusion percentage, and dolomitic lime amendment rate. Three types of manufactured wood substrates (hammermilled, screw-extruded, and disc refined) were individually blended with Sphagnum peat at 20% increments (20, 40, 60, 80, and 100%). Each substrate was amended with 0, 4, 8, or 12 lbs/yd3 dolomitic lime and incubated in plastic bags to measure pH change at 0, 1, 3, 5, 7, 14, 21, and 28 days after blending. Resulting pH values indicate dolomitic lime amendment rates will need to be adjusted based on peat:wood volume ratios. Wood fiber exhibited a higher initial pH than Sphagnum peat and within blends, as wood fiber rate increased, pH increased across all lime rates. Dolomitic lime amendments should be closely monitored at 40% volume or more wood fiber. Moderate pH differences were measured between manufactured wood fiber type within the same peat:wood volume ratio and lime rate, emphasizing interchangeability of wood component type.

Speakers

Hauk Boyes

North Carolina State University

Co-authors

Brian Jackson

North Carolina State University

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture
Funding Source American Floral Endowment (AFE)

2:15pm CDT

GG 2 - Pyrus Pangenome Enables Identification of Genes Involved in Adaptation to Niche Environments

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Foster 2

Pears (genus Pyrus) are one of the most widely cultivated temperate fruit. Both abiotic and biotic stress, however, can be harsh constraints on pear cultivation; in America pear production has nearly ceased in the Eastern half of the nation, and in Europe extreme weather has become a growing threat to production, especially in Southern growing regions. Currently, high-quality reference genomes exist for the most widely cultivated Pyrus species, but little genomic information is available on ornamental, less cultivated, and wild Pyrus species. These species inhabit a wide range of climates across Eurasia, exhibiting diverse physiological adaptations to disease, high temperature, and water stress, while also showing variation in fruiting physiology and tree architecture. Discovery of genomic features responsible for this wide functional diversity could be applied to accelerating the genetic improvement of commercially cultivated Pyrus species. In order to characterize the genetic diversity within Pyrus, Nanopore whole genome DNA sequencing has been completed on 24 Pyrus accessions collected from the National Clonal Germplasm Repository, enabling highly contiguous (median N50 ~30Mb) and complete (median ~99% BUSCO assessed completeness), telomere-to-telomere assemblies with Hifiasm. Ab initio gene prediction via the BRAKER pipeline followed by comparative analysis with OrthoFinder has been used to find biome specific genes, while synteny analysis via MCScanX allows for the exploration of structural alterations in the evolution of Pyrus. These newly characterized Pyrus accessions represent an expansion of genomic resources to aid in the development of more resilient pears for the future.

Speakers

June Labbancz

Texas A

Co-authors

Amit Dhingra

Texas A

Kate Evans

Washington State University

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

2:15pm CDT

PH 3 - Zinc Nanoparticles as a Seed Priming Agent to Improve Postharvest Quality of Onion Bulbs

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Strand 11B

Sweet onions (Allium cepa L.) are becoming increasingly popular due to their mild, sweet flavor and low pungency. Consequently, enhancing their pre- and post-harvest quality attributes has emerged as a key area of research. One promising method is seed nanopriming, where seeds are pre-treated with nanoparticles (NPs) to improve germination, overall plant growth, and quality. Zinc (Zn) plays a crucial role in plant metabolism, acting as a cofactor for various enzymes involved in processes like auxin production and chlorophyll synthesis, and onions are particularly sensitive to Zn deficiency. This study investigated seed nanopriming in four onion varieties: two yellow commercial types (Legend Onion and Pecos Onion) and two Texas A

Speakers

Jelisha Perera

Texas A

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest

2:15pm CDT

VSF 3 - Methyl Jasmonate Influences Health Attributes of Hydroponic Strawberries

Thursday July 31, 2025 2:15pm - 2:30pm CDT

Foster 1

Methyl jasmonate (MeJA) is a plant signaling compound known to influence secondary metabolite production, including phenolic compounds and antioxidants. While many studies have shown MeJA’s effects applied to fruit post-harvest, this study aimed to evaluate its effects applied to the foliage and fruit of strawberries (Fragaria × ananassa ‘Seascape’ and Fragaria × ananassa ‘Ft. Laramie’) before harvest, which has been studied to a lesser extent. The effects were measured by evaluating harvest metrics (number of fruits produced and the total mass of fruit per plant) as well as assays quantifying bioactive compounds related to human health. Strawberries were grown using a deep-water culture (DWC) hydroponics system in a controlled greenhouse environment located in Fargo, North Dakota. Plants were treated with MeJA at varying concentrations (0 mM, 0.25 mM, 0.5 mM, 1 mM) as an aqueous solution, with approximately 15 ml sprayed onto the leaves and developing fruit bi-weekly. Fruit extractions in water and 12% ethanol were analyzed for total soluble phenolics and antioxidant capacity using spectrophotometric assays, while enzyme inhibitory activities were assessed using in vitro biochemical inhibition assays. Results were inconsistent across cultivars with 1 mM MeJA increasing the average mass per fruit by nearly 25% for ‘Ft. Laramie’ plants, with little response and no differences for ‘Seascape’ plants. Bioactive assays produced complicated results, with total soluble phenolics peaking at 0.5 mM MeJA for ‘Seascape’ plants while ‘Ft. Laramie’ plants showed a slightly negative trend of TSP in relation to MeJA concentration for first year plants. Results of antioxidant assays, including ABTS radical inhibition and DPPH radical inhibition will be discussed, as will inhibition of enzymes relating to the management of hypertension and diabetes, including α-amylase, α-glucosidase, and angiotensin-converting enzyme.

Speakers

Mason Hill

North Dakota State University

Plant Science Master's student at NDSU

Co-authors

Harlene HattermanValenti

NDSU

Thursday July 31, 2025 2:15pm - 2:30pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Funding Source North Dakota State University

2:30pm CDT

CE 6 - Light Intensity During Radish and Kale Microgreen Production Influences Nutritional Quality and Consumer Perception

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Strand 12B

Microgreens have become popular due to their high nutritional value, quick production time, and versatile culinary applications. Color has been known to influence consumer purchasing habits but can also inform consumers perception of the nutritional quality. To improve the economic feasibility of controlled environment microgreen production, altering light intensity can be a tool to achieve the desired color and aesthetic profile of microgreens, improve yield, and increase nutritional quality. The objective of this research was to determine the effect of light intensity on the growth, color, and nutritional quality of ‘Red Rambo’ and ‘Daikon’ radish (Raphanus sativas) and ‘KX-1’ and ‘Toscano’ kale (Brassica oleracea), and the subsequent effect on consumer preference and perception of nutritional quality. Radish cultivars were grown for 7 days and Kale cultivars were grown for 14 days in 28 x 28 cm trays filled with a peat-based substrate, irrigated with 12N-1.8P-13.4K fertilizer at 100 ppm N supplemented with 15 ppm MgSO4 in reach-in growth chambers at 22 °C. Light intensities of 175 and 575 µmol·m−2·s−1 at a 16-h photoperiod were provided with broad-spectrum white LEDs. At harvest, growth and nutritional quality were quantified, and representative photographs were taken of each treatment to assess plant color. Photographs were then used in a survey of a representative population of the state of Tennessee made up of 821 participants. Consumers perceived higher nutritional content in the green ‘Daikon’ radish and ‘Toscano’ kale yet dark purple ‘Red Rambo’ radish and ‘KX-1’ kale, achieved with high intensity lighting, ranked higher for overall liking. These results were used in conjunction with appearance and nutritional quality data to assess consumer accuracy in identifying nutritional quality. Thus, the impact of light intensity on radish and kale microgreen appearance and nutritional quality can be linked to consumer perceptions to create effective production and marketing strategies for producers.

Speakers

Jacob Friedrich

University of Tennessee Knoxville

Co-authors

Alicia L Rihn

University of Tennessee

Julia Pope

University of Tennessee Knoxville

Kellie Walters

University of Tennessee Knoxville

Natalie Bumgarner

University of Tennessee

Sarah Armstrong

University of Tennessee Knoxville

Spencer Givens

University of Tennessee Knoxville

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source Funding was provided by the Tennessee Department of Agriculture - USDA Specialty Crop Block Grant.

2:30pm CDT

FLOR 3 - Investigating applications of black soldier fly larvae (Hermetia illucens) frass in ornamental horticultural production

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Strand 11A

Frass is the left-over substrate produced from mass rearing insects as food and feed. Black soldier fly (Hermetia illucens) larvae frass has become a popular option for vegetable production as a potential fertilizer and peat replacement. Controlled environment propagation of ornamental crops requires large amounts of peat, therefore researching alternative substrates has a rising interest for growers. Pansies (Viola x wittrockiana), Marigold ‘Inca II’(Tagetes erecta), and Marigold ‘Safari’(Tagetes patula) were grown in growth chambers to evaluate the incorporation of frass into peat based substrates for ornamental production: 3 treatments from previous studies (BSF 10, 20, and 30%), 1 treatment included to assess the impact of leaching on frass (BSF 40-), and a 100% peat control (CP 100%). Pansies grown in the BSF treatments of were statistically comparable to the control in all parameters except, root weight. Pansy root weight was significantly higher in the treated BSF 40- treatment. BSF 40% produced the lowest values in all crops and parameters, except for Marigold ‘Inca’ root weight, where only BSF 40- was significantly higher. BSF 40- was significantly greater or equal to the control in all crops and parameters, except for Marigold ‘Safari’ plant size and root weight. Chlorophyll concentrations were statistically comparable across all treatment and control in all crops. Past research and this study generally indicate that at large concentrations, like 40%, frass can have negative outcomes for crop production in peat based substrates. However, due to the success of our leached treatment, BSF 40-, it seems frass can be utilized at larger concentrations, but additional alterations may be required before mixing into growing medias and substrates. Additionally, certain crops appear to have more neutral and positive reactions to frass incorporation. Engaging efforts to target ideal crops will improve the application and practicality of this research.

Speakers

Maria Chavez

New Mexico State University

Co-authors

Jennifer Bousselot

Colorado State University

Joshua Craver

Colorado State University

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture
Funding Source CSU Spur

2:30pm CDT

GG 2 - Analysis of Genomic Variation through Whole-Genome Sequencing in Korean Peach Genetic Resources

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Foster 2

Peach (Prunus persica (L.) Batsch) is a member of the genus Prunus within the Rosaceae family and represents one of the most extensively cultivated temperate deciduous fruit crops, ranking after apples and pears in global production. Due to its diploid genome (2n = 16) and relatively small genome size (~230 Mb), peach serves as a model species for fruit tree genome research. In this study, we performed whole-genome sequencing (WGS) on 445 peach genetic resources using the Illumina NovaSeq 6000 platform at a sequencing depth of 15´ coverage. Single nucleotide polymorphisms (SNPs) were identified from the WGS data and used to establish a core collection of peach genetic resources. Additionally, these SNPs will be utilized in a genome-wide association study (GWAS) to investigate key agronomic traits, including fruit shape, pollen fertility, flower morphology, maturity timing and so on. SNP filtration was conducted based on the following criteria: (1) SNPs with a missing rate exceeding 30% were removed, and (2) SNPs with a minor allele frequency (MAF) below 0.05 were excluded. As a result, 944,670 high-confidence SNPs were identified across the peach genetic resources. Based on this dataset, we established a core collection consisting of 150 accessions that retained over 99% of the total genetic diversity observed within the 445 peach genetic resources. Furthermore, we developed a high-resolution melting (HRM) marker derived from WGS-identified SNPs, which enables differentiation between round and flat peach fruit shapes. The SNP regions that can distinguish the fruit shape (round and flat shape) identified in this study were confirmed to be the same regions as the results of previously reported papers. Collectively, we successfully constructed a peach core collection through WGS analysis and developed a HRM marker for fruit shape classification. Also, our results produced in this study should be valuable for peach breeding program, identifying of agriculturally important genes, GWAS analyses, and further genomic studies in peach.

Speakers

Namhee Jeong

National Institute of Horticultural and Herbal Science, RDA

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

2:30pm CDT

PH 3 - Strawberries - A Plea for Common Sense for Research on Edible Coatings

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Strand 11B

A large and expanding literature about the application of skin coatings to fruits and vegetables has developed. Interest in coatings is being driven in part by concerns about the use of plastic films for packaging. While several major crops are routinely treated with coatings, many research studies do not consider the commercial logistics of applying coatings to the product. The prime example of this issue is strawberry fruit, which are usually field packed into clam shell containers, cooled, and in some cases stored in pallet shrouds that are injected with high carbon dioxide, before being sent to market. Despite claims that strawberry storage is problematic because of its short storage life, the market size continues to grow steadily, e.g., internationally from $15.3 billion in 2023 to $15.88 billion in 2024, success being based on cultivar selection and standard technologies. Despite this, numerous reviews on postharvest handling of strawberries cite technologies and treatments as if they are applied commercially. A Web of Science search with the words ‘strawberry’ and ‘skin coatings’ reveals 760 publications, mostly in the last 25 years. The reality is that almost without exception, no commercial application is viable because they do not fit well with harvest and handling processes that are focused on getting fruit market expeditiously. Breeding programs are critically important strategies to improve strawberry fruit storability. Where postharvest technologies or treatments may have a place for further development it most likely through modified atmosphere packaging either passive or active. The best coating for strawberries is chocolate.

Speakers

Chris Watkins

Cornell University

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Strand 11B

Oral presentation, Postharvest 3

Subject Postharvest
Funding Source Hatch multistate NE2336

2:30pm CDT

VSF 3 - Strawberry (Fragaria ×ananassa) yield fluctuations follow a multi-modal Gaussian model

Thursday July 31, 2025 2:30pm - 2:45pm CDT

Foster 1

Strawberries (Fragaria ×ananassa Duch.) are highly perishable and require intensive labor inputs for harvesting. Therefore, yield forecasting is critical for improving labor management and marketing decision-making in strawberry production. In Florida, United States, strawberry yields during winter months have a unique distribution pattern characterized by multiple waves. We hypothesized that individual yield waves can be described using Gaussian distribution, a model that represents a symmetrical bell-shaped curve. Two short-day cultivars (‘Florida Radiance’ and ‘Florida Brilliance’) and one day-neutral cultivar (‘Florida Beauty’) were grown in west-central Florida. Harvesting was performed 30 times, generally twice a week from November through February. Yield data were converted to weekly values prior to model fitting. The first two yield waves were described by a bimodal Gaussian distribution model, which was then converted into two unimodal Gaussian distribution models. The goodness of fit was very high (R2 = 0.934–0.959) for both yield waves in all tested cultivars. Different yield distribution patterns of the tested cultivars were characterized quantitatively by estimating not only the yield but also the timing and duration of each yield wave. Our modeling approach provides insights into understanding cultivar-dependent fruiting phenology, yielding capacity, and fruit earliness. Such information can help optimize yield distribution through breeding and reduce yield gaps by using different cultivars or staggered planting dates. The model developed here only applies to the first two waves of fruit production. Future research will aim to model the following yield waves to fully characterize the strawberry yield distribution.

Speakers

Shinsuke Agehara

University of Florida

Co-authors

Dante Pinochet

Austral University of Chile

I am Profesoor in Soil Science working in horticultural crops nutrition

Thursday July 31, 2025 2:30pm - 2:45pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Poster # csv
Funding Source Florida Strawberry Research and Education Foundation

2:45pm CDT

CE 6 - Quantifying the Effects of Daily Light Integral on Growth of Spring Radish Grown in Hydroponic Systems

Thursday July 31, 2025 2:45pm - 3:00pm CDT

Strand 12B

While recommendations for optimal daily light integral (DLI) exist for numerous food crops grown in controlled environments, this is not the case for spring radish (Raphanus raphanistrum subsp. sativus. This experiment set out to quantify the effect of DLI on growth of spring radishes cultivated in ebb-and-flood hydroponic systems. Seeds of two spring radish cultivars, ‘Red Castle’ and ‘Crunchy King’, were sown into separate 72-cell commercial plug trays filled with a soilless peat-based substrate and placed into one of five ebb-and-flood irrigation systems in a climate controlled greenhouse. To create the DLI treatments, frames were constructed over each flood table and commercial shade cloth was installed to create five differing levels of DLI; ‘very low’ (≤ 2.0 mol·m–2·d–1), ‘low’ (2.0–5.9 mol·m–2·d–1) ‘medium’ (6.0–9.9 mol·m–2·d–1), ‘high’ (10.0–14.9 mol·m–2·d–1) and ‘very high’ (≥ 15.0 mol·m–2·d–1). One frame was left uncovered to create the ‘very high’ treatment. Supplemental light was provided by high pressure sodium lamps with a target intensity of 150 µmol·m2·s1 and were operated to provide a 16-h photoperiod throughout the study. Samples were subirrigated once daily for the first 14-d of the experiment, with an additional irrigation added during the final 14-d. A complete, balanced, water-soluble fertilizer providing 200 ppm nitrogen was supplied at every irrigation. 28-d after seeding, samples were harvested and data collected. Radishes on the edges of the trays were discarded and a block of 10 samples was selected to ensure uniformity. The diameter of the hypocotyl in addition to fresh and dry mass were recorded. Data was additionally taken on shoots, including the number of mature leaves, length of the longest leaf, and fresh and dry mass of excised tissues. Finally, relative chlorophyll concentration was measured using a soil-plant analysis development (SPAD) meter. Results indicate that hypocotyl diameter of spring radish is maximized at 15.2 mol·m–2·d–1 with fresh and dry mass positively correlating strongly with diameter. Additionally, the number of mature leaves increased by up to 2 leaves up to 10.0 mol·m–2·d–1 but not beyond, while leaf length and SPAD decrease beyond DLIs of 14 mol·m–2·d–1. Shoot fresh and dry mass were greatest at DLIs of 14.0-17.0 mol·m–2·d–1. This study provides valuable information for producers interested in incorporating spring radish in their operation, and to those looking to maximize yield and overall plant quality.

Speakers

Christopher Currey

Iowa State University

Co-authors

Peter S. Konjoian

Konjoian's Horticulture Education Services

Ryan Niepagen

Iowa State University

Thursday July 31, 2025 2:45pm - 3:00pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Poster # csv

2:45pm CDT

FLOR 3 - Using Plant Growth-Promoting Rhizobacteria to Enhance Plant Growth with the Ferrous Sulfate Bridge Method of Reducing Ph

Thursday July 31, 2025 2:45pm - 3:00pm CDT

Strand 11A

Phosphorus (P) is an essential macronutrient required for plant growth. In fertilizers used for soilless substrates, P is in the form of phosphate and is readily leached from containers leading to environmental contamination. The FeSO4 bridge method has been proposed to reduce P losses by forming insoluble iron-phosphate complexes that retain P within the substrate, but reduced bioavailability may limit plant growth. The aim of this research was to evaluate the FeSO4 bridge method in combination with inoculation of the substrate with phosphate-solubilizing bacteria (PSB) and siderophore-producing bacteria (SPB) to gradually release P for plant uptake. An experiment was conducted to evaluate the growth of marigolds ‘Durango Yellow’ (Tagetes patula) using a substrate composed of 80% peat and 20% perlite by volume, with substrate either amended or not amended with 3.0 kg·m-3 FeSO4·7H2O. After transplanting, plants received 100 mg·L-1 N from 15N-2.2P-12.5K-2.9Ca-1.2Mg Jack’s Professional water-soluble fertilizer as the P source for two weeks to promote the formation of iron-phosphate complexes. Additionally, two bacterial application strategies were evaluated: one starting from transplanting and another applied when P deficiency symptoms appear, with three weekly inoculations each. The bacterial treatments included: a control without bacterial inoculation; three PSB strains, Bacillus megaterium (C3F10), Pantoea rwandensis (C3A8), and Pseudomonas sp. (C6E7); one SPB strain Pseudomonas soli (C10A8); and a commercial inoculum of Bacillus velezensis (from the biostimulant LalRise Vita, Lallemand, Inc). Plants were grown under controlled greenhouse conditions, with weekly measurements of spectral variables and morphological parameters using the TraitFinder digital phenotyping system. Leachate was collected using the pour-through method and analyzed for P concentrations using ion chromatography. The results confirmed that the FeSO4 bridge method formed iron-phosphate complexes, reducing P leaching when amending the substrate with 3.0 kg·m-3 FeSO4·7H2O compared to non-amended substrate. Visual differences in plant growth were observed among treatments, with better outcomes when bacterial inoculation started at transplanting. In contrast, plants that received bacterial treatment after symptoms appeared could not recover, showing significantly reduced visual quality. Among the bacterial treatments, Pseudomonas soli (C10A8) promoted the highest biomass accumulation and spectral variables such as hue and green leaf index (GLI) indicated improved visual quality compared to the control (no bacteria) and other bacterial strains. These findings demonstrated that amending soilless substrates with FeSO4, combined with bacteria like Pseudomonas soli (C10A8), enhances P retention while promoting plant growth. This method offers growers a practical approach to reducing environmental impact while maintaining crop quality.

Speakers

Alexandra Espinoza

The Ohio State University

Co-authors

James Altland

USDA-ARS

Michelle Jones

The Ohio State University

Thursday July 31, 2025 2:45pm - 3:00pm CDT
Strand 11A

Oral presentation, Floriculture Floriculture 3

Subject Floriculture
Poster # csv

2:45pm CDT

GG 2 - Population Structure Analysis in Peach and Development of KASP Markers using SNPs generated by Capture-Seq technology

Thursday July 31, 2025 2:45pm - 3:00pm CDT

Foster 2

Although peach production worldwide has been increasing for decades, peach production in the United States continues to decline in the face of changing climate, disease pressures, and reduced consumption. Novel and diverse germplasm is required to improve peach breeding efforts with the goal of developing new cultivars better adapted to these challenges. Unfortunately, current peach SNP genotyping platforms are expensive and need to be outsourced to specialized laboratories. The purpose of this project is to use SNPs generated using Capture-Seq technology to evaluate the diversity of potential new sources of breeding material in comparison with germplasm from different regions of the world. In addition, our goal is to create a panel of SNP-based markers that can be used in-house for future studies. Capture-Seq technology yielded 134,424 SNPs when comparing P. persica (221 genotypes) and related Prunus species (29 genotypes). A PCA from these SNPs yielded different clusters representing Asian, Australian, European, and North American germplasm. AMOVA indicated that, among P. persica samples, 21.3% of the genetic variation was between regions with 78.7% of the variation present within regions. STRUCTURE analysis showed differences between regional groups, where the Asian group composition was different to the other regions, North American and European group composition were similar to each other, and the Australian group composition had a large percentage of genotypes sharing a group mostly present in Asia. This study confirms that Australia’s peach populations could be a valuable source of novel germplasm to bolster worldwide peach breeding efforts. Furthermore, a panel of informative SNP markers can be converted into KASP markers, which can be used in-house for numerous applications, including genetic fingerprinting, MAS, GWAS, among others.

Speakers

Caitlin McCann

University of Georgia

Co-authors

Bruce Topp

University of Queensland

Dario Chavez

University of Georgia

Dougal Russel

Queensland Government

Jeekin Lau

USDA

Jose Chaparro

University of Florida

Rachel Itle

University of Georgia

Thursday July 31, 2025 2:45pm - 3:00pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm

2:45pm CDT

VSF 3 - Fruit Ripening and Cell Wall Composition in Cranberry (Vaccinium macrocarpon Ait.) Cultivars With Contrasting Firmness

Thursday July 31, 2025 2:45pm - 3:00pm CDT

Foster 1

Fruit firmness is a critical quality trait that influences both postharvest life and potential commercialization of fruits. In cranberry, fruit firmness is highly correlated with the efficiency of producing higher valuable products such as sweetened and dried cranberries (SDC). As in many fruit crops, cranberry firmness declines during ripening, a process often associated with enzymatic solubilization of cell wall polysaccharide. Calcium (Ca) plays a fundamental role in maintaining cell wall integrity by cross-linking with pectins to form calcium pectates, which strengthen the cell wall and limits its disassembly. The objective of this study was to determine changes in cell wall composition through fruit development in two cranberry cultivars with contrasting fruit firmness. Fruit samples were collected every two weeks from 14 to 91 days after full bloom (DAFB) from cranberry ‘Stevens’ and ‘BG’. External fruit quality traits–such as anthocyanin accumulation, fruit size, and weight– were measured alongside internal fruit quality parameters, including internal structure, cell wall composition, and calcium content. Before fruit color developed, both cultivars were similar in size and firmness; however, ‘Stevens’ had higher fruit elasticity compared to ‘BG’. This difference was attributed to lower pectin solubility in the cell walls of ‘Stevens’. As ripening progressed, notable differences in firmness emerged between the two cultivars, particularly between 84 and 91 DAFB. This divergence was associated with increased solubilization of pectins and hemicellulose. Additionally, solubilization of tightly bound hemicellulose was negatively correlated with Ca content in the fruit cell wall. Differences in cell wall-associated Ca content between cultivars were observed throughout fruit development and may explain the variation in firmness at harvest and after 30 days of storage. These findings suggest that cell wall-bound Ca is an important factor influencing fruit firmness and could serve as a valuable selection parameter in breeding programs. Moreover, understanding these differences may aid cranberry growers in in making informed cultivar selection decisions for their plantings.

Speakers

Pedro Rojas-Barros

Washington State University

Co-authors

Amaya Atucha

University of Wisconsin Madison

Beth Ann Workmaster

University of Wisconsin-Madison

Juan Zalapa

University of Wisconsin-Madison

Thursday July 31, 2025 2:45pm - 3:00pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Funding Source U.S. Department of Agriculture, Grant/Award Number: Hatch project 1025852

2:59pm CDT

PBIG 3 - Oral Session

Thursday July 31, 2025 2:59pm - 3:00pm CDT

Strand 11B

Presiding/Moderator

Heather Gladfelter

University of Georgia

Thursday July 31, 2025 2:59pm - 3:00pm CDT
Strand 11B

Oral presentation, Plant Biotechnology 3

Subject Plant Biotechnology

3:00pm CDT

CE 6 - Quantifying the Effect of Air Temperature on Growth and Development of Spring Radish Grown Hydroponically

Thursday July 31, 2025 3:00pm - 3:15pm CDT

Strand 12B

Temperature moderates various plant physiological processes, in turn affecting the overall rate of development, and is utilized in controlled environment food crop production to influence product yield, quality, and to manage crop scheduling. Root crops, including spring radish (Raphanus raphanistrum subsp. sativus), currently represent a niche segment within commercial controlled environment food production. The lack of reliable cultural information has been noted as a reason producers may be hesitant to introduce new crops to their operations. To expand commercial adoption, this study aims to quantify the effect of air temperature on spring radish development, specifically determining minimum temperature (Tmin), optimum temperature (Topt), maximum temperature (Tmax), and linear temperature range. Two cultivars of spring radish, ‘Crunchy King’ and ‘Red Castle’, were grown in separate climate-controlled environmental growth chambers providing continuous target air temperatures of 8, 13, 18, 23, 28, and 33 °C, a range of 25 degrees. Samples were grown in commercial 72-cell plug trays filled with peat-based substrate and fertigated with custom ebb-and-flood systems providing 200 ppm nitrogen at every irrigation. A 16-h photoperiod was provided, with a target light intensity of 200 µmol·m2·s1. Samples were harvested 28-d after seeding and data collected, including diameter of the hypocotyl, number of mature leaves, and length of the longest leaf. A measure of relative chlorophyll concentration was recorded, and finally, fresh and dry mass of the hypocotyls and shoot tissue was measured. Results indicate that hypocotyl diameter increases linearly from Tmin at 3 °C, reaching a maximum at Topt of 23 °C. Beyond this point, diameter is reduced, with Tmax occurring at 35 °C. Hypocotyl fresh and dry mass followed similar patterns, correlating strongly with diameter. Leaf number was observed to be maximized at 18 °C, with no significant increase beyond this temperature. Leaf length was maximized at 23 °C and decreased with increasing temperature. Average daily temperature was observed to have no significant effect on relative chlorophyll concentration. Notably, we found that there was no significant difference between the two cultivars in their response to air temperature. The results of this study offer important guidance to producers interested in introducing spring radish into their operation, while maximizing crop quality and yield.

Speakers

Christopher Currey

Iowa State University

Co-authors

Peter S. Konjoian

Konjoian's Horticulture Education Services

Ryan Niepagen

Iowa State University

Thursday July 31, 2025 3:00pm - 3:15pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Poster # csv

3:00pm CDT

GG 2 - Unlocking the Citrus Code: 'Hamlin' Genome Sequencing for Breeding Program Advancement in Florida

Thursday July 31, 2025 3:00pm - 3:15pm CDT

Foster 2

‘Hamlin 1-4-1’ sweet orange (Citrus sinensis L. Osbeck) is one of the major varieties cultivated in Florida and is of relevant importance for the orange juice industry as an early maturing variety. While this cultivar does not produce juice of sufficient quality to meet USDA Grade A orange juice standards, it performs relatively well in semitropical climates characterized by high temperatures and humidity levels. To provide the bioinformatics tools required to support the genetic improvement of modern citrus varieties, we present the de novo and fully phased ‘Hamlin’ genome. The DNA of the plant was sequenced using two different platforms. PacBio technology was adopted to generate long reads sequencing, while Oxford Nanopore was employed to produce ultra-long reads. Hi-C technique was used to capture chromosome conformation and facilitate the correct assembly of contigs into two haplotypes. RNA samples were collected from five different tissues (leaves, petals, ovaries, peel, and bark) and sequenced with the Illumina platform. These RNA sequences enabled the identification and annotation of as many functional genes as possible. The results of this study will provide the genomic information required to compare the ‘Hamlin 1-4-1 genome with the more commonly grown industry standard ‘Valencia’ and to investigate the differences between the genomes of these two clonally derived sweet oranges. These data will also aid in comparing budlines of Hamlin and other sweet orange accessions that appear to be HLB tolerant. This research will facilitate the detection of DNA variants related to traits of interest and their integration in new germplasm resources. In addition, it will allow breeders to get further insights into mutations that may have occurred to new budlines originating from ‘Hamlin’.

Speakers

Giuseppe Lana

University of Florida

Co-authors

Frederick Jr. Gmitter

University of Florida

John Chater

University of Florida

Thursday July 31, 2025 3:00pm - 3:15pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm
Poster # csv

3:00pm CDT

PBIG 3 - Effect of Cold Treatments on the Germination of Somatic Embryos of Cornus florida

Thursday July 31, 2025 3:00pm - 3:15pm CDT

Strand 11B

Cornus florida (flowering dogwood) is a valuable tree native to eastern North America and prized for its floral bracts and colorful foliage. However, the tree is highly susceptible to powdery mildew (PM), a common fungal disease that challenges ornamental plant production. There are bioengineering approaches to developing PM resistance that involve the introduction of genes into C. florida cells and the regeneration of plants through somatic embryogenesis (SE). SE is a process by which somatic cells have the capacity to produce embryos without sexual reproduction. In C. florida, the regeneration of transgenic somatic embryos into plants has been problematic. Our work aims to determine the impact of cold treatments on the germination of somatic embryos. We propose that short-term low-temperature treatments will improve embryo germination, considering past research has demonstrated the importance of periodic low temperatures on natural seed germination in woody plant species such as fruit trees. We cultured a transgenic line of C. florida embryogenic callus expressing a visual marker (ß-glucuronidase) and enriched for globular stage embryos. We then introduced these globular embryos into liquid suspension media allowing the embryos to proliferate pro-embryogenic masses (PEMs) needed for mass embryo production. We chose somatic embryos morphologically identical to zygotic embryos of the same stage of development for testing plant regeneration following exposure to four different temperature conditions over four different time periods. The four different temperatures included: (1) 3°C; (2) 4°C; (3) 7°C; and (4) 23°C as the control temperature. The four different time exposures to the different cold periods included 0, 2, 4, and 6 weeks. Following cold exposure for a designated time, we transferred the somatic embryos to germination media, exposing the embryos to fluorescent light at room temperature ( /-) 23°C. Successful germination of the somatic embryos was indicated by taproot elongation with the production of roots, greening of the cotyledons, emergence of the apical shoot, followed by expansion of epicotyl and primary leaves. This research will yield the first transgenic C. florida plants and enable the introduction of PM resistance using bioengineering methods.

Speakers

Heather Gladfelter

University of Georgia

Co-authors

Dayton Wilde

University of Georgia

Oscar de la Torre

University of Georgia

Thursday July 31, 2025 3:00pm - 3:15pm CDT
Strand 11B

Oral presentation, Plant Biotechnology 3

Subject Plant Biotechnology

3:00pm CDT

VSF 3 - Assessing Olive Cultivation Potential in the Subtropical United States: Insights from Florida Trials

Thursday July 31, 2025 3:00pm - 3:15pm CDT

Foster 1

Olive cultivation in Florida has expanded ten-fold over the last decade, with more than 60 growers managing 800 acres across 26 counties. Despite this rapid growth and rising global demand for olive oil, research on cultivar performance and best management practices in Florida remains limited. In summer 2023, data collection began at three research sites: Jay (northwest Florida), Wauchula (southwest Florida), and Fort Pierce (southeast Florida); to evaluate the adaptability and productivity of select olive cultivars under diverse climatic and soil conditions. Due to differences in grove management and tree maturity, cultivar selection varied by site, with ‘Arbequina’ consistently included in all trials. Additional cultivars included ‘Koroneiki’ and ‘Sikitita’ in Wauchula, and ‘Lecciana’ and ‘Sikitita’ in Fort Pierce. Soil nutrients, leaf nutrients, temperature, moisture, and phenological development were monitored biannually. While no nutrient deficiencies were observed, a significant result emerged: ‘Arbequina’ demonstrated superior adaptability across all three sites, showing higher survival rates and more uniform vegetative growth compared to other cultivars. However, flowering and fruit production patterns remain inconsistent, likely due to climatic variability and limited chilling hours. These findings suggest that ‘Arbequina’ may be viable for Florida conditions, but further data are needed to fully assess yield potential and long-term economic feasibility.

Speakers

Lorenzo Rossi

Assistant Professor, Texas A&M University

Co-authors

Alejandro Bolques

Florida A

Audrey Beany

UF/IFAS/IRREC

Davie Kadyampakeni

University of Florida

John-Paul Fox

University of Florida

Michael Garcia

Florida Olive Council, LAA

Thursday July 31, 2025 3:00pm - 3:15pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Funding Source UF/IFAS SEEDIT

3:15pm CDT

CE 6 - Influence of Air Temperature and Cultivar on Lettuce Yield, Morphology, and Production Considerations in Greenhouses

Thursday July 31, 2025 3:15pm - 3:30pm CDT

Strand 12B

Lettuce (Lactuca sativa) is an economically important leafy green widely cultivated in greenhouses, yet the interaction between cultivar and air temperature remains poorly characterized for many of the cultivars currently marketed for controlled environment (CEA) production. Even in climate-controlled greenhouses, internal air temperatures can exceed general recommendations, leading to bolting, excessive stem elongation, bitter flavors, and reduced yields. This study aimed to generate benchmark yield and morphological data for 20 lettuce cultivars grown hydroponically in a greenhouse during a fall (20 °C mean air temperature) and summer (28 °C mean air temperature) production cycle, with harvests at 9 (juvenile stage) and 21 (mature stage) days after transplanting (DAT). Lettuce cultivars were grown in a common nutrient film technique (NFT) system with average pH and electrical conductivity (EC) of 5.6 and 1.5 dS·m−1, greenhouse day and night air temperature setpoints of 21 °C and 18 °C, and a target average daily light integral (DLI) of 17 mol·m−2·d−1. The experiment was set up as a randomized complete block design with two blocks. Depending on the cultivar, air temperature, and harvest time, lettuce shoot fresh mass (SFM) and projected canopy area (PCA) were significantly different. However, regardless of the cultivar or harvest time, yield (kg·m−2·year−1) was always greater at 20 °C than 28 °C. Supraoptimal air temperatures increased stem and leaf elongation, potentially improving light interception and SFM per plant early in production, but required more area per plant to grow without significantly overlapping with neighboring plants, thus reducing planting density and yield potential. Supraoptimal air temperatures decreased specific leaf area (SLA), resulting in thicker leaf lamina. Chlorophyll concentration was more affected by cultivar than harvest date or air temperature. Benchmarking greenhouse lettuce yield and morphology across cultivars and seasons offers growers a valuable tool to reliably assess productivity, select appropriate cultivars, and adjust planting density. These insights also inform breeding efforts to improve the yield from CEA systems, with particular attention to plant architecture and leaf traits suitable for automated harvesting and packaging in greenhouse systems.

Speakers

Eric Stallknecht

Virginia Tech

Thursday July 31, 2025 3:15pm - 3:30pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source USDA National Institute of Food and Agriculture, Hatch project, 160240

3:15pm CDT

GG 2 - Investigating patterns of aneuploidy in potatoes using the R Package Qploidy.

Thursday July 31, 2025 3:15pm - 3:30pm CDT

Foster 2

Aneuploidy refers to a condition in which a cell or organism that has an abnormal chromosome number compared to the base chromosome number. This can cause gene dosage imbalances and a potential decrease in fitness. Most potato (Solanum tuberosum) cultivars are tetraploid (2n=4x=48) with a base chromosome number of 12. In this study, we analyzed 1,014 potato genotypes, 422 from two autotetraploid bi-parental full-sib populations and 592 from a diversity panel. We used allele SNP fluorescent intensity data for each individual to determine their ploidy and identify aneuploid individuals using the R package Qploidy. This package estimates the copy number by evaluating the standardized B allele frequencies (BAF) distributions across a sample, chromosome, or chromosome arm. Within the mapping populations, 41% of the members were aneuploids, compared to only 17% of the in the diversity panel; with an average of 27% aneuploidy level across all individuals included in the study. However, the frequency of aneuploidy for any given chromosome was 3%. As a measure of fitness, we compared 19 phenotypic traits related to tuber yield and quality in one of the full-sib mapping populations. There were significant differences between aneuploid and euploid family members for six traits. Aneuploid genotypes had significantly lower total tuber weight/plant, marketable tuber weight/plant, non-marketable tuber number/plant, tuber density, and overall appearance, while having higher percentage of tubers with heat sprouts compared to euploid family members. Chromosome additions were more common than chromosome losses in aneuploid individuals accounting for 57% and 39% of the aneuploid chromosomes, respectively. By analyzing this large potato genotypic dataset (most autotetraploids), we gained a better understanding of patterns of aneuploidy and their impact on crop performance in polyploid crops.

Speakers

Tessa Hochhaus

Texas A

Co-authors

Amaka Ifeduba

SR1

Cris Taniguti

Cornell University

Jeewan Pandey

Texas A

Maria Isabel Vales

Texas A

Oscar Riera-Lizarazu

Texas A

Thursday July 31, 2025 3:15pm - 3:30pm CDT
Foster 2

Oral presentation, Genetics and Germplasm 2

Subject Genetics and Germplasm
Poster # csv

3:15pm CDT

PBIG 3 - Rapid Race Differentiation of Fusarium oxysporum f. sp. niveum (FON) in Watermelon Using a Single PCR-Based Assay

Thursday July 31, 2025 3:15pm - 3:30pm CDT

Strand 11B

Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (FON), remains a major threat to watermelon production worldwide. Effective management depends on accurate race identification, as resistance in commercial cultivars is race-specific. However, current bioassay-based race differentiation is unreliable due to genetic variability within isolates. While molecular identification exists for FON Races 1 and 2, confirming Race 3 has required multiple PCR reactions, making diagnostics cumbersome and inefficient. This study developed and optimized a multiplex PCR assay that simultaneously differentiates FON Races 1, 2, and 3 in a single reaction, significantly improving diagnostic speed and accuracy. FON isolates and related Fusarium species from Georgia, Florida, and South Carolina were tested to assess the assay’s sensitivity (0.5 ng/µL detection limit) and specificity. Results confirmed that the multiplex PCR effectively distinguishes FON from non-pathogenic Fusarium species while accurately identifying all three pathogenic races. This is the first successful multiplex PCR assay for FON race differentiation, providing a rapid, reliable tool for plant pathologists and diagnosticians to track the spread of virulent FON races. Given the increasing prevalence of Race 3, which lacks effective fungicidal control, this tool will support early intervention strategies to mitigate outbreaks and inform resistance breeding programs. Keywords: Fusarium oxysporum f. sp. niveum (FON), multiplex PCR, race differentiation, watermelon wilt.

Speakers

Abdul-lateef Popoola

Alcorn state university, Lorman, MS

Co-authors

Ali Emran

Alcorn state university

Sumyya Waliullah

Alcorn state university

Thursday July 31, 2025 3:15pm - 3:30pm CDT
Strand 11B

Oral presentation, Plant Biotechnology 3

Subject Plant Biotechnology

3:15pm CDT

VSF 3 - Strawberry Cultivar Assessment under Organic Production in a High Tunnel Tabletop System

Thursday July 31, 2025 3:15pm - 3:30pm CDT

Foster 1

Given the challenges associated with soil fertility management and disease, pest, and weed control in organic strawberry production, different growing practices and systems have been evaluated to address site-specific conditions and constraints. This study was aimed at assessing strawberry cultivar yield responses to the soilless substrate-based tabletop system in organically managed high tunnels. The research trial was carried out on certified land at the University of Florida Plant Science Research and Education Unit in Citra, using a split plot design with four replications (each high tunnel serving as a replication). The tabletop strawberry troughs (1 m long) were filled with the soilless substrate consisting of a mixture of pine bark and locally available composts for growing seven strawberry cultivars, including ‘Ember’, ‘Encore’, ‘Florida Beauty’, ‘Florida Brilliance’, ‘Florida Felicity’, ‘Florida Medallion’, and ‘Florida Pearl’, at two spacings, i.e., 6 plants/trough (S6) vs. 8 plants/trough (S8). Spacing was the whole plot factor and strawberry cultivars were included in the subplots, with two troughs as an experimental unit. In addition to preplant incorporation of the granular organic fertilizer into the substrate, liquid organic fertilizer was applied throughout the production season. Bare-root strawberry plants were transplanted into the tabletop troughs inside high tunnels in October 2024 and the first harvest took place in late November. Fruit yield data were analyzed for the harvest period from November 2024 to early May 2025. ‘Encore’ and ‘Florida Felicity’ were top performers in terms of whole-season marketable fruit yield, while ‘Florida Brilliance’ exhibited the lowest yield potential. ‘Encore’ showed the highest average marketable fruit weight, whereas ‘Florida Pearl’ produced the smallest fruit. The whole-season marketable fruit yield and number per plant were significantly higher at S6 vs. S8, while a significant cultivar by spacing interaction was observed for marketable fruit yield and number per trough. On a per trough basis, ‘Florida Felicity’ and ‘Encore’ produced higher yields at S8 vs. S6, whereas other cultivars yielded similarly between the two spacings. ‘Florida Felicity’, ‘Encore’, and ‘Ember’ demonstrated great potential for producing early yields in this high tunnel tabletop system. Moreover, ‘Florida Felicity’ was the top yielding cultivar during the late season (mid-March to early May). Phytophthora crown and root rot and powdery mildew were among the major plant diseases detected in this study, while varying levels of disease susceptibility and plant health were observed among strawberry cultivars.

Speakers

Xin Zhao

University of Florida

Co-authors

Vance Whitaker

University of Florida

Yifan Jing

University of Florida

Thursday July 31, 2025 3:15pm - 3:30pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Funding Source This work is supported by the Urban, Indoor, and other Emerging Agricultural Production Research, Education and Extension Initiative program, project award no. 2023-70019-39370, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

3:30pm CDT

CE 6 - Comparison of Six Tabletop Hydroponic Systems and Their Performance on Lettuce Growth Characteristics and Yield

Thursday July 31, 2025 3:30pm - 3:45pm CDT

Strand 12B

Hydroponics, the cultivation technique involving soilless media, offer a potential solution to alleviate food insecurity. For this study, six tabletop hydroponic systems were evaluated for their suitability for Romaine lettuce (Lactuca sativa) cultivation. The systems included Ahopegarden, IDOO, Fulsren, LetPot, MUFGA, and Rainpoint. The experiment was set up as a completely randomized design (CRD), with 6 treatments x 3 replicates. The lettuce seeds were sown in horticultural sponges and suspended in nutrient solutions. Following germination, plant growth parameters were recorded every other day during the experimental period. The electrical conductivity (EC), total dissolved solids (TDS), pH, and dissolved oxygen (DO) were monitored weekly for each nutrient solution. The quality and quantity of the lighting systems were measured as correlated color temperature (CCT), photosynthetic active radiation (PAR), and photosynthetic photon flux density (PPFD). The data collected was subjected to analysis of variance (ANOVA). The results showed that the EC, TDS, DO, and pH did not vary greatly among the systems, except for Letpot that showed significantly lower (p

Speakers

Leonard Githinji

Virginia State University

Thursday July 31, 2025 3:30pm - 3:45pm CDT
Strand 12B

Oral presentation, Growth Chambers and Controlled Environments 6

Subject Growth Chambers and Controlled Environments
Funding Source This study was partly funded by the USDA-NIFA Grant Project entitled Optimized micro-farms as a potential solution to food insecurity in urban neighborhoods. Project Award # 2021-38821-34587.

3:30pm CDT

PBIG 3 - Dormancy Dynamics and Carbohydrate Storage in Peaches

Thursday July 31, 2025 3:30pm - 3:45pm CDT

Strand 11B

Dormancy constitutes a critical regulatory mechanism in perennial plants, conferring resilience to winter stress and impacting subsequent reproductive success. While previous investigations have predominantly focused on vegetative and floral buds during the dormancy-regrowth cycle, often neglecting the potential contributions of other plant compartments, this study adopts a comprehensive, whole-tree perspective. Utilizing four-year-old, root-bagged peach (Prunus persica) trees (cv. 'John Boy') we investigated dormancy progression by analyzing carbohydrate metabolism in different tissues relative to accumulated chilling units (CU) and growing degree hours (GDH). Our results demonstrated that roots maintained the highest starch reserves during endodormancy; however, soluble sugar accumulation in roots appeared largely independent of local starch hydrolysis, indicating potential translocation from distal storage tissues. This hypothesis is supported by the concomitant decline in starch content in branches and stems, which coincided with increased soluble sugar accumulation in these tissues. As dormancy progressed, soluble sugars were progressively redistributed, reaching peak concentrations in roots at the onset of ecodormancy and exhibiting a more uniform distribution across tissues during ecodormancy. A significant increase in floral bud soluble sugars preceding budbreak, without a corresponding starch depletion, suggests an enhanced capacity for carbohydrate uptake. Transcriptomic analysis of root tissues across all dormancy stages identified two key gene modules (ME) exhibiting inverse correlations with carbohydrate levels. Genes within ME3, associated with starch accumulation, were significantly enriched in fatty acid metabolism pathways—including SBE2, DBE1, FAD8 and KAS1. Notably, the upregulation of FAD8 during ecodormancy suggests increased membrane fluidity, potentially facilitating carbohydrate transport. Conversely, ME10 genes, associated with soluble sugar levels, displayed enrichment in hormone signaling and carbohydrate metabolism pathways—including SUS3, BAM6, and GH9A1. These findings underscore the coordinated regulation of carbohydrate metabolism and membrane lipid composition during dormancy transitions and bud break. Furthermore, the data indicate that starch catabolism in branches and stems during chilling accumulation serves as a source of soluble sugars for roots, which in turn may sustain metabolic activity and contribute to dormancy release in buds. Future research employing this whole-tree system is warranted to elucidate the comprehensive roles of roots and other storage organs in the regulation of dormancy.

Speakers

khalil Jahed

Virginia Tech

Co-authors

Sherif Sherif

Virginia Tech

Thursday July 31, 2025 3:30pm - 3:45pm CDT
Strand 11B

Oral presentation, Plant Biotechnology 3

Subject Plant Biotechnology

3:30pm CDT

VSF 3 - Assessment of Physiology and Fruit Quality in Intraspecific Hybrid Maypop (Passiflora incarnata) Selections

Thursday July 31, 2025 3:30pm - 3:45pm CDT

Foster 1

This study evaluated physiological and fruit quality traits of 24 intraspecific hybrid maypop (Passiflora incarnata) (Florida × Oklahoma) selections, grown in 3-gallon pots at the Mississippi Agricultural and Forestry Experiment Station South Mississippi Branch in Poplarville, Mississippi, in 2023. Summer physiological measurements revealed significant differences in stomatal conductance, ranging from 0.02 to 0.89 mol/m²s (0.29 mol/m²s average), transpiration, ranging from 0.31 to 7.98 mmol/m²s (3.65 mmol/m²s average), vapor pressure deficit, ranging from 0.83 to 2.56 kPa (1.51 kPa average), chlorophyll fluorescence, ranging from 0.38 to 0.67 (0.53 average), and fruit temperature, ranging from 32.00 to 39.33 °C (34.96 °C average) among selections. Significant differences were also observed in fruit size parameters, including height (45.53-64.94 mm; 56.94 mm average), width (33.83-56.32 mm; 49.56 mm average), shape (1.03-1.36 mm/mm; 1.16 mm/mm average), weight (15.41-59.66 g; 36.62 g average), and density (0.89-1.67 g/cm²; 1.25 g/cm² average). Pulp content also significantly differed, with total soluble solids ranging from 13.57 to 18.73 °Brix (15.90 °Brix average), titratable acidity from 14.77 to 23.33 g/L (17.96 g/L average), pH from 3.38 to 3.81 (3.59 average), total phenolic content from 363.72 to 603.88 mg GAE/L (481.33 mg GAE/L average), lightness (L*) from 73.94 to 80.91 (77.76 average), red-green value (a*) from -5.36 to 0.43 (-2.38 average), and yellow-blue value (b*) from 25.94 to 54.20 (39.62 average). Additionally, differential thermal analysis of the roots of these selections as well as their parents, revealed potential cold hardiness differences within P. incarnata, with Oklahoma roots exhibiting greater hardiness (-14.42 °C average) than Florida roots (-8.26 °C average), and hybrids showing intermediate tolerance (-10.53 °C average). Overall, these findings highlight the variability within P. incarnata, offering valuable insights for broader breeding efforts focused on enhancing both fruit quality and physiological traits within Passiflora.

Speakers

Haley Williams

Mississippi State University

Co-authors

Eric Stafne

Mississippi State University

Jenny Ryals

Mississippi State University

Thursday July 31, 2025 3:30pm - 3:45pm CDT
Foster 1

Oral presentation, Viticulture and Small Fruits 3

Subject Viticulture and Small Fruits
Poster # csv
Funding Source This material is based upon work that is supported by a National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch project under accession number 7003104. This project was funded through a Speciﬁc Cooperative Agreement between Mississippi State University and the National Institute of Food and Agriculture, U.S. Department of Agriculture, number 58-6062-1-007.

3:45pm CDT

PBIG 3 - Establishment of cucumber CRISPR-Cas9 genome editing system

Thursday July 31, 2025 3:45pm - 4:00pm CDT

Strand 11B

Cucumber (Cucumis sativus L.) is an economically important crop and is widely cultivated throughout the world. Cucumber plants often suffer from biotic and abiotic stresses during the whole development life cycle, which lead to reduction in yield and quality. Improvement of cucumber for disease, insect, or nematode resistance and other horticultural traits with conventional strategy is limited by long breeding cycle, narrow genetic basis, and severe incompatibility barriers in related species. Emerging plant genome editing techniques provide trait specific breeding for enhancement of plant yield, quality, stress tolerance, and disease resistance. Highly efficient regeneration and transformation system is a prerequisite for cucumber genome editing. We report an efficient Agrobacterium mediated cucumber CRISPR-Cas9 transformation system with the aid of GFP visual selection. Cotyledons from 7 days old in vitro seedlings were harvested, and inoculated with Agrobacterium tumefaciens strain GV3101 contains a binary vector with CRISPR-Cas9 gene, GFP visual selection maker and hygromycin resistance genes. Transgenic callus and shoots obtained with GFP visual selection with high efficiency. PCR double check confirmed transgenes in transgenic plants. Transgenic plants are phenotyping in the greenhouse.

Speakers

Kedong Ka

North Carolina State University

Director of plant transformation lab at North Carolina State University

Co-authors

Carole Saravitz

North Carolina State University

Huani Leng

North Carolina State University

Seth Cockman

North Carolina State University

Sydney McLennan

North Carolina State University

Thursday July 31, 2025 3:45pm - 4:00pm CDT
Strand 11B

Oral presentation, Plant Biotechnology 3

Subject Plant Biotechnology
Poster # csv

3:59pm CDT

CITR 3 - Oral Session

Thursday July 31, 2025 3:59pm - 4:00pm CDT

Strand 12B

Presiding/Moderator

Alaiha Asif

University of Florida

Thursday July 31, 2025 3:59pm - 4:00pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops

3:59pm CDT

FRBR 2 - Oral Session

Thursday July 31, 2025 3:59pm - 4:00pm CDT

Strand 11A

Presiding/Moderator

Margaret Worthington

University of Arkansas

Thursday July 31, 2025 3:59pm - 4:00pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding

3:59pm CDT

ORGH 2 - Oral Session

Thursday July 31, 2025 3:59pm - 4:00pm CDT

Strand 12A

Presiding/Moderator

Jose Cabezas

Purdue University

Thursday July 31, 2025 3:59pm - 4:00pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic

3:59pm CDT

PLAST - Oral Session

Thursday July 31, 2025 3:59pm - 4:00pm CDT

Foster 2

Presiding/Moderator

Jianying Wang

Washington State University

Thursday July 31, 2025 3:59pm - 4:00pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture

3:59pm CDT

VCM 5 - Oral Session

Thursday July 31, 2025 3:59pm - 4:00pm CDT

Foster 1

Presiding/Moderator

Arshdeep Kaur

Clemson University

Thursday July 31, 2025 3:59pm - 4:00pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management

4:00pm CDT

CITR 3 - What role does cold acclimation play in enhancing the cold hardiness of Valencia oranges?

Thursday July 31, 2025 4:00pm - 4:15pm CDT

Strand 12B

Freezing temperatures is a significant threat to new growing fresh market citrus industry in North Florida, causing big damage to young and established groves. Recent freeze event happened December 2022 caused about 95% loss in fruit yield in southeast citrus comprising of North Florida, South Georgia and Southeastern Alabama. Different physiological, biochemical and molecular factors are associated with freezing tolerance in citrus. The present study investigates the effects of various cold acclimation periods on freezing tolerance of Valencia orange grafted onto two commercial rootstocks i.e., US-942 and C-54. The plants were cold acclimatized at 4°C for 4, 8, 16 and 32 hours and shifted to the programmed cold chamber for freezing stress at -6°C The Valencia plants on both rootstocks exhibited enhanced resistance to freezing stress when cold acclimated at 4°Cfor 16- and 32-hour . The antioxidants enzymatic activities [superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), and ascorbate peroxidase (EC 1.11.1.11)], and carbohydrate metabolic enzymes showed higher activity in response to cold acclimation for 16- and 32-hour. Likewise, osmoprotectants accumulation (proline and glycine betaine), and soluble sugars (glucose, fructose, sucrose, starch, and total soluble solids) were also elevated under when cold acclimated for 16- and 32-hour as compared to the control. The freezing susceptibility was higher in control and 4-hour cold acclimated plants. Overall, the acclimation period of 16 hours found to very effective in improving freezing tolerance than all other acclimation periods. Findings of this study provides valuable insights into optimizing acclimation strategies to improve cold hardiness in citrus and potential platform for further research to use at commercial level.

Speakers

Alaiha Asif

University of Florida

Thursday July 31, 2025 4:00pm - 4:15pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Funding Source Hatch project FLA-NFC-006212

4:00pm CDT

FRBR 2 - Ploidy Induction of Triploid Interspecific Hybrid Blueberries

Thursday July 31, 2025 4:00pm - 4:15pm CDT

Strand 11A

Blueberry is a high value fruit crop and there is an increased demand for its cultivation and consumption all over the world. The blueberries are grown in diverse regions with varied weather, soil, biotic and abiotic stress limiting their yield. Interspecific hybridization plays a significant role in broadening the genetic base of blueberries that subsequently helps in developing improved cultivars adapted to specific regions. The genetic diversity for cultivated rabbiteye (RE) (2n=6x=72) blueberries is very narrow. Introgression from wild and other cultivated species would provide beneficial diversity for RE blueberries. Vaccinium elliottii (2n=2x=24) is an early flowering, tall and highly deciduous wild blueberry with small black fruits. Like RE, it is adapted to a wide range of soil types in the southeastern United States. On the other hand, southern highbush is a cultivated tetraploid (2n=4x=48) with high fruit quality but requires intensive soil amendment. To broaden the genetic base of blueberry breeding, interspecific crosses were made between three southern highbush breeding lines and V. elliottii. The success of these crosses was challenging due to strong triploid block from heteroploid crosses. Out of 422 pollination events only 8 triploid seedlings were produced, and their ploidy level was confirmed by flowcytometric analysis. Three seedlings were confirmed to be triploids (3x) however, it is expected that triploids are sterile. Seedlings of the triploids were established in tissue culture and chromosome doubling of these triploid hybrids was carried out to improve their crossing efficiency with cultivated blueberries. The shoots produced through tissue culture were treated with 0.02% colchicine for 48 hours and transferred to woody plant medium (WPM). Synthetic hexaploid hybrids produced from this study will be cross compatible with RE blueberries. These synthetic hexaploid hybrids will bridge the ploidy gap among diploid, tetraploid and hexaploid blueberry species.

Speakers

Sindoora Nalajala

University of Georgia

Co-authors

Peggy Ozias-Akins

University of Georgia

Ye Chu

University of Georgia

Thursday July 31, 2025 4:00pm - 4:15pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Funding Source Georgia Blueberry Commission

4:00pm CDT

ORGH 2 - Yield and Quality Characteristics Evaluated for Five Vegetable Species Grown Under Organic Management

Thursday July 31, 2025 4:00pm - 4:15pm CDT

Strand 12A

Direct to consumer markets, including farmers market, composed about 12% of the total organic sales ($22 billion) in 2021. Market growers are looking for cultivars that will help them optimize the performance of their organic production system. The aim of this study was to evaluate commercially available hybrid, open-pollinated, and new breeding lines in terms of yield and quality for tomato (Solanum lycopersicum), sweet corn (Zea mays var. saccharata), cabbage (Brassica oleracea var. capitata), bell and roasting peppers (Capsicum annuum), and winter squash (Cucurbita pepo) grown on certified organic land in Fort Collins, CO. The experimental lines were a product of breeding efforts through northern climate universities affiliated with the Northern Organic Vegetable Improvement Collaborative (NOVIC). All five vegetable species were planted in a randomized complete block design with three replicates during the 2016, 2017, and 2018 seasons. Cabbage (19), sweet corn (19), winter squash (21), bell pepper (15), and sweet roasting pepper (14) cultivars were grown under field conditions. Tomato (12) cultivars were grown under an insect netting-covered high tunnel for hail protection. The ‘Lennox’ cabbage cultivar at 38,483 pounds/acre yielded significantly more than ‘Cantasa’ at 16,146 pounds/acre. The tomato cultivar, ‘Mountain Merit’, and the breeding line ‘S200-1-1’, at 47,280 and 44,880 pounds/acre, respectively yielded more than ‘Plum Perfect’ at 20,520 pounds/acre. Further, a sensory evaluation for overall flavor was carried out on a consumer sensory panel (66 participants) at the Larimer County farmers market in 2017, using a 5-point Hedonic scale for tomatoes and a 9-point Hedonic scale for bell peppers. The tomato entry ‘Mountain Merit’ at 3.8 had a significantly better flavor score compared to ‘Stellar’ at 2.9. In bell peppers, ‘Aristotle’ had a significantly higher flavor score than breeding line ‘CU

Speakers

Tyler Mason

Oklahoma State University

Co-authors

Mark Uchanski

Colorado State University

Natalie Yoder

Colorado State University

Thursday July 31, 2025 4:00pm - 4:15pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Funding Source USDA: National Institute of Food and Agriculture

4:00pm CDT

PLAST - Evaluation of Mulch Types on Yield and Quality of Tomato and Lettuce

Thursday July 31, 2025 4:00pm - 4:15pm CDT

Foster 2

High tunnels (HT) are utilized by vegetable growers to extend the growing season and improve the yield and quality of crops. However, concerns about the sustainability of HT soil health can have direct effects on yield and profitability. Recently, growers and researchers have expressed concerns related to soil moisture in high tunnels and potential negative consequences to soil health. The use of non-permeable polyethylene tarps has become popular for urban and small-scale vegetable farmers to manage weeds through occultation. Similar tarps could also be used as mulch, but little is known about how this will affect crop productivity compared to other mulch types. The goal of this study was to examine silage tarps and other mulch types in HTs and the open field to determine how this practice may affect yield and quality of tomato and lettuce. Tomato and lettuce trials were conducted from 2022 to 2024 in HTs and open-field plots to determine the effect of various mulch treatments (bareground, black plastic film, black woven fabric, paper mulch, white silage tarp and black silage tarp) on tomato and lettuce yield and quality. For tomato, harvesting occurred weekly to monitor total, marketable, and non-marketable yield. Texture and organoleptic quality were assessed from 3 harvests across the two years. In 2023, lettuce were harvested and yield data were collected. Leaf color and water content were also assessed. In the HT tomato trials, mulch had the greatest effects on yield during the early season and the application of white silage tarp and plastic film mulch increased early marketable fruit yield by 58% compared to the bareground treatment. Mulch type had no significant effect on tomato or lettuce on the postharvest qualities that were assessed. Our data indicate that silage tarps may be an effective mulch, particularly for HT growers that are looking to conserve soil moisture and ultimately improve soil health. Yield and quality of tomato and lettuce were not penalized when tarps were utilized, and in some cases, yield was improved. As growers continue to adopt practices that help sustain or improve soil health, it is likely that silage tarps and other mulch types can be effective at maintaining crop productivity

Speakers

Claire Barnhart

Kansas State University

Co-authors

Cary Rivard

Kansas State University

Eleni Pliakoni

Kansas State University

Peter Tomlinson

Kansas State University

Thursday July 31, 2025 4:00pm - 4:15pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv
Funding Source K-State Research and Extension Center for Sustainable Agriculture and Alternative Crops 2023 and Kansas State University GRIP Project

4:00pm CDT

VCM 5 - Biofortification In Leafy Greens: Can Iron Be Biofortified Through Tank Mixing With Common Pesticides Without Compromising Their Efficacy?

Thursday July 31, 2025 4:00pm - 4:15pm CDT

Foster 1

Iron deficiency is a major global health issue that has affected approximately 29% of the adult population of US. Plants being the ultimate source of iron in humans (either directly through staple crops and vegetables or indirectly via animal fodder), do not suffice in meeting the average daily requirement of iron. Therefore, there is a need to increase the iron concentration of edible parts of plants, known as biofortification. So far, the most economic and convenient approach to alleviate iron deficiency is agronomic biofortification. However, applying iron fertilizers puts an additional management burden on growers, to manage an already intensive production system. One potential solution to this could be tank mixing with common pesticides. Combining iron fertilizers with already recommended pesticides in vegetable crops can save the farmers from the extra effort. However, knowledge on interactions (synergistic, antagonistic, or neutral) of iron fertilizers with pesticides in a tank mix is lacking. In 2024 we conducted a field experiment to study the effect of tank mixing of different iron fertilizers (FESO4, Fe-EDTA

Speakers

Arshdeep Kaur

Clemson University

Co-authors

Bhupinder Jatana

Clemson University

Thursday July 31, 2025 4:00pm - 4:15pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Poster # csv

4:15pm CDT

CITR 3 - Comparative Analysis of Drought Tolerance in Sour Orange and Trifoliate Orange Rootstocks

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Strand 12B

Citrus, a globally significant fruit crop, is rich in nutrients and vitamins but is adversely affected by environmental stresses, particularly drought. Drought stress hinders plant growth and reduces crop yields. This study focused on sour orange (SO) and trifoliate orange (TO) rootstocks to evaluate their performance under control and drought conditions. Transcriptomic results showed that the control vs drought TO have 3620 differentially expressed genes (DEGs) were down-regulated and 2440 genes were upregulated while the control vs drought SO group showed 3625 genes were down-regulated and 2290 genes were upregulated. Most of the DEGs were associated with different molecular functions and biological processes including metabolic pathways, flavonoids biosynthesis, photosynthesis, and glutathione metabolism in both rootstocks under drought; however, the gene expression analysis showed that the expression of flavonoids and glutathione metabolism genes were higher in SO than TO after 12 days of drought stress (12DS). Moreover, the antioxidative enzymes, free radical scavenging activities, and total flavonoids contents were increased in both rootstocks, but the increase was higher in SO than TO, after 12DS. After 12DS, the TO has significantly higher levels of reactive oxygen species, hydrogen peroxide, electrolytic leakage, and malondialdehyde contents than SO. Our study concluded that SO rootstock enhances genes linked to metabolic pathways, flavonoid biosynthesis, photosynthesis, and glutathione metabolism. It also, boosts antioxidant enzyme activities, antioxidant capacity, and flavonoid levels, while effectively neutralizing the reactive oxygen species. Hence, after 12 days of drought stress, sour orange performs better than trifoliate orange in maintaining these protective mechanisms.

Speakers

Muhammad Sohail

Bahauddin Zakariya University Multan Pakistan

I am Dr Muhammad Sohail from Punjab, Pakistan. I am focused on Horticulture, with a particular emphasis on pomology and the cultivation of citrus (citriculture). I am interested in the physiology and biochemistry of citrus plants to understand their growth, stress responses, and productivity... Read More →

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Poster # csv

4:15pm CDT

EcoPhys 2 - Leaf and plant age-related changes in photosynthetic light responses of strawberry (Fragaria ×ananassa)

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Strand 11B

Photosynthetic light response (Pn–PAR) curves provide insights into optimizing light use efficiency and plant productivity while supporting decision-making on canopy management, such as plant spacing and pruning. In strawberry (Fragaria ×ananassa), previous Pn–PAR studies have primarily focused on mature leaves but ignored how photosynthetic capacity varies with leaf and plant age. To fill this knowledge gap, we examined leaf and plant age-related changes in Pn–PAR of strawberry plants. A field experiment was conducted with ‘Florida Brilliance’ short-day strawberry during the 2023–2024 growing season in West Central Florida. We determined Pn–PAR at three development stages: early (21 Nov.), mid (12 Dec.), and late (1 Feb.) growth stages. Leaves were classified into three categories based on leaf age: young (first fully expanded leaf), mature (fully developed leaf), and old (senescing leaf). Measurements were made using a portable infrared gas analyzer at ten photosynthetically active radiation (PAR) levels ranging from 0 to 2,000 μmol m⁻² s⁻¹ at a constant CO₂ concentration of 400 μmol m⁻² s⁻¹. During the early growth stage, the light-saturated photosynthetic rate (Pmax) was highest in mature leaves, followed by old and young leaves (18.17, 16.33, and 15.48 µmol CO₂·m⁻²·s⁻¹, respectively). Despite the relatively low Pmax, young leaves showed efficient low-light photosynthesis with a notable quantum yield (QY) of 0.0685 mol·mol⁻¹, trailing just behind mature leaves (0.0768 mol·mol⁻¹). During the mid-growth stage, mature leaves had the highest Pmax, followed by young and old leaves (16.38, 15.06, and 9.86 µmol CO₂·m⁻²·s⁻¹, respectively), with corresponding QY values of 0.0574, 0.0588, and 0.0365 mol·mol⁻¹, respectively. During the late growth stage, Pmax remained highest in the mature leaves, followed by young and old leaves (14.83, 13.43, and 6.80 µmol CO₂·m⁻²·s⁻¹, respectively), with corresponding QY values of 0.0574, 0.0588, and 0.0365, respectively. The results show that young leaves achieve efficient photosynthesis under low light, as indicated by their consistently high QY values across all stages, while old leaves exhibit reduced efficiency with both lower Pmax and QY. These results reveal that light use efficiency is highly dependent on both leaf and plant age, with the greatest senescence-associated decline occurring in old leaves at the late growth stage. Optimizing light use efficiency in strawberry plants, whether through light intensity control in indoor production or canopy management in open fields, must account for the leaf- and plant-age-dependent Pn–PAR relationship.

Speakers

Hadi Ghasemi

PhD Graduate Assistant, University of Florida

🌱 Passionate about CEA. 🪻 Love saffron and have expertise in growing it. 🍓 Strawberry physiology and photosynthesis.

Co-authors

Shinsuke Agehara

University of Florida

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

4:15pm CDT

FRBR 2 - Cold Hardiness Variation in Vitis vinifera × Vitis riparia Hybrids: Genetic and Environmental Influences on Low Temperature Exotherm Values

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Strand 11A

Grapevine cold hardiness is a critical trait that determines the geographical distribution and winter survival of cultivars, thus a key consideration for viticulture in regions with severe winter conditions. This study investigated the cold hardiness of 312 Vitis riparia F1 hybrids, using differential thermal analysis (DTA) and survival assessments at 4°C over seven and 28 days. The DTA analyses to identify significant changes in progeny lethal temperature exotherm (LTE) values with a wide range of LTE values from -24.3°C to -12.3°C observed after 28 days of cold acclimation. The mean LTE value improved from -16.8°C after seven days to -18.6°C after 28 days with 80.2% of progenies showing significant decreases in LTE values. Progenies were divided into five groups based on cold hardiness: very cold hardy, cold hardy, moderately hardy, susceptible, and very susceptible. Principal component analysis (PCA) demonstrated clear separation among the five cold hardiness groups, with PC1 accounting for 71% of the variance. This study provides valuable insights into the genetic basis of cold hardiness in V. riparia progenies, offering critical information for grape breeding programs aimed at developing cold-resistant cultivars. The identification of highly cold-hardy progenies and the understanding of their genetic diversity will aid in selecting parent plants for breeding, ultimately improving grape production in cold regions.

Speakers

Harlene HattermanValenti

NDSU

Co-authors

Hava Delavar

North Dakota State University

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Funding Source VitisGen 3
Funding Option SCRI funded all or part of the research associated with this abstract

4:15pm CDT

ORGH 2 - The growth and yield of organic sweet corn grown with clover living mulch and reduced tillage in the Northern Great Plains

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Strand 12A

Sweet Corn (Zea mays) is a popular warm season specialty crop grown in the United States and around the world. Sweet corn production can encounter obstacles including weed competition and nutrient losses, particularly nitrate leaching. This study explored the influence of third-year clover living mulch systems on organic sweet corn production, and the impact of historic in-row soil management practices on sweet corn growth and yield. Conducted in 2024 at the SDSU Southeast Research Farm, Beresford, SD, USA, this research investigated the impact of established clover living mulch on ‘Who Gets Kissed©’ sweet corn (High Mowing Seeds). Two years prior to sweet corn planting, three clover cultivars were established: ‘Domino’ white clover (Trifolium repens), ‘Aberlasting’ white x kura clover (T. repens x ambiguum), and ‘Dynamite’ red clover (Trifolium pratense), which were compared with a bare-ground control. During the past two seasons, within each clover whole plot, four in-row soil management subplots (till, till landscape fabric, no-till, no-till landscape fabric) were established. The established plots were planted with acorn squash (cucurbita pepo) in the first year, followed by fall cabbage (Brassica oleraceae var. capitata) in the second. Prior to sweet corn production, all treatments were strip-tilled to temporarily delay clover and prepare a planting bed for direct seeding of sweet corn with a single row planter. No landscape fabric was used in-row to align with medium to large scale production practices. Till treatments were weeded with a stirrup hoe and represented tilled cultivation. No-till treatments were hand weeded with the proper hand tool to minimize soil disturbance. Sweet corn data was collected to understand the impact of clover variety and soil management practices on crop health, weed suppression, and yield. Yield was graded in accordance with the USDA Marketable Standard for sweet corn cash crop production. Weed biomass decreased as the season progressed and sweet corn canopy closed; however mid-season drought conditions decreased clover growth. Prior years of soil management did not affect yield and production (p ≤ 0.8), but clover living mulch systems did (p ≤ 0.04). Over 50% of the graded sweet corn was in the US No1 and US No 2 categories. Bare ground treatment plots were first to reach maturity and produced the highest percentage of marketable ears. Farmers who are interested in growing sweet corn could utilize living mulch systems after key considerations such as water availability, early season maintenance, and scale of production.

Speakers

Kristina Harms

South Dakota State University

Co-authors

Kristine Lang

South Dakota State University

Nitish Joshi

South Dakota State University

Thandiwe Nleya

South Dakota State University

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic
Poster # csv

4:15pm CDT

PLAST - Mulch Technologies to Reduce Agriculture Plastic Waste Generation in Strawberry Cultivation

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Foster 2

Polyethylene (PE) mulch is a valuable tool that suppresses weeds, optimizes the soil and canopy microclimate, and enhances efficient production of quality fruits and vegetables. However, PE mulch is not biodegradable and limited cost-effective waste management options lead to large amounts of used PE mulch being annually landfilled, stockpiled on farms, burned, and sometimes buried in soil. The objective of this presentation is to review the status of alternative mulch technologies that have the potential to reduce plastic waste generation in strawberry (Fragaria × ananassa) cultivation with an emphasis on soil-biodegradable plastic mulch (BDM), hydromulch, and cellulose-based film. Several commercial BDM products have been available in the market since the 1990s and are made using a blend of fossil-fuel derived and biobased ingredients. Trials conducted in Washington State show strawberry yield and fruit quality are comparable when plants are grown with black PE mulch or BDM. Green BDM deteriorates rapidly depending on environmental conditions. Rapid deterioration may lead to increased weed pressure and reduced production similar to bare ground cultivation. Hydromulch is a sprayable mulch alternative that can be formulated with ingredients that meet the requirements for certified organic production in North America, whereas commercially available BDMs do not meet these requirements. Trials carried out in Washington State and North Dakota demonstrated hydromulch maintains strawberry yield and fruit quality. Hydromulch formulations with guar gum demonstrate superior mechanical properties relative to formulations without or with other tackifiers. Reduced weed suppression, the logistics of sourcing hydromulch feedstock, lack of specialized application equipment, and high material and application costs are current barriers to this emerging technology. Cellulose-based film, such as lignocellulose film, is another fully biodegradable and emerging alternative to PE mulch and can be made with ingredients suitable for certified organic production. Field trials with cellulose-based film are limited, but current findings show high levels of biodegradability and maintenance of crop growth. Growers, crop consultants, and marketers should consider biodegradable mulch alternatives to reduce plastic waste generation and persistent plastic pollution in agricultural and environmental settings, particularly if recycling is not available or a cost-effective option.

Speakers

Makonya Givemore Munashe

Washington State University

Co-authors

Aidan Williams

Washington State University

Andrew Durado

Montana State University

Ben Weiss

Washington State University

Ben is from Philadelphia and has been interested in food systems since an early age. He attended his first natural products expo before kindergarten because his parents worked in the natural foods industry. During late adolescence, he started a prolific tomato garden that blossomed... Read More →

Carol Miles

Washington State University

Deirdre Griffin LaHue

Washington State University

Dilpreet Bajwa

Montana State University

Greta Gramig

North Dakota State University

Haishun Du

University of Wisconsin-Madison

Lisa Wasko DeVetter

Washington State University

Nataliya Shcherbatyuk

Washington State University

Nayab Gull

Washington State University

Nayab is a Ph.D. student in the crop and soil science department Washington state University. She received her masters degree in Crop Cultivation and Farming Systems from China Agricultural University.

Suzette Pedroso Galinato

Washington State University

Waqas Ahmad

North Dakota State University

Xuejun Pan

University of Wisconsin-Madison

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv
Funding Source Funding was provided by the USDA Specialty Crops Research Initiative Award 2022-51181-38325, Agriculture and Food Research Initiative Award 2023-68016-38933, and Organic Research and Extension Initiative 2021-51300-34909 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. Additional support was provided by NIFA Hatch projects 7003737, 7001317, and W5188 Multi-State Project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA.
Funding Option SCRI funded all or part of the research associated with this abstract

4:15pm CDT

VCM 5 - Effects of Magnesium Fertilization on Phytonutrient Accumulation in Cress Grown Hydroponically

Thursday July 31, 2025 4:15pm - 4:30pm CDT

Foster 1

Leafy greens like cress have generated significant interest worldwide due to their health and nutritional benefits. Cress is a nutrient-dense leafy green unique for its peppery flavor and phytonutrient content. Its hydroponic cultivation coupled with targeted nutrient fertilization provides a controlled environment enabling optimal growth conditions and phytonutrient accumulation. Particularly, magnesium as a macronutrient is known for influencing biosynthesis of plant metabolites including chlorophyll, carotenoids and other antioxidants. The need for biofortification and optimization of hydroponic cultivation for nutrient-dense crops warrant this study. Due to the importance of beta-carotene in human health and its role as a source of vitamin A, it is crucial to understand how fertilization affects its accumulation. Therefore, this study seeks to contribute to optimization of nutrient management in hydroponics and ultimately improve nutritional value of leafy greens. In this research, four magnesium fertilization rates (100 mg/l, 150 mg/l, 200 mg/l and 250 mg/l) were applied to watercress and upland cress in a hydroponic environment. The study aimed to examine the effects of these treatments on phytonutrient accumulation with a focus on beta-carotene. The hydroponic cultivation was done under controlled environment, ensuring desirable nutrient application, temperature, light, pH and electrical conductivity. The treatments were applied in a Nutrient Film Technique (NFT) system under a split-plot design. Biomass, chlorophyll, beta-carotene and antioxidant activity were analyzed to determine the relationship between magnesium application and the biosynthesis of phytonutrients. Spectrophotometric methods were used to quantify beta-carotene and chlorophyll and determine antioxidant potential. Initial findings indicate increasing content of beta-carotene, chlorophyll, biomass and antioxidant activity with increasing magnesium application rates, with the highest rate maximizing beta-carotene accumulation. The results show variations between watercress and upland cress, indicating strain-specific responses under magnesium application. These results will contribute to insights into the influence of magnesium fertilization on the synthesis of phytonutrients in leafy greens, particularly cress plants. It will guide farmers on optimizing fertilization, eventually improving yields and nutritional quality of the two cress varieties. Additionally, it will recommend dietary guidelines, catering to the demand for nutrient-rich foods among health-conscious consumers. Keywords: Cress, Magnesium fertilization, Phytonutrients, Hydroponics, Spectrophotometry

Speakers

Richard Kabanda

Graduate Research Assistant, Kentucky State University

Co-authors

Cora Teets

Kentucky State University

THEONESTE NZARAMYIMANA

Kentucky State University

Thursday July 31, 2025 4:15pm - 4:30pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Poster # csv

4:30pm CDT

CITR 3- Multi-Omics Dissection of Drought-Priming-Induced Cold Hardiness in Grapefruit (Citrus paradisi)

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Strand 12B

Climate change-induced abiotic stresses, particularly drought and freezing, threaten citrus production worldwide. Understanding how drought priming enhances cold hardiness is pivotal for sustaining grapefruit (Citrus paradisi) production under increasingly unpredictable climatic conditions. This study employed an integrative approach combining transcriptomic and metabolomic profiling and physiological and morphological observations to unravel the complex regulatory networks underlying drought-primed freezing tolerance in grapefruit plants. Drought-primed plants exhibited significantly improved photosynthetic efficiency, as measured by chlorophyll fluorescence and gas exchange parameters, and remained higher in primed plants under freezing stress. Scanning Electron Microscopy (SEM) revealed ultrastructural changes, including intact stomatal architecture and less plasmolysis in leaf tissues of drought-primed plants. Transcriptome analysis revealed a distinct reprogramming of stress-responsive genes, particularly those involved in transcriptional regulation and hormone signaling pathways. Notably, genes encoding transcription factors such as DREB, NAC, and WRKY showed marked upregulation in primed plants. Metabolomic profiling complemented these findings by identifying key metabolic shifts, including accumulating compatible solutes (e.g., proline, sugars) and modulation of central carbon metabolism and amino acid biosynthesis pathways. Hormonal analysis indicated a synergistic interaction between abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA), suggesting their critical roles in stress signal integration. Our results demonstrate that drought priming activates a robust transcriptional-metabolic network, enhancing physiological resilience and structural integrity under freezing stress. This study provides novel insights into the cross-adaptive mechanisms of abiotic stress tolerance and establishes a foundational framework for developing climate-resilient citrus cultivars.

Speakers

Shahid Iqbal

University of Florida

Co-authors

Carlos Aucique

University of Florida

John Chater

University of Florida

Matthew Mattia

USDA, ARS

Muhammad Shahid

University of Florida

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Poster # csv

4:30pm CDT

EcoPhys 2 - Stomatal Density, Function, and Transpiration Dynamics in Developing Southern Highbush Blueberry Fruits

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Strand 11B

The water balance of fleshy fruit is heavily influenced by fruit transpiration. Transpiration is driven by the vapor pressure gradient between the fruit and the atmosphere. Stomatal closure is the main form of resistance to water loss. Thus, stomatal density (the number of stomata per unit area) and function are critical for regulating transpiration. In Northern Highbush blueberry (NHB, Vaccinium corymbosum L.), transpiration rates decline as the fruit develops. However, these dynamics remain unknown in Southern Highbush blueberry (SHB, Vaccinium corymbosum L. interspeciﬁc hybrids). This study examines the relationship between stomatal density, stomata function, and fruit transpiration rates in SHB. Three SHB cultivars were analyzed: ‘Jewel’, ‘Sweetcrisp’, and ‘Keecrisp’. Fruits were sampled weekly between petal fall and the ripe stage. Stomatal imprints were collected from six fruit regions: calyx basin, calyx, distal (calyx) end, distal middle, proximal middle, and proximal (pedicel) end. Stomatal density and distribution were quantified using StoManager, an artificial intelligence tool that uses convolutional neural networks to count and measure stomata in micrographs. Stomata density varied by genotype and fruit region. Distal regions exhibited the highest stomata densities in all varieties. No stomata were observed in the proximal middle or proximal (pedicel) end for either genotype. Fruit transpiration rates were measured using an infrared gas analyzer equipped with a custom-built chamber. Results indicated a progressive decline in transpiration rates as the fruit matured. The results suggest that SHB and NHB exhibit similar stomata morphology and transpiration patterns during fruit development.

Speakers

Scott Cruz

University of Florida

Co-authors

Gerardo Nunez

University of Florida

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

4:30pm CDT

FRBR 2 - Linkage Mapping and Genomic Insights in Vitis x Muscadinia Hybrids

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Strand 11A

Combining muscadine (M. rotundifolia) with bunch grapes (V. vinifera) addresses the challenges faced by each species. Muscadines provide strong disease resistance and adaptability to the southeastern U.S climate but lack key fruit quality traits such as seedlessness and crisp texture. In contrast, V. vinifera, produces high-quality fruit but is highly susceptible to diseases like Pierce’s disease and powdery mildew. Hybridization between the two aims to retain the desirable fruit characteristics of V. vinifera while incorporating the resilience of muscadines. Understanding the genetic basis of key agronomic traits in Vitis × Muscadinia (V × M) hybrids is essential for introgressing valuable traits such as seedlessness, disease resistance, and flavor into breeding populations. This study aimed to develop a high-density genetic linkage map to investigate the inheritance of seedlessness, sterility, and recombination patterns in wide hybrids. The mapping population was derived from a cross between AM-116, a seeded Muscadinia rotundifolia selection, and JB15-43-N0-25, a seedless V × M hybrid. Phenotypic evaluations of traits such as flower sex, winter injury, berry size, berry, color, yield, seedlessness, cluster architecture, and vigor were collected and integrated with genotypic data to create a linkage map and identify quantitative trait loci for these traits. RhAmpSeq genotyping was initially used as the primary method to genotype the population and assess recombination frequency across homeologous and homologous chromosome regions. However, because rhAmpSeq markers were designed using Vitis genomes without incorporating Muscadinia, marker coverage in Muscadinia genomic regions was limited. To overcome this limitation, SkimSeq whole-genome sequencing was later employed to construct a high-density linkage map. Principal Component Analysis (PCA) of genomic data revealed that individuals positioned closer to the V × M parent (JB15-43-N0-25) had a higher proportion of Vitis ancestry and an increased number of homeologous chromosomes. This pattern suggests that structural genomic incompatibilities affecting segregation distortion and recombination rates may result in reduced recombination in homeologous regions in V × M hybrids. These findings provide new insights into the genetic mechanisms governing sterility, recombination, and trait introgression in Vitis × Muscadinia hybrids, contributing to the development of breeding strategies aimed at integrating desirable traits across subgenera. Understanding these factors is crucial for overcoming genetic barriers in interspecific breeding and optimizing hybrid vigor for commercial muscadine grape production.

Speakers

Isabella Vaughn

University of Arkansas

Co-authors

Carmen Johns

University of Arkansas

Cheng Zou

Cornell University

Dustin Wilkerson

Cornell University

Lacy Nelson

University of Arkansas

Margaret Worthington

University of Arkansas

Qi Sun

Cornell University

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Funding Source This work was funded by VitisGen3, which was provided by Specialty Crop Research Initiative Competitive Grant, Award No. 2022-51181-38240, of the USDA National Institute of Food and Agriculture.
Funding Option SCRI funded all or part of the research associated with this abstract

4:30pm CDT

ORGH 2 - Optimizing Organic Pepper Production with Selected Microbial Consortia and Rootstocks

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Strand 12A

Grafting and microbial inoculation are promising strategies for enhancing organic pepper production, mainly to manage soil-borne diseases and optimize nutrient utilization. This study conducted in a high tunnel environment evaluated the performance of two Phytophthora-resistant rootstocks, CM-334 and YC-207, grafted with a common scion (Mama Mia Giallo), and the application of a mycorrhizal and bacterial mix consortium under two organic fertilization rates (100:40:60 kg NPK ha-1 as optimal rate and reduced to half as low rate). Our hypothesis explored whether the synergy of microbial inoculation and grafting could compensate for the reduced growth of the low rate by improving nutrient use efficiency. Chlorophyll content was higher (~10 %) in inoculated plants compared to non-inoculated plants under low fertilization. At the peak bloom stage, leaf net photosynthesis was similar at both fertilization rates, while inoculated plants had an increase in plant water use efficiency (~12 %). Microbial inoculation and low fertilization induced early flowering compared to non-inoculated plants grown at optimal fertilization rate. Under low fertilization, inoculated YC-grafted plants exhibited higher electron transport rate, stomatal conductance, and transpiration rate than other inoculated plants. CM-grafted plants responded negatively to inoculation at optimal fertilization, as shown by the lower net photosynthesis (~16 %) and stomatal conductance (~44 %) compared to non-inoculated plants. The correlation of these physiological traits with fruit yield, quality, and soil health will provide further understanding applicable to rootstock selection and microbial inoculation to optimize pepper production, particularly in resource-limited conditions.

Speakers

ASMITA NAGILA

Graduate Research Assistant, Texas A&M university

Co-authors

Daniel Leskovar

Texas A

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic
Poster # csv

4:30pm CDT

PLAST - Increased Profitability and Sustainability in Vegetable Production through Plastic Mulch Management

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Foster 2

An estimated two million tons of plastic mulch films (PMFs) are used in horticultural production worldwide due to the benefits these films provide that may lead to yield increases. Despite the high usage rates of PMFs, there are many environmental drawbacks to the implementation of plastic mulches. To investigate potential mitigation strategies, two plastic and two biodegradable plastic films were used for multiple consecutive growing seasons. Soil conditions, plant yield and mulch durability were used to evaluate the soundness of reusing mulch films for multiple growing seasons. There were no significant differences between mulch types for the first season, with the highest yield being 307.23 pounds of tomatoes and the lowest yield being 235.62 pounds of tomatoes per 50 row feet. There were significant yield differences between mulch types for the second season, where each cabbage head produced on plastic mulches weighed an average of 3.68 pounds while each cabbage head produced on biodegradable mulches weighed between 1.22 and 1.84 pounds. The yield differences observed in season two may be in part due to increased soil penetration resistance under the biodegradable mulches, which had to be replaced at the end of the first season. The biodegradable mulches had to be replaced at the end of the first season due to their extreme degradation, but they were replaced at unfavorably high soil moisture conditions which led to considerable compaction, and higher penetration resistance, in those plots. Biodegradable mulched plots exhibited more than 50% bare ground at the end of the first growing season while plastic mulched plots both exhibited less than 10% bare ground. In addition to their in-field degradation, biodegradable films are also significantly weaker materials than PMFs, with average tensile strengths of 2.02 N and 2.91 N at the end of season one, compared to the average tensile strength of 4.56 N of conventional polyethylene. These results suggest that biodegradable PMFs may not be a good option for use over multiple seasons. Further research is needed to determine the optimum management practices for increased profitability PMFs in vegetable production systems while also improving environmental friendliness.

Speakers

Melanie Hill

Auburn University

Co-authors

Andre Luiz Biscaia Ribeiro da Silva

Auburn University

Paul Bartley

Auburn University

Robert Harriman

The Ohio State University

Wheeler Foshee

Auburn University

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv

4:30pm CDT

VCM 5 - Seed Priming Treatments Affect Germination, Shoot Growth and Mineral Nutrient Compositions of Four Herbal Microgreen Species

Thursday July 31, 2025 4:30pm - 4:45pm CDT

Foster 1

Microgreens are young seedlings that are harvested between 7 and 21 days after germination with height of generally 2 to 4 inches depending on the species. They are considered to be nutrient-dense functional foods and have been reported to be rich in mineral nutrients such as calcium (Ca), magnesium (Mg), potassium (K) and iron (Fe) as well as health beneficial phytochemicals. Seed priming treatments have been used to activate metabolic activity within the seed and promote fast and uniform germination, which is critical in microgreen production. The objectives of this study were to assess the effect of four seed priming treatments on the shoot growth, visual quality, and mineral nutrient compositions of four herbal microgreen species grown on hydroponic mats made from jute fibers. Four microgreen species including chives (Allium schoenoprasum), dill (Anethum graveolens), scallion (Allium fistulosum) and shiso (Perilla frutescens var. crispa) were used in this study. Four priming treatments were applied including hydro priming with distilled water (20-22°C), chemical priming with hydrogen peroxide (0.3%), biostimulant priming with a plant growth promoting rhizobacteria (PGPR) (0.528 ml·L-1), and another biostimulant derived from kelp extract (5 ml·L-1). Microgreen seeds were soaked for 6 hours in each of the priming solutions and then allowed to dry overnight to their original weight. The control treatment consisted of non-primed raw seeds. Data including germination percentage, shoot height, visual quality, fresh and dry shoot weights, shoot color, and mineral nutrients were all collected. Fresh shoot weight was significantly affected by the interaction between microgreen species and priming treatment. The four priming treatments and control resulted in similar fresh shoot weights in chives, scallion, and shiso. Dill from the control treatment had a significantly higher fresh shoot weight of 1302 g·m-2 compared to kelp extract, PGPR, and hydropriming with weights of 737 g·m-2, 740.7 g·m-2, and 345.8 g·m-2, respectively. Microgreen shoot height was affected by species and priming treatment separately with no interaction. The non-priming control produced shoots with height of 6.9 cm, significantly higher than those from the kelp extract or the hydropriming treatment with heights of 6.3 cm and 6.2 cm, respectively. Chives produced the lowest shoot height of 5.3 cm compared to dill, scallion and shiso with shoot heights of 6.9 cm, 7.0 cm, and 6.8 cm, respectively.

Speakers

Jacob Arthur

Mississippi State University

Co-authors

Abby Pennington

Mississippi State University

Ali Alsughayyir

Mississippi State University

Guihong Bi

Mississippi State University

Shecoya White

Mississippi State University

Tongyin Li

Mississippi State University

Thursday July 31, 2025 4:30pm - 4:45pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Poster # csv
Funding Source Mississippi Department of Agriculture and Commerce

4:45pm CDT

CITR 3 - Enhancing Freezing Tolerance in Valencia Orange: Exploring the Synergistic Role of Photoperiod and Cold Acclimation

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Strand 12B

Freezing tolerance is a critical factor affecting the productivity and sustainability of citrus cultivation in subtropical regions. Photoperiod and cold acclimation work together to enhance a plant’s freezing tolerance by triggering specific biochemical and molecular pathways that help it withstand low temperatures and avoid cellular damage during freezing events. This study aims to investigate the interactive effects of photoperiod and cold acclimation on the freezing tolerance of Valencia orange (Citrus sinensis) plants grafted onto US942 rootstock, focusing on how these environmental factors modulate physiological and molecular responses to freezing stress. We hypothesize that varying photoperiods, when combined with cold acclimation, will synergistically enhance the freezing tolerance of Valencia orange plants by modulating biochemical and physiological traits associated with cold hardiness. Two-year-old Valencia orange plants will be grown under different photoperiods (8, 10, 12, 14, and 16 hours) for four weeks. After the photoperiod treatment, plants from each photoperiod group were divided into two treatments: one group undergo cold acclimation by being exposed to 4°C for 16 hours, while the other group was placed at 25°C for 16 hours (non-cold-acclimated). Following this, both cold-acclimated and non-cold-acclimated plants were exposed to freezing stress at -6°C in walk-in freezing chambers for 1 hour. The freezing temperature reached by gradually lowering the temperature by 1°C per hour, starting from 0°C to -6°C. We measured the photosynthesis, chlorophyll content and ELL. These results showed that the freezing stress showed the photosynthesis limitation, there are problem in enzymatic machinery in carbon dioxide assimilation. According to ELL and spad index GBT3R2 shows lowest cellular damage and the results show preserved the chlorophyll content. This research identifies how photoperiods and cold acclimation interact to enhance freezing tolerance in Valencia oranges, providing key markers for breeding more freeze resilient citrus cultivars.

Speakers

Nazneen Qureshi

University of Florida

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Poster # csv

4:45pm CDT

EcoPhys 2 - Leaf-Level Photosynthesis is Maintained Under Far-Red Photon Substitution Across Five Species

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Strand 11B

Recent studies show that far-red photons (FR; 700–750 nm), when combined with photosynthetically active radiation (PAR; 400–700 nm), can drive canopy-level photosynthesis as effectively as PAR alone. This has prompted suggestions to redefine PAR as extended PAR (ePAR; 400–750 nm). However, few studies have evaluated whether FR and PAR photons produce equivalent photosynthetic rates at the leaf level. We investigated whether photosynthesis is maintained under increasing FR substitution at equal total photon flux (1000 µmol·m⁻²·s⁻¹). Five crop species (apple, blueberry, corn, strawberry, and tomato) were grown under natural field conditions (tomato in a hoop house) and sampled for leaf gas exchange using A/Ci curves under three light spectra: 0%, 15%, and 30% FR substitution. Leaf transmittance of FR photons was 3–11 times greater than PAR across species, indicating reduced FR absorption compared to PAR photons. Nonetheless, maximum photosynthetic rates were similar across treatments for all species. For most species, FR substitution did not affect Vc,max or Jmax, indicating that rubisco activity and electron transport capacity remained stable. However, blueberry showed declines in both parameters with increasing FR, while corn exhibited increased Jmax under FR substitution. Despite reduced FR absorption, photosynthetic performance was largely unchanged with up to 30% FR substitution. These results support the inclusion of FR photons in the PAR definition and reinforce the relevance of ePAR in both natural and controlled environments.

Speakers

John Ertle

Plant Physiologist, PP Systems

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

4:45pm CDT

FRBR 2 - Gene Expression Analysis in the Linkage Group 7 Eastern Filbert Blight Resistance Region in Hazelnut

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Strand 11A

Eastern filbert blight (EFB) disease caused by the fungal pathogen Anisogramma anomala (Peck) E. Müller is a major threat to Oregon’s hazelnut (Corylus avellana) industry. Although cultivars with ‘Gasaway’ resistance have sustained the Oregon hazelnut industry, ‘Jefferson’ and ‘McDonald’ trees protected by a dominant allele for resistance from ‘Gasaway’ have shown small cankers when under high disease pressure for several years. In late 2023, a few orchards in the northern Willamette Valley reported infections on ‘Gasaway’ protected trees with highly aggressive cankers and fully developed stromata, indicating the ability to reproduce on resistant varieties and signaling the breakdown of ‘Gasaway’ resistance in Oregon. The OSU hazelnut breeding program has conducted extensive EFB screening efforts on curated germplasm, and more than 30 sources of EFB resistance have been assigned to a linkage group (LG) using SSR loci and disease score correlation analyses. Fine mapping of the LG7 resistance region using the ‘Ratoli’ and OSU 1166.123 backgrounds with simple sequence repeat (SSR) and PCR allele competitive extension (PACE) SNP genotyping assays narrowed the resistance region. However, gene expression profiling is desired to further elucidate which candidate genes overlap between fine-mapping efforts and gene expression to refine marker development efforts for LG7 resistance. The objective of this study was to identify differentially expressed genes (DEGs) in six hazelnut genotypes (‘Ennis’, OSU 1026.073, OSU 1166.123, OSU 541.147, ‘Ratoli’, and ‘Sacajawea’) at different stages of EFB infection. Layered and grafted trees with ‘McDonald’ rootstocks were grown in 3L pots at the OSU West Greenhouses in Corvallis, OR in spring 2023. Inoculations were conducted in an outdoor container pad and new shoot tips with at least two true leaves were spray inoculated with a spore suspension (1x106 spores·mL-1) until run-off. Apical shoots (2-3 internodes) from four biological replicates were collected at 0, 12, 24, 48, 72, 96, 168, and 240 hours post-inoculation, with the addition of two biological mocks sprayed with deionized water. Total RNA was extracted and sequenced using a BRB-seq library prep for the Illumina NovaSeq X Plus platform. Detailed analyses of differentially expressed genes between susceptible and resistant genotypes during the initial stages of EFB infection will be discussed. The results of this study will provide valuable insights into the molecular resistance of hazelnut to EFB, aid marker development for breeding EFB-resistant cultivars, and facilitate the pyramiding of R-genes in a single clonal selection for more durable resistance.

Speakers

Rion Mooneyham

Oregon State University

Co-authors

Gaurab Bhattarai

Oregon State University

Jacob Snelling

Oregon State University

Shawn Mehlenbacher

Oregon State University

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Poster # csv

4:45pm CDT

ORGH 2 - Low Salmonella spp. Prevalence in Organic Cover Crop–Pastured Chicken–Tomato Rotations with No Significant Differences Among Management Practices

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Strand 12A

Modern agricultural production systems have become highly specialized and input-intensive models that boost food production and lower production costs. While this has allowed us to meet our rising food demand, it has led to environmental degradation. Moreover, these systems lack resilience and sustainability against higher supply costs and shifting environmental conditions. Integrated Crop Livestock Systems (ICLS) at the field level are an alternative that balances productivity with environmental responsibility by combining crop and animal rotations. Often incorporating practices such as cover crops, reduced or no-tillage and minimal external inputs. ICLS can improve soil health, enhance nutrient cycling, and improve resilience through diversification. Livestock is central to ICLS and can be adapted to farm specific needs. For small organic farmers, poultry is an attractive option due to its easy handling and regular production of meat or eggs. However, chickens can carry pathogens such as Salmonella.spp and Listeria monocytogenes, raising food safety concerns. With no specific guidelines for ICLS implementation, organic farmers are encouraged to follow the 90 -120 USDA National Organic Program (NOP) rule for application of raw manure. This research aims to clarify food safety implications when integrating poultry into specialty crops systems The study followed organic practices on organic land. Designed as a Randomized Complete Block Design (RCBD) with split plots with poultry foraging on high or low cover crop residue, or no grazing as the main plot with tillage or no-tillage as the split plot factor. Chickens foraged for 5 weeks before processing for-carcass weight, meat yield and Salmonella.spp cecal prevalence. After chickens were removed from the cover crop, organic tomato (Solanum lycopersicum ‘Granadero’) seedlings were planted. We measured tomato yield per plant. Prevalence of Salmonella Spp. was determined from cecal and soil and tomato surface samples at two-time points; directly after chicken removal at harvest (n= 348 environmental samples). Neither foraging nor tillage type had a significant effect on tomato yield, suggesting that animal integration is a viable option for cover crop management and farm diversification. After the chicken removal all environmental samples tested negative for Salmonella spp. At harvest, Salmonella appeared in 17 of 348 samples (4.88%), suggesting that integrating chickens does not necessarily elevate the risk of produce contamination and that other environmental factors affecting Salmonella prevalence should be further studied.

Speakers

Jose Cabezas

Purdue University

Co-authors

Hannah Robalino

Purdue University

Joseph Tilstra

Purdue University

Moriah Bilenky

Purdue University

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic
Funding Source Organic Center- FFAR Joint Organic Reseearch Program

4:45pm CDT

PLAST - Life Cycle Assessment Insights into Environmental Trade-offs and End-of-Life Strategies for Soil-Biodegradable Mulch Films

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Foster 2

Mulch films play a crucial role in enhancing crop yields and suppressing weeds; however, conventional plastic mulch films (PEMs) contribute significantly to environmental burdens, particularly at the end-of-life (EOL) stage. In response, soil-biodegradable mulch films (BDMs) have emerged as an alternative, offering potential benefits in reducing waste and emissions. This study conducts a cradle-to-grave life cycle assessment (LCA) of BDMs (PBAT/PLA, 30/70 PBAT/TPS, 70/30 PBAT/TPS blends) compared to PEMs (LDPE) across ten environmental impact categories in the production of 1 kg of strawberries per hectare in California, USA. Multiple EOL scenarios were evaluated, including soil-biodegradation, anaerobic digestion, and composting for BDMs, and landfill (with and without energy recovery) for PEMs. Results indicated that during the manufacturing stage, BDMs exhibited the lowest fossil fuel depletion, with the 30/70 PBAT/PLA achieving a 72% reduction; however, all BDMs had higher global warming potential (GWP). The highest environmental burdens in manufacturing were associated with BDM-PBAT/PLA due to its high energy requirements. During the mulch use stage, all BDMs consistently outperformed PEMs slightly in key impact categories such as GWP (reducing emissions by approximately 4.7%), acidification, and smog formation. No significant differences were observed among BDMs in this stage, suggesting that primary environmental distinctions arise from manufacturing and EOL scenarios rather than field application. The EOL stage significantly influenced the overall sustainability of mulch films. In terms of fossil fuel consumption, carbon emissions, and human toxicity potential, the most favorable scenarios were BDM-soil-biodegradation (-2.65 kg CO2-eq) and BDM-anaerobic digestion (-20.9 kg CO2-eq), both of which also reduced ecotoxicity (approximately -51 CTUe) and carcinogenic effects while minimizing fossil fuel depletion (approximately -1.72 MJ). In contrast, BDM-composting resulted in higher acidification (up to 0.344 kg SO2 eq) and smog formation, making it a less favorable option. PEMs, even under energy recovery scenarios, exhibited higher impacts and lacked the benefits of biodegradability, emphasizing the sustainability advantages of BDMs. When considering the full cradle-to-grave life cycle, BDMs demonstrated superior environmental performance under optimal EOL strategies. Although PEMs had a lower manufacturing footprint, their EOL challenges negated these benefits. Among BDMs, PBAT/TPS blends, particularly the 30/70 PBAT/TPS, exhibited the most balanced performance, offering reduced manufacturing burdens alongside excellent EOL outcomes. This study provides a detailed analysis of the environmental benefits and trade-offs of BDMs. The findings, along with nuanced recommendations, support the transition toward more sustainable mulch film applications.

Speakers

Oluwatunmise Israel Dada

Graduate Research Assistant, Washington State University

A Ph.D. Candidate passionate about the natural environment and sustainable solutions.

Co-authors

Liang Yu

Kentucky State University

Ting Chi

Washington State University

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv
Funding Source USDA National Institute of Food and Agriculture, Specialty Crops Research Initiative Award 2022-51181-38325
Funding Option SCRI funded all or part of the research associated with this abstract

4:45pm CDT

VCM 5 - Exploring the Plant Microbiome of Commercial Spinach: Bacterial and Fungal Community Structure and Functional Potential

Thursday July 31, 2025 4:45pm - 5:00pm CDT

Foster 1

The study explored bacterial and fungal communities in two commercially cultivated spinach (Spinacia oleracea L.) cultivars across five ecological niches: bulk soil, rhizosphere, root endosphere, leaf episphere, and leaf endosphere. Using high-throughput sequencing of 16S rRNA and ITS amplicons, we assessed microbial diversity, composition, co-occurrence networks, and functional potential, revealing that alpha microbial diversity was highest in bulk soil and lowest in the leaf endosphere. Beta diversity analysis demonstrated significant niche differentiation, with fungal communities exhibiting notable cultivar-driven variation, while bacterial communities were more influenced by niche. The bacterial microbiome displayed a wide range of taxa, while the fungal microbiome comprised two primary groups, with differential abundance analysis indicating niche-specific microbial enrichment in both bacterial and fungal communities. Tracking microbial contributions to different niches showed minimal influence of bulk soil on the rhizosphere, with fungal communities presenting higher niche transfer rates than bacteria. Co-occurrence network analysis highlighted cultivar-specific microbial interactions. Functional predictions indicated niche-dependent microbial metabolic adaptations, particularly in carbohydrate and amino acid metabolism. These findings offer valuable insights into the spinach microbiome, highlighting niche differentiation and cultivar-specific microbial interactions that influence plant-associated microbial communities.

Speakers

Dhivya Thenappan

Texas A

Co-authors

Gabriele Berg

Graz University of Technology

Vijay Joshi

Texas A

Wisnu Adi Wicaksono

Graz University of Technology

Thursday July 31, 2025 4:45pm - 5:00pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Poster # csv

5:00pm CDT

CITR 3 - From Defense to Damage: The Oxidative Toll of Huanglongbing (HLB) on Sweet Oranges

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Strand 12B

The study was conducted at the Southwest Florida Research and Education Center (SWFREC), University of Florida (UF), between 2012 and 2013. It focused on evaluating oxidative stress metabolism in two-year-old 'Valencia' sweet orange (Citrus sinensis) plants grafted onto Swingle rootstock (Citrus paradisi × Poncirus trifoliata). Both healthy and HLB-affected plants were cultivated under controlled greenhouse conditions. Leaf samples, ranging from young to fully expanded stages, were analyzed to observe biochemical responses to HLB infection. Early-stage HLB-affected leaves appeared asymptomatic but later developed blotchy patterns, characteristic of the disease. Hydrogen peroxide (H₂O₂) levels increased in both healthy and HLB-affected leaves, with significantly higher concentrations observed in the latter. Healthy leaves showed H₂O₂ levels ranging from 0.5 to 3.8 µmole per gram of fresh weight (FW), while affected leaves exhibited levels from 0.56 to 6.5 µmole per gram FW, especially in fully expanded leaves. Enzymatic activities related to oxidative stress were also evaluated. Catalase (CAT) and ascorbate peroxidase (APX) activities increased during the leaf expansion phase but declined in fully expanded leaves, with a sharper decrease observed in HLB-affected samples. The reduced CAT and APX activity in affected leaves contributed to the accumulation of H₂O₂, exacerbating oxidative stress. Guaiacol peroxidase (GPOD) activity was low during early leaf expansion but increased in fully expanded leaves. HLB-affected leaves showed significantly higher GPOD activity, possibly contributing to elevated H₂O₂ levels. Glutathione reductase (GR) activity, vital for maintaining redox balance by regenerating reduced glutathione (GSH), was higher in healthy leaves but declined in HLB-affected samples. This decline suggested impaired recycling of GSH, disrupting redox homeostasis and weakening antioxidant defenses. In contrast, glutathione-S-transferase (GST) activity was elevated in HLB-affected leaves, likely as an adaptive response to detoxify reactive oxygen species (ROS). However, the combination of increased GST and reduced GR activity led to a depletion of reduced glutathione, further intensifying oxidative stress. Overall, the study highlights the disruption of oxidative stress metabolism in HLB-affected sweet orange leaves. The compromised antioxidant defense system, characterized by reduced CAT, APX, and GR activities, contributes to increased cellular damage. These findings provide insights into plant defense mechanisms and suggest potential intervention strategies for managing HLB-induced stress.

Speakers

Naveen Dixit

University of MD Eastern Shore

Co-authors

R C Ebel

Consultant

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Poster # csv

5:00pm CDT

EcoPhys 2 - Light attenuation effects on productivity, yield and fruit quality of cranberries under Massachusetts conditions

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Strand 11B

Light attenuation effects on productivity, yield and fruit quality of Cranberries under Massachusetts conditions. Brian Makeredza, Giverson Mupambi and Peter Jeranyama University of Massachusetts Cranberry Station, 1 State Bog Rd, East Wareham, MA 02538 Cranberry (Vaccinium macrocarpon Ait.) is a fruit of significant commercial importance in North America. The fruit is consumed for its high vitamin C and antioxidants such as phenols, including anthocyanins and quercetin. Radiation stress poses significant challenges to production of high-quality marketable cranberries. Elevated exposure to high visible and ultraviolet (UV) light negatively impacts physiological and stress defensive mechanisms of the fruit, made up of biochemicals such as antioxidants, pigments and organic acids. We investigated the effects of light levels and quality on the productivity of two cranberry cultivars, Stevens’ and ‘Mullica Queen’ at two different sites. A sun exposed control was compared to three light reduction treatments. The treatments were two shade net treatments that filtered 17% and 34% visible light and a particle film spray (Raynox®), that filtered UV light. Sensors were installed to log micro-climatic weather conditions. Net carbon assimilation, stomatal conductance and transpiration were measured at the green, blush and full red stage of fruit development. The ratio of carbon isotopes as described by the δ13C value were assessed to determine carbon discrimination as a stress indicator. Fruit quality parameters measured at harvest were flesh firmness, titratable acidity (TA), total soluble solids (TSS), total anthocyanins (TAcy) and fruit rot. Raynox®, did not have an effect on carbon assimilation, yield and fruit quality. Reducing visible light did not affect stomatal conductance and transpiration but decreased carbon assimilation and yield but the effects were not statistically significant in some cases. Micro-climatic conditions under shade nets were conducive to the development of cranberry fruit rot which consequently contributed to yield reduction of marketable fruit. There were no differences in carbon isotope composition indicating no differences in abiotic stress levels. Fruit firmness decreased with an increase in shading. Trends for TA and TSS were inconsistent and unclear between the cultivars, but TAcy was only impeded by reducing light up to 34% level. Keywords: Cranberry, shade nets, light levels, particle film spray, carbon isotope

Speakers

Brian Makeredza

University of Massachusetts

Co-authors

Giverson Mupambi

University of Massachusetts Amherst

Peter Jeranyama

University of Massachusetts Amherst

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

5:00pm CDT

FRBR 2 - Genetic Dissection of Resistance to Peach Fungal Gummosis: Detection and Validation of Loci Originating from Almond and Peach Germplasm

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Strand 11A

Peach fungal gummosis (PFG), caused by fungal pathogens in the Botryosphaeriaceae family, including Botryosphaeria dothidea, Lasiodiplodia theobromae, and Diplodia seriata. This disease is a major threat to Prunus production worldwide. The initial symptoms often remain latent until trees are exposed to stress, at which point it can lead to substantial yield losses and even tree mortality. Given the lack of curative fungicide options and the difficulty of managing prolonged latent infections, genetic resistance has become a central focus for integrated PFG management strategies. A key breakthrough in this effort was the identification of Botd8, a major resistance locus derived from the almond cultivar ‘Tardy Nonpareil.’ Mapped to linkage group 8, Botd8 confers dominant resistance to B. dothidea and co-segregates with the red leaf locus (Gr). Its resistance effect was validated in multiple environments and under different inoculation methods, including field, trellis, and wound inoculation. Further validation using detached stem and leaf assays confirmed that genotypes homozygous or heterozygous carrying Botd8 exhibited significantly reduced lesion development following inoculations with B. dothidea and D. seriata. However, Botd8 was not effective against L. theobromae, underscoring the need for additional resistance sources. The strong correlation between detached stem assay results and field ratings also demonstrated the utility of these rapid, non-destructive screening tools in breeding programs. To expand resistance options beyond almond-derived sources, a recent study focused on the low-chill peach landrace ‘Okinawa’. A segregating F1 population from ‘Okinawa’ × (‘Flordaguard’ × PI91459) was phenotyped for disease severity and genotyped via Genotyping-by-Sequencing. QTL analysis revealed a novel resistance locus on linkage group 6, distinct from Botd8. This QTL consistently explained 29–41% of the phenotypic variation across two years, suggesting a polygenic basis for resistance in peach. Notably, the Botd8 haplotype was common in high-chill cultivars but absent in low-chill germplasm, positioning ‘Okinawa’ as a valuable resistance source for subtropical breeding efforts. Collectively, these studies establish a comprehensive framework for developing PFG-resistant peach cultivars

Speakers

Daniel Mancero

UNIVERSIDAD AGRARIA DEL ECUADOR

Fruit researcher with experience in multidisciplinary projects for plant protection and plant breeding

Co-authors

Gabriel Matsumoto

University of Florida

Jose Chaparro

University of Florida

Phillip Harmon

University of Florida

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Poster # csv

5:00pm CDT

ORGH 2 - Anaerobic Soil Disinfestation with Organic Amendments Improves Organic Strawberry Yield and Quality

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Strand 12A

Anaerobic soil disinfestation (ASD) is a potential biological alternative to chemical fumigation for managing soilborne pathogens and enhancing soil health in strawberry production. The effectiveness of ASD for improving organic strawberry systems deserves more in-depth research. Building upon an ASD input rate study, this on-station experiment, conducted at Citra and Balm in Florida, assessed the impacts of two ASD treatments, including molasses (13.9 m³/ha) combined with either 9.5 (ASD1) or 14.25 Mg/ha (ASD2) of Everlizer, a heat-processed poultry manure product on strawberry yield performance. Using a split-plot design with four replications, the three-week ASD treatments and no ASD control were included in the whole plots and six strawberry cultivars (i.e., ‘Florida127’, ‘Florida Brilliance’, ‘Florida Medallion’, ‘Florida Pearl’, ‘Ember’, and ‘Encore’) were included in the subplots. A sunn hemp summer cover crop was grown, and the soil was incorporated before ASD establishment and Fall strawberry planting. At Citra, ASD1 and ASD2 significantly increased marketable fruit yield compared to the no ASD control by about 25% and 21%, respectively. However, this increase was accompanied by a modest increase in unmarketable yield, particularly under ASD1. The cultivar effect was also significant (p < 0.001), with ‘Encore’ and ‘Ember’ exhibiting the highest marketable fruit yield, while ‘Florida Brilliance’ had the highest unmarketable fruit yield. A similar trend was observed at Balm, where ‘Encore’ was the cultivar with the highest marketable yield. In addition, marketable fruit yield was increased by 7% under ASD1 and 36% under ASD2 relative to the control. On the other hand, ASD1 and ASD2 also led to higher unmarketable fruit yields by 13% and 35%, respectively, relative to the control. While the main effects of ASD treatment and strawberry cultivar were significant at both locations, no ASD by cultivar interaction was observed, indicating that cultivar performance trends were relatively stable across ASD treatments. Across locations, ASD significantly improved total fruit yield, with ASD1 promoting a higher level of marketability by lowering the amount of unmarketable fruit. These results demonstrate the application of ASD for enhancing strawberry yield in sandy soils and subtropical environments and highlight the importance of cultivar selection for optimizing organic strawberry production systems and assisting with organic transition. Further assessments of ASD inputs and implementation, fruit compositional quality, plant nutrient uptake, and soil microbial activity are expected to provide more insights into developing ASD practices for advancing sustainable strawberry production in Florida and the Southeastern region.

Speakers

Bikash Adhikari

University of Florida

Co-authors

David Moreira

University of Florida

Erin Rosskopf

USDA Agricultural Research Service

Isaac Vincent

University of Florida

Jason Hong

USDA Agricultural Research Service

Johan Desaeger

University of Florida

Nan Xu

University of Florida

Xin Zhao

University of Florida

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic
Funding Source This work is supported by the Organic Agriculture Research and Extension Initiative program, project award no. 2021-51300-34914, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.
Funding Option OREl or ORG funded all or part of the research associated with this abstract

5:00pm CDT

PLAST - Beyond Plastic: Biobased Mulch Maintains Plant Growth with Rapid Degradation

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Foster 2

Lignocellulosic film is a biodegradable alternative to traditional, non-biodegradable polyethylene (PE) mulch, and is made with fully biobased feedstocks. The biobased composition of lignocellulose film renders it suitable for certified organic production in the United States and Canada, whereas soil-biodegradable plastic mulches are not permitted given they are not made with fully biobased feedstocks. However, information regarding the horticultural performance of lignocellulose film as a mulch is lacking. The objective of this study was to address this knowledge gap by comparing the functionality of lignocellulosic film to other mulch treatments using raspberry grown in a greenhouse. ‘Cascade Premier’ tissue culture transplants were planted in 12.7 x 12.7 cm (1.89 L) pots and grown for 112 days. Mulch treatments were placed over the surface of the media and around the base of the plants before being arranged in a randomized complete block design with eight replicates. Treatments included PE, soil-biodegradable mulch (starch-based, PBAT copolyester), paper mulch, lignocellulosic film, lignocellulosic film with biochar, cellulose film, and no mulch. Mulch treatment did not significantly impact overall plant growth throughout the trial, although variations in soil temperature were observed with lignocellulosic film having the highest reported temperature overall. Following the greenhouse experiment, new mulch samples were subjected to a soil biodegradation assay whereby samples were buried in two contrasting climates in Washington (i.e., warm-summer Mediterranean and cold semi-arid climates) with four replicates per location. Lignocellulosic film made with a hot press and lignocellulosic film with biochar and a hot press were added as additional treatments. Mesh bags containing the mulch samples were collected and analyzed for visual breakdown. Differences in breakdown were observed across mulch treatments with cellulose film being the most degraded, PE mulch being the least degraded, and lignocellulose being intermediate. After 3 months, lignocellulose had degraded by approximately 50% in both locations. Results to date indicate films made with lignocellulose maintain plant growth relative to PE mulch and biodegrade rapidly once incorporated into the soil. Future work should focus on scaling up lignocellulose material generation so they may be evaluated in open-field settings.

Speakers

Aidan Williams

Washington State University

Co-authors

Haishun Du

University of Wisconsin-Madison

Lisa Wasko DeVetter

Washington State University

Teng Li

University of Maryland

Xuejun Pan

University of Wisconsin-Madison

Yuan Yao

Yale University

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv
Funding Source USDA

5:00pm CDT

VCM 5 - Elucidating Collembola-seed interactions to advance seed bank management

Thursday July 31, 2025 5:00pm - 5:15pm CDT

Foster 1

Collembola, commonly known as springtails, are soil microarthropods which play important roles in organic matter decomposition, nutrient cycling, and microbial interactions in agricultural systems. However, little research has assessed their direct interactions with plants. The few studies that have researched these direct interactions have found mixed effects of Collembola on germination and plant growth outcomes. This research aims to further investigate the role of Collembola in seed germination and early seedling development. Two complementary lab experiments were conducted using species in the Amaranthus family, spinach (crop) and waterhemp (weed), to explore the role of seed coat thickness in Collembola-seed interactions. We hypothesize that spinach, with its thick seed coat, would be stimulated by Collembola grazing without sustaining damage, whereas waterhemp, with its thin seed coat, would experience adverse effects, leading to physiological stress. The first experiment was conducted using deli cups lined with germination paper. The treatments included the two plant species and the Collembola Isotomiella minor at three abundance levels (none (0), low (15), and high (30)). Each treatment combination was replicated 5 times. For each plant species, ten seeds were randomly arranged in each deli cup and the Collembola treatments were added. Mesocosms were maintained in growth chambers at 24°C and deionized water was added as needed to maintain moisture. Germination was recorded after 5, 7, and 10 days. Both the spinach and waterhemp germination were not affected by the Collembola treatments. However, spinach had consistently high germination, whereas waterhemp had consistently low germination. The second experiment was conducted using transparent mesocosms filled with a transparent plant growing medium to simulate a 3-D soil structure. The treatments were the same as the experiment described previously. The sealed mesocosms were maintained in growth chambers at 24°C for four weeks. Germination was recorded 5, 7, 10, and 14 days after planting. Collembola interactions with the root systems were monitored using video and photographic recordings throughout the experiment. After four weeks, in mesocosms with true leaf development, plant leaves were measured for stomatal conductance, transpiration, photosystem II efficiency, and chlorophyll content. Each plant was then harvested, and aboveground and root biomass was collected, dried, and weighed. Overall, germination in the mesocosms was low for both spinach and waterhemp, and the Collembola treatments did not have any significant effects. Our initial findings suggest that seed coat thickness may not play a role in the outcomes of Collembola-seedling interactions.

Speakers

Ashley Jernigan

Assistant Professor, Virginia Tech

Co-authors

Haylie Brown

Virginia Tech

Thursday July 31, 2025 5:00pm - 5:15pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Poster # csv
Funding Source Dr. Ashley Jernigan’s Hatch Research Project VA-160250

5:15pm CDT

CITR 3 - The 'OLL-8' Sweet Orange Appears to be Relatively More HLB Tolerant Than Standard 'Valencia' and 'Hamlin' Budlines

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Strand 12B

The citrus industry in Florida has been decimated by huanglongbing (HLB), a disease vectored by the Asian citrus psyllid. Industry standard budlines of sweet orange in Florida have all been deemed susceptible to HLB and do not produce profitable yields at the vast majority of commercial groves. Symptoms of HLB include low yield, premature fruit drop, stunted growth, poor fruit and juice quality, blotchy mottle of leaf tissue, and eventual tree decline, dieback, and tree death. There is not yet a therapy or treatment that has cured this disease. A relatively new selection of sweet orange called 'OLL-8' has shown increased tolerance to HLB as measured by yield, fruit quality, tree growth and multispectral imaging metrics. The 'OLL' acronym represents the names of Orie and Louise Lee, who were citrus farmers in the State of Florida for decades. The 'OLL-8' sweet orange is a somaclone of the original 'OLL' tree that was found in St. Cloud, FL. Evidence of the enhanced tolerance of OLL-8 versus standard 'Valencia' and 'Hamlin' will be presented in the form of fruit and juice quality, yield, tree growth and size, and multispectral drone imagery data, including normalized difference vegetation index (NDVI). The 'OLL-8' sweet orange outperformed both conventional scions at multiple sites over multiple seasons in Polk County FL. Several drone flights were used to determine tree size and health over time. The results demonstrate the possibility of enhanced plant performance with the use of somaclonal variation in sweet orange in the HLB environment. More research is needed to confirm 'OLL-8' sweet orange's tolerance, and if confirmed, the biological mechanisms of this budline's tolerance could be elucidated for developing more HLB tolerant germplasm via conventional breeding or biotechnological methods.

Speakers

John Chater

University of Florida

Co-authors

Emily Worbington

University of Florida-IFAS CREC

Joe Volpe

University of Florida

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Strand 12B

Oral presentation, Citrus Crops 3

Subject Citrus Crops
Funding Source USDA Agricultural Marketing Service (AMS) MultiState Specialty Crop Block Grant through the California Department of Food and Agriculture project number 19-1043-002-SF

5:15pm CDT

EcoPhys 2 - Microclimate Effects on Cranberry Fruit Rot and Quality

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Strand 11B

The American cranberry (Vaccinium macrocarpon Aiton), commonly known as the large-fruited cranberry, is native to North America. Fruit quality remains a major challenge for cranberry growers, with the cranberry fruit rot (CFR) complex posing a significant threat. Cranberry fruit rot is associated with over a dozen taxonomically diverse fungi. In the northeastern United States, growers typically apply three to five fungicide treatments per growing season to manage CFR. Even with well-timed applications, growers often observe rot levels between 1% and 15%, or sometimes higher. When rot exceeds 12%, growers face financial penalties, and crops with more than 20% rot are often rejected by processors. Managing CFR has become increasingly difficult, particularly in high-yielding and newer cultivars. This challenge is further compounded by regulatory restrictions over the past decade on key fungicides such as chlorothalonil and mancozeb. As conventional control options decline, interest in alternative strategies continues to grow. However, the influence of microclimate, cultural practices, and plant physiological factors on CFR incidence and overall fruit quality remains poorly understood. In this study, we investigated 22 cranberry bogs in Massachusetts over a three-year period (2021–2023) to elucidate the relationships among weather variables (temperature, humidity, growing degree days [GDD], soil moisture), plant traits (fruiting upright-to-total upright ratio, leaf area index [LAI], canopy height), cultural practices (fungicide choice and frequency), and fruit quality metrics (rot incidence, yield, anthocyanin content, and firmness). Statistical analyses included year-to-year comparisons, predictor-response modeling, and time-series evaluations to identify critical periods influencing fruit quality outcomes. Key findings indicate that interannual microclimatic variation significantly affects fruit quality. Temperature influenced anthocyanin accumulation throughout the growing season, while GDD accumulation influenced fruit yield. A higher fruiting upright ratio was associated with increased yield and firmness, while greater LAI correlated with higher anthocyanin content. Although fungicide choice and application frequency varied widely among participating bogs, a marked reduction in fruit rot and an increase in yield were observed with up to four fungicide applications; however, additional applications beyond this threshold did not result in further significant improvements. Notably, bog age did not have a significant effect on fruit quality. These findings highlight the need for integrated, site-specific strategies that combine environmental monitoring with targeted interventions to improve cranberry production and support long-term sustainability.

Speakers

Leela Uppala

UMass-Amherst

Leela grew up in a rural part of southern India. She received her B.S degree in Agriculture from Acharya N.G. Ranga Agricultural University and M.S degree in Plant Pathology from Kerala Agricultural University in India. She received her Ph.D. in Plant Pathology from Auburn University... Read More →

Co-authors

Giverson Mupambi

University of Massachusetts Amherst

Michael Nelson

New Jersey Institute of Technology

Peter Jeranyama

University of Massachusetts Amherst

Salisu Sulley

University of Massachusetts-Amherst-Cranberry Station

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

5:15pm CDT

FRBR 2 - Pedigree analysis of rabbiteye blueberry (Vaccinium virgatum Aiton) indicates limited genetic diversity

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Strand 11A

As a native species in the southeastern U.S., rabbiteye blueberry (Vaccinium virgatum Aiton) is known for its resilience to environmental stresses and adaptability to various soil types. Rabbiteye was the dominant species grown in the southern U.S. before the rise of southern highbush blueberries (V. corymbosum L. interspecific hybrids). Compared to southern highbush, rabbiteye cultivars are often perceived as seedy and have thick skin. Limited genetic diversity, compounded by repeated use of elite parents and decreased breeding efforts, poses challenges for rabbiteye improvement. To facilitate more efficient rabbiteye breeding in the future, this study aims to assess the genetic diversity of rabbiteye cultivars through pedigree analysis and evaluate the impact of interspecific hybridization on modern cultivars. The pedigree data of 180 rabbiteye blueberry accessions were analyzed to calculate inbreeding coefficients, coefficients of coancestry and the genetic contribution of founders. Five founders ‘Myers’, ‘Black Giant’, ‘Ethel’, ‘Clara’, and ‘W4’, collectively account for a minimum of 73% of the genetic composition of rabbiteye cultivars. The level of interspecific hybridization has been limited in rabbiteye breeding, with V. corymbosum contributing 3% of the genetic composition of rabbiteye cultivars and 1% from other species such as V. constablaei and V. darrowii. The narrow genetic base and repeated use of common parents led to an increase in inbreeding coefficients, from an average of less than 0.0002 before 1980 to 0.014 in the 2000s. In the future, it would be valuable to increase the use of exotic materials from other species or within the rabbiteye germplasm to broaden the genetic base while introducing valuable alleles. Further evaluation of population structure with genomic information is needed to validate pedigree information and provide a more accurate assessment of the genetic diversity and population structure.

Speakers

Sushan Ru

Auburn University

Co-authors

Craig Hardner

University of Queensland

Dorrie Main

Washington State University

Juliet Chu

University of Georgia

Roohollah Abdolshahi

Auburn University

Sook Jung

Washington State University

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Funding Source This work is supported by the Specialty Crop Research Initiative project award no. 2022-51181-38449 from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.
Funding Option SCRI funded all or part of the research associated with this abstract

5:15pm CDT

ORGH 2 - Organic Aminoethoxyvinylglycine delays ripening pre-and postharvest on apples

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Strand 12A

Aminoethoxyvinylglycine (AVG) is a plant growth regulator widely used in apple production to delay ethylene-mediated ripening and improve fruit quality. This has become a key tool for delaying ripening, optimizing harvest time, and reducing preharvest drop. The development of an organic AVG is key for organic apple production, where growers currently lack effective tools to delay ripening and manage fruit quality, both at harvest and postharvest. A new organic-compliant formulation, Retain® OL, was developed to meet the needs of the organic industry. To assess the potential of organic AVG, field trials were conducted over three seasons in commercial Gala and Honeycrisp orchards. Different application rates were tested, and fruit samples were collected at preharvest, harvest, and postharvest intervals. Fruit maturity and quality attributes including flesh firmness, skin color, Index of Absorbance Difference (IAD), starch index, total soluble solids (TSS), among others were measured. Postharvest evaluations continued for up to nine months in controlled atmosphere (CA) storage. Retain® OL application effectively delayed fruit maturity in both Gala and Honeycrisp apples in a dose- and timing-dependent manner. Treated fruit exhibited higher firmness at harvest and after extended storage. IAD values were consistently improved, indicating a slower ripening process and delayed loss of chlorophyll. In Gala, red skin color development was maintained or enhanced, whereas Honeycrisp showed a slight reduction in coloration. The starch index was higher in the untreated control at both preharvest and harvest stages, indicating more advanced ripening. Total soluble solids (TSS) showed variable responses across seasons, influenced by treatment rate, timing, and cultivar. Depending on these factors, TSS levels were maintained, improved, or slightly reduced compared to the control. This study provides new insights into the pre- and postharvest effects of Retain® OL. Overall, organic AVG demonstrated benefits comparable to the conventional formulation, offering a valuable tool for harvest management in organic apple production. These findings support the integration of organic AVG into organic systems to enhance harvest flexibility, improve storability, and increase overall fruit marketability.

Speakers

Isabel Ortega-Salazar

Washington State University

Co-authors

Carolina Torres

Washington State University

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Strand 12A

Oral presentation, Organic Horticulture 2

Subject Organic
Poster # csv

5:15pm CDT

PLAST - Beyond Disposal: A Comparative Life Cycle Assessment of End-of-Life Strategies for Agricultural Plastic Mulch

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Foster 2

While agricultural plastic mulch significantly enhances crop yields, its widespread use generates substantial plastic waste, raising serious environmental concerns. Traditional disposal methods such as landfilling and incineration not only contribute to greenhouse gas emissions but also result in valuable resource losses. To address these challenges, this study performs a systematic life cycle assessment (LCA) comparing five end-of-life (EOL) strategies for polyethylene (PE) mulch films in strawberry cultivation: conventional landfilling, incineration, pyrolysis-based conversion, wood-plastic composite (WPC) production, and asphalt modification. A gate-to-gate LCA framework was adopted, with system boundaries spanning from on-farm mulch collection to final material or energy recovery. Environmental impacts were evaluated using the TRACI 2.1 methodology, encompassing global warming potential (GWP), cumulative energy demand, air/water pollution, land occupation, resource recovery efficiency, microplastic leakage risks, and human health impacts. Results reveal distinct trade-offs among the EOL pathways. Pyrolysis emerges as the optimal energy recovery strategy, reducing fossil fuel dependence by converting 85% of plastic waste into syngas while mitigating microplastic release. WPC production demonstrates superior material circularity, repurposing 92% of waste into durable construction materials with a 40-year service life. Asphalt modification offers the lowest GWP (1.2 kg CO₂-eq/kg plastic) and reduces virgin polymer demand by 30%, though its long-term microplastic leaching requires further investigation. In contrast, landfilling and incineration exhibit 60-75% higher life cycle emissions and fail to recover material value. This study provides the first comprehensive comparison of agricultural plastic waste management strategies that integrates both energy recovery and material upcycling paradigms. By extending traditional LCA boundaries to include microplastic pollution risks and long-term degradation effects, the findings offer actionable insights for policymakers to prioritize scalable, resource-efficient solutions that align with circular economy principles in agri-plastic management.

Speakers

Jianying Wang

Washington State University

Co-authors

Liang Yu

Kentucky State University

Ting Chi

Washington State University

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv
Funding Source USDA SCRI 2022-51181-38325
Funding Option SCRI funded all or part of the research associated with this abstract

5:15pm CDT

VCM 5 - Growth Rate and Yield of High Tunnel Grown Water Spinach (Ipomea aquatica) in Georgia, USA

Thursday July 31, 2025 5:15pm - 5:30pm CDT

Foster 1

Water spinach (Ipomoea aquatica) is leafy green vegetable that is routinely cultivated in Southeast Asia. Due to its aggressive growing habit and potential to become established in waterways, it has been classified as a federal noxious weed within the United States. However, recently, ethnic communities in the Atlanta, Georgia, USA metropolitan region have expressed an interest in being able to cultivate water spinach for local sale. The objective of this study was to develop recommendations for the establishment of growing degree day (GDD) estimates and yields for harvest for three planting periods for organic cultivation of two selections of water spinach in a high tunnel environment during the summer months in Watkinsville, Georgia USA. Selection 1 had a hastate leaf shape, while selection 2 had a more lanceolate leaf shape. Plantings were conducted on three dates (May, June, July) during summer 2023. Plots contained 36 plants and were arranged factorial randomized complete block design with four replicates with selection and planting date being the main effects. Once plants reached a marketable harvest size, the above-ground portions were cut near the plant base, which repeated during the growing season. Our results indicated that planting water spinach in May resulted in significantly greater yields compared to June and July plantings due to a greater number of harvests and biomass production at each harvest. Using a sweetpotato (Ipomea batatas) growth model, the GDD at harvest for the May planted water spinach were 390, 271, and 301 for the 7 Jul, 1 Aug and 26 Aug harvest periods, respectively. The rate of fresh weight biomass production for these harvests ranged from 41,469 kg ha-1 to 49,398 kg ha-1 for selection 1 and 24,266 kg ha-1 to 45,432 kg ha-1 for selection 2. Total Fresh weight biomass for all three harvests (7 Jul through 26 Aug) for the May plantings were 136,800-1 and 102,300 kg ha-1 for selections 1 and 2 respectively. July plantings had a greater GDD accumulation at harvest, but yields were significantly lower than earlier plantings. Our results suggest that water spinach could be successfully grown in high tunnels in Georgia, USA during the summer months. Further, while some plants did produce flowers, the chance for off-site movement of seeds and plant material was minimal as plants were confined to a high tunnel structure.

Speakers

Timothy Coolong

University of Georgia

Co-authors

Juan Carlos Diaz Perez

University of Georgia

Nick Basinger

University of Georgia

Shelbie Bohensky

Universty of Georgia

Thursday July 31, 2025 5:15pm - 5:30pm CDT
Foster 1

Oral presentation, Vegetable Crops Management 5

Subject Vegetable Crops Management
Funding Source Specialty Crop Block Grant Georgia Department of Agriculture

5:30pm CDT

EcoPhys 2 - Applications of the Laisk Method for Understanding Intraspecies Variation in Ci* and RL in Apple (Malus spp.) Rootstocks

Thursday July 31, 2025 5:30pm - 5:45pm CDT

Strand 11B

The balance between photosynthetic carbon fixation and leaf respiration drives our expectations of crop performance. The Laisk method is a technique used to estimate the CO2 concentration in the intercellular air space when Rubisco’s oxygenation velocity is inferred to be twice its carboxylation velocity (Ci*) and leaf respiration in the light (RL). These parameters serve as the basis for understanding leaf carbon dynamics at the physiological level and can also be incorporated into global carbon models. While Ci* and RL estimates have been well characterized in model plant species, there is a paucity of information available for horticultural crops. Further, intraspecies variation in these parameters has not been explored. We used the Laisk method to estimate Ci* and RL in three apple rootstock genotypes—G65, G11 and B10. The Laisk method was conducted in the steady-state along with chlorophyll fluorescence measurements to fit the solar induced fluorescence (SIF) model for estimating rates of net assimilation (An). In addition, the Laisk method was conducted in the nonsteady-state using the Dynamic Assimilation Technique (DAT). We found there were no statistically significant differences between genotypes nor technique used for the Laisk method when estimating Ci* and RL across the three genotypes. The findings of this study suggest that Ci* and RL values are conserved within species, the SIF model accurately predicts An for Laisk method data, and the DAT can be used to reliably estimate Ci* and RL.

Speakers

Griffin Erich

Cornell University

Co-authors

Jason Londo

Cornell University

Thursday July 31, 2025 5:30pm - 5:45pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

5:30pm CDT

FRBR 2 - Insights from Chromosome Painting in wide Vitis x Muscadinia Hybrids

Thursday July 31, 2025 5:30pm - 5:45pm CDT

Strand 11A

The development of Vitis × Muscadinia (V x M) wide hybrids, combining the disease resistance of muscadines (M. rotundifolia) with the berry quality attributes of V. vinifera grapes has be en a longstanding ambition of breeders. Stenospermocarpic seedless muscadine hybrids and wine grapes carrying powdery and downy mildew resistance introgressed from muscadines have been developed using classical techniques without the assistance of molecular tools through sustained effort over a century. However, progress has been impeded by differences in chromosome number (Vitis=38 chromosomes and Muscadinia=40 chromosomes) and genetic distance between the subgenera. A major objective of the new Vitis x Muscadinia Specialty Crop Research Initiative project is to develop and deploy new genotyping platforms and chromosome painting visualization tools to help grape and muscadine breeders track introgressed chromosomal regions in wide hybrids and accelerate trait discovery and cultivar development in new V x M hybrids. In order to develop a chromosome-painting visualization tool for V x M hybrids, we first conducted a large-scale population diversity analysis using historical data from the rhAmpSeq Vitis core panel. Structure analysis was performed to identify individuals belonging to Muscadinia and five additional subpopulations within subgenus Vitis. Approximately 33,000 marker haplotypes were identified as unique to Muscadinia and 671,000 haplotypes were identified as present only in Vitis. This haplotype information was used to create automated chromosome painting visualizations of introgressed segments in historical and modern V x M hybrids. These visualizations allow us to identify which Vitis-type hybrids carry muscadine introgressions in known resistance loci on chromosomes 12 (Run1/Rpv1), 18 (Run2/Rpv2), and 14 (Ren5) and which Muscadinia-type hybrids have introgressions associated with stenospermocarpy and other fruit-quality alleles from Vitis. This information will assist grape and muscadine breeders in planning crosses and discovering new disease resistance and fruit quality alleles. In the coming months, we intend to extend this strategy to a new low-cost DArTag genotyping panel that has been designed to amplify polymorphic markers in both subgenera. Breeders will then be able to rapidly assess which chromosomal regions and major-effect fruit quality and disease resistance alleles are present in a homozygous or heterozygous state in all new V × M hybrids.

Speakers

Margaret Worthington

University of Arkansas

Co-authors

Cheng Zou

Cornell University

Dustin Wilkerson

Cornell University

Isabella Vaughn

University of Arkansas

Lance Cadle-Davidson

USDA-ARS

Qi Sun

Cornell University

Thursday July 31, 2025 5:30pm - 5:45pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Funding Source USDA NIFA Award # 2024-51181-43236
Funding Option SCRI funded all or part of the research associated with this abstract

5:30pm CDT

PLAST - Two-Year Evaluation of Biodegradable Plastic Mulches for Winter Strawberry Production in Florida: Mulch Deterioration, Plant Growth, Yield, and Fruit Quality

Thursday July 31, 2025 5:30pm - 5:45pm CDT

Foster 2

Biodegradable plastic mulches (BDMs) have been introduced as a sustainable alternative to polyethylene (PE) mulches, which can contribute to plastic contamination and incur high removal and disposal costs. The objective of this study was to evaluate the performance and suitability of BDMs for winter strawberry production in Florida. We conducted field experiments using ‘Florida Brilliance’ short-day strawberry during the 2023–2024 (Season 1) and 2024–2025 (Season 2) winter seasons in West Central Florida. Five mulch treatments were evaluated: black PE mulch, black Mater-Bi® BDM (black MB–BDM), black Ecovio® BDM (black EV–BDM), white Mater-Bi® BDM (white MB–BDM), and white Ecovio® BDM (white EV–BDM ). Mater-Bi® is primarily starch-based but also contains polyester resins such as polybutylene adipate terephthalate (PBAT) and polycaprolactone. By contrast, Ecovio® is predominantly resin-based, comprising PBAT, polylactic acid, and other biodegradable polymers. The film thickness was 27.9 μm for the black PE and 22.9 μm for all BDMs. Season-dependent trends were observed in some results. In Season 1, all BDMs exhibited minimal deterioration with only minor tearing, and there was no significant difference in marketable yield compared to the black PE. In Season 2, all BDMs developed splits or tears within a month after transplanting, with the black EV–BDM and both white BDMs showing higher deterioration rates than the black PE. Orthogonal contrast analysis was used to assess BDM performance based on color and composition. Compared to the black PE, marketable yield was reduced by 28% for the black BDMs (34.0 vs. 26.5 t·ha–1) and by 8% for the white BDMs (34.0 vs. 31.3 t·ha–1). The white BDMs produced 18% higher yield than the black BDMs (31.3 vs. 26.5 t·ha–1), whereas no significant difference was found between the MB–BDMs and the EV–BDMs (28.8 vs. 29.1 t·ha–1). Soluble solid content remained unaffected by mulch treatment across both seasons and all growth stages. These results suggest that the performance of BDMs depends on seasonal weather conditions, mulch color, and composition, presenting challenges for commercial adoption. Enhancing the reliability and adoption of BDMs may require optimization of color, material composition, and film thickness.

Speakers

Hadi Ghasemi

PhD Graduate Assistant, University of Florida

🌱 Passionate about CEA. 🪻 Love saffron and have expertise in growing it. 🍓 Strawberry physiology and photosynthesis.

Co-authors

Lisa Wasko DeVetter

Washington State University

Nathan Boyd

University of Florida

Shinsuke Agehara

University of Florida

Thursday July 31, 2025 5:30pm - 5:45pm CDT
Foster 2

Oral presentation, Plasticulture

Subject Plasticulture
Poster # csv

5:45pm CDT

EcoPhys 2 - Diversity in Canopy Architecture and its Effect on Light Interception in Southern Highbush Blueberry

Thursday July 31, 2025 5:45pm - 6:00pm CDT

Strand 11B

Southern highbush blueberry (Vaccinium corymbosum interspecific hybrids) cultivars exhibit diverse canopy architectures. Plant architecture phenes influence light interception in other plant species. However, the relationship between canopy architecture and light interception is still poorly understood in southern highbush blueberry. We evaluated 29 genotypes, including cultivars and breeding selections from the University of Florida Blueberry Breeding and Genomics program. Plants were grown under commercial conditions in Citra, FL. We employed photogrammetry, field measurements, and a plant canopy analyzer to measure canopy density, canopy volume, base angle, and plant height in four plants per genotype. We found that genotypes differed in all measured phenes. Intercepted PAR in the bottom of the canopy varied among genotypes according to their plant architecture. Taller, wider, and denser genotypes received less light in the bottom of the canopy than shorter, narrower, and more sparse ones. We used principal component analysis to assess the relative contributions of each plant architecture phene to intercepted PAR. Canopy density and volume strongly contributed to intercepted PAR. These results suggest that plant architecture could be optimized, through breeding and agronomic practices, to maximize photosynthetic light interception in southern highbush blueberry.

Speakers

Md Zohurul Kadir Roni

University of Florida

Co-authors

Gerardo Nunez

University of Florida

Patricio Munoz

University of Florida

Thursday July 31, 2025 5:45pm - 6:00pm CDT
Strand 11B

Oral presentation, Ecological Physiology 2

Subject Ecological Physiology
Poster # csv

5:45pm CDT

FRBR 2 - Finding Gene Locations Influencing Citrus Leaf Morphology Using Genome Wide Association

Thursday July 31, 2025 5:45pm - 6:00pm CDT

Strand 11A

Citrus leaves exhibit remarkable morphological diversity, yet the genetic underpinnings of this variation remain poorly understood. In this study, we investigated the genetic architecture controlling citrus leaf shape by performing genome-wide association studies (GWAS) on over 3,000 digitized leaves collected from 150 citrus varieties across two years (2021 and 2022). Using a 50K SNP Axiom array, we identified consistent genomic regions on chromosomes 2, 3, 5, and 7 that were significantly associated with leaf length, width, and area. Linkage disequilibrium patterns within these regions revealed variability, and gene ontology enrichment indicated that genes involved in cell division, photosynthesis, and transcriptional regulation are overrepresented. Our results highlight the strong and heritable basis of leaf morphology in citrus and suggest that regulatory mechanisms play a major role in shaping these traits. This work provides key insights into the genetic control of leaf form and has potential implications for citrus breeding and functional genomics.

Speakers

Ryan Traband

UC Riverside

Co-authors

Xuesong Wang

UC Riverside

Zhenyu Jia

UC Riverside

Thursday July 31, 2025 5:45pm - 6:00pm CDT
Strand 11A

Oral presentation, Fruit Breeding 2

Subject Fruit Breeding
Poster # csv

7:59am CDT

HEMP - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Foster 2

Presiding/Moderator

Brian Poel

Fluence

Friday August 1, 2025 7:59am - 8:00am CDT
Foster 2

Oral presentation, Cannabis and HEMP

Subject Cannabis and Hemp

7:59am CDT

INPR - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Strand 10

Speakers

Tina McIntyre

UF/IFAS Extension

Friday August 1, 2025 7:59am - 8:00am CDT
Strand 10

Oral presentation, Invasive Plants Research

7:59am CDT

ORGH 3 - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Strand 11A

Presiding/Moderator

Moriah Bilenky

Purdue University

Friday August 1, 2025 7:59am - 8:00am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic

7:59am CDT

PUBHORT - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Foster 1

Presiding/Moderator

Lauren Errickson

Director of Rutgers Gardens & Campus Stewardship, Rutgers, the State University of New Jersey

Friday August 1, 2025 7:59am - 8:00am CDT
Foster 1

Oral presentation, Public Horticulture

Subject Public Horticulture

7:59am CDT

RHIZ - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Strand 12A

Speakers

Arthur Villordon

Professor, Louisiana State University AgCenter

No roots left behind! The sweetpotato's root system architecture integrates internal, environmental, and management determinants of storage root yield, quality, and shape attributes. Root architectural adaptations to biotic and abiotic stress variables provide insights about traits... Read More →

Friday August 1, 2025 7:59am - 8:00am CDT
Strand 12A

Oral presentation, Root Growth and Rhizosphere Dynamics

Subject Root Growth and Rhizosphere Dynamics

7:59am CDT

VSF 4 - Oral Session

Friday August 1, 2025 7:59am - 8:00am CDT

Strand 11B

Presiding/Moderator

Guo-qing Song

Michigan State University

Friday August 1, 2025 7:59am - 8:00am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits

8:00am CDT

HEMP - Differential effects of macro- and micronutrients on secondary metabolite production in drug-type (medical) cannabis

Friday August 1, 2025 8:00am - 8:15am CDT

Foster 2

The medical potential of cannabis (Cannabis sativa L.) is based on the complex chemical profile, comprising hundreds of secondary metabolites including cannabinoids, terpenoids and flavonoids. Cultivation conditions were demonstrated to affect plant development, function and production of secondary metabolites in cannabis. Understanding regulation of plant response to environmental conditions is key for development of optimal chemical profile for modern medicine. We have recently demonstrated sensitivity of the secondary metabolite profile in medical cannabis to mineral nutrition, with considerable responses to N, P, and K nutrition. Therefore, knowledge on the cannabis plant response to fertigation schemes is essential for the optimization of cultivation for production of high quality standardized material for the medical market, as well as for development of plant products containing specific desirable phytochemical profiles. In the talk, we will discuss our recent results concerning the potential of additional macronutrients and micronutrients to regulate plant development and the profile of active secondary metabolites in ‘drug-type’ medical cannabis. In pot experiments under controlled conditions, we demonstrated differential induction of changes in the cannabinoid and terpene profiles in ‘drug-type’ medical cannabis also by Ca, Mg, Zn and Mn. Furthermore, rate of uptake and deposition in the plants of individual macronutrients and micronutrients changes between the vegetative and the reproductive developmental stages, and along the reproductive phase.

Speakers

Nirit Bernstein

Volcani Center

Friday August 1, 2025 8:00am - 8:15am CDT
Foster 2

Oral presentation, Cannabis and HEMP

Subject Cannabis and Hemp
Poster # csv

8:00am CDT

INPR - Plant This Not That: Impacting Invasive Species One Flipbook At A Time

Friday August 1, 2025 8:00am - 8:15am CDT

Strand 10

Some invasive plants are listed as “prohibited for sale” on the Florida Department of Agriculture and Consumer Services Noxious Weed List, however many invasive plants are commercially available. Plant This, Not That: A Guide to Avoiding Invasive Plant Species in Florida is a laminated, ring-bound-flipbook written to provide safe alternatives to commonly sold invasive ornamental plants. Perfect for the resident or professionals visiting or running a nursery or garden center, this relevant resource includes 22 invasive plants that are commonly available for sale along with native or Florida-Friendly alternatives. Over 1,350 copies have been sold or distributed, bringing in $14,234. Concepts from the book have been integrated into classes for landscape professionals, industry nursery owners, master gardeners and the general public. Results from the classes show 1.) 367/376 or 97.6% increased their knowledge about the impact invasive species have in Florida, 2.) 371/373 or 99.4% intend to use the information from the class to choose plants that are not invasive, and 3.) 323/344 or 93.9% of participants felt more confident they could identify invasive plant species. Follow up surveys indicated participants used hand pulling to remove invasives (85% or 51/60), avoided invasives from the book (76% or 45/59) and educated others about invasive species (75% or 44/59). Intentional efforts to widely publicize the usefulness of this guidebook and its impact in extension programming have resulted in 11 articles reaching thousands of people, 2 interviews one on NPR and another on the radio, 3 webpages, one press release published on behalf of ASHS, and one journal article in the Journal of Hort Technology.

Speakers

Tina McIntyre

UF/IFAS Extension

Co-authors

Morgan Pinkerton

UF/IFAS Extension Seminole County

sandra wilson

University of Florida

Dr. Sandra Wilson is a Professor of Environmental Horticulture at the University of Florida’s main campus in Gainesville. She received B.S. and M.S. degrees from the University of Delaware and a Ph.D. in Plant Physiology from Clemson University. Dr. Wilson completed postdoctoral... Read More →

Friday August 1, 2025 8:00am - 8:15am CDT
Strand 10

Oral presentation, Invasive Plants Research

Subject Invasive Plants Research
Funding Source Extension Seminole budget

8:00am CDT

ORGH 3 - To Roll or not to roll: for sunn hemp that is not such an easy question

Friday August 1, 2025 8:00am - 8:15am CDT

Strand 11A

Despite its challenges, non-chemical, reduced tillage vegetable production is of continued interest among researchers and growers as a way to improve soil health. Primarily success in this production method has been use of high biomass cover crops such as cereal rye terminated with a roller crimper. However alternative cover crops should be explored to diversify reduced tillage systems and to improve nitrogen synchrony. Sunn hemp (Crotelaria juncea) is a high biomass producing legume with potential to achieve weed suppression while reducing nitrogen immobilization in non-chemical, no-till vegetable production. A two-year study was conducted at the Meigs Horticulture Facility (Meigs) in Lafayette IN to assess the potential of sunn hemp as a cover crop suitable for rolling in a non-chemical, no-till vegetable production system. At Meigs roll success of three sunn hemp rolling dates was evaluated. Followed by Swiss chard production. Sunn hemp was rolled with and I and J roller crimper 60, 70, and 80 days after seeding. Prior to rolling sunn hemp height, above ground biomass (sunn hemp and weed), and roll success was measured 4 weeks after rolling by collecting terminated (senesced) and non- terminated (non- senesced) sunn hemp from 0.25m2 quadrats. Roll success was most related to sunnhemp height and biomass at time of rolling (R2 = 0.76 P < 0.01 ,0.68 P =0.15). In year one rolling was only successful 80 days after seeding, however in in year two rolling was successful at all seeding dates. More research is needed to understand mechanisms contributing to sunn hemp rolling success.

Speakers

Moriah Bilenky

Purdue University

Friday August 1, 2025 8:00am - 8:15am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic
Poster # csv

8:00am CDT

PUBHORT - Botanic Garden Stakeholder Priorities Include Ecology, Conservation, and Biodiversity: A Case Study of Rutgers Gardens

Friday August 1, 2025 8:00am - 8:15am CDT

Foster 1

Understanding stakeholder priorities helps botanic gardens serve current visitors and develop relevant future programs. A strategic vision planning process investigated stakeholder priorities for university-affiliated Rutgers Gardens in central New Jersey, USA through an online survey conducted February – March 2024. Specific objectives included 1) determining priorities of botanic garden stakeholders to guide vision planning; 2) identifying key learning topic preferences among stakeholders, toward program development; and 3) understanding associations between overall priorities and learning interest to align visioning and programming efforts. Respondents (n=688) included university students (20.6%), faculty/staff (20.1%), and alumni (27.6%); garden visitors, staff, volunteers, members, and donors; and community members at large. The majority identified as white/Caucasian (64.5%), age 50 (50.2%), visit multiple times per year (39.9%), and reside in-state (94.7%). Asked to select their top three priorities, respondents identified Ecology, Conservation, and Biodiversity (41.9%), Display and Demonstration Gardens (34.9%), and Climate Change Resilience (27.3%) as overall leaders. Decreasing in priority were Preservation of Historic Plant Collections (25.0%), Horticultural Research (24.6%), Sustainable Agriculture (20.2%), Public Recreation (17.4%), Horticultural Therapy and Wellness (14.4%), Food Security (11.0%), Culture and Arts (9.2%), and Diversity, Equity, and Inclusion (6.7%). Respondents identified primary learning interest in Home Gardening

Speakers

Lauren Errickson

Director of Rutgers Gardens & Campus Stewardship, Rutgers, the State University of New Jersey

Co-authors

Theresa Hyslop-Gaden

ETM Associates, LLC

Tim Marshall

ETM Associates, LLC

Friday August 1, 2025 8:00am - 8:15am CDT
Foster 1

Oral presentation, Public Horticulture

Subject Public Horticulture

8:00am CDT

RHIZ - Modeling the Timing of Sweetpotato Storage Root Initiation and Initial Bulking Stages

Friday August 1, 2025 8:00am - 8:15am CDT

Strand 12A

The most economically important physiological process in sweetpotato is storage root initiation. The number of adventitious roots (ARs) that undergo storage root initiation can vary within and among individual plants. This extends to entire fields, which can vary in storage root yield by up to 50%. This unpredictability is further compounded by the fact that crop yield can only be evaluated post-factum and above-ground growth frequently provides little or no indication of productivity in commercial production settings. Significant progress has been achieved in understanding the environmental, physiological, and molecular cues of storage root formation but current evidence cannot be reconciled with root system architecture variability. Functional-Structural Plant Models (FSPM) such as OpenSimRoot are used to explore and understand the complex interactions among morphological and architectural traits, environment variables, and source-sink relations. OpenSimRoot is capable of simulating spatiotemporal dynamics of plant growth, including 3D root architecture, nutrient and water acquisition, and carbon processes underlying plant growth, but requires extensive parameterization. Here we describe the parameterization of OpenSimRoot to model the timing of storage root initiation and initial bulking stages. The model was parameterized using data from sweetpotato cultivar ‘Beauregard’ grown under greenhouse and irrigated field conditions, along with available data from literature. We will outline subsequent work that links root system architecture to storage root initiation, leading to future studies on the dynamics of carbon-related processes that determine the competency of adventitious roots to become storage roots.

Speakers

Marissa Barbosa

Lousiana State University

Co-authors

Arthur Villordon

LSU Agcenter

Christian Kuppe

Forschungszentrum Jülich

Don La Bonte

Louisiana State Univ

Johannes Postma

Forschungszentrum Jülich

Lisa Arce

Louisiana State University

Mae Ann Bravo

Louisiana State University

Friday August 1, 2025 8:00am - 8:15am CDT
Strand 12A

Oral presentation, Root Growth and Rhizosphere Dynamics

Subject Root Growth and Rhizosphere Dynamics
Poster # csv
Funding Source Us-Israel Agricultural Research Development Fund

8:00am CDT

VSF 4 - Pollination Insights - Optimizing Honey Bee Mediated Pollination in Highbush Blueberry

Friday August 1, 2025 8:00am - 8:15am CDT

Strand 11B

Pollination is a prerequisite for optimizing both yield and fruit quality within commercial highbush blueberry (Vaccinium spp.) production systems. Although many insects can pollinate blueberry flowers, the honey bee (Apis mellifera) provides most of the pollination services within commercial settings due to the large number of foraging individuals within a single colony. Despite this, insufficient pollination frequently limits growers from achieving their full yield potential, and research-based recommendations to inform pollination strategies are lacking. The objective of this presentation is to summarize how the cross-disciplinary and multi-institutional Blueberry Pollination Project has addressed some of these barriers by investigating best practices to achieve optimal honey bee-mediated pollination and formulate decision-aid tools. Key findings that will be highlighted include the role of cross-pollination for optimizing yields in northern and southern highbush blueberry cultivars, the effects of hive placement on flower visitation and overall crop pollination, effects of changing stocking density and colony placement on farm income, and how landscape density and colony population size are more influential in determining flower visitation and pollination outcomes than traditional stocking density recommendations. Decision-aid tools that predict bloom phenology for the timely arrival and departure of honey bee colonies will also be introduced alongside other project resources available on our website (https://blueberrypollination.org/).

Speakers

Lisa Wasko DeVetter

Washington State University

Co-authors

Andony Melathopoulos

Oregon State University

Clark Kogan

StatsCraft LLC

Emma Rogers

Washington State University

Jenna Walters

University of Maine

Kayla L Brouwer

Washington State University NWREC

Laura Goldstein

Michigan State University

Maxime Eeraerts

University of Ghent

Meghan Milbrath

Michigan State University

Rachel Mallinger

University of Florida

Rufus Isaacs

Michigan State University

Stan Chabert

French National Institute for Agriculture,

Suzette Galinato

Washington State University

Friday August 1, 2025 8:00am - 8:15am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Funding Source This article is based upon research supported by the National Institute of Food and Agriculture (NIFA), U.S. Department of Agriculture, under award number 2020-51181-32155 from the Specialty Crops Research Initiative, and NIFA Hatch project 1014919. ME was supported as a Belgian American Educational Foundation postdoctoral fellow and as an FWO postdoctoral fellow (grant no. 1210723N).
Funding Option SCRI funded all or part of the research associated with this abstract

8:14am CDT

GG 3 - Oral Session

Friday August 1, 2025 8:14am - 8:15am CDT

Strand 12B

Speakers

John Larsen

Graduate Student, University of Minnesota

John works with winter hardy landscape plants, with a special emphasis on Salix pellita (Satiny Willow). A major interest of John's is looking at the horticultural potential of certain native flora, hoping this could lead to new means of conservation for Minnesota's threatened sp... Read More →

Friday August 1, 2025 8:14am - 8:15am CDT
Strand 12B

Oral presentation, Genetics and Germplasm 3

Subject Genetics and Germplasm

8:15am CDT

GG 3 - Characterizing genetic diversity in wild collected satiny willow (Salix pellita) using GBS

Friday August 1, 2025 8:15am - 8:30am CDT

Strand 12B

Salix pellita (satiny willow) is a state-threatened shrub willow species which is native to Minnesota and offers appealing ornamental traits. The natural distribution of this taxon in Minnesota is limited primarily by habitat loss. Because the disjunct populations of this species in Minnesota are in decline and because no prior efforts have been made to conserve this taxon, horticultural practices and cultivation could offer a preservation outlet for satiny willow. Prior to this project, Salix pellita was not represented in any germplasm repository in the United States. This study uses GBS (genotyping by sequencing) to characterize diversity among, between, and within wild collected Salix pellita populations from Minnesota, Michigan, and New Hampshire. Diversity metrics Fis, Fst , pairwise Fst and He were used to categorize genetic diversity. High Fis was found within most populations, which can be attributed to population isolation and small population size. Pairwise Fst between state populations (MN-MI, MN-NH, MI-NH) showed high levels of genetic differentiation, which can be attributed to the lack of gene flow between these populations. Ultimately, these metrics will be used to establish a genetically diverse ex situ collection of Salix pellita.

Speakers

John Larsen

Graduate Student, University of Minnesota

Co-authors

Brandon Miller

University of Minnesota

Seth Wannemuehler

University of Minnesota

Friday August 1, 2025 8:15am - 8:30am CDT
Strand 12B

Oral presentation, Genetics and Germplasm 3

Subject Genetics and Germplasm

8:15am CDT

HEMP - Evaluation of High and Low Red-content Lighting During the Vegetative Phase of Cannabis Production

Friday August 1, 2025 8:15am - 8:30am CDT

Foster 2

As a short-day crop, Cannabis sativa, benefits from early-phase cultivation under long days to increase vegetative growth before transitioning to a generative flower phase. Previously, this long-day or “veg” phase has occurred under ceramic metal-halide lamps due to their relative increased blue content compared to the spectra of high-pressure sodium lamps used during the short-day or “flower” phase. Increased relative blue light during young plant production is desired due to the promotion of plant compactness and root development. Due to the relative efficacy of red diodes to blue, there is a benefit to maximizing red content without affecting plant performance. While many spectral recommendations arise from research in leafy greens and ornamentals, cannabis is cultivated under intensities three-fold greater, 600 µmol·m-2·s-1 during the long-day phase to 200 µmol·m-2·s-1 in leafy greens. Therefore, due to the high light intensity, it may be possible to produce optimal young plant quality under relatively low blue content. To test this, three cannabis cultivars rooted for 14 days were transplanted into 2-gallon coco coir bags and grown under long days with spectral treatments for an additional 14 days before finishing in a 12-hour short-day common environment. During the long-day phase, plants were exposed to high (~80%) or low (~40%) red at an average intensity of 500 µmol·m-2·s-1. Plant height at transfer to short days was similar regardless of light treatment. Additionally, final plant height and total flower yield after transfer into short days in a common environment was also similar. Therefore, it is beneficial to cultivate cannabis plants during long days under a high-red spectrum to minimize lighting cost while avoiding any negative morphology effects.

Speakers

Brian Poel

Fluence

Co-authors

Dave Hawley

Fluence

Friday August 1, 2025 8:15am - 8:30am CDT
Foster 2

Oral presentation, Cannabis and HEMP

Subject Cannabis and Hemp
Poster # csv

8:15am CDT

INPR - Weeding Out the Truth: How Glufosinate Sparks Oxidative Chaos in Horseweed (Conyza canadensis (L.) Cronquist)

Friday August 1, 2025 8:15am - 8:30am CDT

Strand 10

Horseweed (Conyza canadensis) is a prevalent weed species that has garnered significant attention due to its increasing resistance to multiple herbicides. Glufosinate, a widely utilized herbicide, is among the agents employed for its control. This study investigated the causes and impacts of glufosinate-induced oxidative stress in horseweed. During the flowering stage, glufosinate ammonium (GA) was applied at recommended concentrations. The plants were cultivated in a controlled greenhouse environment maintained at day/night temperatures of 27/25°C, with a 16-hour photoperiod and 75% relative humidity. Morphological symptoms, including curling and burning of leaf tips, were observed within 24 hours of GA application. Elevated levels of hydrogen peroxide (H2O2), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected four hours post-application and persisted for 48 hours. In contrast, activities of catalase (CAT) and ascorbate peroxidase (APOX) were reduced. Notably, guaiacol peroxidase (GPOD) activity increased in GA-treated horseweed leaves. Senescence of leaves and flower inflorescences was evident five days post-application. This study enhances the understanding of glufosinate-induced oxidative stress in horseweed, elucidating the plant's biochemical and molecular responses. The findings contribute valuable insights for improving weed management strategies and promoting agricultural sustainability.

Speakers

Naveen Dixit

University of MD Eastern Shore

Friday August 1, 2025 8:15am - 8:30am CDT
Strand 10

Oral presentation, Invasive Plants Research

Subject Invasive Plants Research
Funding Source Maryland Soybean Board

8:15am CDT

ORGH 3 - Organic High Tunnel and Field Comparison in Specialty Hybrid Tomato: Impacts on Yield, Nutrition, and Marketability Characteristics

Friday August 1, 2025 8:15am - 8:30am CDT

Strand 11A

Tomatoes (Solanum lycopersicum L.) are the largest vegetable crop in the US by dollar value and represent a significant source of income for organic growers in the southeast. High tunnels allow growers to capture more profitable early markets, and the protection they offer provides additional benefits such as extended growing seasons and reduced leaf wetness/foliar disease. Most research on organic high tunnel tomatoes to date focuses on heirloom varieties due to their popularity among organic growers. However, advances in plant breeding in recent decades have yielded hybrids that combine the desirable culinary and aesthetic characteristics of heirlooms with the superior vigor and disease resistance of modern genetics. The objective of this study was to compare the performance and characteristics of such specialty hybrids under organic high tunnel, and organic and conventional field conditions in the Georgia Piedmont region. Two indeterminate cultivars were chosen for this project: ‘Estiva’, a mediterranean variety noted for setting fruit under high temperatures; and ‘Tomimaru Muchoo’, a Japanese pink slicer with thin skin and low acidity. Transplants of both varieties were grown under organic greenhouse conditions for several weeks before planting in organic field, organic high tunnel, or conventional field plasticulture systems. Data loggers were placed in each site to record temperature, relative humidity, PAR, and soil moisture. Fruits were harvested once per week and sorted by USDA marketability standards. Both total and marketable yield were recorded for each plot, as well as disease, pest, and physiological disorder damage. Subsampled fruits from each plot were measured for dimensions, mass, and qualitative aesthetic rating. Fruit and aboveground biomass samples from each plot were harvested, dried, and ground, then analyzed for elemental nutrient content. Soil samples were also taken from each plot prior to planting and after termination for nutrient analysis, pH, and organic matter. In 2023, the highest marketable yields were from the organic high tunnel, with ‘Estiva’ and ‘Tomimaru’ averaging 15491 and 15992 lb/A (FW), respectively; while the conventional field performed better in 2024, with average yields of 11807 (‘Estiva’) and 11611 lb/A (‘Tomimaru’). In 2024, ‘Estiva’ had substantial losses in the high tunnel due to blossom end rot, with 30% of the harvest being marketable as opposed to the 53% obtained from ‘Tomimaru’. These results suggest that under optimal conditions, organic growers can achieve similar yields of high-quality tomatoes to their conventional counterparts through proper application of high tunnels and superior varieties.

Speakers

Micah Jones

University of Georgia

Co-authors

Anish Malladi

University of Georgia

Dorcas Franklin

University of Georgia

Kate Cassity-Duffey

University of Georgia

Friday August 1, 2025 8:15am - 8:30am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic
Poster # csv

8:15am CDT

PUBHORT - National Survey on Consumer Preferences of Community Garden Signage

Friday August 1, 2025 8:15am - 8:30am CDT

Foster 1

Community gardens provide numerous opportunities and benefits to volunteers, visitors, and communities. While there are many benefits to community gardens, there are also many obstacles, including volunteer struggles. Recruiting, organizing, training, and educating volunteers are among the biggest issues with volunteerism. Signage has the potential to alleviate some of these struggles. Signs can advertise the garden’s presence to attract volunteers, promote events and opportunities to keep volunteers engaged, and provide education through interpretive signage. However, many design elements and content choices for signage in community gardens have not been studied. A survey was sent out to a national sample that reflects the USA’s census data (N= 345) for gender, age, region, and household income with a screening question inquiring if participants had an interest with gardening. Photos and questions were prepared to reflect various aesthetic and functional attributes of signage. Questions asked participants their opinion on which design elements were most likely to gain attention, what information is needed to complete a task, and important information to have on a community garden sign. Results showed clear winners for design choices for attention gathering, those being primary colors, wood material, graphically designed, with a non-serif font, and pictures. Educational signage preferences showed that infographics with text and pictures were preferred overall. Signage element survey questions showed that participants preferred pictures over written text. Interactions between findings with demographics and gardening familiarity were also analyzed. Overall, people who had more experience gardening had more positive outlooks on signage compared to those who do not. These findings will allow community gardens to design more purposeful and engaging signage.

Speakers

Jonah Trevino

Texas Tech University

Co-authors

Catherine Simpson

Texas Tech University

Laura Fischer

Texas Tech University

Leslie Thompson

Texas Tech University

Vikram Baliga

Texas Tech University

Friday August 1, 2025 8:15am - 8:30am CDT
Foster 1

Oral presentation, Public Horticulture

Subject Public Horticulture

8:15am CDT

RHIZ - Effects of Polystyrene Nanoplastics on Root Architecture, Nutrient Uptake, and Anatomy in Aeroponically Grown Citrus Rootstocks

Friday August 1, 2025 8:15am - 8:30am CDT

Strand 12A

Plastic pollution is an emerging concern for both aquatic and terrestrial ecosystems. Recent studies, primarily focused on cereals and vegetable crops, have demonstrated that nanoplastics (NPs) can enter root tissues and translocate throughout the plant. However, the accumulation and impact of NPs in woody perennial crops, particularly citrus, remain largely unexplored. This study investigated the effects of green, fluorescent polystyrene nanoplastics (PS-NPs) of two particle sizes (20 nm and 50 nm diameter) on citrus root development, nutrient uptake, and root anatomical features. ‘US-942’ citrus rootstock plants were grown under sterile aeroponic conditions and treated with PS-NPs for 15 and 30 days. Root system architecture traits, including total root length, surface area, and number of forks, were analyzed using WinRHIZO™ software. Concurrently, macronutrient and micronutrient concentrations (N, P, K, Mg, S, B, Fe, Cu, Mn) were assessed in plant tissues, and root anatomy was examined using fluorescence and light microscopy. Exposure to 20 nm PS-NPs significantly reduced total root length (–28%), surface area (–31%), and the number of root forks (–35%) at both timepoints compared to controls. Nutrient uptake was also adversely affected, with notable reductions in N, P, K, Mg, and several micronutrients. Microscopic analyses revealed that both PS-NP sizes were retained at the root surface, with no evidence of internalization or translocation into root tissues. However, alterations in epidermal and cortical cell layers suggested structural stress responses, despite the development of intact apoplastic barriers near root tips. These findings highlight the potential phytotoxic effects of PS-NPs on citrus, particularly at smaller particle sizes, and suggest that while internal uptake may be limited in woody perennials, surface-level interactions may disrupt root development and function. This study contributes to a growing understanding of nanoplastic interactions in horticultural tree crops and raises important questions regarding long-term impacts on soil-plant systems.

Speakers

Khalid Hussain

University of Florida

Co-authors

John-Paul Fox

University of Florida

Lorenzo Rossi

Texas A

Xingmao Ma

Texas A

Friday August 1, 2025 8:15am - 8:30am CDT
Strand 12A

Oral presentation, Root Growth and Rhizosphere Dynamics

Subject Root Growth and Rhizosphere Dynamics
Poster # csv
Funding Source Higher Education Commission, Pakistan

8:15am CDT

VSF 4 - Optimizing nursery practices for the production of grafted blueberry liners

Friday August 1, 2025 8:15am - 8:30am CDT

Strand 11B

Blueberry (Vaccinium corymbosum interspecific hybrids) production in many regions of the world requires significant investments, including the use of soil amendments like pine bark. Prior research has identified V. arboreum as a potential rootstock which may reduce the need for costly soil inputs for growing southern highbush blueberries (SHB). Furthermore, use of V. arboreum as a blueberry rootstock may improve drought tolerance, increase plant longevity, confer tolerance to bacterial leaf scorch (Xylella fastidiosa), and make mechanical harvesting more feasible. However, V. arboreum propagation and grafting can be challenging. Thus, there is a critical need to develop nursery practices for the production of grafted blueberry liners. Preliminary observations suggest that interspecific hybrids of SHB × V. arboreum may have desirable rootstock characteristics like greater rooting success and wider scion compatibility than V. arboreum. This study aimed to identify optimal grafting practices by evaluating the effects of different grafting timings on subsequent plant development of SHB grafted onto SHB × V. arboreum hybrids and V. arboreum rootstocks. ‘Sentinel’ and ‘Albus’ SHB scion cultivars were grafted onto V. arboreum and hybrid rootstocks at four times in the year: February, March, September, and November. Scion takes and growth were evaluated. Grafting success and subsequent plant development were assessed using a bud development scale. Results showed that grafting in the spring improved scion development compared to fall grafting. Additionally, hybrid rootstocks exhibited greater compatibility with SHB scions than V. arboreum. The findings from this project will contribute to the optimization of nursery practices for producing grafted SHB nursery plants efficiently which is necessary for adoption of rootstock use in commercial blueberry production.

Speakers

Valentina Goles

University of Florida

Co-authors

Gerardo Nunez

University of Florida

Jeffrey Williamson

University of Florida

Friday August 1, 2025 8:15am - 8:30am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Poster # csv

8:30am CDT

GG 3 - Global Distribution and Diversity of Phytophthora capsici Infecting a Broad Host Range Revealed by Mitochondrial Genes

Friday August 1, 2025 8:30am - 8:45am CDT

Strand 12B

Phytophthora capsici is one of the top ten oomycete plant pathogens infecting a wide range of economically important crops. P. capsici was first reported to infect chile pepper (Capsicum annuum L.) in New Mexico Agricultural Research Station in Las Cruces, NM, and is currently a major threat on chile pepper production worldwide. The pathogen affects multiple plant parts at all stages of growth leading to death and significant economic losses. The diseases caused by P. capsici are difficult to eliminate which can be attributed to its broad host range, complexity of the inheritance of disease resistance, its global distribution, and diversity of the pathogen population. This study aims to analyse global distribution and diversity of P. capsici isolates infecting different hosts including Cucumis sativus, Cucurbita pepo, Capsicum annuum, Cucurbita maxima, Piper nigrum, Solanum lycopersicum, and Theobroma cacao by examining mitochondrial genes (secY, cox2, nad9, rps10) using Clustal Omega. Phylogenetic analyses based on different mitochondrial genes revealed diversity of P. capsici isolates. Based on secY, cox2, and nad9 genes, clustering patterns are found based on both the host from which they were isolated from and their geographical origin, while for rps10 gene, most of the isolates are found in one cluster. Notably, a separate analysis focusing on P. capsici isolates collected from C. annuum showed five isolates from South Korea (P15103, P1514, P15157, P15160, and P15161) clustered together, as did three isolates from New Mexico (P10199, P1091, and P3605). Similarly, isolates P10736 and P3941 from China, along with P15155 and P6741 from South Korea, consistently clustered together across all four genes analyzed. Future genetic diversity studies will include analysing the pangenome of P. capsici isolates from Texas, Florida, Arizona, Illinois, New Jersey, and New Mexico, USA; and screening of C. annuum recombinant inbred lines using different isolates with varying levels of virulence. Understanding genetic makeup of isolates may provide insights of their pathogenicity. Meanwhile, the results of screening of C. annuum recombinant inbred lines will aid in understanding the inheritance of disease resistance. Altogether, these approaches can contribute to the development of more effective and sustainable disease management strategies against P. capsici.

Speakers

Jerlie Mhay Matres

New Mexico State University

Co-authors

Dennis Nicuh Lozada

New Mexico State University

Shahab Nourbakhsh

New Mexico State University

Friday August 1, 2025 8:30am - 8:45am CDT
Strand 12B

Oral presentation, Genetics and Germplasm 3

Subject Genetics and Germplasm

8:30am CDT

HEMP - Can Induced Water-deficit Stress Act As a Catalyst For Maximizing Cannabis Sativa Production and Secondary Metabolite Levels?

Friday August 1, 2025 8:30am - 8:45am CDT

Foster 2

Cannabis (Cannabis sativa L.) is an annual herbaceous plant that belongs to the Cannabaceae family and produces economically important secondary metabolites called cannabinoids. According to the literature, controlled or induced water-deficit stress can increase secondary metabolite concentration in some essential oil-producing plants. Therefore, induced water-deficit stress (DS) may be an effective technique to maximize cannabinoid yield. This study investigated how different frequencies of induced water-deficit stress during the flowering stage affect cannabinoid yield and cannabis development compared to well-irrigated controls. By exploring the optimal stress conditions conducive to maximizing cannabinoid production, our study aims to offer strategic insights to inform cultivation practices and optimize cannabinoid production. This research contributes to advancing our understanding of cannabis cultivation techniques and may ultimately enhance the efficiency and efficacy of cannabinoid production on a commercial scale. Our hypothesis posits that induced water-deficit stress enhances plant secondary metabolism by modulating physiological responses. The treatments consisted of four frequencies of water-deficit stress periods during the cannabis flowering stage: WS0 – no stress, WS1 – one period of water-deficit stress, WS2 – two periods of water-deficit stress, and WS3 – three periods of water-deficit stress. The experiment was conducted using clones of the Heidi cultivar, which were randomly placed in the controlled-environment growth units. Weekly plant parameters included plant height, stem diameter, NDVI, chlorophyll content, photosynthetic efficiency, and stomatal conductance. After-harvest parameters included biomass partitioning, yield mass, bucked biomass, trichome density, and cannabinoid and terpenes levels. This is an ongoing study, but the preliminary data analysis shows interesting results regarding higher trichome density with no penalty for bucked biomass in the treatments under one period of water-deficit stress (WS1).

Speakers

Jose Leme

Assistant Professor, Southern Illinois University

The Cannabis Biology and Cultivation Systems lab focuses on areas of controlled environment agriculture, plant stress, secondary metabolites, nutraceutical/pharmaceutical biology, and growing practices. The research team aims to determine how to leverage environmental controls (light... Read More →

Co-authors

Aldwin Anterola

Southern Illinois University

Dila Ozev

University of Bonn

Fardad Didaran

University of Tehran

Jennifer Weber

Southern Illinois University

Shiksha Sharma

Southern Illinois University

Friday August 1, 2025 8:30am - 8:45am CDT
Foster 2

Oral presentation, Cannabis and HEMP

Subject Cannabis and Hemp
Poster # csv

8:30am CDT

INPR - Biochemical Tug-of-War: Unraveling Resistance and Compensation in Palmer Amaranth (Amaranthus palmeri)

Friday August 1, 2025 8:30am - 8:45am CDT

Strand 10

Non-target-site herbicide resistance was evaluated in commercially available herbicides labeled for the management of Palmer Amaranth (Amaranthus palmeri). Seven treatments (T1: Control, T2: Flexstar (22.1%), T3: Buccaneer 5 Extra (53.8%), T4: Flexstar (5.88%) GT3.5 with Glyphosate (22.40%), T5: Defy LV-6 (88.4%): 2,4-D, T6: Enlist Duo (Glyphosate: 22.1% 2,4-D: 24.4%), and T7: Dicamba were applied at recommended rates. Glutathione-S-Transferase (GST) and Glutathione Reductase (GR) activities were measured in leaf samples after 15 minutes of herbicide exposure. Glyphosate exhibited the highest GST activity, followed by Fomesafen > Fomesafen Glyphosate > 2,4-D > Dicamba > 2,4-D Glyphosate. Treatments with a single mode of action exhibited higher GST activity, while mixed-mode treatments showed lower GST levels. Interestingly, an inverse relationship between GST and GR activity was observed, suggesting a compensatory mechanism. When GST activity was low, GR activity increased, indicating that the plant may enhance glutathione regeneration through GR to sustain detoxification capacity and manage oxidative stress. This biochemical compensation could enable the plant to survive herbicide exposure, even when direct detoxification (via GST) is limited. Such adaptability might contribute to the gradual development of non-target-site resistance, as the plant's defense system finds alternative pathways to mitigate herbicidal damage. These findings highlight that herbicide with a single mode of action, which trigger higher GST activity, may accelerate resistance evolution. In contrast, mixed-mode herbicides, which induce lower GST activity and potentially limit compensatory responses, can slow the progression of resistance. Thus, diversified herbicide strategies are essential for sustainable and effective management of Palmer Amaranth.

Speakers

Naveen Dixit

University of MD Eastern Shore

Friday August 1, 2025 8:30am - 8:45am CDT
Strand 10

Oral presentation, Invasive Plants Research

Subject Invasive Plants Research
Funding Source Delaware Soybean Board

8:30am CDT

ORGH 3 - Aerate organic nutrient film technique (NFT) reservoir tank, not for the crop but for microorganisms

Friday August 1, 2025 8:30am - 8:45am CDT

Strand 11A

Organic lettuce production in hydroponic systems often yields less than conventional production. A previous study from the lab found that organic nutrient film technique (NFT) system with Pre-Empt organic fertilizer contained high concentrations of nitrite ions, which likely induce stress and resulted in lower lettuce yield. To address this toxicity, we conducted a series of studies investigating the effect of reservoir aeration, with the hypothesis that aeration would enhance microbial mineralization of organic nitrogen and reduce the concentrations of phytotoxic compounds such as nitrite and ammonium. In the first study, we aerated NFT reservoir tanks with 15.9 mL/L (2 oz/gal) Pre-Empt organic fertilizer. Aeration increased dissolved oxygen (from 6.4 to 7.8 mg/L) and decreased the ratio of nitrite-nitrogen to nitrate-nitrogen (from 1.1 to 0.2) but did not affect ammonium. As a result, aeration increased yield of ‘Casey’ lettuce by 2.6 times. In the second study, aeration did not increase lettuce growth when the concentration of Pre-Empt fertilizer decreased to 10.6 mL/L (1.4 oz/gal). Furthermore, in the third study, we found cultivar-specific response to the aeration of organic fertilizer. These results suggested that aeration can enhance mineralization of organic nitrogen, reduce root-zone nitrite toxicity and increase lettuce yield at high fertilizer rates and potentially depending on cultivar.

Speakers

Jun Liu

Texas A

Co-authors

Genhua Niu

Texas A

Joseph G. Masabni

Texas A

Friday August 1, 2025 8:30am - 8:45am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic
Funding Source USDA NIFA hatch project TEX07726

8:30am CDT

PUBHORT - Using Geographic Information Systems (GIS) to Strengthen Extension Master Gardener Program Evaluation

Friday August 1, 2025 8:30am - 8:45am CDT

Foster 1

Extension Master Gardeners (EMGs) are volunteer educators trained by land-grant universities to teach their local communities about plants and gardening. While EMGs work on a variety of outreach projects, demonstration gardens are a popular project choice for Master Gardener volunteers. In Georgia alone, there are over 250 EMG projects associated with physical garden locations across the state. However, the geographic location of each garden site is not maintained in the state project database. Geographic Information Systems (GIS) have been used to evaluate outreach programs in both public health and environmental sciences, but these techniques have not been applied to EMG programs. This project aimed to determine the location of active EMG demonstration gardens in Georgia using existing project database listings and reported volunteer activity from 2023-2024. Project sites were located using Google Earth keyword searches, and analysis was performed in R Statistical Software. Overall, most EMG garden projects in Georgia could be successfully located, but locatability varied across county programs. Geospatial analysis revealed that multiple garden projects are located outside of their managing program’s county, suggesting actual geographic reach of EMG programs in Georgia may be wider than previously estimated. Collecting and maintaining geographic data associated with EMG projects has many potential applications for program coordinators at local, state, and national levels. These applications include matching new volunteers with conveniently located projects, identifying underserved populations, and visualizing program reach for both public audiences and program stakeholders.

Speakers

Alana Edwards

University of Georgia

Friday August 1, 2025 8:30am - 8:45am CDT
Foster 1

Oral presentation, Public Horticulture

Subject Public Horticulture
Poster # csv
Funding Source University of Georgia Department of Horticulture

8:30am CDT

RHIZ - Safer Roots: Variation in root architectural adaptations in putatively low- and high lead-accumulating sweetpotato cultivars

Friday August 1, 2025 8:30am - 8:45am CDT

Strand 12A

The plant root system is vital for nutrient uptake and plays a significant role in abiotic stress adaptation and defense. In sweetpotato, optimum root system architecture (RSA) development determines storage root (SR) yield potential. Root architectural responses to simulated natural lead levels (Pb) during the establishment and SR formation phases were characterized in two sweetpotato cultivars with known contrasting storage root yield potentials. Cultivars ‘Bayou Belle’ (BB) and ‘Beauregard’ (BX) grown on sand substrate were provided with 0.5X Hoagland’s nutrient solution with varying levels of Pb: 0, 10, 20, and 30 mg⋅L-1. The first experiment sampled entire root systems at 5, 10, and 15 days, corresponding to key adventitious and SR development stages. The cultivars varied in RSA attributes in response to Pb levels. In contrast to the cultivar BB, BX provided with 10 mg⋅L-1 Pb showed 83%, 21%, and 15% increases in main root length relative to the untreated controls at 5, 10, and 15 days, respectively. The cultivar BB consistently showed increased lateral root number and length relative to BX across all treatment levels. A second experiment was performed to produce SR samples at 50 days. The cultivar BX accumulated a 200- and 300-fold increase in Pb in SR at 20 and 30 mg⋅L-1 Pb, respectively, relative to BB storage roots at similar Pb levels. There were no differences in Pb accumulation across treatment levels in the cultivar BB. These findings are consistent with the hypothesis that increased root mass was associated with low accumulation of Pb and provide a basis for incorporating RSA traits in selecting Pb-tolerant cultivars.

Speakers

Mae Ann Bravo

Graduate Student Assistant, Louisiana State University

Co-authors

Arthur Villordon

LSU Agcenter

Brenda Tubana

Louisiana State University

Don La Bonte

Louisiana State Univ

Jack Baricuatro

Louisiana State University at Shreveport

Lisa Arce

Louisiana State University

Marissa Barbosa

Lousiana State University

Friday August 1, 2025 8:30am - 8:45am CDT
Strand 12A

Oral presentation, Root Growth and Rhizosphere Dynamics

Subject Root Growth and Rhizosphere Dynamics
Poster # csv
Funding Source Gerber Products Company

8:30am CDT

VSF 4 - Metabolic alterations and the role of ethylene in regulating ripening in blueberry (Vaccinium ashei)

Friday August 1, 2025 8:30am - 8:45am CDT

Strand 11B

Blueberry fruit are rich in antioxidants and have become popular due to their numerous health benefits. In many fruits, a significant metabolic shift in carbon metabolism during fruit ripening leads to an increase in sugars, decrease in acids and accumulation of anthocyanins. The alterations in metabolic programs during fruit ripening in blueberry remain uncharacterized. Further, the role of ethylene in metabolic reprograming during blueberry ripening has not been studied. We quantified sugars, acids, anthocyanins and determined the expression of genes related to their metabolism. This study revealed that sucrose import into the fruit continues throughout ripening, with a corresponding increase in glucose and fructose. The transcript abundance of SUCROSE SYNTHASE and NEUTRAL INVERTASE was detected, suggesting sucrose catabolism in the cytosol. The high transcript abundance of VACUOLAR INVERTASE suggested that this gene plays a predominant role in sequestration of glucose and fructose in the vacuole. Malate and quinate were the major acids that displayed a decrease in concentration during ripening. The expression of MALATE DEHYDROGENASE and high transcript abundance of PHOSPHOENOLPYRUVATE CARBOXYKINASE suggested conversion of malate to phosphoenolpyruvate (PEP) during ripening. One of the potential fates of PEP, the generation of shikimate for anthocyanin production, was supported by the upregulation of multiple anthocyanin biosynthesis genes. Further, applications of ethephon and 1-aminocyclopropane-1-carboxylic acid, suggested that ethylene transiently stimulates sugar, acid and anthocyanin metabolism. This indicated ethylene is important for ripening initiation in blueberry. Overall, this study provided insights into metabolic programs, and the role of ethylene during blueberry ripening.

Speakers

Savithri Nambeesan

University of Georgia

Co-authors

Tej Prasad Acharya

University of Georgia

Friday August 1, 2025 8:30am - 8:45am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Poster # csv

8:45am CDT

GG 3 - Transcriptomic Analysis of Powdery Mildew Response Reveals Differentially Expressed Genes in Susceptible and Tolerant Bigleaf Hydrangea Cultivars

Friday August 1, 2025 8:45am - 9:00am CDT

Strand 12B

Bigleaf hydrangea (Hydrangea macrophylla) is an economically important ornamental shrub produced worldwide for the floral trade, as a container crop, and as a landscape plant. Powdery mildew (PM), caused by Golovinomyces orontii, is a widespread disease of bigleaf hydrangea impacting production and salability of plants. However, mechanisms of resistance to PM of bigleaf hydrangea are still largely unexplored. The purpose of this study was to investigate whole-plant response to PM infection and identify differentially expressed genes (DEGs) that contribute to the PM disease response in bigleaf hydrangea. Mature plants of four cultivars (‘Blushing Bride’, ‘Endless Summer’, ‘Nigra’, and ‘Veitchii’) were chosen based on their variable responses to natural PM infection. Powdery mildew was collected by harvesting naturally infected leaves from field plants and applied via spray inoculation averaging ~20ml per plant, with inoculum rate being 1 x 104 CFUmL-1, to six replicate plants per cultivar; one plant per cultivar was sprayed with water as a control. Whole plant response (% of plant tissue infected) was measured visually on a scale of 0-100% disease severity weekly starting from 29 Nov 2023 to 14 Feb 2024 and used to calculate Area Under the Disease Progress Curve (AUDPC). Plant tissue was sampled at 12 different time points, from 1 hour after inoculation (HAI) to 5 days after inoculation (DAI) using a leaf disc puncher and immediately flash frozen in liquid nitrogen. RNA was extracted using a Qiagen RNeasy Plant Mini kit and sequenced using NovaSeq. Adapters were removed from raw reads using fastp (0.23.4) and trimmed reads were aligned to the ‘Endless Summer’ reference genome using STAR (2.7.11b). STAR bam files were sorted with samtools (1.21) and featurecounts (2.0.6) was used for the gene model counting. DESeq was used to identify DEGs between ‘Veitchii’ and ‘Nigra’. There were significant differences among cultivars for AUDPC, with disease severity ranging between 7.7 and 19.2%. Bigleaf hydrangea ‘Nigra’ and ‘Endless Summer’ were the most susceptible to PM infection and ‘Veitchii’ the most tolerant. There were 11,629 DEGs total with 6,145 upregulated compared to ‘Veitchii’ and 5,484 downregulated compared to ‘Nigra’. DEGs were sorted by their P-adjust value followed by the Log 2-fold change. Many of the top 25 strongest DEGs include genes for plant stress such as serine threonine-protein kinase, PAN_AP, and leucine-rich repeat family proteins. These genes are currently being tested for expression levels among bigleaf hydrangea cultivars.

Speakers

Lisa Alexander

Research Geneticist, USDA-ARS U.S. National Arboretum

Co-authors

Christina Jennings

Tennessee State University

Fulya Baysal-Gurel

Tennessee State University

Margaret Staton

University of Tennessee

Ryan Kuster

University of Tennessee

Friday August 1, 2025 8:45am - 9:00am CDT
Strand 12B

Oral presentation, Genetics and Germplasm 3

Subject Genetics and Germplasm

8:45am CDT

HEMP - Beyond Static Spectrum: The Promises and Pitfalls of Dynamic Lighting for Cannabis Cultivation

Friday August 1, 2025 8:45am - 9:00am CDT

Foster 2

Dynamic lighting has recently evolved from theoretical research to commercial viability. As the cannabis industry faces increasing margin pressure, optimization techniques that enhance product quality while maintaining cost efficiency are essential for cultivation. But is dynamic lighting a silver bullet for enhanced cannabis cultivation? In this session Dr. Hawley will present research on UV, blue, red, and far-red light as it pertains to cannabis inflorescence quality and yield. New results will be presented that will inform how growers light their crops to maintain or exceed their current quality and yield while improving their lighting efficacy by 15% and reducing their lighting operational costs by 19%.

Speakers

David Hawley

Fluence

In his role as Fluence’s Principal Scientist, Dr. David Hawley steers the company’s global Cannabis Crop Sciences program, encompassing photobiological research, data analytics, and cultivation consultation. Fluence’s research has identified specific and diverse lighting strategies... Read More →

Friday August 1, 2025 8:45am - 9:00am CDT
Foster 2

Oral presentation, Cannabis and HEMP

Subject Cannabis and Hemp
Poster # csv

8:45am CDT

ORGH 3 - Paving the Way to Certified Naturally Grown Certification

Friday August 1, 2025 8:45am - 9:00am CDT

Strand 11A

As environmental concerns grow, the horticultural sector is increasingly encouraged to adopt sustainable production practices. Certified Naturally Grown (CNG), established in 2002, offers a peer-reviewed certification rooted in organic principles and aims to foster a strong community network for small-scale producers. This research documents the process of certifying previously unmanaged farmland through the CNG program, offering research-based insights for growers considering certification. The project began with the revitalization of an overgrown, neglected field, focusing first on soil improvement and field preparation to support sustainable crop production. To build soil health and fertility, we planted both summer and fall/winter cover crop mixtures, which helped improve nutrient cycling and restore organic matter. In addition to soil improvement, we developed an integrated pest management (IPM) protocol tailored to our production system and selected OMRI-listed products to meet fertilization, pest, and disease control needs in compliance with CNG standards. To support certification, we also established a record-keeping system to document field activities, input usage, and compliance measures. Finally, we created postharvest handling protocols aligned with CNG principles to help ensure both food safety and product quality from field to market. Soil testing has shown an improvement in soil organic matter, plant-available soil nutrients, and an increase in soil microbial biomass. These gains reflect an improvement in overall soil health and provide a strong foundation for sustainable crop production. Ultimately, this project highlights the planning and steps required for successful CNG certification. The educational tools we create will serve as a guide for producers transitioning to CNG, equipping them with the knowledge to implement sustainable and resilient farming practices.

Speakers

Shelby Mendoza

Oklahoma State University

Friday August 1, 2025 8:45am - 9:00am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic
Poster # csv

8:45am CDT

PUBHORT - Computer Vision-Based Study on the Distribution of Blueberry Fruits Across Canopy Zones

Friday August 1, 2025 8:45am - 9:00am CDT

Foster 1

Blueberry (Vaccinium spp.) production has been expanding globally, driven by its unique flavor and numerous health benefits. With increasing demand, it is essential to implement techniques aimed at improving yield in commercial blueberry fields. The distribution of blueberries across the canopy profile is a key factor linked to several management aspects, including the efficiency of mechanical harvesting, pest control strategies, and overall fruit quality. Understanding fruit distribution within the canopy is essential to optimize machine calibration, apply precision agriculture techniques for pest management, and incorporate technologies that enhance fruit quality and maximize production by reducing losses caused by uneven vertical distribution. This study aimed to determine the vertical distribution of blueberry fruits using RGB images and the YOLOv8s model. Data was collected from a commercial Southern Highbush blueberry field in Homerville, GA. Using a cellphone camera, a total of 200 images were collected from 40 plant samples, with each plant photographed from the top to the base at a consistent angle. The images were annotated and classified according to the fruit’s position on the plant (upper, middle, or lower third). The YOLOv8s model was trained on the labeled images and evaluated using standard metrics, including precision, recall, and Intersection over Union (IoU). The dataset was divided into 70% for training, 15% for validation, and 15% for testing, over 200 training epochs. The final outputs consisted of annotated images, performance metrics, and a summary table showing the number of plants analyzed and fruit concentration by canopy zone. Using the YOLOv8s model, we successfully mapped the spatial distribution of blueberry fruits across different canopy zones (upper, middle, and lower thirds). The model achieved moderate to high accuracy metrics, demonstrating good performance in fruit detection and localization. These results indicate the model's potential for practical field applications, although performance could be further enhanced by expanding the dataset and incorporating additional training cycles. Future work aims to test the model across different blueberry varieties and integrate it into a user-friendly web platform. These findings highlight the feasibility of using deep learning tools to support data-driven management decisions in commercial blueberry production systems.

Speakers

Regimar dos Santos

University of Georgia

Friday August 1, 2025 8:45am - 9:00am CDT
Foster 1

Oral presentation, Public Horticulture

Subject Public Horticulture
Poster # csv

8:45am CDT

RHIZ - RNA-sequencing of Two Southern Pea (Vigna unguiculata L. Walp.) Cultivars Identifies Differentially Expressed Genes and Pathways Involved in Aluminum Toxicity Tolerance

Friday August 1, 2025 8:45am - 9:00am CDT

Strand 12A

Cowpea is an excellent crop for growers with small-to-medium farms and marginal lands prevalent throughout the southeast, but a thorough understanding of its response and tolerance to aluminum toxicity is lacking. This study characterized the transcriptome of two cowpea varieties, the tolerant Mississippi Pinkeye 2 Purple Hull (MSP2PH) and sensitive White Acre (WA), using RNA sequencing 6, 24, and 48 hours after treatment with 50µM AlCl3. RNA integrity number (RIN) scores of all samples were above 9.0 indicating high-quality, and the total number of reads from each sample ranged from about 20,000,000 – 60,000,000. Sample groups clustered by variety, treatment, and time point after principal component analysis. A threshold of 1 log-fold change (logFC) and a false-positive discovery rate of p ≤ 0.01 was used to identify differentially expressed genes (DEGs) for all comparisons. The number of DEGs between plants of the same variety under control and aluminum-toxic conditions at 6, 24, and 48 hours after treatment were 308, 385, and 173 for MSP2PH and 935, 1029, and 1208 for WA. 12 and 58 of these DEGs were detected across all three time points for MSP2PH and WA, respectively. Among DEGs between MSP2PH and WA that were unique under aluminum treatment there were 401, 613, and 623 at 6, 24, and 48 hours, respectively, with 58 across all time points. The number of common DEGs detected that were unique between MSP2PH samples under aluminum and control and those between MSP2PH and WA under aluminum only were 24, 67, and 19 after 6, 24, and 48 hours, respectively. Furthermore, three DEGs across all time points were detected using these criteria, and all were up-regulated in MSP2PH. One of these genes is annotated as a leucine-rich repeat (LRR) receptor-like kinase, which are well-known to regulators of aluminum-toxicity response and tolerance. Arabidopsis homologues for corresponding genes from different up- and down-regulated DEG sets were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis. The number of enriched genes categorized into specific GO terms varied by time point, treatment, and variety. The number of transcription factors up- and down-regulated from specific transcription factor families were also evaluated for select comparisons and showed similar variability. These findings provide insights into expression pathways involved in aluminum toxicity tolerance and response while providing candidate genes that may be used to develop aluminum-tolerant cultivars.

Speakers

Max C. Miller II

Tennessee State University

Co-authors

Matthew W. Blair

Tennessee State University

Friday August 1, 2025 8:45am - 9:00am CDT
Strand 12A

Oral presentation, Root Growth and Rhizosphere Dynamics

Subject Root Growth and Rhizosphere Dynamics
Poster # csv
Funding Source USDA NIFA-AFRI

8:45am CDT

VSF 4 - Genetic Approaches for Fast-Track Breeding of Blueberry and Grapevine: Strategies, Potentials, and Challenges

Friday August 1, 2025 8:45am - 9:00am CDT

Strand 11B

Conventional breeding of woody fruit crops through hybridization is more time-consuming, labor-intensive, and costly than breeding annual plants, primarily due to their prolonged juvenile phase before flowering. Over the past two decades, significant efforts have been made to accelerate woody plant breeding, also known as as FasTrack breeding, by shortening juvenility using cutting-edge technologies. One key strategy involves genetic engineering of flowering pathway genes, particularly members of the phosphatidylethanolamine-binding protein (PEBP) family, such as FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1). Constitutive expression of FT or knockout/knockdown of TFL1 has proven effective in inducing early flowering. These approaches have successfully enabled FasTrack breeding in blueberry (Vaccinium cormbosum) and plum (Prunus domestica). In this presentation, I will share our success in blueberry FasTrack breeding and discuss recent progress in applying this strategy to grapevine (Vitis vinifera). More recently, we have developed FasTrack breeding blueberry (Vaccinium cormbosum) and made significant progress in applying this strategy to grapevine (Vitis vinifera) though FT overexpression and TFL1 gene editing.

Speakers

Guo-qing Song

Michigan State University

Co-authors

Gan-yuan Zhong

USDA-ARS

Friday August 1, 2025 8:45am - 9:00am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Poster # csv

9:00am CDT

GG 3 - Identification of resistance in tomato cultivars against Tomato Brown Rugose Fruit Virus (ToBRFV) and Horse Nettle Virus

Friday August 1, 2025 9:00am - 9:15am CDT

Strand 12B

Tomato is one of the economically important agricultural crops worldwide. Approximately 80% of tomatoes are consumed fresh, while 20% are used in various processed food products. The tomato production in the United States (US) contribute and $2.8 billion to the national economy annually. However, virus infections are a major threat to tomato production and fruit quality. Tomato brown rugose fruit virus (ToBRFV) which was reported in 2014 and has spread in more than 50 countries since then, is a highly infectious and stable Tobamovirus spreads mechanically and can stay on a surface for weeks. Its ability to overcome existing resistance genes in tomato is the main concern, emphasizing the urgent need to identify tolerance or resistance in tomatoes cultivars. Besides this, horse nettle virus A (HNVA), recently reported to infect tomatoes in Oklahoma was previously limited to a weed named horse nettle (Solanum carolinense), and exhibits a concerning host shift, causing symptoms such as curling, cupping, and brown discoloration of leaves in tomatoes plants. The objective of this study was to evaluate commercially cultivated tomato cultivars in the US for resistance against both ToBRFV and HNVA. The tomato seedlings were inoculated mechanically with ToBRFV and HNVA and were observed and scored weekly at 7-, 14-, 21-, and 28-days post-inoculation (dpi) on a severity scale of 0 to 3 where 0,1, 2, and 3 correspond to no symptoms, mild, mildly severe and severe symptoms respectively. At 28 dpi, representative plants were tested using virus-specific RT-PCR assays to confirm systemic infection. The findings suggest that there are no resistant cultivars against ToBRFV while there are some showing tolerance based on the symptom severity scores. For HNVA, 22 cultivars have been screened so far and were mostly tolerant but not resistant. These results provide insights into the interaction of these emerging viruses with widely grown tomato cultivars and help us to identify tolerant cultivars to inform the growers and the variation in disease severity which would be valuable for breeders to guide future breeding strategies aimed at ToBRFV and HNVA resistance.

Speakers

Jasmine Sidhu

The University of Tulsa

Co-authors

Akhtar Ali

The University of Tulsa

Friday August 1, 2025 9:00am - 9:15am CDT
Strand 12B

Oral presentation, Genetics and Germplasm 3

Subject Genetics and Germplasm
Funding Source Oklahoma Department of Agriculture, Food and Forestry- USDA

9:00am CDT

ORGH 3 - Targeting Challenges in the Transition to Organic Production with Educational Solutions

Friday August 1, 2025 9:00am - 9:15am CDT

Strand 11A

Momentum for sustainable and organic farming remains strong, driven by concerns for environmental stewardship, health, and social responsibility. As of the 2022 USDA Organic Certified Survey, the number of certified organic operations in the United States grew to 18,263, covering 5,083,623 acres. However, Mississippi continues to have a limited presence, with only 5 certified specialty crop operations as per the USDA Organic Integrity Database. Building on our initial findings, this year’s research continues to investigate the motivations and barriers producers face when adopting organic principles. In year two, we expanded the reach of our survey, pushing the 43-question instrument into all 50 states with the assistance of our partners. The survey remains focused on key challenges including social, environmental, and technical concerns. The core themes from year one—environmental consciousness, financial constraints, and the knowledge-implementation gap—remain prevalent, but we have also observed evolving trends in the responses. Producers continue to cite environmental and market motivations as key drivers. They emphasize the benefits of education on the producer and consumer level as a potential solution. Financial challenges remain a significant barrier, with many producers expressing concerns about the high costs of transition and the economic uncertainty during the process. New insights have emerged regarding the growing role of social networks and community support in facilitating the adoption of organic practices, suggesting that social capital may help mitigate some of the technical and financial challenges producers face. Our case study of a beginning farmer in Calhoun City, Mississippi, highlighted valuable insights into the specific challenges faced by farmers in a region where organic practices are still uncommon. It also highlighted the importance of bridging the knowledge gap and improving support systems for producers. The insights and data garnered have been used to develop a regional database of interested producers. These growers are helping refine recommendations and contribute to the development of targeted programs aimed at supporting the transition to organics including conferences, publication, and other educational efforts. These ongoing experiences continue to guide our understanding of the complexities of transitioning to organic agriculture, offering real-world examples that complement the survey data. As we move forward, we are also exploring how farmers' willingness to adopt organic practices evolves over time and how external factors may influence their decisions. This ongoing research plays a crucial role in advancing the transition to organic certification, ensuring producers are supported in their effort to pursue sustainable practices.

Speakers

Brenton Breland

Mississippi State University

Co-authors

Christine Coker

Mississippi State University

Ronald Stephenson

Plant Sciences Hall

Friday August 1, 2025 9:00am - 9:15am CDT
Strand 11A

Oral presentation, Organic Horticulture 3

Subject Organic
Funding Source USDA AMS

9:00am CDT

VSF 4 - Plant Growth and Fruit Quality Assessment of Two Promising Maypop (Passiflora incarnata) Cultivars, ‘PinkPop’ and ‘SnowPop’ in Kentucky

Friday August 1, 2025 9:00am - 9:15am CDT

Strand 11B

Maypop (Passiflora incarnata) is a perennial vine native to North America, valued for its tropical fruit flavor, adaptability, and resilience to cold and drought. Unlike Passiflora edulis (Passion fruit), which thrives only in tropical and subtropical climates, Maypop has potential as a high-value fruit crop for temperate regions. In addition to its edible fruit, its leaves and flowers have medicinal applications, and its seed oil is rich in omega-3 and omega-6 fatty acids, making it valuable for cosmetic and therapeutic use. This study evaluated the performance of two Maypop cultivars, ‘PinkPop’ and ‘SnowPop,’ in a field trial at Kentucky State University’s Harold R. Benson Research Farm. A randomized complete block design was used to assess plant growth, fruit yield, fruit quality, and seed characteristics in 2024. Fruits from a wild relative were also analyzed for comparison. Preliminary results showed no significant difference in plant height (~86 cm) and stem diameter (~5.5 mm) between cultivars in June. ‘SnowPop’ produced more fruits and had higher yield than ‘PinkPop,’ though the difference was not statistically significant. However, ‘PinkPop’ produced significantly heavier fruits (30.8 g) compared to ‘SnowPop’ (26.09 g), while both had a similar average fruit diameter (~36 mm). The wild relative produced comparatively larger fruits (45.92 g, 55.67 mm diameter). Soluble solids content was comparable between ‘PinkPop’ (13.6° Brix) and ‘SnowPop’ (12.9° Brix), whereas the wild relative had significantly lower Brix (6.6°). Seed analysis indicated that ‘PinkPop’ had more and heavier seeds per fruit, contributing to a higher edible pulp content, while ‘SnowPop’ had fewer seeds, making it potentially more desirable for fresh consumption and processing. Overall, both cultivars demonstrated strong potential for commercial cultivation in Kentucky, and their traits, along with those of the wild relative, highlight opportunities for breeding programs to develop improved Maypop cultivars with enhanced fruit quality.

Speakers

Srijana Thapa Magar

Kentucky State University

Co-authors

Dipesh Shrestha

Kentucky State University

Kirk Pomper

Kentucky State University

Friday August 1, 2025 9:00am - 9:15am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Poster # csv

9:15am CDT

VSF 4 - Molecular Marker Resources for Breeding Heat-tolerant Blueberries

Friday August 1, 2025 9:15am - 9:30am CDT

Strand 11B

Blueberries (Vaccinium spp.) are small fruit crops native to North America but grown commercially in several countries worldwide. Blueberries are highly vulnerable to changing climatic conditions and prolonged heat waves. High temperatures pose a significant challenge for developing strategies for enhancing crop resilience and food security. As blueberry is a recently domesticated crop, the availability of genomic resources is minimal for accelerating climate-resilient blueberry breeding programs, especially for heat stress tolerance. Previously, we identified several single-nucleotide polymorphisms (SNPs) associated with heat-tolerant traits in blueberries. In this study, we developed 96 Kompetitive Allele-Specific PCR (KASP) marker assays and 10 Cleaved Amplified Polymorphic Sequences (CAPS) markers for heat tolerance-associated SNPs. KASP assays were screened on 384 plants comprising diploid and tetraploid intercross derivatives, cultivars, and wild germplasm. We found a high level of heterozygosity for these markers. A principal component analysis of the genotype data differentiated wild accessions and hybrids, whereas tetraploid derivatives and cultivars formed a single cluster. A diverse panel of 42 accessions was evaluated under controlled high-temperature conditions (40 °C for 4 days) in a separate study. Physiological responses to heat stress were quantified by measuring leaf malondialdehyde (MDA) content (an indicator of oxidative membrane damage) and chlorophyll fluorescence parameters to assess photosystem II efficiency. Cultivars varied in stress response: heat-tolerant genotypes accumulated significantly less MDA and sustained higher photochemical efficiency than sensitive ones. Five CAPS markers showed substantial allele-associated differences in MDA levels, effectively distinguishing tolerant vs. sensitive groups. Cluster analysis based on the CAPS genotypes further separated cultivars according to genetic background (highbush vs. rabbiteye), revealing the known heat-resilient cultivars (often with wild Vaccinium ancestry) grouped together. These findings highlight robust marker–trait associations between SNP-derived CAPS markers and heat-tolerance indicators. Upon further validation in diverse germplasm, the newly developed markers will facilitate breeding heat-tolerant blueberry cultivars.

Speakers

kalpalatha Melmaiee

Delaware State University

Co-authors

Krishnanand P. Kulkarni

Delaware State University

Richmond K. Appiah

Delaware State University

Friday August 1, 2025 9:15am - 9:30am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits
Funding Source The United States Department of Agriculture (USDA-NIFA-CBG) awards 2022-38821-37298 and 2023-38821-39921

9:30am CDT

VSF 4 - Targeting Triple-Negative Breast Cancer: Omics-Based Discovery of Cytotoxic Agents in Muscadine Seeds

Friday August 1, 2025 9:30am - 9:45am CDT

Strand 11B

Muscadine grape seeds are a rich source of polyphenols with known health benefits, yet the specific compounds responsible for their anticancer effects remain poorly understood. This study investigates the cytotoxic potential of muscadine seed metabolites against African American triple-negative breast cancer using an integrated OMICS approach combining genomics, metabolomics, cytotoxicity assays, HPLC, gene expression profiling, molecular modeling, and statistical analysis. Among 1,781 metabolites identified by LC/MS-MS, we identified three compounds that exhibited the strongest anticancer activity by targeting Eph receptor signaling, cell proliferation, and inducing apoptosis. These findings highlight the therapeutic potential of muscadine seed phytochemicals and support their development as functional food components or leads for targeted cancer therapies.

Friday August 1, 2025 9:30am - 9:45am CDT
Strand 11B

Oral presentation, Viticulture and Small Fruits 4

Subject Viticulture and Small Fruits

9:59am CDT

POM 3 - Oral Session

Friday August 1, 2025 9:59am - 10:00am CDT

Foster 2

Presiding/Moderator

Franz Niederholzer

University of California Cooperative Extension

Friday August 1, 2025 9:59am - 10:00am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology

10:00am CDT

POM 3 - Phosphorus Uptake and Partitioning in Young Peach Trees

Friday August 1, 2025 10:00am - 10:15am CDT

Foster 2

Phosphorus (P) is an essential plant nutrient required for growth. However, it is a finite natural resource that can cause environmental issues when overused in agriculture. Due to challenging soil relationships, the availability and uptake of P can be challenging to predict. Furthermore, soil tests can be misleading for guiding management decisions regarding P fertilizer applications. The objective of this study was to evaluate the influence of soil P levels on the uptake and partitioning of P in young peach trees. We planted a new peach orchard at the Musser Fruit Research Center near Clemson, SC. This orchard contained a widely variable range of P in the soil. Representative trees were removed in August and January and all plant parts were subjected to P analysis. Soil test P levels had no clear relationship with total plant P uptake or partitioning patterns and are likely a poor reference point for P fertilizer management decisions in peach orchards.

Speakers

Noah Willsea

Clemson University

Co-authors

Juan Carlos Melgar

Clemson University

Friday August 1, 2025 10:00am - 10:15am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv

10:14am CDT

CE 7 - Oral Session

Friday August 1, 2025 10:14am - 10:15am CDT

Strand 11B

Presiding/Moderator

Abby Pace

Cornell University

Friday August 1, 2025 10:14am - 10:15am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

10:14am CDT

CHMG 2 - Oral Session

Friday August 1, 2025 10:14am - 10:15am CDT

Strand 12A

Presiding/Moderator

Sheri Dorn

Friday August 1, 2025 10:14am - 10:15am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener

10:14am CDT

PH 4 - Oral Session

Friday August 1, 2025 10:14am - 10:15am CDT

Foster 1

Presiding/Moderator

Sushan Ru

Auburn University

Friday August 1, 2025 10:14am - 10:15am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

10:14am CDT

VCM 6 - Oral Session

Friday August 1, 2025 10:14am - 10:15am CDT

Strand 11A

Presiding/Moderator

Jordan White

Washington State University

Friday August 1, 2025 10:14am - 10:15am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

10:15am CDT

CE 7- Tomato Germination and Seedling Growth in Response to Plasma Activated Water (PAW)

Friday August 1, 2025 10:15am - 10:30am CDT

Strand 11B

Plasma activated water (PAW) is produced when plasma generated by high-voltage discharge is delivered to an atmospheric gas and interacts with water to create a new solution containing reactive species. The resulting water contains nitrate nitrogen (ca. 20-176 ppm N), small amounts of nitrite and ammonium, as well as reactive oxygen species. The benefits of PAW use for agricultural crops can include improved germination, increased seedling vigor and health, resistance to pests and disease, an alternative nitrogen source, and an overall improved plant health and yield. However, further research is needed to understand the characteristics of PAW, PAW shelf-life stability, crop specific PAW application and timing, and its overall effects in plant production. Our overall objective is to determine if PAW can enhance plant quality/yield in organic greenhouse tomato production. Studies were conducted to evaluate tomato germination and seedling growth in response to PAW application. A study was conducted to evaluate if germination of tomato seeds and subsequent growth in seedling trays with container media is affected when soaked prior to seeding with plasma water or tap water for three, six, or 12 hours. The study was replicated four times over time, with each replicate lasting for 15 days. Data was collected on daily germination, weekly heights and widths, and fresh mass, dry mass, and leaf area at harvest. Most seed treatments for 6 or 12 hours, regardless of water treatment, enhanced germination on day 5 and day 6 compared to control. However, by final harvest at day 15 there were no significant differences between treatments and control. Our second phase of research evaluated PAW application during organic tomato seedling production stage. Seedlings were treated with a drench of 4 mL per cell of different PAW sources generated for 5, 10, 30, or 60 minutes for a total of three applications every three days. On day 7, 30-minute PAW had significantly greater germination counts compared to the control. At final harvest on day 22 60-minute PAW had significantly greater fresh mass, dry mass, and leaf area compared to the control. In conclusion, a pre-seed soaking treatment for 12 hours is recommended for earlier germination and a drench application of PAW generated at a duration of 60 minutes is recommended for greater seedling growth. Further research includes PAW application timing and frequency and its carry-over effects in tomato crops grown to fruiting.

Speakers

Abby Pace

Cornell University

Co-authors

Neil Mattson

Cornell Unviersity

Nicholas S. Kaczmar

Cornell Unviersity

Friday August 1, 2025 10:15am - 10:30am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

10:15am CDT

CHMG 2 - Smart Landscaping for a Sustainable Future: Extension Education for Homeowners

Friday August 1, 2025 10:15am - 10:30am CDT

Strand 12A

Florida faces significant environmental challenges due to population growth and the widespread use of fertilizers and pesticides. Key concerns include water contamination from lawn and landscape chemicals, soil erosion, and the loss of biodiversity and wildlife habitat. Home landscapes offer a valuable opportunity to implement sustainable practices that conserve water, reduce chemical inputs, recycle yard waste, prevent erosion, and support local wildlife. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Extension provides residents with research-based recommendations to promote sustainable landscaping. In 2024, the UF/IFAS Extension Hillsborough County residential horticulture program educated 1,477 residents on these practices. A six-month follow-up survey (n=55) revealed that participants adopted various sustainable strategies: 78% replaced high-maintenance plants with low-maintenance alternatives, 86% selected plants suited to site conditions, 51% used rain gauges to monitor rainfall, 66% applied a 2-3" layer of organic mulch, 76% enhanced landscapes with plants or water sources to attract wildlife, 88% opted for less toxic pesticides, 49% started composting, and 50% maintained a 10-foot no-treatment zone near water bodies. These changes contribute to reducing stormwater runoff and nutrient leaching, leading to cleaner water bodies and improved environmental health. The success of these educational programs highlights the impact of extension efforts in fostering sustainable landscapes and protecting Florida’s natural resources.

Speakers

Tia Silvasy

University of Florida

Friday August 1, 2025 10:15am - 10:30am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Poster # csv

10:15am CDT

PH 4 - Sensory and Quality Assessment of Rabbiteye and Southern Highbush Blueberry Genotypes

Friday August 1, 2025 10:15am - 10:30am CDT

Foster 1

Rabbiteye blueberries (RE; V. virgatum A.) are perceived to have poor fruit quality compared to southern highbush (SHB; V. corymbosum L). Comprehensive quality assessments of RE genotypes during storage are scarce. To understand fruit quality differences firmness, general composition and phytonutrient contents in 5 RE (‘Brightwell’, ‘Vernon’, ‘MS1110R’, ‘T-3072’ and ‘T-3075’) and 1 SHB (‘Legacy’) genotype were evaluated. Fruit harvested from E.V. Smith Research Center (Tallassee, AL) were stored at 4°C at 85% relative humidity. Measurements were taken on days 0 and 14 (0d and 14d) in storage. Firmness was measured using a FruitFirm1000 (g/mm). Soluble solids content (SSC, °Brix), titratable acidity (Tacid) and pH were assayed. Total anthocyanins (mg/g), phenolics (mg/100g), and DPPH antioxidant capacity (mM/100g) were quantitated via UV-VIS spectrophotometry. Days in storage*genotype were significant in firmness, Tacid, pH, anthocyanins, phenolics, and antioxidants. ‘T-3072’ had the highest firmness (0d; 289.97 g/mm) compared to ‘MS1110R’ (0d; 130.61 g/mm). ‘Vernon’ (0d; 0.66) had the highest Tacid while ‘Legacy’ (0d; 0.34) was lowest. Conversely, pH was highest in ‘Legacy’ (0d; 3.68) and lowest in ‘T-3075’ (0d; 3.12). Anthocyanins and antioxidants were highest in ‘MS1110R’ on 0d (28.62 mg/g and 29.59 mM/100g) and phenolics were highest in ‘Brightwell’ after 2 weeks of storage (426.97 mg/100g). Genotype differences indicated SSC was highest in ‘Brightwell’ (16.19) compared to ‘Legacy’ (12.03). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on 0d and 14d among the genotypes to better determine how composition changed during storage. PCA indicated ‘Legacy’ clearly separated from the RE genotypes and was negatively correlated to firmness and all composition and nutritional traits. HCA determined three clusters of interest with similar genotype characteristics from 0d to 14d. In cluster I, ‘T-3072’ and ‘T-3075’ maintained moderate to enhanced firmness. ‘Legacy’ had consistently suppressed SSC and Tacid (Cluster II). While ‘Brightwell’ and ‘MS1110R’ had enhanced anthocyanins, phenolics and antioxidants (Cluster III). Reduced SSC and Tacid are associated with lower perceived sweetness and sourness. RE genotypes demonstrated higher SSC and enhanced nutritional content, making them appealing for health-conscious consumers. Sensory analysis on 4 RE and 2 SHB genotypes will be conducted utilizing a trained panel to determine differences in sweetness, sourness, texture and aroma. We expect analyzing sensory data with physicochemical assays will further provide insightful information helpful in developing acceptable RE genotypes with preferred flavor and texture.

Speakers

Sushan Ru

Auburn University

Co-authors

Clarisse Cochran-Chipura

Auburn University

Elina Coneva

Auburn University

Marlee Trandel Hayse

Auburn University

Sungeun Cho

Auburn University

Friday August 1, 2025 10:15am - 10:30am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

10:15am CDT

POM 3 - Understanding the Role of Nutrient Leaching in Young Peach Trees: Implications for Growth and Development in Orchard Man

Friday August 1, 2025 10:15am - 10:30am CDT

Foster 2

Nutrient leaching remains a significant environmental concern due to its adverse effects on soil quality, groundwater contamination, human health, and the eutrophication of aquatic ecosystems. The urgency of addressing this issue has escalated with the increasing frequency and intensity of climate variability and extreme weather events, which exacerbate nutrient losses from agricultural systems. For this study, three peach cultivars (Prunus persica L.), including 'Crimson Joy', 'Liberty Joy', and 'Rich Joy', were planted at Auburn University's Research and Extension Center in Chilton, Clanton, Alabama, on February 23, 2024, using a Randomized Complete Block Design (RCBD) with four blocks. Each block consists of 9 peach trees, totaling 36 trees. The aim of this study is to evaluate the extent of nutrient leaching on the growth of three distinct young peach cultivars, using recommended fertilization rate (by The Southeastern peach guide). A soil sampling method is used to compare the nutrient levels at selected depths. The soil depths are 25.4 and 50.8 cm within and 76.2 and 101.6 cm below the peach tree root zone. The collected soil samples are analyzed for Nitrate Nitrogen (NO3-N (mg/kg)), Ammonium nitrogen (NH4-N (mg/kg)) and pH. Additionally, the young peach trees are assessed by measuring plant height (cm), trunk cross-sectional area (cm2) and annual leaf nitrogen analysis (%). The preliminary results of this study, which is still in progress indicate that both depth and cultivar significantly influence NH4-N concentrations over time, while rainfall events and cultivar interactions affect NO3-N leaching dynamics. Although pH levels changed, they did not differ statistically. Each cultivar exhibited TCSA increases and height growth, with all cultivars maintaining leaf nitrogen levels within the optimum range. This study will help the Alabama peach growers to understand the impacts of nutrient leaching and utilize better alternatives that can help to not only get maximum profit economically but also ensure that the environment is safe and sound for the current and future generations.

Speakers

Winfred Nziku

Auburn University

Co-authors

Audrey Gamble

Auburn University

Bernardo Chaves-Cordoba

Auburn University

Dario Chavez

University of Georgia

Edgar Vinson

Auburn University

Juan Carlos Melgar

Clemson University

Melba Ruth Salazar Gutierrez

Auburn University

Friday August 1, 2025 10:15am - 10:30am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv

10:15am CDT

VCM 6 - Assessing sweetpotato growth response to growing degree days in western Washington

Friday August 1, 2025 10:15am - 10:30am CDT

Strand 11A

Studies in the Northeast United States and Canada have shown that sweetpotato yield can be comparable to the national average when grown with black plastic mulch. Western Washington has a diversity of microclimates, from the Pacific Coast to the Cascade Mountains, and assessing yield in response to growing degree days (GDD) will help growers determine if soil warming strategies are needed to achieve acceptable yield. This experiment was carried out in Mount Vernon, WA in 2024 and is being repeated in 2025. The experimental design was a split-split plot: the main plot treatment was bare soil and black polyethylene mulch (25.4 µm); the split plot treatment was cultivar, Covington and Cascade; and the split-split plot treatment was harvest date, every two weeks from 8 weeks after transplanting (WAT) to 18 WAT to assess root growth in response to accumulated GDDs. The experiment included 4 replications with 10 plants per plot, and raised beds with drip irrigation. Soil temperature was measured at 15-min intervals with sensors installed in both the mulch and bare soil plots. GDDs were calculated at two base temperatures, 10°C and 15.5°C, as both are reported in the literature. In 2024, for bare soil and plastic mulch treatments at base temperature 10°C, GDDs were 528 and 667 at 8 WAT (29 July), respectively, and 1080 and 1300 at 18 WAT (7 Oct.), respectively. At base temperature 15.5°C, GDDs for bare soil and plastic mulch treatments were 238 and 375 at 8 WAT and 428 and 635 at 18 WAT, respectively. At 8 and 18 WAT, GDDs for AgWeatherNet air temperature located 410 m from the field site were 629 and 1308 for 10°C base temperature and 138 and 275 for 15.5°C. Overall, black plastic mulch increased soil temperature by 1.78°C on average, and soil GDDs were 44% and 21% higher with plastic mulch compared to bare soil for a base temperature of 15.5°C and 10°C, respectively. At 18 WAT, root yield (US No. 1 and US No. 2) without accounting for wireworm damage was 11.7 t/ha for ‘Covington’ and 9.9 t/ha for ‘Cascade’ with plastic mulch and 7.7 t/ha for ‘Covington’ and 8.4 t/ha for ‘Cascade’ with bare soil. Sweetpotato yield in Mount Vernon, WA, was 35% greater on average with plastic mulch, but plastic mulch may not be necessary in warmer regions of the Pacific Northwest.

Speakers

Jordan White

Washington State University

Co-authors

Carol Miles

Washington State University

Laura Schulz

Washington State University

Friday August 1, 2025 10:15am - 10:30am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

10:30am CDT

CE 7 - UV-B and Blue Light Supplementation Enhance the Yield and Quality of Greenhouse-grown Tomato Fruit

Friday August 1, 2025 10:30am - 10:45am CDT

Strand 11B

Light of different wavelengths influences the crop yield and quality by modulating metabolic pathways, resulting in variations in phytochemical abundances. Therefore, optimized light conditions could enhance the plant-protecting and health-promoting attributes of tomato fruit. However, the effects of supplemental blue (B) and ultraviolet-B (UV-B) light on amino acids (AAs) and phenolics, particularly hydroxycinnamic acids (HCAs), as well as fruit firmness and yield characteristics in tomatoes, are not well understood. Therefore, the current study examined the effects of supplemental light on yield, firmness, and levels of amino acids (AAs) and hydroxycinnamic acids (HCAs) in red-ripe, greenhouse-grown tomato fruits. This study was conducted with two tomato varieties (Plum Regal and TAM Hot-Ty) exposed to supplemental blue light (238 µmol m-2 s-1 at 40 cm from the plants for 8 hours), UV-B light (5 µmol m-2 s-1 at 46 cm from the plants for 4 hours), a combination of blue and UV-B light (B UV-B), and a control group with no supplemental lighting. Our findings revealed that blue light alone significantly enhanced yield and firmness in both varieties. Similarly, UV-B light alone resulted in increased yield and higher HCA levels. The combined B UV-B treatment produced firmer fruits with high HCAs without compromising yield. Important amino acids like γ-amino butyric acid (GABA) and glutamine were also significantly enhanced by B UV-B. Therefore, supplemental blue and UV-B light could be used to improve nutritional value by increasing the abundance of bioactive compounds in tomato fruits grown under controlled environmental conditions. This work was partially supported by USDA-NIFA-2024-51181-43464, USDA-NIFA-AFRI 2023-67013-39616 through the Vegetable and Fruit Improvement Center and Institute for Advancing Health Through Agriculture of the Texas A

Speakers

Samikshya Bhattarai

Graduate Research Assistant, Texas A&M University

Co-authors

Bhimanagouda Patil

Texas A

Deepak Jha

Texas A

Friday August 1, 2025 10:30am - 10:45am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

10:30am CDT

CHMG 2 - Consumers and the green industry: What do they really know about the realities of plant production?

Friday August 1, 2025 10:30am - 10:45am CDT

Strand 12A

Green industry businesses face many challenges in production including finding and retaining employees as well as increasing materials and shipping costs. To address production hurdles, implementation of various types of automation are a key focus in many horticultural production operations. Automation has the potential to not only address key production challenges but can also improve working conditions and employee experience, including health and well-being. A focus on employee health and wages has been shown to be valued by consumers of a range of horticultural food crops and have been a key element in price premiums for food crops and businesses who demonstrate their positive benefit for worker or community well-being. However, less is known about consumer perceptions of green industry production practices or their valuation of businesses prioritizing employee well-being. Therefore, a nationwide consumer survey was undertaken to assess consumer knowledge and perception about automation overall and automation within horticultural production. While the focus on the survey was to investigate automation technologies in the nursery industry, the survey included a range of greenhouse and nursery crops to assess consumers’ understanding of the current use of automation as well as perceptions about automation as well as the impact of automation on employee health and well-being. The focus on the presentation will be on consumer knowledge and opinion on automation in plant production as well as the role of consumer demographics, work experiences, and industry knowledge. Results will be summarized to share opportunities for strengthening consumer valuation of horticultural crops.

Speakers

Natalie Bumgarner

Assistant Professor, University of Tennessee Knoxville

Co-authors

Alicia L Rihn

University of Tennessee

Anna Duncan

University of Tennessee

Taylor Ruth

University of Tennessee

Friday August 1, 2025 10:30am - 10:45am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Funding Source USDA-NIFA

10:30am CDT

PH 4 - Climate and weather's effects on sweet cherry quality and maturity in extended storage

Friday August 1, 2025 10:30am - 10:45am CDT

Foster 1

Climate variability causes unpredictable seasonal weather events during the fruit-growing period. This affects fruit set and quality by affecting ripening and deterioration rates postharvest. The goal of this research was to study how different weather conditions affected fruit quality at harvest and their storage potential. Four sweet cherry cultivars (Rainier, Bing, Skeena, Sweetheart) grown commercially in Central WA during 2021-2024 were harvested at two different times and stored in air (0-1 oC) for 30 days. Maturity indices (weight, color, firmness, soluble solids), stem condition, and defects were evaluated every two weeks plus 2 days at 5-6 oC simulating refrigerated shelf-life. Overall, the seasonal weather had a significant impact on fruit quality at harvest and postharvest. Fruit firmness varied among seasons in all cultivars and increased over time in storage in most cases. Skin color was only affected by harvest time. No clear trends across cultivars were observed with soluble solids content or fruit weight. The stem condition declined with time postharvest, but the rate was season- and cultivar-dependent. Positive correlations between bioclimatic indexes and the rate of deterioration (including pitting and pebbling) were found that need further investigation.

Speakers

Carolina Torres

Washington State University

Co-authors

Gabriela Bolanos-Pabon

Washington State University

Rene Mogollon

Washington State University

Friday August 1, 2025 10:30am - 10:45am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest
Funding Source USDA-AFRI

10:30am CDT

POM 3 - Rapid and quantitative analysis of leaf calcium using X-ray fluorescence scanning

Friday August 1, 2025 10:30am - 10:45am CDT

Foster 2

Development of control measures for nutrient-related apple fruit disorders like bitter pit requires a better understanding of calcium metabolism in the tree. Limiting this understanding is a rapid and accurate method for measuring the concentration of calcium in various plant organs including the leaves. Optimally, measuring calcium levels could be done at the single leaf level, or better yet for whole leaves at a resolution of sub-millimeter dimensions. We report on the use of X-ray fluorescence for apple leaf tissue to quantitatively measure leaf calcium tissue. Using 7-mm diameter discs taken from Granny Smith apple leaves mid-season, we were able to demonstrate that the emission data from a scanning Bruker X-ray fluorescence instrument could be easily transformed to predict accurate and precise calcium levels in apple leaf tissue. If similar relationships can be determined for other minerals, this type of analysis will enable the quantitation of multiple minerals within minutes. Provided software analysis of the samples can be automated, the turn-around time for tissue analysis would be on the order of one or two hours for hundreds of samples

Speakers

Randolph Beaudry

Michigan State University

Co-authors

Claudia Moggia

University of Talca

Gustavo Lobos

University of Talca

Marcelo Pirinoli

University of Talca

Ricardo Cabeza

University of Talca

Sebastian Romero-Bravo

University of Talca

Friday August 1, 2025 10:30am - 10:45am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv
Funding Source FONDECYT

10:30am CDT

VCM 6 - Assessing the Effect of Processing on Volatile Organic Compounds in Tomatoes Using Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

Friday August 1, 2025 10:30am - 10:45am CDT

Strand 11A

The profile of volatile organic compounds (VOCs) in tomato (Solanum lycopersicum) fruit significantly influences their sensory attributes, particularly aroma, which affects consumer preference. This study examines variation in VOCs between commercially processed tomato products and greenhouse-grown tomatoes, focusing on processing techniques and how they alter VOC profiles. Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed for detailed VOC profiling. Optimization of HS-SPME parameters, including salt-assisted extraction, extraction temperature, and fiber selection, enabled precise identification and quantification of VOCs. The optimized conditions involved extracting samples in a 30% NaCl solution to maximize volatile release, adsorption onto a 50/30 µm DVB/CAR/PDMS fiber at 80 °C for 30 minutes, and analysis using a Restek Rtx-Wax column with helium as the carrier gas. SPME-GC-MS analysis confirmed that processing techniques significantly influence the release, chemical nature, and composition of VOCs. Commercially processed tomato products exhibited elevated levels of volatiles such as (Z)-3-hexenal and (E)-2-hexenal. Since processed products often undergo thermal treatments such as pasteurization and decontamination, the reduction in volatile composition compared to fresh, unprocessed tomatoes could be attributed to the thermal degradation of heat-sensitive compounds such as cis- and trans-hexanol, hexanal, geranial, and methyl salicylate, contributing to a pronounced cooked tomato aroma. In contrast, greenhouse-grown tomatoes, cultivated under controlled conditions, contained lower overall VOC concentrations but retained higher levels of methyl salicylate and norisoprenoids, yielding a milder, sweeter aroma profile, which is generally absent in processed products. This study underscores the impact of processing on tomato aroma and highlights the importance of optimizing analytical methods for VOC profiling. Detailed VOC profiling offers valuable insights for breeders and food processors seeking to enhance the flavor quality of both greenhouse-grown and processed tomato products. This research was supported by USDA-NIFA-2024-51181-43464 and USDA-NIFA-AFRI-2023-67013-39616 through the Vegetable and Fruit Improvement Center and the Institute for Advancing Health Through Agriculture at Texas A

Speakers

Debanjan Chatterjee

Texas A

Co-authors

Bhimanangouda S. Patil

Texas A

Braulio Cervantes Paz

Texas A

Deepak Kumar Jha

Texas A

Vikas Dadwal

Texas A

Friday August 1, 2025 10:30am - 10:45am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

10:45am CDT

CE 7 - Dynamic Lighting Is Essential to Mitigate Long Photoperiodic Injury in Greenhouse Tomatoes

Friday August 1, 2025 10:45am - 11:00am CDT

Strand 11B

Consumers want year-round supply of high quality fresh produce. However, the low sunlight has limited greenhouse vegetable during the winter months in high-latitude region. In order to boost yields and meet market demand, supplemental lighting is required. However, utilizing electric lighting, even high-efficient LED fixtures results in high electricity costs. Photoperiod extension (up to 24h) is a promising strategy which can be implemented in many countries as the utility companies incentivize the use of low cost, off-peak electricity use during the night. In this way, extending the photoperiod from the conventional 16h up to 24h can result in reduced electricity cost when the daily light integral (DLI) remains the same. In this study, we look at the impact of two different 24h lighting strategies in two cherry tomato cultivars and their impact on photoperiod injury compared to a 16h control. One 24h treatment involved a change from white light during the day to blue light at night at a reduced photosynthetic photon flux density (PPFD; i.e., dynamic) while the other kept a static spectrum and PPFD for 24h. In addition, each treatment also had a low blue (10%) and high blue (30%) variation. The experiment took place in a glass greenhouse at the Harrow Research and Development Centre in Harrow, Ontario, Canada. It was determined that the 24h dynamic lighting strategy has similar maximum quantum yield of photosystem II (Fv/Fm) values as the 16h controls while the 24h static treatments values were drastically reduced. What’s more, the Fv/Fm value from the 24h static treatment with high blue content was lowest among all treatments indicating that elevated levels of blue light may be detrimental during a 24h photoperiod. In addition, the overall yield from the 24h dynamic treatments were similar to the 16h controls while the 24h static treatments were statistically lower. Taken together, these results indicated that a 24h dynamic light treatment is essential to mitigate photoperiodic injury in cherry tomato. This data suggests that the use of such a lighting strategy could also reduce electricity costs for greenhouse cherry tomato producers.

Speakers

Xiuming Hao

Agriculture and Agri-Food Canada (AAFC)

Co-authors

Celeste Little

Agriculture and Agri-Food Canada

Jason Lanoue

AGRICULTURE AND AGRIFOOD CANADA

Rose Seguin

Sollum Technologies Inc.

Saman Soltaninejad

Sollum Technologies Inc.

Sarah St. Louis

Agriculture and Agri-Food Canada

Friday August 1, 2025 10:45am - 11:00am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

10:45am CDT

CHMG 2 - Understanding Consumer Trust Regarding Environmental Information about Plant Purchases

Friday August 1, 2025 10:45am - 11:00am CDT

Strand 12A

Consumer decision making is heavily influenced by not only the information made available about products but also the degree of trust consumers have in that information. As online sources increase, so do opportunities to find information about products that is both factual and misleading. Especially with regards to green products and sustainability claims, predatory marketing practices, undisclosed advertisements, and uninformed influencers contribute to consumer vulnerability regarding purchases. With regards to plant products - both plant-based foods and ornamental plants - and the environment, little research has been invested in understanding where and how consumers are getting information and what they trust. This study investigates how plant consumers access and trust information regarding environmental and climate issues, their purchases, and the sustainability qualities of plant products. Using the results of an online survey, consumer profiles were identified using Ward’s Linkage clustering so that stakeholders, such as science communicators, marketing professionals, consumer protection agencies, and consumers themselves can better understand the state of consumer trust in information about plant products.

Speakers

Abigail Lauterbach

The University of Georgia

Co-authors

Julie Campbell

University of Georgia

Friday August 1, 2025 10:45am - 11:00am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Poster # csv

10:45am CDT

PH 4 - Continuous High-Pressure Homogenization for Reducing Thermal Degradation and Preserving Bioactive Compounds in Fruit Juices

Friday August 1, 2025 10:45am - 11:00am CDT

Foster 1

The preservation of bioactive compounds in fruit juices is essential for maintaining their nutritional value and consumer appeal. This study explores the potential of Continuous Flow High-Pressure Homogenization (CFHPH) as a promising alternative to traditional thermal processing methods, such as High-Temperature Short-Time (HTST), in fruit juice production. CFHPH has demonstrated effectiveness in preserving bioactive compounds, including ascorbic acid, carotenoids, anthocyanins, and phenolic acids, while significantly reducing the thermal degradation of heat-sensitive compounds associated with HTST. In this research, we compared CFHPH to HTST in juices from horticultural crops, including watermelon, blueberry, and grapefruit. CFHPH treatment at 300 MPa and an inlet temperature of 4 °C maintained higher levels of carotenoids, anthocyanins, and ascorbic acid during storage, while also reducing the activity of oxidative enzymes such as polyphenol oxidase (PPO) and peroxidase (POD) across all tested fruits. In contrast, HTST processing resulted in a considerable loss of bioactive compounds due to oxidation and thermal degradation. CFHPH not only preserved essential nutrients but also extended shelf life under market-simulated storage conditions by minimizing oxidative damage and reducing particulate sedimentation, making it an ideal solution for the growing demand for minimally processed, nutrient-rich fruit juices. This technology offers significant potential for the horticulture and food industries, ensuring fresh, nutritious, and appealing juices for health-conscious consumers.

Speakers

Jayashan Adhikari

Texas A

Co-authors

Bhimanagouda Patil

Texas A

Koushik Adhikari

University of Georgia

Rakesh Singh

University of Georgia

Friday August 1, 2025 10:45am - 11:00am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

10:45am CDT

POM 3 - Horticultural Performance and Physiological Responses of a Mature Peach Orchard to Mulch and Poultry Litter Application.

Friday August 1, 2025 10:45am - 11:00am CDT

Foster 2

Plant nutrient acquisition and responses to different fertilization programs in fruit orchards oftentimes depend on many biotic or abiotic factors or a combination of both, including tree or orchard age and nutrient source. This study aims to evaluate the effect of topically applied, slow-release source of essential nutrients from mulch mixed with poultry litter (PLM) or without (M) and fast-release growers’ standard rate of mineral fertilizer on an eight-year-old replanted orchard containing ‘Juneprince’ and ‘Scarletprince’ peach trees in South Carolina. Soil health indicators such as soil moisture and nutritional status, and tree health parameters, including yield and fruit quality (specifically on the incidence of diseases and physiological disorders), were evaluated over two years. The results showed that soil organic matter and cation exchange capacity were significantly higher in PLM across both years of this study when compared with other treatments. Both PLM and M treatments had higher moisture retention than the grower’s standard. However, yields between the two cultivars used in this study varied considerably in response to treatment and years. Yield of ‘Juneprince’ trees treated with GS was significantly higher in the first year of this study when compared with PLM and M but did not significantly differ in the second year. In contrast, yield of ‘Scarletprince’ trees treated with PLM and M were consistently higher numerically when compared with GS in both years. PLM significantly reduced bacterial spot incidence and severity in both cultivars across the study years. This result suggested that amending the soil through surface covering with mulch mixed with poultry litter provides the nutritional requirement, increases yield and significantly lower disease pressure and improves the quality of the marketable fruit in a mature orchard.

Speakers

Ayodeji Idowu

Clemson University

I am a third-year Ph.D. student working on improving soil health and ecosystem conservation through rigorous enhancement of soil organic matter and strategic soil nutrient management for agricultural and environmental sustainability. To achieve this, I am testing different soil amendment... Read More →

Co-authors

Juan Carlos Melgar

Clemson University

Friday August 1, 2025 10:45am - 11:00am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv
Funding Source United States Department of Agriculture - Sustainable Agriculture Research and Education (USDA-SARE)

10:45am CDT

VCM 6 - Phenological Assessment of Artichoke Grown with Gibberellic Acid–Induced Vernalization in a Subtropical Climate

Friday August 1, 2025 10:45am - 11:00am CDT

Strand 11A

Globe artichoke (Cynara cardunculus var. scolymus L.) is an herbaceous, perennial plant native to the Mediterranean region and belongs to the Asteraceae family. It requires adequate winter chilling for bud induction, yet susceptible to freeze damage. In subtropical or tropical climates, artificial flower induction or vernalization is necessary for winter crops. Our preliminary results indicate that gibberellic acid (GA3) effectively induces bud formation without chilling. Understanding crop phenology facilitates management planning and performance assessment under diverse conditions. This study used the Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale to characterize the phenological development of artichoke cultivated in a subtropical climate with insufficient winter chilling. Seedlings of ‘Green Queen’ (GQ), ‘Imperial Star’ (IS), ‘Opal’ (OP), ‘20-063’, ‘22-017’, ‘23-057’, and ‘24-060’ cultivars were transplanted on 18 October 2024 in West Central Florida. Plants initially exhibited vegetative growth characterized by leaf development (Stage 1) and rosette formation (Stage 3–4) up to 79 DAP. GA3 applications at 62 and 76 days after planting (DAP) promoted vegetative growth by increasing both leaf number and size. Vegetative growth was most vigorous in ‘GQ’ and least in ‘20-057’, whereas in the Mediterranean climate, growth at this stage typically arrests through winter due to low temperatures. GA3 applications successfully induced bolting, initiating the transition to reproductive growth between 80 and 82 DAP. Buds reached the optimum maturity stage to harvest with the maximum diameter at around 115 DAP, earlier than the typical 120 to 150 days in annual culture. Marketable yields varied significantly among cultivars, from 2.69 t·ha–1 for ‘OP’ to 7.33 t·ha–1 for ’20-063’. By 160 DAP, mature buds exhibited floral opening with characteristic lilac-colored florets (Stage 6: flowering and capitulum formation). In Florida, although hot and humid summers constrain the harvest window, our results suggest that GA3-induced vernalization enables artichoke production during the winter months in a timeframe that is 5 to 35 days shorter than under Mediterranean conditions. This study advances understanding of artichoke adaptability to subtropical climates, promoting its potential as a winter specialty crop for edible and ornamental uses.

Speakers

Avninder Kaur

University of Florida

Co-authors

Shinsuke Agehara

University of Florida

Friday August 1, 2025 10:45am - 11:00am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

11:00am CDT

CE 7 - Comprehensive Analysis of Heat Stress Responses in Tomato Genotypes Across Vegetative and Reproductive Stages

Friday August 1, 2025 11:00am - 11:15am CDT

Strand 11B

The thermotolerance responses of tomato plants have been assessed using various physicochemical parameters. However, even within the same genotype, thermotolerance strategies can vary among plant organs. This study aimed to investigate heat stress responses in tomato genotypes across vegetative and reproductive stages, focusing on a comprehensive analysis of thermotolerance mechanisms. Ten tomato varieties, including seven commercial cultivars and three Texas A

Speakers

Chungkeun Lee

Texas A&M University

Co-authors

Daniel Leskovar

Texas A

Friday August 1, 2025 11:00am - 11:15am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

11:00am CDT

CHMG 2 - Quantifying Consumer Mental Health Benefits from Home Propagation

Friday August 1, 2025 11:00am - 11:15am CDT

Strand 12A

Home propagation is a common practice among horticulturalists and green industry consumers due to the simplicity of the activity and the gratification of successfully growing new plants. While discussions of propagation often emphasize its environmental and economic benefits, far less attention has been given to its individualistic impacts. These impacts may include psychological, therapeutic, and social benefits. This study examines the relationship between home propagation and improvements in mood, self-confidence, and opportunities for interaction with other plant enthusiasts. Through surveys with plant propagators, we will learn how successful propagation attempts create a sense of personal fulfillment, accomplishment, and a desire for interaction with other propagators. By further investigating these benefits, this research aims to determine if home propagation functions as a therapeutic and community-building activity and should be acknowledged as something deeper than a casual hobby.

Speakers

Leandria Garrett

University of Georgia

Co-authors

Julie Campbell

University of Georgia

Friday August 1, 2025 11:00am - 11:15am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Poster # csv

11:00am CDT

PH 4 - Texture Profiling of 7 Rabbiteye and 3 Southern Highbush Blueberry Genotypes During Postharvest Cold Storage

Friday August 1, 2025 11:00am - 11:15am CDT

Foster 1

Blueberry (Vaccinium spp.) texture is a key trait in breeding programs primarily due to its influence on consumer acceptance, machine harvestability, transportability, shelf-life, and overall quality. Variations in firmness have been extensively studied on southern highbush (SHB; Vaccinium corymbosum L.), with little reported on rabbiteye (RE; Vaccinium virgatum) genotypes. Various texture instruments, including FruitFirm1000, FirmTech II, and TA.XT2 Plus texture analyzers, are used, but not all assess multiple mechanical parameters on blueberry fruit. Initial firmness evaluations on 17 RE and SHB genotypes using a FruitFirm1000 identified genotype-specific variations over six weeks of storage (4 °C, 85% relative humidity). At harvest (day 0), ‘Titan’ (RE) had the highest firmness (287 g.mm-1), while ‘MS1110R’ (RE) had the lowest (152 g.mm-1). After 4 weeks in storage (day 28), RE genotypes of ‘Titan’, ‘Vernon’, ‘T-3075’, and SHB ‘Legacy’ maintained high firmness (˃200 g.mm-1). While ‘Alapaha’ (RE), ‘New Hanover’(SHB), and ‘MS1110R’ (RE) did not retain firmness (˂150 g.mm-1). Texture is a complex and multi-component trait; a single firmness measurement cannot comprehensively capture all attributes influencing blueberry texture variations. To further understand blueberry mechanical parameters, our current study utilizes a TA.XT2Plus texture analyzer equipped with 2 mm needle and 2 mm flat probe. The needle probe will measure force parameters across different blueberry tissues: epidermis (Fep), hypoderm (Fh), parenchyma (Fp), and inner pulp (Finner). The 2 mm flat probe will measure mechanical parameters derived from force-distance curves, which relates to skin elasticity, internal firmness, graininess/grittiness, skin strength, and stiffness (Young’s modulus). Ten blueberry genotypes (7 RE and 3 SHB) representing distinct crisp/high, medium, and low firmness levels will be harvested and stored at 4 °C and 85% relative humidity. Texture measurements will be taken at two postharvest timepoints, day 0 and 14. By integrating advanced texture analysis (TA.XT2Plus) compared to FruitFirm1000, a comprehensive understanding of firmness variability and texture changes in RE compared to SHB blueberries will be obtained. The advanced textural assessment will enable data-driven insights to inform breeding selections for improved texture in fresh-market cultivars.

Speakers

Peter Ephraim

Graduate Research Assistant, Auburn University

Peter Ephraim is a PhD student in the Department of Horticulture at Auburn University. Peter has a strong background in food science, holding a bachelor’s degree in food science and technology from Lilongwe University of Agriculture and Natural Resources in Malawi and a Master’s... Read More →

Co-authors

Camila Rodrigues

Auburn University

Marlee Trandel Hayse

Auburn University

Michael Miller

Auburn University

Sushan Ru

Auburn University

Suzanne Johanningsmeier

United States Department of Agriculture-Agricultural Research Service (USDA-ARS)

Friday August 1, 2025 11:00am - 11:15am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest

11:00am CDT

POM 3 - Cutting Propagation of Southwest Peach Seedlings

Friday August 1, 2025 11:00am - 11:15am CDT

Foster 2

Southwest Native American Tribes, such as the Navajo, Hopi, and other Pueblo, have grown peaches since at least the early 1600’s, making them a nutritionally and culturally important food source. Historically, peach propagation was primarily done by seed, with only one written account of stem cutting propagation occurring within the Zuni Pueblo. Little is known about the effectiveness of different propagation methods for rapidly replicating Southwest seedling accessions and maintaining parent tree genetics. The purpose of this study was to evaluate the rooting success of softwood and hardwood cuttings taken from Southwest peach seedling accessions originating from five locations within the Navajo and Hopi Tribal communities. All cuttings were collected from mature trees established in Thatcher, UT. Two trials of cuttings were conducted in July and November of 2024. Each seedling tree had 18 cuttings per trial. Trial one had softwood and hardwood cuttings and trial two had only hardwood cuttings. Each cutting was measured 12 cm long, had at least three nodes planted into the potting media. Trial one cuttings had the first 3 node leaves cut in half, with all other leaves removed. Cutting treatments included a control (no treatment), Hormodin 1, and Hormodin 2, with six replications for each treatment. All cuttings were placed under a mist system with controlled temperature and relative humidity. Rooting success was assessed over three months by visually evaluating live tissue and new growth. Rooting success was dependent upon seedling parent location, treatment, time of year, as analyzed by analysis of variance. Cuttings from Canyon del Muerto had greater rooting success compared with those from Navajo Mountain. The Hopi and Navajo Mountain cuttings had decreased rooting success as the Hormodin concentrations increased. Canyon del Muerto cuttings benefited from Hormodin 1 treatment. The results of this study will help determine the potential of Southwest peach seedlings for replication as a viable rootstock for the fruit industry.

Speakers

Reagan Wytsalucy

Utah State University

Native American food crops of the Southwest.

Co-authors

Bud Lopez

New Mexico State University

Kevin Lombard

New Mexico State Univeristy

Youping Sun

Utah State University

Friday August 1, 2025 11:00am - 11:15am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv
Funding Source San Juan County Extension with Utah State University and New Mexico State University Agriculture Science Center

11:00am CDT

VCM 6 - Enhancing Bell Pepper Production: Exploring the Effects of AMF Application on WUE in Greenhouse Bell Pepper Production

Friday August 1, 2025 11:00am - 11:15am CDT

Strand 11A

Arbuscular mycorrhizal fungi (AMF) are a widespread and naturally-present soil microorganism that form symbiotic relationships with the roots of terrestrial plants. These fungi have been credited with numerous host plant benefits, the most relevant to this study being their ability to improve plant-water relations through multiple mechanisms. Bell peppers are extremely vulnerable to drought stress and require high amounts of water, so the colonization of AMF could potentially help fortify peppers against this prevalent stressor. However, AMF populations are greatly affected by the disruptive agricultural practices utilized in vegetable production. Therefore, there is a need to research the integration of AMF into traditional production systems. Existing research on AMF is often inconclusive and inconsistent when compared across locations and environments due to their complex nature. An AMF trial was carried out at greenhouses in Raleigh, NC to examine the effect of AMF application on water use efficiency (WUE) in bell peppers. ‘Red Knight’ F1 hybrid bell pepper seeds were inoculated with a commercially available AMF spore product (Endomycorrhizae formulation). The seeds then germinated and grew for eight weeks to allow the AMF root colonization to establish. Afterwards, the pepper seedlings were transplanted into 2 gal pots and placed on weighing lysimeters before growing for four more weeks to allow the roots to establish in the pots. Two irrigation treatments were then applied to the plants: 100% container capacity (CC) and water deficit (WD). The 100% CC treatments were irrigated in daily intervals to keep the media at maximum soil moisture. The WD treatments were individually irrigated back up to 100% CC each time visual wilting symptoms presented for a plant. Water use for each plant was calculated throughout the growing season by weighing the pots and runoff-catchment containers at each irrigation event to precisely determine the amount of water available to each plant. At the end of the growing season, WUE was determined for each plant by comparing the total water used to the total biomass produced. Results show no difference in WUE for the control vs AMF inoculated plants under water deficit. However, there were some differences observed in other measurements collected, such as floral abortion rates, plant height, biomass, stomatal conductance, and water pressure potential.

Speakers

Brooke Matusko

North Carolina State University

Co-authors

Amanda Cardoso

North Carolina State University

Emmanuel Torres Quezada

North Carolina State University

Kevin Garcia

North Carolina State University

Ricardo Hernandez

North Carolina State University

Friday August 1, 2025 11:00am - 11:15am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

11:15am CDT

CE 7 - Performance of Tomato in the Dutch Bucket Hydroponic System with Different Soilless Substrates

Friday August 1, 2025 11:15am - 11:30am CDT

Strand 11B

Small-scale greenhouse growers commonly use perlite as substrate in the Dutch bucket hydroponic production of vine crops such as tomatoes. However, perlite is prone to an excessive nutrient solution leaching primarily due to its free-draining and low water holding capacity properties. Alternative organic substrate to perlite is needed for a sustainable hydroponic production of these fruiting vegetables in the Dutch bucket system. This study thus evaluated the growth and yield performance of two tomato cultivars (BHN 589 and Geronimo) in five substrates (clay pebbles, loose rockwool, perlite, coco coir, and Lensli) in a randomized complete block design with three replications inside a polyethylene film greenhouse from February to July 2024. Results showed no significant effects of the interaction of substrates and cultivars on all the measured growth and yield traits. Averaged over the two cultivars, the substrates tested significantly influenced the total yield ranging from 338 to 464 Mg/ha and marketable yield ranging from 328 to 445 Mg/ha. More specifically, Lensli increased marketable yields by 15, 31, and 36% than those of coco coir, perlite, and clay pebbles, respectively. These increases are primarily due to a significant increase in the number of marketable fruit per plant (19%) and average marketable fruit weight (10%). Lensli also increased leaf area index by 44 and 60% than those of perlite and clay pebbles, respectively. Based on these results, Lensli, a blend of fine Baltic and superfine black peat, is proving to be a promising organic alternative substrate for tomato production in the Dutch bucket hydroponic system.

Speakers

Cristian Camacho

East Texas A

Co-authors

Desire Djidonou

East Texas A

Friday August 1, 2025 11:15am - 11:30am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments

11:15am CDT

CHMG 2 - Using Gardener Identity to Fine-tune Extension Programming for Consumer Audiences

Friday August 1, 2025 11:15am - 11:30am CDT

Strand 12A

Identity has been used as a measure of individuals to better understand values and behavior, such as concern for the environment and subsequent behaviors. Applying the same approach to horticulture, measure of identity as a gardener can help researchers, educators, and industry stakeholders have knowledge of existing and potential clients to deliver relevant goods and services. In a 2023 national survey, respondents (n=2435) completed measures of gardener identity (GI) as well as assessments of five elemental and three functional gardening practices. Gardener identity scores were significantly higher among self-reported gardeners than nongardeners, with a weak positive correlation between GI score and spending on supplies and services (r = .310, p=.01). Despite perception that gardening is a solitary activity, findings highlight the role of social networks in positive, early gardening experiences that shape behaviors across the lifespan. Coupled with demographic data, these scores provide additional insight and guidance for developing and supporting individuals who spend money on green industry supplies and services.

Speakers

Sheri Dorn

Co-authors

Heather Kirk-Ballard

University of Georgia

Julie Campbell

University of Georgia

Natalie Bumgarner

University of Tennessee

Friday August 1, 2025 11:15am - 11:30am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Poster # csv

11:15am CDT

PH 4 - Hyperspectral Imaging for Haskap Berry Firmness Prediction: A Non-Destructive Approach.

Friday August 1, 2025 11:15am - 11:30am CDT

Foster 1

Firmness is an important quality attribute for assessing fruit maturity, postharvest management, and consumer acceptance. Texture profile analyser and penetrometers are two destructive and time-consuming traditional methods for measuring firmness. Hyperspectral imaging presents a potential non-destructive alternative by acquiring the spectral and spatial data of fruits. The ability of hyperspectral imaging to predict firmness of Haskap berries (Lonicera caerulea) at various ripening stages is investigated in this study. Hyperspectral images of the Aurora cultivar were collected at 3 harvesting stages (early, mid, late), 3 growing positions (high, middle, low), and different sunlight exposure conditions (partial shade, full sun). The spectral data was collected for a selected region of interest. The reflectance spectra (396.92-1033.95 nm) were analysed, and different models were developed using neural network (R2= 0.44; RMSE= 0.35), general regression (R2= 0.41; RMSE= 0.36), partial least squares (R2= 0.45; RMSE= 0.35) and bootstrap (R2= 0.63; RMSE= 0.28) predictive modelling methods. The preliminary results of the research study findings imply that hyperspectral imaging is a viable tool for promptly estimating firmness and classifying the ripeness stage of haskap berries. By integrating hyperspectral imaging and data-driven approaches, growers can significantly enhance fruit quality and optimize decision-making processes, enabling better pre- and postharvest management.

Speakers

Mohit Sharma

Université Laval

Co-authors

Arturo Duarte Sierra

Université Laval

Rani Puthukulangara Ramachandran

Agriculture and Agri-Food Canada

Friday August 1, 2025 11:15am - 11:30am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest
Poster # csv

11:15am CDT

POM 3 - Root-to-leaf ratio contributes to drought recovery and resilience in northern highbush blueberry genotypes

Friday August 1, 2025 11:15am - 11:30am CDT

Foster 2

Plant canopy and root architecture characteristics play a crucial role in water uptake and plant growth. Blueberry roots are shallow and lack dense root hairs, making them more susceptible to drought than most fruit crop species. In northern highbush blueberry (Vaccinium corymbosum), differences in root size, root architecture, and root-to-leaf balance may impact drought resilience, particularly in maintaining photosynthesis (A) under limited soil moisture. However, this has not yet been examined in this species. This study evaluated drought resilience in two V. corymbosum genotypes with contrasting canopy and root architecture characteristics (Bluecrop, low root-to-leaf ratio; Draper, high root-to-leaf ratio). During the pre-drying period, both genotypes exhibited similar A and stem water potential (Ψ stem). Irrigation water was withheld to initiate drought conditions. By day 4 of withholding water, Bluecrop showed a decline in A, but its Ψ stem did not significantly change until day 6. In contrast, Draper did not show a decline in A or Ψ stem until day 6 of withholding water. Both cultivars reached a critical threshold of stomatal conductance (gs) (90% reduction from well-watered conditions) on day 10 of withholding water. Following re-watering, Ψ stem recovered immediately in both cultivars on day 2 of re-watering (day 12 of withholding water). However, the recovered Ψ stem of Bluecrop did not correspond with any increase in gs until day 14 of rewatering (day 24 of withholding water). Meanwhile, Draper exhibited a much higher gs and A than Bluecrop throughout the post-rewatering period, suggesting that Bluecrop is more sensitive to drought conditions than Draper. Post-experiment analysis confirmed that Draper had a larger root-to-leaf ratio than Bluecrop, which likely enhanced water absorption and supported faster recovery following rehydration. No significant difference in root architecture characteristics were found between these two cultivars, considering the number of root tips, root length, and surface area per root diameter at different levels (< 0.25 mm, 0.25- 0.5 mm, and >0.5 mm). These results suggest that root-to-leaf ratio and root-to-leaf hydraulic conductance play a central role in determining drought resilience in V. corymbosum genotypes. Future studies will be carried out to confirm this finding across a greater number of genotypes.

Speakers

Sheng-yang Li

Michigan State University

Co-authors

Josh VanderWeide

Michigan State University

Friday August 1, 2025 11:15am - 11:30am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv

11:15am CDT

VCM 6 - Optimizing Harvest Timing for Enhanced Hop Quality in a Subtropical Climate

Friday August 1, 2025 11:15am - 11:30am CDT

Strand 11A

Optimizing Harvest Timing for Enhanced Hop Quality in a Subtropical Climate Alvaro J. Bautista* and Shinsuke Agehara University of Florida, Institute of Food and Agricultural Sciences, Gulf Coast Research and Education Center, 14625 County Road 672, Wimauma, FL 33598, United States *Presenter: Alvaro J. Bautista Corresponding author: Shinsuke Agehara (sagehara@ufl.edu) Hops (Humulus lupulus L.) are a key ingredient in brewing, contributing bitterness, aroma, and microbiological stability. While traditionally cultivated in temperate climates, our previous research has demonstrated that subtropical regions like Florida offer unique opportunities for hop production, enabling two production cycles per year with supplemental lighting. Harvest timing is critical for optimizing hop cone biochemical composition, particularly alpha acids (AA), beta acids (BA), and essential oils, which directly influence beer quality. This study examined the seasonal and developmental dynamics of ‘Cascade’ hop cone chemistry to determine the optimal harvest window for both spring and fall growing seasons. Data were collected from 2021 to 2024 from the plants established in 2021 at the University of Florida’s Gulf Coast Research and Education Center in west-central Florida. Cone samples were collected at different days after flower induction (DAFI) to assess changes in AA and BA, cohumulone and colupulone, and essential oil composition. Acid levels showed significant seasonal variation. In spring, AA and BA ranged from 9.38% and 5.48% in 2021 to 4.48% and 2.0% in 2024, respectively. In fall, AA and BA ranged from 4.7% and 2.49% in 2021 to 2.97% and 2.0% in 2024, respectively. Acid accumulation also showed seasonal patterns, peaking at 36–48 DAFI in spring compared to 24–30 DAFI in fall. In contrast, cohumulone and colupulone maintained stable levels around 27.54% of total AA and 47.79% of total BA, respectively, throughout the study. Essential oil content increased during cone maturation, reaching its optimal aromatic profile at 36–42 DAFI (1.5 ml/100g). Myrcene (81.8% of total oil), the dominant terpene across all seasons, followed the same trend as total essential oil content. Humulene and caryophyllene peaked between 24 and 36 DAFI (19.7% and 10.9.% of total oil, respectively), while geraniol and linalool remained stable (0.5% and 0.7% of total oil, respectively) throughout maturation. These findings provide a foundation for optimizing hop production in non-traditional climates and highlight the importance of precise harvest timing to enhance hop quality for brewing applications. Future research will explore additional environmental, physiological, and management factors influencing hop maturation under subtropical conditions.

Speakers

Alvaro J. Bautista

University of Florida

Co-authors

Shinsuke Agehara

University of Florida

Friday August 1, 2025 11:15am - 11:30am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

11:30am CDT

CE 7 - Establishing Sap-Based Sufficiency Ranges for Lettuce, Cucumbers, and Tomatoes in CEA

Friday August 1, 2025 11:30am - 11:45am CDT

Strand 11B

Real-time nutrient management is crucial in controlled environment agriculture (CEA) for enhancing crop production, reducing fertilizer costs, and mitigating environmental impacts. Inadequate fertilization can reduce crop productivity and nutrient runoff. Sap-based sufficiency ranges could maintain balanced fertilization. The main objective of this study is to establish sap-based sufficiency ranges for lettuce (Lactuca sativa), tomatoes (Lycopersicon esculentum), and cucumbers (Cucumis sativus) across developmental stages and fertilizer levels in CEA. Lettuce was grown using a Randomized Complete Block Design (RCBD) with three cultivars (‘Casey,’ ‘Cherokee,’ ‘Chicarita’) and three fertilizer levels (low 50%, medium 100%, and high 200%) in a vertical farm and greenhouse. A split-plot in RCBD was used for tomatoes (‘Grandice,’ ‘Macxize,’ ‘Prodice’) and cucumbers (‘Georgia,’ ‘Verdon,’ ‘Camaro’) under the same fertilizer levels. Rockwool substrate was used for lettuce, and coco-coir for tomatoes and cucumbers. We monitored and maintained the environmental parameters: daily light integral (DLI) ranged from 17–23 mol/m²/day for tomatoes and cucumbers and 12–18 mol/m²/day for lettuce. Tomatoes received supplemental light from 1 AM to 10 AM. Temperature and relative humidity (RH) were maintained at 18–22°C and 70–80% RH for lettuce, and 22–25°C and 60–70% RH for tomatoes and cucumbers. We monitored pH and EC weekly. Sap samples were collected at half and final stages for lettuce and four stages for tomatoes and cucumbers. Chlorophyll and anthocyanin content, yield, number of fruit, soluble solids content (SSC), and titratable acidity (TA) were recorded, while fresh/dry weight, leaf area, SSC, and TA were measured for lettuce. The tissue crushing method was used to establish sap-based sufficiency ranges for nitrogen (NO₃⁻-N), phosphorus (PO₄³⁻-P), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), and sulfur (SO₄²⁻-S). Our results provide general sufficiency recommendations (in mg/L): For greenhouse lettuce, the sufficiency ranges were NO₃⁻-N (546–1027), PO₄³⁻-P (520–616), K⁺ (6250–7052), Ca²⁺ (690–899), Mg²⁺ (280–371), and SO₄²⁻-S (93–101). For lettuce in vertical farm, NO₃⁻-N (1122–1139), PO₄³⁻-P (524–629), K⁺ (5455–5672), Ca²⁺ (426–595), Mg²⁺ (173–205), and SO₄²⁻-S (102–129). For tomatoes, NO₃⁻-N (547–805), PO₄³⁻-P (730–927), K⁺ (5360–7151), Ca²⁺ (3139–3716), Mg²⁺ (1133–1427), and SO₄²⁻-S (2796–3127). For cucumbers, NO₃⁻-N (888–1081), PO₄³⁻-P (25–38), K⁺ (4291–5478), Ca²⁺ (2147–2493), Mg²⁺ (1458–1813), and SO₄²⁻-S (1615–1946). In conclusion, sap-based sufficiency ranges were established which enable real-time nutrient monitoring and support more efficient fertigation in CEA.

Speakers

Husnain Rauf

University of Georgia

Co-authors

Cristian Toma

Kalera, Orlando

Daniel Jackson

University of Georgia

Jason Lessl

University of Georgia

Miguel Puebla

Pure flavor, Fort Valley

Rhuanito S. Ferrarezi

University of Georgia

Timothy Coolong

University of Georgia

Zilfina Rubio

University of Georgia

Friday August 1, 2025 11:30am - 11:45am CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments
Funding Source USDA
Funding Option SCRI funded all or part of the research associated with this abstract

11:30am CDT

CHMG 2 - Are Consumers Knowledgeable of Integrated Pest Management (IPM)?

Friday August 1, 2025 11:30am - 11:45am CDT

Strand 12A

Residential landscape pest management presents many challenges and pesticide management is accomplished via use of synthetic pesticide rotations. As consumer concerns related to pesticide use and the environment rise, landscapers have the opportunity to offer an integrated pest management (IPM) approach, using a combination of chemical and non-chemical control methods to reduce pesticide usage and reliance. However, consumer acceptance of and understanding of IPM is still not fully understood. We surveyed 1,000 respondents to quantify consumer knowledge of IPM. Questions were vetted using the Delphi method with nine industry and academic experts. Over 75% of respondents had some knowledge or were very knowledgeable of IPM. The more educated the respondents, the more knowledgeable they were of IPM. To capitalize on this to enhance economic outcomes for landscape service providers, future research should quantify how much consumers are willing to pay for IPM-grown plants or landscape services.

Speakers

Andrew Jeffers

Clemson University

I am a native of the mountains of eastern Tennessee. I have a B.S. in Agriculture â€“ Plant and Soil Science, and M.S. in Plant and Soil Science from the University of Tennessee. My thesis project focused on woody tree and shrub liner production. I have worked as an herbaceous... Read More →

Co-authors

Bridget Behe

Michigan State University

Michael Vassalos

Clemson University

Sarah White

Clemson University

William Bridges

Clemson University

Friday August 1, 2025 11:30am - 11:45am CDT
Strand 12A

Oral presentation, Consumer Horticulture and Master Gardeners 2

Subject Consumer Horticulture and Master Gardener
Poster # csv

11:30am CDT

PH 4 - Non-destructive assessment of sunscald at harvest improves storage outcome for Granny Smith apples

Friday August 1, 2025 11:30am - 11:45am CDT

Foster 1

Although sunlight is crucial for optimal apple production, excessive sun exposure can negatively impact appearance and alter internal quality of the fruit. Sun stress-related disorders are the primary cause of economic losses in major apple-growing regions. Granny Smith, the third most produced variety in Washington State, is notably prone to sunscald, a postharvest disorder manifested by the superficial darkening of the peel, rendering the fruit unmarketable. Lower chlorophyll and higher carotenoid concentration in Granny Smith peel is associated with increased sunlight exposure and a higher likelihood of sunscald development. In this research, the chlorophyll-to-carotenoid ratio measured non-destructively with a hyperspectral imager at harvest was used to categorize apples according to sunscald susceptibility: high, moderate, low, and very low. The quality parameters for apples in each sunscald risk category were evaluated to determine whether pre-storage sorting based on sun exposure could enhance the consistency of cold chain quality and performance. It was hypothesized that relative sun exposure has a significant influence on apple quality parameters and ripening patterns during storage. Apples were harvested from three orchards over three consecutive years and subsequently stored in air for six months before quality analyses. During the final year, additional assessments were conducted at four and five months of storage to monitor the progression of ripening and sunscald incidence. A multi-year analysis including firmness, soluble solids, titratable acidity, greenness (Iad), peel lightness (L*), and the chromatic shift from green to yellow (a/b) resulted in similar classifications among categories. However, changes in internal quality parameters attributable to relative sun exposure were evident when analyzing fruit from a single location and season. Overall, apples classified as having high and moderate sunscald risk exhibited elevated soluble solids and reduced titratable acidity compared to those in lower sunscald risk categories. Additionally, these quality parameters were more variable for fruit with high and moderate sunscald risk. The ripening pattern was similar for fruit in the low and very low categories, with a more homogeneous data distribution. The incidence of sunscald increased over time and with increased sun exposure, resulting in 11% fruit loss after 6 months of storage. Although the primary benefit of the sunscald susceptibility index is to enhance commercial viability by enabling apples in high-risk categories to be sold before sunscald symptoms render them unmarketable, sorting and grouping fruit based on relative sun exposure rendering a more homogenous storage outcome, potentially reducing economic losses for growers and packers.

Speakers

Manoella Mendoza

WA State University

Co-authors

Carolina Torres

Washington State University

David Rudell

USDA

Lee Kalcsits

WA State University

Rene Mogollon

Washington State University

Friday August 1, 2025 11:30am - 11:45am CDT
Foster 1

Oral presentation, Postharvest 4

Subject Postharvest
Funding Source This work was supported by the USDA-NIFA-OREI (grant 2021-51300-34914); The USDA-ARS Penn State Cooperative Agreement: 58‐6034‐3‐016 and by the Grant PRE2021-100809 funded by MICIU/AEI/10.13039/501100011033 and by European Social Fund Plus (ESF+). F. Di Gioia’s contribution was supported by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project no. PEN04723 and Accession no. 1020664.
Funding Option OREl or ORG funded all or part of the research associated with this abstract

11:30am CDT

POM 3 - A review of progress and obstacles on a path towards consistent production of high quality ‘Improved French’ prune crop

Friday August 1, 2025 11:30am - 11:45am CDT

Foster 2

Consistent production (CP) of quality crops supports economic sustainability of individual farms and maintains market share for a larger industry. For the last 30 years, annual prune production in California has been highly variable, ranging from < 1 to >3 dried tons per acre. ‘Improved French’ is the primary cultivar grown in California. This variety, like most plums, often requires thinning to maintain CP and grower income where fruit size (count per pound) is positively correlated to fruit quality and price to the grower. Mechanical shaking at reference date, ~45 days after full bloom, is now a common thinning practice although questions have been raised regarding the potential benefit to earlier thinning a phantom practice that would have to be chemical thinning. However, in the last two decades, extreme bloom weather can virtually eliminate a prune crop if warm weather precedes bloom. This talk reviews work by University of California researchers towards improving CP through 1) better understanding of the weather related factors contributing to very low fruit set in prunes, 2) testing ‘Improved French’ prune fruit growth development to determine if and when source limited fruit growth occurs, and 3) identifying chemical thinning practices, materials, and rates to remove flowers before fruit set. Early bloom years are those with risk of crop loss due to extended and wet or extremely warm (>27oC) bloom weather conditions. [The risk of freezing damage is relatively low for prunes in CA given usual March bloom timing.] Relative prune fruit growth rate studies revealed resource limited fruit growth occurs ahead of current thinning timings (reference date), so earlier thinning may improve fruit growth and possibly yield compared to the current thinning practice. Finally, potassium thiosulfate (KTS) applied 2x at 1-2% (v/v) shows promise in thinning prunes. Lime sulfur and fish oil can be effective but is inconsistent in bloom thinning. Obstacles to CP of ‘Improved French’ prune include difficulty identifying practices to quantify bloom strength and help grower with the decision to thin or not. In addition, no ‘rescue’ spray has been found to improve fruit set in years with early, risky, bloom. Grower testing of the current research results awaits successful overcoming of the two obstacles listed above.

Speakers

Franz Niederholzer

University of California Cooperative Extension

Co-authors

Katherine Jarvis-Shean

UC ANR

Luke Milliron

University of California Agriculture Natural Resources

N. Jamie Ott

UC ANR

Richard Rosecrance

California State University, Chico

Sara Castro

UC Davis

Ted DeJong

UC Davis

Friday August 1, 2025 11:30am - 11:45am CDT
Foster 2

Oral presentation, Pomology 3

Subject Pomology
Poster # csv
Funding Source California Prune Board

11:30am CDT

VCM 6 - Quantifying Yield Attributes of Spring Sweet Corn Varieties (Bicolor, White, and Yellow) in the Southeastern USA

Friday August 1, 2025 11:30am - 11:45am CDT

Strand 11A

A comprehensive, two-year field evaluation of bicolor, white, and yellow sweet corn (Zea mays var. saccharata) varieties was conducted in southern Georgia during the spring seasons of 2022 and 2024. This research aimed to evaluate the yield and quality performance of commercial supersweet sweet corn varieties for the main kernel color market segments. The experiment was conducted at the Hort Hill Research Farm on the University of Georgia Tifton Campus. A total of ten bicolor, five white, and five yellow sweet corn varieties were used in this study. Significant interactions were observed between years and varieties, impacting ear characteristics and marketability. Overall, 2022 exhibited significantly higher ear and shank lengths, while 2024 had increased blank tip lengths and higher unmarketable ear counts. Among the bicolor varieties, ‘Redemption’ demonstrated exceptional performance with the highest ear length and width measurements, shank length, and the lowest blank tip measurements. ‘Grizzly’ had the lowest ear width, shank length, and highest blank tip measurements, while ‘American Dream’ recorded the shortest ear length. ‘Obsession’ and ‘Seminole Sweet’ had the highest marketable yield and 48-ear boxes per acre, reflecting their superior yield performance, whereas ‘Grizzly’ exhibited the lowest performance parameters, including the lowest marketable yield, total ear counts, and 48-ear boxes per acre. Additionally, ‘Superb’, ‘American Dream’, and ‘Courage’ recorded higher unmarketable ear counts per plot, which ultimately resulted in a significantly lower percentage of marketable ears. For the white varieties, there were no significant differences in ear characteristics and yield parameters. However, the yellow varieties displayed statistically significant differences in ear width and shank length. ‘GSS1170’ excelled, with the highest ear width and shank length, making it an excellent option for yellow corn production. Varieties ‘SC1336,’ ‘Astronaut,’ and ‘Passion’ had significantly higher unmarketable ear counts, with total ear counts also varying significantly among varieties, indicating differences in both productivity and marketability. Based on these research findings, the recommended varieties for optimal performance in ear characteristics and marketability are ‘Obsession’, ‘Seminole Sweet’, and ‘Redemption’ for bicolor corn and ‘GSS1170’ for yellow corn. These varieties exhibited excellent yield performance, making them ideal choices for growers seeking to increase yield. Conversely, since white corn varieties did not exhibit significant differences for any ear characteristics or marketability parameters, no specific recommendations can be made for this category.

Speakers

Manisha Kumari

Post-Doctoral Research Associate AD, The University of Georgia

Manisha Kumari is a post-doctoral research associate AD at Horticulture department, University of Georgia, Tifton campus, Tifton 31793, GA, USA.

Co-authors

Ted McAvoy

University of Georgia

Friday August 1, 2025 11:30am - 11:45am CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management

11:45am CDT

CE 7 - Comparison of In-situ Sensors and Pour-through Method of Monitoring Substrate Fertility

Friday August 1, 2025 11:45am - 12:00pm CDT

Strand 11B

The Pour-through method is a recommended best management practice (BMP) for nurseries in Florida for managing nutrient levels in container-grown crops. An investigation into fertility management in container nurseries was conducted by comparing traditional methods of monitoring EC with more recently developed sensor-based technologies. A field experiment was conducted to establish a relationship between sensor-based EC measurements and the pour-through method under two different irrigation methods (sprinkler and drip irrigation) and fertilizer rates (low and high) under open field and high tunnel environments. A sensor system was designed for field deployment, and wireless communication was established to monitor sensor data remotely. Results showed that a correlation could be established under sprinkler irrigation, but no correlation could be established under drip irrigation. Salt stratification was shown to vary significantly with irrigation type, with results suggesting that sensor installation in the center of the container is an optimal choice for monitoring EC of the root zone under multiple irrigation methods. Finally, variation in the data was modeled to determine the minimum number of sensors needed to maintain the same precision as the pour-through method. It was estimated that four sensors per 1000 pots are necessary. However, more sensors may be required to maintain this precision at higher EC levels.

Speakers

Ying Zhang

Assistant Professor, University of Florida

Co-authors

Ana Martin Ryals

University of Florida

Kaiwen Xiao

University of Florida

Michelle Ezequelle

University of Florida

Paul Fisher

University of Florida

Friday August 1, 2025 11:45am - 12:00pm CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments
Funding Source Florida Department of Agriculture and Consumer Services, Office of Agricultural Water Policy

11:45am CDT

VCM 6 - Agrivoltaics: How Solar Panels Affect Bell Pepper 'SVPB8415' Production

Friday August 1, 2025 11:45am - 12:00pm CDT

Strand 11A

Agrivoltaics is a production system that allows for dual land use through the deployment of solar panels for energy production while maintaining agricultural production underneath and/or between solar panels. This study was conducted at the Alliant Solar farm at Iowa State University, Ames, IA. Treatments included bell pepper (Capsicum annuum ‘SVPB8415’) grown between and outside (open-field) the solar panels. For the solar panel treatment, two raised beds with white plastic mulch were created on each side of the single-axis solar tracking panels. Each bed was 19.5m long. Two beds on each side were spaced 1.5m (center to center). Two rows of open-field peppers served as the control treatment. Control beds were 6.7m long. All treatments were replicated three times. Peppers were transplanted on June 6, 2024 at 0.3m spacing, double row. HOBO soil temperature, air temperature, and light intensity sensors were installed on the same day. No pesticides were needed to manage pests. A total of 6 harvests occurred throughout the season on a weekly basis between September 6 and October 14. Plants between the solar panels yielded 52.1 kg per row while the open-field yielded 27.0 kg, a 48% increase in the solar treatment. From June to September, the air temperature was cooler than the control on average by 4 degrees Fahrenheit while the soil temperature was 3 degrees Fahrenheit cooler. Based on first year results, bell peppers show promise within an agrivoltaics production system. More data will be collected in the coming years on plant growth characteristics, soil moisture, and postharvest quality of peppers.

Speakers

Raymond Wilmes

Iowa State University

Co-authors

Ajay Nair

Iowa State University

Friday August 1, 2025 11:45am - 12:00pm CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management
Funding Source United States Department of Energy

11:59am CDT

QUAL - Oral Session

Friday August 1, 2025 11:59am - 12:00pm CDT

Foster 2

Presiding/Moderator

Daniel Leiva

Research Assistant, Louisiana State University

Friday August 1, 2025 11:59am - 12:00pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties

12:00pm CDT

CE 7 - A Cost-Effective 3D-Printed Sensor Network for Water Monitoring in Controlled Environments and Space

Friday August 1, 2025 12:00pm - 12:15pm CDT

Strand 11B

Timely detection of aqueous analytes is essential for informed decision-making in agriculture, particularly in controlled environments such as greenhouses, vertical farms, and space-based cultivation systems. Traditional aqueous sensing technologies typically depend on single-point measurements, capturing data at fixed times and locations. This constraint limits their ability to detect analytes that may emerge elsewhere in the system or at different intervals. In response, we present an innovative, low-cost sensor platform featuring a 3D-printed housing integrated with a mass-manufactured, nanotextured diffraction surface. This housing includes a lighting element and a camera sensor to enable continuous image-based analysis of water quality. Designed for seamless integration into hydroponic lines, the sensor units are both affordable and easily reproducible, allowing for deployment at multiple points within a system to provide real-time monitoring. Our results demonstrate the sensor’s capability to detect and quantify a range of aqueous analytes—including visible and UV-absorbing compounds, dust particles, and various microalgae species. Our sensor performs similarly to a commercial UV-Vis instrument, often used to measure contaminants present in water. Specifically, calibration curves derived from increased concentrations of a simulated contaminant had a calculated R2 value of 0.998 from the UV-Vis instrument and 0.996 from our device. Performance is further enhanced through machine learning algorithms that improve detection and classification. This scalable and cost-effective sensing system offers a practical solution for real-time water quality assessment across controlled environment agriculture, greenhouse systems, and extraterrestrial farming applications—particularly in contexts where labor is limited and rapid response is critical.

Speakers

Ankit Singh

University of Maine

www.aksapsjb.weebly.com

Friday August 1, 2025 12:00pm - 12:15pm CDT
Strand 11B

Oral presentation, Growth Chambers and Controlled Environments 7

Subject Growth Chambers and Controlled Environments
Poster # csv

12:00pm CDT

QUAL - First Season Crop Yield, Soil Chemical Properties, and Heavy Metal Accumulation Responses to Soil Amendments in Organically Grown Sweetpotato

Friday August 1, 2025 12:00pm - 12:15pm CDT

Foster 2

An on-farm field trial was conducted to investigate the feasibility of applying commonly used soil amendments to reduce the accumulation of arsenic (As), cadmium (Cd), and lead (Pb) in sweetpotato (Ipomoea batatas L.) storage roots. The cultivar ‘Beauregard’ was grown in an organically managed field with natural As, Cd, and Pb levels. The following soil amendments were applied: agricultural lime (AGL) (1 t·ac−1), gypsum (GYP) (1 t·ac−1), biochar (BIO) (1 t·ac−1), and silicon provided as wollastonite (WOL) (2.5 t·ac−1). Agricultural lime and WOL increased soil pH and calcium levels, ranging from 14% to 25% and 16% to 90%, respectively. Soil amendments were not associated with storage root yield variation. Wollastonite and BIO were associated with a trend for reduced As, Cd, and Pb in storage roots. These first-season study results suggest that WOL and BIO are potentially useful for follow-up studies to reduce the bioavailability and subsequent uptake of As, Cd, and Pb accumulation in sweetpotato under organic production systems.

Speakers

Mae Ann Bravo

Graduate Student Assistant, Louisiana State University

Co-authors

Arthur Villordon

LSU Agcenter

Brenda Tubana

Louisiana State University

Don La Bonte

Louisiana State Univ

Lorin Harvey

Mississippi State University

Friday August 1, 2025 12:00pm - 12:15pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties
Poster # csv
Funding Source Gerber Products Company

12:00pm CDT

VCM 6 - Assessing the Efficacy of Green Manure and Mycorrhizae in Reducing Salt Stress on Tomatoes Grown in Miami Dade County, Florida

Friday August 1, 2025 12:00pm - 12:15pm CDT

Strand 11A

Climate change presents a serious challenge for the future of agricultural production, with communities around the world undergoing agroecological disaster as a result of rapidly developing climatic conditions. Among the most pressing concerns for coastal production is sea level rise and salt intrusion into agricultural soils. Such is the case with Florida, which is regarded as a developing “ground zero” of the climate crisis. Along with California, Florida is the largest tomato producer in the country but is greatly at risk from sea level rise and saltwater intrusion, and tomato crop suffers considerably under salt stress. However, regenerative agriculture (RA) techniques present an opportunity for reducing the effects of saltwater intrusion, as they can enhance crop resistance to stresses and facilitate Na leaching out of soil biomes and improve crop yields. This research project aims to test two RA techniques (green manure and mycorrhizal inoculation) as ameliorating agents of salt stress in tomato (Solanum lycopersicum cv. “Sanibel”). In greenhouse controlled conditions, two treatments of pigeon pea green manure was applied to soil prior to the planting of tomatoes (0g mulch [control] and 60g) and tomatoes were subject to two mycorrhizae inoculation conditions (no inoculation [control] and inoculation with the salt-resistant species Glomus intraradices). Tomato plants were then subjected to four irrigation water salinities (0, 4, 8, and 12 dS m-1). Saline treatments were prepared using Instant Ocean® Sea Salt and distilled water. Tomato plant chlorophyll content and fruit texture quality parameters were analyzed in order to determine the salt-stress ameliorating efficacy of these regenerative techniques.

Speakers

Luis Cendan

Florida International University

Co-authors

Amir Khoddamzadeh

Florida International University

Imran Ahmad

Florida International University

Madhugiri Nageswara-Rao

United States Department of Agriculture - Agricultural Research Service, Subtropical Horticulture Research Station

Friday August 1, 2025 12:00pm - 12:15pm CDT
Strand 11A

Oral presentation, Vegetable Crops Management 6

Subject Vegetable Crops Management
Poster # csv

12:15pm CDT

QUAL - Pathogen Species Causing Brown Rot of Peaches in Illinois and Efficacy of Fungicides for Managing the Disease

Friday August 1, 2025 12:15pm - 12:30pm CDT

Foster 2

Pathogen Species Causing Brown Rot of Peaches in Illinois and Efficacy of Fungicides for Managing the Disease Harrison Seitz1, Andrew N. Miller2, and Mohammad Babadoost1 1Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA; and 2Illinois Natural History Survey, University of Illinois, Champaign, IL 61820, USA Brown rot is one of the important diseases of peaches in Illinois. This study was conducted to: (i) identify pathogen species causing brown rot disease in commercial peach orchards in Illinois, and (ii) evaluate the efficacy of fungicides for managing the disease. Results of orchard surveys showed 9 of 14, 4 of 8, and 6 of 13 orchards had symptomatic brown rot fruits in 2020, 2021, and 2022, respectively. No blossom blight or shoot blight was observed. Symptomatic fruits were collected from eight peach cultivars throughout the state and the associated fungi were isolated. Based on the cultural characteristics and sequences of the ITS region, 127 of 129 collected isolates were identified as Monilinia fructicola, and two isolates as M. laxa. Fungicide sensitivity of M. fructicola isolates was conducted in the laboratory against azoxystrobin, captan, fenhexamid, trifloxystrobin, penthiopyrad, difenoconazole cyprodinil, fluopyram tebuconazole, fluopyram trifloxystrobin, fluxapyroxad pyraclostrobin, propiconazole, and thiophanate-methyl. The EC50 of azoxystrobin, captan, and penthiopyrad for the colony development of the isolates were significantly (P = 0.05) higher than the other fungicides tested. Field trials were conducted on ‘Redhaven’ and ‘Contender’ peaches for two years to evaluate efficacy of the commercial product of the above-mentioned fungicides. Trees were sprayed with fungicides at 10- and 14-day intervals. Luna Experience 3.34SC (fluopyram tebuconazole), Luna Sensation 4.20SC (fluopyram trifloxystrobin), and Merivon 4.18SC (fluxapyroxad pyraclostrobin) were the most effective fungicides for managing brown rot and other summer diseases of peach.

Speakers

Mohammad Babadoost

University of Illinois

Co-authors

Andrew Miller

University of Illinois

Harrison Seitz

University of Illinois

Friday August 1, 2025 12:15pm - 12:30pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties
Poster # csv

12:29pm CDT

GG 4 - Oral Session

Friday August 1, 2025 12:29pm - 12:30pm CDT

Strand 12B

Presiding/Moderator

Samaneh Tajik

the ohio state university

Friday August 1, 2025 12:29pm - 12:30pm CDT
Strand 12B

Oral presentation, Genetics and Germplasm 4

Subject Genetics and Germplasm

12:30pm CDT

GG 4 - Preliminary Study of Growth Dynamics and Yield Assessment of Five Jerusalem artichoke Varieties in Wooster Ohio

Friday August 1, 2025 12:30pm - 12:45pm CDT

Strand 12B

Jerusalem artichoke (Helianthus tuberosus L.) (sunchoke) presents a resilient and low-input crop alternative with potential for both biomass and tuber production. However, a comprehensive understanding of varietal performance in specific environments like Ohio is essential to unlock its full agricultural potential. This study evaluated the growth and yield performance of five Sunchoke varieties (Beaver Valley, Dwarf Sunray, Jack's Copperclad, Supernova, and White Fuseau) in Ohio, during the 2024 growing season. Plant height, tuber number, root system weight, and morphological characteristics were assessed. Variations were observed among the varieties in terms of growth and yield. "Dwarf Sunray" exhibited the highest growth rate, while "Jack's Copperclad" had the lowest. "White Fuseau" yielded the highest tuber count and weight, approximately nine times more than "Jack's Copperclad". Tuber production was positively correlated with root system weight. Varieties also differed in branching patterns, flowering time, tuber shape, and tuber color. This study provides preliminary data for selecting varieties suitable for further research and evaluation in Ohio. The study emphasizes the importance of considering root system development for improved tuber yield and suggests future research should focus on the genetic basis of trait variations and varietal performance under diverse conditions.

Speakers

Samaneh Tajik

the ohio state university

Co-authors

Florence Sessoms

The Ohio State University

Friday August 1, 2025 12:30pm - 12:45pm CDT
Strand 12B

Oral presentation, Genetics and Germplasm 4

Subject Genetics and Germplasm
Poster # csv

12:30pm CDT

QUAL - Harnessing Plasma-Activated Water: Impact of Processing and Storage Time on Pea Microgreen Productivity and Nutritional Quality

Friday August 1, 2025 12:30pm - 12:45pm CDT

Foster 2

Plasma-activated water (PAW) is a novel irrigation medium enriched with reactive oxygen and nitrogen species (RONS) which significantly modify the physiochemical properties of water, yet their inherent instability is influenced by processing parameters such as plasma exposure time and storage conditions. Although studies have demonstrated PAW’s promising effects on seed germination and plant growth, knowledge regarding its application to enhance microgreen production is limited. Therefore, the objective of this study was to elucidate the effects of PAW processing time and storage duration on the PAW chemical properties and on the yield and quality of pea (Pisum sativum L.) microgreens. Tap water was treated using a gliding arc plasma generator (200 mA, 2.6–2.7 kV) provided by Plasma Licensing Authority Inc. (New York, NY) for 30, 60, 90, and 120 minutes. Controls included untreated tap water and tap water supplemented with 100 ppm NH₄NO₃. PAW properties- pH, EC, NO₃-N, NO₂-N, and H₂O₂- were analyzed immediately after treatment and at 5, 24, 48, 72, and 96-hours post-treatment. PAW was applied to pea microgreens in two experimental sets: (1) within 12-hour post-generation and (2) after 72-hour of storage at ambient temperature. PAW initially exhibited lowered pH in all treatments; but after 96 hours in the first experiment, pH of the 30-minute treatment increased to 7.68±0.01 compared to tap water (7.62±0.01), while in the second experiment, all treatments remained lower. NO3-N increased with processing time and storage duration compared to tap water. Fresh weight of microgreens receiving immediately generated PAW exceeded that of tap water (979.48±26.88 g/m²) except for the 120-minute treatment (864.48±66.08 g/m²). After 72 hours of storage, all PAW treatments improved fresh weight compared to tap water, with 60-min and 90-min treatments exceeding NH₄NO₃ by 4.06% and 6.11%, respectively. Shoot length decreased slightly with 120-min PAW (-1.06%) compared to tap water in the first experiment but increased across all treatments in the second. Storing 120-min PAW for 72 hours raised total N pea shoot content (7.66±0.079%) compared to tap water (7.48±0.136%), while Ca levels increased in all PAW treatments relative to tap water and NH₄NO₃. These findings suggest that PAW processing and storage time influence reactive species and nitrogen levels, impacting microgreen yield and quality. Overall, these results highlight the potential dual function of PAW in the sustainable production of microgreens: i) as sanitizer and/or as eustressor immediately post-generation and ii) as a synthetic nitrogen fertilizer replacement after storage.

Speakers

Sanchita Saha

The Pennsylvania State University

Co-authors

Francesco Di Gioia

Pennsylvania State University

Friday August 1, 2025 12:30pm - 12:45pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties
Poster # csv
Funding Source The research was funded by the Pennsylvania Department of Agriculture Specialty Crop Block Grants No. C940001529 “Developing Plasma Agriculture Solutions to Improve Vegetable Yield and Quality” and was supported by Plasma Licensing Authority Inc. that provided us with the plasma generator, and by the Strategic Networks and Initiatives Program (SNIP) “Developing the Penn State Interdisciplinary Initiative on Plasma Agriculture”, funded by the Penn State College of Agricultural Sciences. FD's contribution was funded by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project #PEN05002, Accession #7007517.

12:45pm CDT

GG 4 - Genomic Characterization of ‘Munson’ Grape Cultivars

Friday August 1, 2025 12:45pm - 1:00pm CDT

Strand 12B

With an economic value exceeding $68 billion USD, grapes are third in global horticultural crop production, with production across 93 countries. Recurring incidents of extreme weather conditions are forcing growers to alter conventional production practices. Reduced production areas, shifts in pest management, decreased water availability, increased temperature stress, and extreme weather events have all negatively impacted global grape production. There is a need to develop resilient grape cultivars that can survive the vagaries of nature. In the late 1800s, American horticulture scientist Thomas Volney Munson utilized 10 of the 13 Vitis spp. native to Texas and SW USA to develop cultivars that were adapted to the North American environment and resistant to the pests and pathogens of this area. Munson introduced 300 cultivars, of which 87 remain today. These cultivars have the potential to offer improved fruit quality combined with pest and pathogen resistance, traits that are sought after in modern grape breeding programs. Due to the wide range of parental material used to improve these native grapes, Munson’s cultivars offer a largely untapped genetic resource. By performing whole genome sequencing on the remaining 87 cultivars and the parental lines, we aim to develop a pangenome encompassing the full range of genetic diversity within the remaining Munson cultivars. This study will help clarify the lineage and shed light on any discrepancies in the records. The genomic characterization of the Munson cultivars will also aid in identifying potential resistance genes in these cultivars. This work is expected to secure profitable and resilient production of grapes in the US.

Speakers

Amit Dhingra

Head of the Department of Horticultural Sciences, Texas A&M University

Dr. Amit Dhingra is the Head of the Department of Horticultural Sciences, Professor of Genomics and Biotechnology, and Senior Scientist at the Norman Borlaug Institute for International Agriculture at Texas A&M University. After his post-doctoral training at Rutgers University, the... Read More →

Co-authors

Jacob Muras

Texas A

Justin Scheiner

Texas A

Friday August 1, 2025 12:45pm - 1:00pm CDT
Strand 12B

Oral presentation, Genetics and Germplasm 4

Subject Genetics and Germplasm
Funding Source Texas A&M University and Texas A&M AgriLife Startup Funding to the Dhingra Genomics and Biotechnology Lab

12:45pm CDT

QUAL - Postbiotic Biopolymers as Natural Antimicrobial Emulsifiers for Post-Harvest Preservation and Food Safety

Friday August 1, 2025 12:45pm - 1:00pm CDT

Foster 2

Ensuring food safety and extending shelf life remain key challenges in post-harvest management of fresh produce. This study investigates the potential of postbiotic biopolymers, specifically Lactobacillus-derived exopolysaccharide (EPS), as a natural and sustainable emulsifier for stabilizing the bioactive antimicrobial volatiles limonene, and eugenol in oil-in-water nanoemulsions. The developed EPS-based nanoemulsion exhibited strong antimicrobial activity against Escherichia coli, Listeria monocytogenes, and Salmonella Poona, achieving >3.0 log reductions on fresh lettuce through immersion and spray applications, while preserving sensory attributes such as texture, color, and taste. Additionally, the nanoemulsion demonstrated a bacteriostatic effect, achieving up to a 3.17 log CFU/cm² biofilm reduction on stainless steel and plastic surfaces (p < 0.05), and a 3-log reduction of Salmonella and E. coli on tomato and blueberry fruit surfaces, along with a 4-log reduction of L. monocytogenes on the soft cheese queso fresco. Stability assessments confirmed that the emulsions remained highly effective across diverse environmental conditions, including temperatures of −20 to 70°C, pH 2–9, and salinity levels from 1%–30%, making them well-suited for real-world agricultural and food processing applications. The synergistic action of EPS and bioactive volatiles not only prolonged shelf life and reduced microbial colonization but also provided a non-toxic, biodegradable alternative to synthetic preservatives, addressing sustainability concerns in food safety and post-harvest preservation. These findings highlight EPS-based nanoemulsions as a promising alternative for enhancing food safety, reducing microbial risks, and supporting sustainable post-harvest practices across fresh produce, dairy, and food-contact surfaces. This work was supported by USDA-NIFA-2024-51181-43464 through the Vegetable and Fruit Improvement Center of Texas A

Speakers

SANGEETA BALYAN

Graduate Student, Texas A & M

Co-authors

Bhimanagouda S Patil

Texas A

Deepak Kumar Jha

Texas A

Vikas Dadwal

Texas A

Friday August 1, 2025 12:45pm - 1:00pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties
Poster # csv
Funding Source This work was supported by USDA-NIFA-2024-51181-43464 through the Vegetable and Fruit Improvement Center of Texas A&M University and partially funded by the Texas A&M Institute for Advancing Health through Agriculture

1:00pm CDT

GG 4 - Comparative Phenotypic Profiling of Cold Hardiness in Two Bi-parental Grape Populations: Vitis riparia × Vitis vinifera ‘Fresno Seedless’ and Vitis amurensis × Vitis vinifera ‘Valley Pearl’

Friday August 1, 2025 1:00pm - 1:15pm CDT

Strand 12B

Freezing injuries account for an estimated 15 % of global grape production losses annually, posing a significant challenge to sustainable viticulture. This study investigated phenotypic variation correlated with cold hardiness in two biparental mapping populations to explore potential markers for selecting cold‐hardy genotypes. Quantitative trait locus (QTL) mapping was also performed to identify loci that could accelerate the development of environmentally resilient grape cultivars. We examined two F₁ families—312 hybrids from V. riparia × V. vinifera ‘Fresno Seedless’ and 302 hybrids from V. amurensis × V. vinifera ‘Valley Pearl’. Differential thermal analysis (DTA) was used to assess bud cold tolerance, and we recorded additional traits including bud water content, trunk and cane diameters, and post–bud‐break phenology. Significant variation was observed in cold hardiness and all measured phenotypes. High‐quality genetic linkage maps were generated for both populations, providing a solid foundation for subsequent QTL analysis and marker development. This research offers a sustainable strategy for breeding cold‐hardy grape cultivars that maintain productivity under harsh conditions and speeds breeding efforts in support of climate‐adaptive viticulture.

Speakers

Hava Delavar

North Dakota State University

Co-authors

Harlene HattermanValenti

NDSU

Friday August 1, 2025 1:00pm - 1:15pm CDT
Strand 12B

Oral presentation, Genetics and Germplasm 4

Subject Genetics and Germplasm
Funding Source Vitisgen3

1:00pm CDT

QUAL - Assessing the Impact of Biological Soil Amendments of Animal Origin on Radish Microbial Safety, Soil Properties, and Quality

Friday August 1, 2025 1:00pm - 1:15pm CDT

Foster 2

The need to shift toward sustainable food production systems has forced farmers to explore alternative practices, such as the use of biological soil amendments of animal origin (BSAAOs), to fulfill consumer-driven requirements. However, concerns due to food safety regulations restrict the use of BSAAOs on crops consumed raw. The present study evaluated the effects of untreated BSAAOs, raw poultry litter (PL), cow manure (CM), and no BSAAO on soil fertility, microbial contamination indicators, and marketable yields in radish (Raphanus sativus) production over two growing seasons at the LSU AgCenter Burden Botanical Gardens. In the agronomic assessment, radish marketable yields were significantly enhanced by PL application, with an average yield of 8.13 lb. per 3.66 m² plot compared to 4.24 lb. in CM-treated plots and 4.62 lb. in no BSAAO amended plots. Moreover, the method of manure application further influenced radish yields, with tilled PL (PLT) plots yielding 9.45 lb. per plot versus 6.81 lb. in non-till (PLNT) plots. Poultry litter application sustained higher levels of nitrogen through the production cycle as well, during Year 1 only, in comparison to CM and no BSAAO application. The evaluation of the safety of raw manure application focused on indicator organisms. In Year 1, soil samples from PL-treated plots exhibited significantly higher Escherichia coli (E. coli) levels (1.81 and 1.75 log CFU/g, respectively, for tilled and not tilled plots) relative to no BSAAO and CM-amended plots (≤1 to 1.01 log CFU/g), while harvested radish samples from PL-amended plots registered 0.8 log CFU/radish compared to non-detectable levels (≤0.75 log CFU/radish) for CM and no BSAAO-amended plots. In Year 2, soil samples from cow manure tilled (CMT) plots had much higher E. coli counts at first (3.23 log CFU/g in Week 1), but these dropped to 1.17 log CFU/g by Week 3, while other treatments kept their counts steady around or below 1 log CFU/g. Results obtained in the present study demonstrate that raw poultry litter substantially improved radish yields by supplying richer nutrient inputs; it also elevated soil and produces microbial contamination indicator levels relative to cow manure and conventional chemical fertilizer. Although radish surface contamination by E. coli remained low, the observed trends highlight the necessity for optimized manure application practices, particularly regarding incorporation methods and waiting periods, to mitigate potential food safety risks and prevent foodborne illness outbreaks.

Speakers

Daniel Leiva

Research Assistant, Louisiana State University

Co-authors

Achyut Adhikari

Louisiana State University AgCenter

Kathryn Fontenot

LSU AgCenter

Lisa Fultz

United Stated Department of Agriculture

Friday August 1, 2025 1:00pm - 1:15pm CDT
Foster 2

Oral presentation, Produce Quality Safety and Health Properties

Subject Produce Quality Safety and Health Properties
Poster # csv
Funding Source United States Department of Agriculture Specialty Crop Block Grant

1:14pm CDT

NUR - Oral Session

Friday August 1, 2025 1:14pm - 1:15pm CDT

Foster 1

Presiding/Moderator

Eric Stallknecht

Virginia Tech

Friday August 1, 2025 1:14pm - 1:15pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops

1:15pm CDT

NUR - Optimizing Daily Light Integral for Adventitious Rooting of Ornamental Woody Nursery Crops

Friday August 1, 2025 1:15pm - 1:30pm CDT

Foster 1

The primary form of propagation of ornamental woody nursery liners (young plants) is through stem cuttings to maintain genotypic and phenotypic uniformity. However, high rates of rooting failure in propagation remain a significant challenge, leading to economic loss. Greenhouses offer opportunities to leverage the environment for specific plant growth responses. Manipulation of the daily light integral (DLI) has been used extensively to hasten adventitious rooting and increase propagule quality in annual bedding plants, herbaceous perennials, and culinary herbs. Thus, there is a critical need to also identify the optimal DLI to improve and maximize adventitious rooting in woody taxa. Therefore, this study aimed to quantify the impact of DLI on root growth and development of ornamental woody nursery cuttings. Unrooted stem cuttings of four ornamental nursery taxa were obtained from commercial nurseries and individually inserted into 6.4-cm diameter containers filled with a propagation substrate. Cuttings were placed in a diffused glass-glazed greenhouse under a propagation environment with 20 °C air temperature, 80% relative humidity, and ambient daylight supplemented with ≈120 µmol·m–2·s–1 delivered from light-emitting diode arrays from 0600 to 2200 hr. Cuttings were rooted under fixed 4-mil clear construction film covered with one of four different fixed-woven shade cloths providing ≈72%, 52%, or 30% diffuse shading or no shade (0%). After 14, 28, and 42 d, data was collected including callusing and rooting percentage, root number, longest root length, stem length and caliper, leaf area, and shoot and root dry mass. The results of this study determined the optimal DLI, across an array of important woody taxa, to hasten adventitious rooting and improve liner quality.

Speakers

Olivia Liebing

The Ohio State University

Co-authors

Garrett Owen

The Ohio State University

Friday August 1, 2025 1:15pm - 1:30pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source The Ohio State University College of Food, Agricultural, and Environmental Sciences - New Investigators Grant; USDA Agricultural Research Service - Floriculture & Nursery Research Initiative 5082-21000-001105S

1:30pm CDT

NUR - Quantifying the Effects of Root-Zone Temperature to Improve Rooting of Ornamental Woody Nursery Cuttings

Friday August 1, 2025 1:30pm - 1:45pm CDT

Foster 1

Ornamental woody nursery plants are primarily propagated from stem cuttings to maintain genotypic and phenotypic uniformity. However, high rates of rooting failure in propagation remain a significant challenge, leading to economic loss. Greenhouses offer technologies to precisely control the environment. Thus, there is a critical need to identify cost-effective strategies, such as providing root-zone heating, to improve and maximize adventitious rooting. Root-zone heating has been used extensively to hasten adventitious rooting and increase root density in various plant species. However, optimal root-zone temperatures are largely unknown for many woody nursery crops. Therefore, this study aimed to quantify the impact of root-zone temperature on root growth and development of ornamental nursery cuttings. Unrooted stem cuttings of four ornamental nursery taxa were obtained from commercial nurseries. Cuttings of each taxon were individually inserted into 6.4-cm diameter containers filled with a propagation substrate. Cuttings were placed in a glass-glazed greenhouse under a propagation environment with 20 °C air temperature, 80% relative humidity, and ambient daylight supplemented with ≈120 µmol·m–2·s–1 delivered from light-emitting diode arrays from 0600 to 2200 hr. A closed-loop root-zone heating system circulated hot water (49 °C) across greenhouse bench-tops. Forty-eight cuttings of each taxon were placed in root-zone heating environments with set points of 21, 24, 27, 30, and 33°C. After 14, 28, and 42 d, data was collected including callusing and rooting percentage, root number, longest root length, stem length and caliper, leaf area, and shoot and root dry mass. The results of this study determined the extent root-zone temperature can be leveraged to hasten adventitious rooting and improve liner quality.

Speakers

Olivia Liebing

The Ohio State University

Co-authors

Garrett Owen

The Ohio State University

Friday August 1, 2025 1:30pm - 1:45pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source The Ohio State University College of Food, Agricultural, and Environmental Sciences - New Investigators Grant; USDA Agricultural Research Service - Floriculture & Nursery Research Initiative 5082-21000-001105S

1:44pm CDT

CE 8 - Oral Session

Friday August 1, 2025 1:44pm - 1:45pm CDT

Strand 10

Presiding/Moderator

Jacob Schwab

University of Maine

Friday August 1, 2025 1:44pm - 1:45pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments

1:44pm CDT

CITR 4 - Oral Session

Friday August 1, 2025 1:44pm - 1:45pm CDT

Strand 11A

Presiding/Moderator

Fernando Alferez

UF-IFAS

Friday August 1, 2025 1:44pm - 1:45pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops

1:44pm CDT

PNM 4 - Oral Session

Friday August 1, 2025 1:44pm - 1:45pm CDT

Strand 11B

Presiding/Moderator

Adekunle Adeyeye

Kentucky State University, Frankfort, KY

Friday August 1, 2025 1:44pm - 1:45pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management

1:44pm CDT

POM 4 - Oral Session

Friday August 1, 2025 1:44pm - 1:45pm CDT

Foster 2

Presiding/Moderator

Brent Black

Utah State University

Friday August 1, 2025 1:44pm - 1:45pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology

1:44pm CDT

VGBR 3 - Oral Session

Friday August 1, 2025 1:44pm - 1:45pm CDT

Strand 12B

Presiding/Moderator

Byron Manzanero

Horticultural Sciences Department, University of Florida

My name is Byron Manzanero a Ph.D. Candidate in plant breeding.

Friday August 1, 2025 1:44pm - 1:45pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding

1:45pm CDT

CE 8 - Effect of Light Quality and Intensity on Monoterpene Indole Alkaloid Accumulation in Catharanthus roseus Grown in a Vertical Farm

Friday August 1, 2025 1:45pm - 2:00pm CDT

Strand 10

Vertical farms and the controlled environmental conditions they provide can produce high-quality food crops, but these facilities have high construction and operation costs. Therefore, characterizing the growth of high-value crops using these systems is important for the sustainability of vertical farming operations. Catharanthus roseus is a strong candidate for production in vertical farms due to its compact growth habit, quick production timeline, and a secondary metabolite profile with diverse therapeutic potential making it a high-value crop. Two medicinally important secondary metabolites derived from C. roseus are the monoterpene indole alkaloids (MIAs) vincristine and vinblastine which are used as anti-tumor chemotherapy drugs. Extracting these metabolites from field-grown C. roseus is challenging due to low plant yields. Cultivating C. roseus in vertical farms has the potential to increase the yield of these and other desirable plant metabolites by using environmental controls to stimulate relevant metabolite growth pathways. Evidence suggests that these pathways may be influenced by light exposure, but there is limited knowledge concerning the production of C. roseus in vertical farms for alkaloid production. The objective of this study was to identify the effect of light quality and intensity on the growth and alkaloid accumulation of C. roseus grown hydroponically in a vertical farm. We tested two light spectrums (white and white red) with three light intensities (~200, 360 and 500 µmol m-2 s-1) arranged in a factorial randomized complete block design with four replications. High-light treatments expectedly increased plant biomass, while low-light treatments unexpectedly increased vinblastine accumulation. These results demonstrate the feasibility of modifying alkaloid production in C. roseus grown with vertical farm systems, but additional work is needed to identify and optimize environmental conditions for maximizing alkaloid production. This work will inform pharmaceutical studies and other downstream uses of these compounds.

Speakers

Matthew Housley

Research Paraprofessional, Graduate Student, University of Georgia

Co-authors

Anish Malladi

University of Georgia

Daniel Jackson

University of Georgia

Emily Lariscy

University of Georgia

Erin Howell

University of Georgia

Jason Lessl

University of Georgia

Rhuanito S. Ferrarezi

University of Georgia

Robin Buell

University of Georgia

Friday August 1, 2025 1:45pm - 2:00pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Poster # csv

1:45pm CDT

CITR 4 - Unlocking the Power of Brassinosteroid for Resilient Citrus Production in Florida

Friday August 1, 2025 1:45pm - 2:00pm CDT

Strand 11A

Brassinosteroids (Brs) are a natural group of hormones known for their significant impact on responses to both biotic and abiotic stresses across various plant species. Brs can also influence plant growth and fruit maturation. With the recent availability of commercial formulations, this plant growth regulator is becoming an increasingly popular management tool in agriculture. Our team has been working on understanding BRs mode of action in citrus, because information is still scarce. In Florida, citrus industry is now in decline due mainly to the citrus greening disease (HLB), which has become endemic in the state, with no potential cure in the horizon. The disease reduces internal fruit quality and compromises viability of young, newly planted citrus trees. Our work has unveiled that Homobrassinolide (HBr) may increase internal maturation in sweet orange under citrus greening endemic conditions. We have determined the optimal application rate and the most effective timing for Hamlin and Valencia cultivars. We have shown that the beneficial effects of HBr are more pronounced in the healthier trees. This has led us to adapt the use of HBr in combination with oxytetracycline (OTC) injections, as growers in Florida are now injecting OTC in mature trees to reduce HLB. Our results show that HBr, when used on OTC-injected trees, improve internal fruit quality significantly. In addition, we have found that treating young, newly planted trees with HBr induces a strong immune response by activating the salicylic acid pathway, resulting in a delay in HLB infection. We have also shown that other Br analog, Epibrassinolide (EBL) improve the cold tolerance of citrus trees when young, treated plants were exposed to -4 ℃ for 24 hours. In addition, we have also observed EBL are helpful in improving the postharvest fruit quality. This is of special interest in the northern part of the state, where fresh market citrus industry is expanding, as region often experiences frequent chilling conditions during winter months. All in all, we are showing that Brs may be a ready-to-use tool in Florida citrus industry.

Speakers

Fernando Alferez

UF-IFAS

Co-authors

carlos aucique-perez

UF-IFAS

Divya Aryal

SWFREC - University of Fl

Muhammad Shahid

UF-IFAS

Saoussen Ben Abdallah

SWFREC - University of Florida/IFAS

Shahid Iqbal

University of Florida

Friday August 1, 2025 1:45pm - 2:00pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops

1:45pm CDT

NUR - Greenhouse Propagation for Tea Varieties in Western Washington

Friday August 1, 2025 1:45pm - 2:00pm CDT

Foster 1

Tea (Camellia sinensis) was first grown commercially in the Pacific Northwest in Salem, OR in 1988 (Minto Island Growers), and cv. Minto Pacific, selected at that site, was established in a small-scale planting in Burlington, WA in 1997. To test other cultivars for production in the Pacific Northwest region, the successful Washington State University (WSU) vegetative propagation method for ‘Minto Pacific’ was carried out with 14 tea cultivars at WSU Northwestern Washington Research and Extension Center (NWREC): BL1, BL2, Large Leaf, Small Leaf, Christine’s Choice, Dave’s Fav, Sochi, Black Sea, var. Assamica from Mississippi State University; Yukata Midori, Benikaori, Yabukita, Bohea from the USDA National Plant Germplasm System (NPGS) in Hilo, Hawaii; and Minto Pacific from Burlington (year 2 only). For this 2-year greenhouse propagation trial, tea shoots arrived at WSU NWREC on 16 Aug (Mississippi) and 14 Sept 2023 (Hawaii) for year 1, and 16 Sept (Mississippi), 23 Sept (Hawaii) and 25 Sept 2024 (Burlington) for year 2. Both years, shoots were processed into one-node cuttings within 1 day of arrival, the bottom stem of each cutting was scored with a knife, dipped into a rooting hormone for 5-10 seconds, then placed into a treepot filled with a propagation medium (peatmoss, vermiculite, perlite, 5:3:2 ratio). Cuttings were placed in a misting chamber in the greenhouse for 1 year, then moved to a greenhouse bench for 7 months. In February 2024 (Year 1), overall plant survival was 83%, average plant height was 1 cm, plants had 2.5 leaves on average, and the average plant health rating was 4.9/5. Cv. Large Leaf (100%) had the highest survival followed by Dave’s Fave (98%) and Black Sea (98%), while Benikaori (60%) and BL1 (62%) had the lowest survival. In October 2024, the final overall plant survival was 31%, average plant height was 35 cm, plants had 19 leaves on average, and the average plant health rating was 3.6/5. Cv. Christine’s Choice (46%) had the highest survival followed by Large Leaf (43%) and BL2 (42%), while Benikaori (13%) and BL1 (15%) still had the lowest survival. In January 2025 (Year 2), overall plant survival was 73%, average plant height was 2 cm, plants had an average of 1.2 leaves, and average plant health rating was 4.2/5. Cv. Minto Pacific had 100% survival followed by Large Leaf, Christine’s Choice, and Assamica (all 95% survival), while Benikaori (40%) and Sochi (51%) had the lowest survival.

Speakers

McKenzie Shelton

Washington State University

Co-authors

Carol Miles

Washington State University

Chakradhar Mattupalli

Washington State University

Srijana Shrestha

Oregon State University

Friday August 1, 2025 1:45pm - 2:00pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source Western SARE, Northwest Agriculture Research Foundation

1:45pm CDT

PNM 4 - Enhancing Vitamin C Biofortification in Lettuce for Improved Nutrition

Friday August 1, 2025 1:45pm - 2:00pm CDT

Strand 11B

Vitamin C is a vital antioxidant that plays a crucial role in plant photosynthesis, enzymatic reactions, and stress resistance, while also being a key micronutrient for human health. Evaluating the potential of enhancing vitamin C content in food crops like lettuce (Lactuca sativa L.) can contribute to better health outcomes and disease prevention. This study investigates the effect of ascorbic acid foliar application on biomass, phytochemicals, and mineral nutrient content in lettuce using a Nutrient Film Technique (NFT) hydroponic system. Lettuce was treated with different concentrations of ascorbic acid (0, 500, 750, and 1000 ppm) via foliar application. Chlorophyll and biomass were recorded, while vitamin C content was analyzed using high-performance liquid chromatography (HPLC). Other micronutrients were also analyzed and assessed based on treatments. Results from this study will contribute to understanding how micronutrient deficiency in humans can be addressed and potentially maximized through agronomic biofortification.

Speakers

Katerina Mojica Vargas

Graduate Research Assistant, Texas Tech University

Co-authors

Catherine Simpson

Texas Tech University

Haydee Laza

Texas Tech University

Leslie Thompson

Texas Tech University

Sukhbir Singh

Texas Tech University

Friday August 1, 2025 1:45pm - 2:00pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv

1:45pm CDT

POM 4 - Adjusting the carbohydrate balance sub-models for use in Washington State

Friday August 1, 2025 1:45pm - 2:00pm CDT

Foster 2

Precision crop load management is important for increasing yield, fruit size, and quality of apple production, particularly for the ‘Honeycrisp’ variety, which is highly susceptible to biennial bearing and difficult to thin. The MaluSim model, developed at Cornell University, can be used to guide crop load management by modeling carbohydrate balance to optimize fruitlet thinning. However, this model was developed using tree performance in New York and may not account for higher temperatures in Washington State, which may affect canopy growth and development. The objective of this study was to assess early season canopy growth and evaluate carbon partitioning of Honeycrisp apples grown in Washington state climatic conditions. The first experiment compared the canopy growth of Honeycrisp topworked in 2016 onto a ‘Granny Smith’ planting with M.9T337 as a rootstock. The topworked trees were trained to single, double, or triple-axis trees. The second experiment assessed carbon partitioning of Honeycrisp trees conducted under single, double, and triple leader(s) training systems. Training systems significantly impacted shoot length and the number of shoots. Single-axis trees had significantly longer shoot lengths and higher shoot numbers than the double and triple-axis training systems. Canopy imaging was also used to assess canopy infill and light interception. The second experiment weighed the biomass partitioning of the various tree parts (spurs, 1-year growth, leaves, branches, roots, rootstock, inter-stem, and fruits). Below-ground portions of all training systems accounted for more biomass than above-ground portions. There was smaller wood and a greater proportion of spur buds in the double and triple-axis trees compared to single-axis trees. The differences in carbon partitioning and canopy development among different training systems compared to the types of trees used when developing the MaluSim model may affect how the MaluSim model performs.

Speakers

Harriet Ampofo

Washington State University-TFREC

Co-authors

Lee Kalcsits

Washington State University-TFREC

Friday August 1, 2025 1:45pm - 2:00pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv
Funding Source USDA-SCBGP

1:45pm CDT

VGBR 3 - Genome-Wide Association Study of Seed Spine in Spinach

Friday August 1, 2025 1:45pm - 2:00pm CDT

Strand 12B

Spinach (Spinacia oleracea L.) produces two types of seeds: spiny and spineless. Seed spine is one of the most important agronomic traits that affect seed treatment, mechanized harvesting and planting, and sowing. This study aimed to identify single nucleotide polymorphism (SNP) markers associated with seed spines in spinach through a genome-wide association study (GWAS), with the goal of developing SNP markers for marker-assisted selection (MAS). GWAS was conducted for the seed spine trait in a panel of 307 diverse spinach accessions using 147,977 SNPs generated from whole genome resequencing. Using MLM, FarmCPU, and BLINK models in GAPIT 3 and TASSEL 5, two significant SNPs associated with seed spines: SOVchr3_141167900, and SOVchr3_141168649 were identified on the chromosome 3. (LOD) values of t-test analysis identified homozygous alleles associated with the spiny and spineless traits in each of the two SNP markers, with LOD values greater than 80.00, and 80.00, respectively. The gene SOV3g042220, located between 141,172,904 bp and 141,183,504 bp on chromosome 3, is proposed as a potential candidate gene associated with the seed spine trait. This research provides valuable insights for MAS in spinach breeding, facilitating the development of spinach lines with desirable seed characteristics.

Speakers

Ainong Shi

Associate Professor, University of Arkasnas

Co-authors

Beiquan Mou

Sam Farr U.S. Crop Improvement and Protection Research Center, U.S. Dept. of Agriculture, Agricultural Research Service (USDA-ARS)

Derrick Harrison

university of arkansas

Haizheng Xiong

Wenzhou Academy of Agricultural Sciences

Hanan Alkabkabi

university of arkansas

Ibtisam Alatawi

university of arkansas

Kenani Chiwina

University of Arkansas

Muhammad Ullah

university of arkansas

Qun Luo

university of arkansas

Renjie Du

university of arkansas

YUEJUN QU

University of Arkansas

Friday August 1, 2025 1:45pm - 2:00pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv

2:00pm CDT

CE 8 - Effects of Planting Density on Growth and Biomass Yield in Lettuce Grown in Indoor Vertical Farming

Friday August 1, 2025 2:00pm - 2:15pm CDT

Strand 10

Maximizing crop yield is essential for the economic viability of indoor vertical farming, where operational costs are high. Among the many factors influencing productivity, planting density stands out as a manageable and cost-effective variable. Optimizing planting density offers a practical approach to improving yields without requiring major structural or technological changes. In this study, we evaluated the effects of planting density on lettuce (Lactuca sativa) yield and individual plant growth characteristics. Two cultivars with contrasting growth habits were used: butterhead lettuce ‘Rex’, known for its compact form, and green leaf lettuce ‘Fusion’, which exhibits an upright growth habit. Plants were cultivated for 24 days after transplanting in a controlled indoor environment maintained at 22 °C, under a photosynthetic photon flux density of 200 μmol∙m-2∙s-1 with an 18-hour photoperiod. Using a deep-water culture hydroponic system, we tested five planting densities: 21, 42, 82, 109 and 131 plants∙m-2. The nutrient solution was prepared with deionized water and a water-soluble fertilizer (12N–1.75P–13.3K; Jack’s Nutrients FeED 12–4–16 RO), providing 150 mg∙L⁻¹ of nitrogen. As planting density increased from 21 to 131 plants∙m-2, total shoot fresh mass per unit growing area rose from 1.6 to 7.2 kg∙m-2 in ‘Rex’ and from 2.6 to 10.9 kg∙m⁻² in ‘Fusion’. However, in ‘Fusion’, increasing density led to a 29% reduction in plant diameter, 19% in leaf number, 25% in leaf area, 33% in shoot fresh mass, and 5% in root fresh mass. Similarly, in ‘Rex’, leaf area and shoot fresh mass decreased by 23% and 26%, respectively, while root fresh mass, plant diameter and leaf number remained relatively consistent across densities. Our results suggest that while increasing planting density from 21 to 131 plants∙m-2 reduces individual plant growth, it increases overall lettuce crop yield per growing area in indoor lettuce production.

Speakers

Nicholas Barnett

Arizona State University

Co-authors

Lila Rose

Arizona State University

Yujin Park

Arizona State University

Zhihao Chen

Arizona State University

Friday August 1, 2025 2:00pm - 2:15pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Poster # csv

2:00pm CDT

CITR 4 - Methyl Salicylate and Gibberellic Acid in the Rehabilitation of Huanglongbing-Affected Sweet Oranges

Friday August 1, 2025 2:00pm - 2:15pm CDT

Strand 11A

Huanglongbing (HLB), a devastating bacterial disease presumed to be caused by Candidatus Liberibacter asiaticus, disrupts normal plant physiology by inducing hormonal imbalances that impair growth, fruit development, and defense responses. With no known citrus germplasm exhibiting resistance to HLB, effective management strategies are essential for sustaining citrus production. This study focuses on the combined application of methyl salicylate (MeSA), a systemic acquired resistance (SAR) inducer, and gibberellic acid (GA₃), a growth-promoting hormone, as a potential strategy to improve tree health and mitigating symptoms in HLB-affected citrus orchards. The study is being conducted at UF-CREC in Lake Alfred, Florida, on 15-year-old Valencia trees grafted onto Swingle rootstock. Four treatments are being evaluated: Control, GA₃, MeSA, and GA₃ MeSA. Trees were sprayed every 45 days from July to November 2024 with GA₃ and MeSA at 10 ounces per acre. The study assesses key production parameters, including yield, fruit drop, canopy density, and fruit quality. Preliminary results indicate that GA₃ application reduced preharvest fruit drop by 57% compared to the control. The leaf water content was significantly higher in Ga MeSa (58.42%) as compared to Control. No significant differences in canopy density were observed across treatments. Leaves were collected for molecular analysis on Days 7, 14, 30, 46, and 60 after the first treatment application. Differential gene expression analysis revealed significantly lower transcript levels of Rboh and LOX2 within 7 to 14 days post-treatment in GA MeSA, suggesting a potential reduction in oxidative stress. In contrast, CDR1 expression was significantly higher in MeSA treated leaves between days 30 and 45, likely indicating SAR activation. These physiological responses may contribute to improved tree performance under HLB pressure. The study will continue into the next year to refine application strategies and better understand the sustained impact of these treatments on tree health and productivity.

Speakers

Gurleen Kaur

CREC, University of Florida

Co-authors

Tripti Vashisth

University of Florida

Friday August 1, 2025 2:00pm - 2:15pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops

2:00pm CDT

NUR - Managing extreme substrate temperatures in container nursery produciton.

Friday August 1, 2025 2:00pm - 2:15pm CDT

Foster 1

Plants evolved with roots in the soil, providing a temperature buffer to the root zone most of the year. However, as the nursery industry has primarily moved plants out of the ground and into thin plastic containers with very coarse organic substrates, we are faced with added challenges of managing substrate temperature to ensure healthy plant production. Moreover, resource efficiency, particularly regarding mineral nutrients, is a critical factor in the long-term success of the nursery industry. Fertilizer release is controlled by water and temperature in container-grown ornamental nursery production systems. Thus, it was hypothesized that pragmatic management of substrate temperature and moisture could extend the longevity of controlled-release fertilizer in a container system. This study was conducted to determine the effect of irrigation scheduling, container color, and stratified substrates on substrate temperature management, crop health and development, and fertilizer longevity. ‘Limelight’ Hydrangea (Hydrangea paniculata) were grown in either black or white containers and subjected to a single daily irrigation or the same volume applied in three increments throughout the day (cyclic). Hydrangeas grown in white containers with cyclic irrigation increased plant growth by up to 50% compared to those grown in black containers with single-application irrigation, and stratified substrates reduced phosphorus leaching by 30%. Across all treatments, plant health, root development and fertilizer efficiency were improved with substrate temperature management strategies. The results indicate growers should pursue root zone temperature mitigation strategies to enhance crop growth and salability, increase fertilizer use and efficiency, and decrease phosphorus leaching from nursery containers.

Speakers

Jeb Fields

University of Florida

Co-authors

Ashley Hickman

LSU AgCenter

Friday August 1, 2025 2:00pm - 2:15pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source Floriculture Nursery Research Initiative

2:00pm CDT

PNM 4 - Effects of Perlite Content and Aeration on Lettuce Growth in Food Waste Liquid Anaerobic Digestate

Friday August 1, 2025 2:00pm - 2:15pm CDT

Strand 11B

Food waste liquid anaerobic digestate (FWLAD) has strong potential as an organic fertilizer due to its nutrient-rich composition. However, organic nutrient solutions often have lower dissolved oxygen (DO) levels than inorganic ones, which may limit oxygen availability in the root zone, restricting nutrient uptake and plant growth. This study examines whether increasing perlite content in a soilless substrate and aerating the nutrient solution can enhance root-zone oxygen availability and improve lettuce (Lactuca sativa 'Muir') growth when cultivated with FWLAD. Lettuce seeds were sown in a 128-cell plug tray filled with a peat-based growing mix blended with perlite at 100%:0%, 70%:30%, and 40%:60% (v:v). Increasing perlite content from 0% to 60% increased substrate porosity from 47% to 56%, while air space remained between 30% and 33%. One week after sowing, seedlings were sub-irrigated with four nutrient solutions prepared from either crude or nitrified FWLAD at an electrical conductivity (EC) of 2 dS·m-1, each under aerated and non-aerated conditions. Control nutrient solutions were prepared using inorganic fertilizer at 2 dS/m EC. Lettuce seedlings were grown indoors for three weeks at the air temperature of 24°C with a photosynthetic photon flux density of 210 µmol·m-2·s-1 under an 18-hour photoperiod. Regardless of nutrient solution type, increasing perlite from 0% to 60% had little to no effects or decreased leaf number (by 7-13%), leaf area (by 13-26%), and shoot fresh mass (by 10-42%). DO levels remained below 1.5 ppm in non-aerated crude or nitrified FWLAD solutions, while aerated solutions and inorganic fertilizer treatments maintained DO above 6 ppm. Aerating the nutrient solution with crude FWLAD decreased total leaf number (by 4-17%), total leaf area (by 28-45%), and shoot fresh mass (by 37-44%) across all substrate conditions, whereas aeration with nitrified FWLAD increased these parameters by 22-35%, 174-343%, and 138-325%, respectively. At each substrate condition, lettuce seedlings grown with inorganic fertilizer had the highest leaf number, leaf area, and shoot fresh mass. These results suggest that increasing perlite content did not enhance lettuce growth under FWLAD. Aeration improved growth with nitrified FWLAD but reduced it with crude FWLAD. Across all conditions, inorganic fertilizer resulted in the highest growth, suggesting that factors beyond oxygen availability may limit the effectiveness of FWLAD as a nutrient source.

Speakers

Kevin Kasper

Arizona State University

Co-authors

Emily-Jane Crawford

Arizona State University

Yujin Park

Arizona State University

Friday August 1, 2025 2:00pm - 2:15pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv
Funding Source Foundation for Food & Agriculture Research

2:00pm CDT

POM 4 - Improving Apple Crop Load Management Using Digital Tools: Matching Data Collection With Accurate Treatment Application

Friday August 1, 2025 2:00pm - 2:15pm CDT

Foster 2

Multiple digital imaging companies can gather apple orchard data to map flower bud load, flower cluster number and fruitlet number at the tree level. However quickly matching photographic survey data to maps which can accurately guide management decisions remains challenging. Over the past year, Cornell University has partnered with several companies which can collect and apply survey data to guide precision pruning, precision blossom thinning, and precision fruitlet thinning in high density apple orchards of Western New York. Photographs and surveys from companies which collect single tree information provided the highest resolution information to guide precision sprayers. Precision sprayers were able to successfully apply treatments to the tree level, but the survey data first needed to be transformed into task maps which defined unique tree positions using the same GPS system used to collect the data and then control the sprayer to avoid an offset. Improving orchard management using digital tools may help improve crop load management but the success of this effort depends on the treatment resolution (section of row vs individual tree) as well as when crop load was modified, such as pruning, blossom, and or fruitlet timing.

Speakers

Brian Lawrence

Cornell University

Co-authors

Terence Robinson

Cornell University

Yu Jiang

Cornell University

Friday August 1, 2025 2:00pm - 2:15pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv

2:00pm CDT

VGBR 3 - GWAS-derived Markers Improves Genomic Prediction of Vitamin C Content in Spinach

Friday August 1, 2025 2:00pm - 2:15pm CDT

Strand 12B

Vitamin C (VC), also known as ascorbic acid and ascorbate, is a water-soluble antioxidant in plants that promotes skin health and immune function in humans. Spinach (Spinacia oleracea L.), a leafy green vegetable widely valued for its health benefits, has been identified as a target for nutritional enhancement, including increased VC content. However, the complex inheritance of VC necessitates advanced selection methods to accelerate cultivar development. In this study, VC- associated single nucleotide polymorphism (SNP) markers identified through genome-wide association (GWAS) were employed for genomic prediction (GP) to estimate prediction accuracy (PA) for VC content in spinach. A dataset of 147,977 SNPs generated from whole genome resequencing was analyzed in a panel of 347 spinach genotypes using six GWAS models. Sixty-two SNP markers, distributed across six spinach chromosomes, were significantly associated with VC content. PA was assessed using randomly selected SNP sets and GWAS-derived SNP marker sets across various GP models. Results demonstrated that PA exceeded 40% when using 1,000 or more SNPs. Furthermore, incorporating GWAS-derived SNP markers improved PA, achieving a r-value greater 0.70 through Bayes ridge regression (BRR) model. This study highlights the potential of GWAS-derived SNP markers for marker-assisted selection (MAS) and genomic selection (GS) in spinach breeding programs aimed at enhancing VC content. Keywords: Genomic Selection, Genome-Wide Association Study, Spinach, SNP, Prediction Accuracy

Speakers

Jana Jeevan Rameneni

Texas A

Co-authors

A S M Faridul Islam

Texas A

Ainong Shi

University of Arkasnas

Carlos Avila

Texas A

Friday August 1, 2025 2:00pm - 2:15pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv
Funding Source This work was supported by USDA-NIFA SCRI project # 2023–51181-41321 to AS and CA; Texas A&M AgriLife Vegetable and Fruit Center (VFIC) seed grant FY2024 to CA; The Texas A&M AgriLife Institute for Advancing Health through Agriculture Research Capacity Funds to CA; and USDA-NIFA HATCH project #TEX0-1–9618 to CA.

2:15pm CDT

CE 8 - Optimizing Nutrient Solution Volume for Hydroponic Production of Four Leafy Greens Species Based on Nutrient Content and

Friday August 1, 2025 2:15pm - 2:30pm CDT

Strand 10

Efficient nutrient management is critical for optimizing hydroponic production. However, limited research exists on optimizing nutrient solution volume for various leafy green vegetables in recirculating hydroponic cultivation. To address this gap, we evaluated the growth and nutrient responses of four leafy green vegetables: butterhead lettuce (Lactuca sativa ‘Salanova Red Butter’), arugula (Eruca sativa ‘Standard’), kale (Brassica oleracea ‘Red Russian’), and red Malabar spinach (Basella alba ‘Rubra’). These crops were grown in a nutrient film technique (NFT) hydroponic system under two nutrient solution volumes, Low (76 liters) and High (151 liters), in a greenhouse during both summer and fall. Electrical conductivity (EC) of 1.8 mS/cm was maintained across treatments. Results indicated that leaf nitrogen (N) and potassium (K) content significantly increased with High nutrient solution volume while phosphorous (P) and K followed a similar trend in the fall. Low nutrient solution volume reduced nitrate levels in arugula tissue during both seasons, suggesting that lower volume may help minimize excessive nitrate levels in plant tissues. In summer, nitrate levels in red Malabar spinach (Low volume) and red butter lettuce (High volume) slightly exceeded recommended limits, while kale consistently surpassed safe nitrate levels regardless of treatment. Additionally, nutrient solution volume influenced key postharvest attributes such as color, texture, vitamin C, and anthocyanin content, with species-specific responses. These findings highlight the importance of crop-specific nutrient solution management to optimize plant health, improve nutrient use efficiency, minimize nitrate accumulation and nutrient waste, and support sustainable hydroponic production.

Speakers

Puja Subedi

Kansas State University

I am a graduate research assistant working at the Kansas University Olathe, 22201 W Innovation Dr, Olathe, KS 66061. My major is urban food system under the department of horticulture and natural resources. Currently, I am working in the hydroponics research project.

Co-authors

Kimberly Williams

Kansas State University

Riu Calvin Liu

Kansas State University

Teng Yang

South Dakota State University

Xuan Xu

Kansas State University

Friday August 1, 2025 2:15pm - 2:30pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Poster # csv

2:15pm CDT

CITR 4 - Fine-tuning Propionic Acid Dosage for Reducing Pre-harvest Fruit Drop in 'Hamlin' Sweet Oranges and Mechanisms Involved

Friday August 1, 2025 2:15pm - 2:30pm CDT

Strand 11A

Pre-harvest fruit drop significantly challenges citrus orchard yield and economic viability, especially those affected by Huanglongbing (HLB). This issue is relevant in Florida’s citrus industry. This study investigated the efficacy of propionic acid he experiments applied three monthly doses of propionic acid in two consecutive years—in 2023 treated doses were 300 ppm, 1,100 ppm and 2,200 ppm— to trees, with an untreated group serving as the control. For this experiment, results indicated that the 1,100 ppm of propionic acid was most effective in controlling fruit drop, significantly reducing losses by 30% compared to the control. In 2024, the second experiment aimed to fine-tune doses. Trees were treated with three monthly doses of propionic acid utilizing 700 ppm, 1,100 ppm, and 1,400 ppm, with an untreated group serving as the control. Results showed that the 700 ppm dose was the most effective treatment in preventing fruit drop, retaining 15% more fruit than untreated trees. In both years, propionic acid increased average fruit weight. The 700 ppm dose improved yield by 36% compared to the control in 2024, while the 1,100 ppm dose led to a 17% increase in 2023 and 6% in 2024. Propionic acid did not alter fruit quality parameters, including °Brix and acidity. These findings suggest that propionic acid is a promising management tool for reducing pre-harvest fruit drop under HLB conditions.

Speakers

Pablo Orozco

SWFREC

Friday August 1, 2025 2:15pm - 2:30pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops

2:15pm CDT

NUR - KBTrack: Long Term Tracking for Plant Counting with Cloud-Enabled Plant Segmentation Framework for Ornamental Nursery In

Friday August 1, 2025 2:15pm - 2:30pm CDT

Foster 1

Efficient and accurate counting of plants is critical for nursery inventory management to support yield prediction, sales forecasting, and monitoring. Current practices in nurseries depend heavily on manual methods, which are labor-intensive and prone to errors. Researchers have made efforts in utilizing computer vision and deep learning to address these issues, yet a seamless solution for plant counting and inventory management remains unavailable. Image-based counting systems often struggle with classification accuracy in diverse, real-world scenarios, while tracking plants in videos faces challenges such as identity switches, misclassifications, and varying field conditions, limiting the reliability of existing methods. To overcome these challenges, we developed a cloud-based complete solution specifically for ornamental plant nursery inventory management. Our system introduces a novel tracking algorithm KBTrack, optimized for precision and scalability. At its core is an ensemble deep learning model that combines a transfer learning-based YOLOv11 and a CutMix-enhanced YOLOv11 model for plant detection. The KBTrack was developed on top of ByteTrack multi object tracking framework by adding a layer that compares segmentation masks across multiple frames for long term matching of the objects. This addition addressed identity switches and misclassifications, ensuring accurate plant counting even in complex field conditions. The segmentation capabilities of YOLOv11 are also utilized to generate masks for individual plants, enabling customizable plant-specific quality assessments through an interactive dashboard. The system utilizes GPS to allow users to monitor nursery plant beds on a map making it easier to monitor and track changes and updates across the plant beds. The platform is deployed in cloud with a microservice architecture where users can upload field videos and access results through an intuitive interface designed to ensure scalability. To evaluate the capabilities of the proposed framework, data was collected using an autonomous ground vehicle equipped with an OAK-D Pro camera, capturing 4K resolution videos. Experiments conducted on Azalea and Sunshine plants demonstrated the system's effectiveness, achieving a high mAP@50 of 0.982 for detection and 0.981 for instance segmentation on the ensemble model, MOTP 0.916 in the KBTrack multi object tracking algorithm and counting accuracy of 0.988 with an RMSE of 0.669. This confirms its ability to accurately detect and track plants. This solution provides a robust framework for addressing the limitations of current methods, offering an effective and scalable approach to modernize ornamental plant inventory systems.

Speakers

Mohtasim Hadi Rafi

Graduate Research Assistant, Auburn University

Co-authors

Faraz Ahmad

AUBURN UNIVERSITY

Hamid Syed

Auburn University

Jeremy Pickens

AUBURN UNIVERSITY

Tanzeel Rehman

AUBURN UNIVERSITY

Friday August 1, 2025 2:15pm - 2:30pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source This study was supported in part by the by the United States Department of Agriculture (USDA)’s National Institute of Food and Agriculture (NIFA) competitive grant (Award No. 2023-67021-40617) and Auburn University Research Support Program (2022-2023). Department of Biosystems Engineering, Auburn University, provided funding for this study under Hatch Grant No. ALAO 14-1-19204.
Funding Option OREl or ORG funded all or part of the research associated with this abstract

2:15pm CDT

PNM 4 - Impact of Ascorbic Acid on Iron Biofortification and Nutritional Quality in Sunflower Microgreens

Friday August 1, 2025 2:15pm - 2:30pm CDT

Strand 11B

Iron (Fe) deficiency is one of the leading micronutrient deficiencies in the world, impacting almost two billion people globally. Contributing factors include non-diverse diets (cereal grain-centered diets, processed and junk foods) that are characterized by relatively low bioavailable Fe levels. Additionally, 30% of cultivated soils around the world report low Fe availability. Inadequate levels of dietary Fe can cause numerous physiological disorders and impaired cognitive functioning, with pregnant women and infants being particularly vulnerable. To help alleviate the harm of Fe malnutrition, a straightforward and sustainable solution to increase dietary Fe availability is through agronomic biofortification of crops. Unfortunately, Fe uptake by plants is problematic, especially in alkaline and oxidizing conditions. However, various studies have reported the role of ascorbic acid (AA) as an enhancer of Fe absorption. A suitable candidate crop for Fe biofortification are microgreens, as they are nutritional powerhouses that have low phytic acid levels, short growth cycles, and are typically consumed raw. Testing the use of AA for Fe biofortification in microgreens has received limited attention in literature. Therefore, in this study we investigate in a soilless system the effect of different Fe sources with and without organic acids (Ferric sulfate, Ferric sulfate 0.1% Ascorbic acid, Ferric citrate), applied via fertigation at different concentrations (0, 15, 30, 45 mg/L of Fe), on Fe content of sunflower microgreens. Treatments were arranged in a completely randomized factorial design using three replications. We discovered that Ferric sulfate 0.1% AA provided at 45 mg/L was the most effective source and rate in increasing Fe content, resulting in approximately 300% increase compared to the untreated control. Fertigating with Ferric sulfate 0.1% AA also showed a significant increase in total antioxidants and total phenol concentrations, but a decrease in chlorophyll and carotenoid levels. When using sodium hydroxide (NaOH) to adjust the nutrient solution pH, the same treatment was associated with relatively high Na content and resulted in an average reduction in fresh and dry biomass of 50% and 30%, respectively. Further assessment of Fe sources, concentrations, and bases for pH adjustment should be considered to not compromise yield and nutritional quality. However, these results indicate that through fertigation, the supplementation of AA with Fe fertilizers can significantly promote the enrichment of Fe as well as certain phytochemicals in sunflower microgreens. This strategy can produce Fe-biofortified functional foods that can potentially improve health outcomes of Fe-deficient individuals.

Speakers

Rishi Ravichandran

Student, Pennsylvania State University

Co-authors

Benedikt Nuesslein

Pennsylvania State University

Erin L. Connolly

Pennsylvania State University

Francesco Di Gioia

Pennsylvania State University

Friday August 1, 2025 2:15pm - 2:30pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv
Funding Source Open Philanthropy through the grant Food Resilience in the Face of Catastrophic Global Events with the support of the PDA SCBG award # C940001096 and the USDA NIFA and Hatch Appropriations under Project #PEN04723 and Accession #1020664.

2:15pm CDT

POM 4 - High relative growth rates during early fruit development in apple are facilitated by processes that promote cell produc

Friday August 1, 2025 2:15pm - 2:30pm CDT

Foster 2

Fruit growth across various stages of development determines the extent of final fruit size, and is therefore of high economic value. The two main processes that mediate growth, cell production and cell expansion, contribute differentially to growth across various stages of fruit development. In apple, growth during early fruit development is largely facilitated by cell production. Mid and late stages of fruit development display growth mediated mostly by cell expansion. Mechanisms that regulate these processes and consequently the growth rates of fruit are not well understood. The objective of this study was to determine the molecular processes associated with higher relative growth rates (RGR) in the apple fruit during different stages of development. To address this objective, we exploited the inherent natural variation in RGR within a population of ‘Empire’ fruit. These evaluations were performed during early and mid-fruit development stages. At each stage, change in fruit size (volume) was determined across a 4 d interval to obtain the RGR. The population of fruit was grouped into two classes based on their RGR values: High and Low RGR. RNA-sequencing analyses were performed to compare the transcriptomes of the two classes of fruit. During early fruit development, the High RGR class fruit displayed 1.46-fold greater growth rates than the Low RGR fruit. Transcriptome analysis indicated that genes associated with cell division processes such as HISTONES, CYCLINS and CYCLIN DEPENDENT KINASES were more abundant in fruit with higher RGR. During mid-fruit development, fruit displayed relatively lower RGR. Yet the High and Low RGR fruit classes differed by 1.76-fold. However, only a limited set of genes, mostly associated with oxidation-reduction processes, were differentially expressed across these two groups. Overall, these data suggest that processes that regulate cell division control the growth rates of apple fruit during early fruit development.

Speakers

Anish Malladi

University of Georgia

Co-authors

Bayleigh Roussel

University of Georgia

Friday August 1, 2025 2:15pm - 2:30pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv

2:15pm CDT

VGBR 3 - Genome-wide association study reveals genetic loci associated with leaf base color variation in spinach (Spinacia olerac

Friday August 1, 2025 2:15pm - 2:30pm CDT

Strand 12B

Leaf base color in spinach (Spinacia oleracea L.) exhibits substantial phenotypic variation, potentially influencing consumer preference and nutritional content. To elucidate the genetic basis of this variation, we conducted a genome-wide association study (GWAS) utilizing a diverse panel of 313 USDA-GRIN accessions of spinach. This population, characterized by a predominance of white (65%) and red (35%) leaf base colors, was genotyped using whole-genome resequencing (WGR) resulting in the identification of 83,261 high-quality single nucleotide polymorphisms (SNPs) after rigorous filtering. Genetic diversity analyses and association mapping were performed using multiple statistical models, including mixed linear model (MLM), generalized linear model (GLM), BLINK, and FarmCPU, implemented in GAPIT 3, TASSEL 5, and rMVP software. The GWAS identified three significantly associated SNPs (SOVchr3_140405053, SOVchr3_140405474, SOVchr3_140412359) located on chromosome 03, which collectively contribute to leaf base color variation. Within a 50kb flanking region of these SNPs, we identified three candidate genes: SOV3g042000 (membrane protein), SOV3g041980 (mariner transposase), SOV3g041990 (pentatricopeptide repeat). These genetic loci explained 30.55% of the phenotypic variation observed in leaf base color. These findings provide critical insights into genetic architecture governing leaf base color in spinach. The identified SNPs and candidate genes represent valuable targets for marker-assisted selection and gene editing, facilitating the development of improved spinach cultivars with desired leaf base color. Overall, this study contributes to a comprehensive understanding of the genetic control of leaf pigmentation, ultimately supporting targeted breeding strategies for spinach varieties.

Speakers

Muhammad Ullah

university of arkansas

Co-authors

Ainong Shi

University of Arkasnas

Awais Riaz

University of Arkansas

Beiquan Mou

USDA

Hanan Alkabkabi

university of arkansas

Kenani Chiwina

University of Arkansas

Renjie Du

university of arkansas

YUEJUN QU

University of Arkansas

Friday August 1, 2025 2:15pm - 2:30pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv

2:30pm CDT

CE 8 - Evaluating the Impact of Aeration Location and Method on Root Zone Dissolved Oxygen and Growth of Arugula and Spinach in

Friday August 1, 2025 2:30pm - 2:45pm CDT

Strand 10

Adequate aeration in deep-water culture (DWC) sustains high dissolved oxygen (DO) levels, promoting nutrient uptake and root development. In multi-layered DWC systems, where a single reservoir supplies multiple trays, strategic aeration placement is essential for uniform oxygen distribution. This study examines how aeration location (reservoir vs. growing tray) and oxygenation method (air pump vs. oxygen concentrator) affect root zone DO levels and the growth of arugula (Eruca sativa ‘Astro’) and spinach (Spinacia oleracea ‘Auroch’). Plants were grown for 25 days in an indoor vertical farm at the air temperature of 22 °C under sole-source LED lighting (18-h photoperiod, 215 µmol∙m⁻²∙s⁻¹). Six aeration treatments were applied in a DWC system comprising a reservoir and a growing tray: no aeration (control), air pump aeration (reservoir, tray, or both), and oxygen concentrator aeration (reservoir or tray). The average DO level in the rootzone without aeration was 5.6 ppm. Aeration using the air pump increased DO to 6.0 ppm when placed in the reservoir, 7.3 ppm when placed in the tray, and 7.3 ppm when applied to both the reservoir and the tray. The oxygen concentrator treatment resulted in a higher increase in DO in the root zone, reaching 9.5 ppm when aeration was applied in the reservoir and 19.7 ppm when applied in the growing tray. Regardless of the oxygenation method, aeration in the reservoir had no effect on the growth of arugula or spinach compared to no aeration. Air pump aeration in the growing tray or both locations similarly increased leaf area, shoot fresh mass, and shoot dry mass in both species. In arugula, leaf area, shoot fresh mass, and shoot dry mass increased by 294%, 227%, and 120%, respectively. In spinach, leaf area, shoot fresh mass, and shoot dry mass increased by 184%, 216%, and 100%, respectively. Oxygen concentrator aeration in the growing tray increased leaf area by 217%, shoot fresh mass by 224%, and shoot dry mass by 73% in arugula, while having minimal effects on spinach. Our findings indicate that aerating the growing tray is more effective at increasing DO concentration than aerating the reservoir. Additionally, oxygen concentrators were more efficient than air pumps at elevating DO levels. However, regardless of DO concentration, aeration in the growing tray with the air pump was most effective at promoting growth in both arugula and spinach.

Speakers

Keaton Schlink

Arizona State University

Co-authors

Noah Adams

Arizona State University

Yujin Park

Arizona State University

Zhihao Chen

Arizona State University

Friday August 1, 2025 2:30pm - 2:45pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Funding Source USDA NIFA Urban, Indoor, and Emerging Agriculture (UIE) program

2:30pm CDT

CITR 4 - Evaluating Root Uptake of Gibberellic Acid as an Alternative to Foliar Application in Citrus

Friday August 1, 2025 2:30pm - 2:45pm CDT

Strand 11A

Huanglongbing (HLB), also known as citrus greening, is a devastating disease of citrus and has severely impacted the citrus industry in Florida, causing substantial economic losses. With no known cure, management practices just aim to mitigate the harmful effects on the tree. Recent studies have shown that the 5 monthly foliar applications (September-January) of gibberellic acid (GA) can reduce preharvest fruit drop, improve fruit set, and enhance tree health. The potential impact of these findings is huge for commercial citrus production; however, growers are looking for alternatives to foliar application as foliar sprays are highly weather dependent and expensive, currently an air blast sprayer application can range anywhere from $30 to $50 per acre. Therefore, it becomes critical to find alternatives to foliar GA application. Supply of GA to the plants through irrigation could be a valid alterative instead of foliar application. This study explores the feasibility of GA application through irrigation as an alternative to foliar sprays. Specifically, we investigated GA uptake efficiency through citrus roots, its effects on overall plant growth, and transcriptomic changes in leaves and roots. Preliminary results indicate that both foliar (GF) and root applications (GR) induced tree responses, altering the hormone profiles in leaves and roots. Fifteen days post application, GR showed significantly higher concentration of GA₁ (950 ng/g fresh weight (FW)), GA₃ (450 ng/g FW), and GA8(112 ng/g FW) in the roots whereas these hormones were undetectable in the GF or untreated controlled. In the leaves, GA3 was significantly higher (210 ng/g FW) in GF but undetectable in untreated and GR. At 30 days post treatment, an enhanced leaf growth response was observed in GF trees with a mean new growth of 35 leaves as compared to 20.2 in GR and 17.8 in untreated control. Similarly, a 60-day hydroponic study demonstrated that root GA application significantly increased leaf production (p = 0.04). Bud growth was also significantly higher in root-treated plants compared to controls at both 10 days (p = 0.01) and 20 days (p = 0.01) post-application These preliminary findings suggest that root-applied GA does not mimic foliar application effects but offers some benefits for plant growth. An in-depth, long-term analysis is underway to validate the potential of GA delivery via irrigation.

Speakers

Abhishek Neupane

University of Florida

Co-authors

Tripti Vashisth

University of Florida

Friday August 1, 2025 2:30pm - 2:45pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops
Poster # csv

2:30pm CDT

NUR - Identification and Management of Botryosphaeria dothidea, the Causal Agent of Canker Disease of Eastern Redbud in Tennes

Friday August 1, 2025 2:30pm - 2:45pm CDT

Foster 1

Eastern redbuds (Cercis canadensis), valued for their vibrant flowers and heart-shaped foliage, are economically important trees in Tennessee nurseries. However, large-scale production is challenged by fungal canker pathogens that compromise tree health and marketability. In 2023, field and container-grown eastern redbuds in Tennessee exhibited dieback, dark, sunken necrotic lesions, and vascular discoloration. Fungal isolates from diseased tissue exhibited morphological and microscopic characteristics consistent with members of the Botryosphaeriaceae family. Molecular identification was done by amplifying the ribosomal internal transcribed spacer (ITS), β-tubulin (TUB), and translation elongation factor (EF1-α) gene markers. The phylogenetic analysis of concatenated ITS, TUB, and EF1-α sequences confirmed the pathogen as B. dothidea, and the pathogenicity test further established its pathogenic nature. Currently, there is no effective strategy for managing Botryosphaeria canker in redbuds. This study aimed to identify the causal agent and assess the efficacy of fungicides and biofungicides for canker disease management. Greenhouse trials were conducted from May to November in 2023 (Trial 1) and 2024 (Trial 2) using a completely randomized design with 14 treatments, which included non-treated, inoculated control, non-treated, non-inoculated control, and wound control, with six replications per treatment. Treatments included chemical fungicides (Avelyo, Pillar SC_LR, Pillar SC_HR, Postiva, SP2700WP, SP2478, and Kleengrow) and biofungicides (BotryStop WP, RootShield PLUS, Stargus, and Tril-21). These treatments were applied as foliar spray, wound treatment, drench, or sprench at 14-day intervals. One-year-old container-grown healthy eastern redbuds were wounded and artificially inoculated with fungal mycelial plugs, followed by fungicide applications. Disease progression was monitored over a six-month period by measuring plant height, width, lesion length, and pathogen recovery. All tested fungicides and biofungicides significantly reduced canker lesion length and pathogen recovery compared to the non-treated, inoculated controls. The most effective treatments in reducing Botryosphaeria canker severity were BotryStop WP (Ulocladium oudemansii strain U3), RootShield PLUS (Trichoderma harzianum T. virens G-41), and Pillar SC (triticonazole pyraclostrobin). However, no significant difference was observed in plant height and width among different treatments. These findings provide nursery growers with an idea of the causal agent and effective management strategies for reducing the severity of Botryosphaeria canker in redbud production.

Speakers

Pratima Subedi

Tennessee State University

PhD student working on Identification and Management of Fungal Canker Pathogens of Woody Ornamentals.

Co-authors

Fulya Baysal

Tennessee State University

Sujan Dawadi

Tennessee State University

Terri Simmons

Tennessee State University

Friday August 1, 2025 2:30pm - 2:45pm CDT
Foster 1

Oral presentation, Nursery Crops

Poster # csv

2:30pm CDT

PNM 4 - Differential Impacts of Nitrogen on Circadian Transcriptional Rhythms in Spinach

Friday August 1, 2025 2:30pm - 2:45pm CDT

Strand 11B

Circadian rhythm, a vital adaptive mechanism in green organisms, synchronizes plants' physiological processes with daily and seasonal environmental changes. Circadian clock oscillator genes significantly regulate transcriptional and post-transcriptional changes, emphasizing their role in mediating plant responses to environmental stresses. Understanding these regulatory mechanisms is essential for optimizing plant growth, enhancing productivity, and improving resilience to ecological changes, contributing to sustainable agriculture and food security. Nitrogen is an essential plant nutrient; both depleted and excessive nitrogen fertilization can negatively impact plant growth, development, and yield. Overapplication of nitrogen fertilizers can disrupt soil properties, limiting nutrient availability and altering soil composition (including soil acidification, salinization, and disruption of beneficial microbial communities). Additionally, excessive nitrogen usage contributes to harmful gas emissions from the soil into the atmosphere, which can affect human health, climate, and overall ecosystems. Effective nitrogen management is crucial for promoting healthy plant growth and minimizing environmental damage, making a balanced approach essential for sustainable agriculture. This study evaluated the daily regulation of transcriptional changes in nitrogen metabolism under nitrogen depletion (Low N: 50 ppm) and spinach leaf repletion (High N: 200 ppm) conditions. The RNA-Seq analysis reveals that high nitrogen (HN) conditions induce more significant transcriptomic changes than low nitrogen (LN), particularly in nitrogen assimilation, transport, and amino acid metabolism genes. Expression patterns of these genes vary across time points, with distinct regulation during light and dark cycles. Validation through qPCR and RNA-Seq confirms that nitrogen assimilation peaks at the end of the dark cycle. In contrast, nitrogen transport (NRT1) and amino acid synthesis are more pronounced during the light cycle under HN conditions. The circadian clock gene Late Elongated Hypocotyl (LHY) regulates the timing of nitrogen assimilation. LHY expression increases at the end of the dark cycle, correlating with higher expressions of nitrogen assimilation genes, including Nitrate Reductase (NIA) and Nitrite Reductase (NiR). These results underscore the significance of circadian rhythms, mainly through LHY, in optimizing nitrogen acquisition and utilization.

Speakers

Benedict Analin

Texas A

Co-authors

Vijay Joshi

Texas A

Friday August 1, 2025 2:30pm - 2:45pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv
Funding Source USDA-Agriculture Marketing Service (Specialty Crop Multi-State Program; CDFA 21-0730-001-SF

2:30pm CDT

POM 4 - Rethinking Pollination and Crop Load Management: Multi-Year Evaluation of Insect-Exclusion Netting in Apple Orchards

Friday August 1, 2025 2:30pm - 2:45pm CDT

Foster 2

Thinning remains a critical yet challenging practice in apple production, especially for organic systems where chemical tools are limited. Since 2017, our research has evaluated the use of insect-exclusion netting as a sustainable, non-chemical strategy to simultaneously manage crop load and reduce pest pressure. What began as small-scale trials has expanded to commercial-scale implementation in Michigan, supported by USDA funding. Over the course of eight years, we evaluated netting on a diverse suite of cultivars including 'Gala', 'Fuji', 'SweeTango’, Liberty’ and 'Honeycrisp' in multiple locations. Canopies were enclosed at varying bloom stages, and results consistently demonstrated that netting significantly reduced fruit set in proportion to the amount of open bloom at the time of application. Cultivar-specific responses were observed: Gala’ and 'Fuji' achieved optimal crop loads when netted between 25% and 50% bloom, while ‘SweeTango’ and 'Honeycrisp' often required higher percentage of open bloom. In several trials, netted trees yielded commercial fruit numbers without requiring hand or chemical thinning. Fruit size and quality remained similar to conventional treatments, while seed content was reduced without negatively impacting fruit development. In many cases, trees netted at the ‘pink’ phenology stage produced adequate fruit set of low seed-content fruit despite the exclusion of pollinators. Importantly, molecular genotyping using 16 SNP markers revealed that seed parentage in netted canopies overlapped with known pollinizer genotypes. This ruled out self-pollination and suggested that wind, rather than insects, facilitated cross-pollination under netted conditions. Additionally, fruit retention was linked to seed content at the population level, not the individual fruit level, further supporting the viability of non-insect pollination under netting. In 2024, we implemented nets in commercial orchards in Michigan to validate scalability. Netting treatments at 30% and 60% King Bloom produced yields and fruit quality metrics comparable to conventional thinning. Pest monitoring confirmed male codling moth exclusion and reduced San Jose scale captures, though woolly apple aphid and flower thrips populations increased under nets given the exclusion of natural predators Collectively, our results indicate that exclusion netting is a promising, multifunctional tool for organic and sustainable apple production. Beyond thinning and pest control, netting systems enable effective crop set through wind-mediated pollination, challenging traditional assumptions of insect dependency. Adoption of this system may require revised orchard design to optimize pollen flow, but offers significant environmental benefits, including reduced chemical inputs, support for pollinator conservation, and improved climate resilience in Midwestern apple orchards.

Speakers

Mokhles Elsysy

Michigan State University

Co-authors

Todd Einhorn

Michigan State University

Friday August 1, 2025 2:30pm - 2:45pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv
Funding Source SARE

2:30pm CDT

VGBR 3 - Genome-Wide Association Study and Genomic Prediction of Leaf Texture in USDA GRIN Spinach Germplasm

Friday August 1, 2025 2:30pm - 2:45pm CDT

Strand 12B

Spinach (Spinacia oleracea L.) is a globally valued vegetable, renowned for its rich nutritional content and health-enhancing benefits. Leaf texture, ranging from smooth to savoy, is an important trait influencing consumer preference, taste, and nutritional compositions. This study aimed to conduct a comprehensive genome-wide association study (GWAS) to identify single nucleotide polymorphism (SNP) markers associated with leaf texture in spinach, along with genomic prediction (GP) to facilitate trait screening in breeding programs. GWAS was performed on a panel of 103 USDA spinach germplasm accessions using 12,744 high-quality filtered SNPs obtained from whole-genome resequencing. Several statistical models, including MLMM, MLM, FarmCPU, and BLINK, were applied using the GAPIT 3 tool. Two significant quantitative trait locus (QTL) regions were identified on chromosome 1, spanning from 13,798,232 bp to 51,588,552 bp. Within this region, three SNP markers—SOVchr1_13798232 (LOD 5.84), SOVchr1_51500008 (LOD 9.73), and SOVchr1_51588552 (LOD 5.77) and—showed strong associations with leaf texture. Additionally, another SNP marker, SOVchr2_8225269, on chromosome 2, also exhibited a strong association with this trait. Furthermore, the gene SOV1g002810, located between 13,795,625 bp and 13,803,405 bp on chromosome 1, encodes a ULP_PROTEASE domain-containing protein and is proposed as a potential candidate associated with the trait. GP revealed strong predictive accuracy (PA), with an r value of 0.43. The identified SNP markers and PA metrics provide valuable tools for breeders to spinach breeding programs through marker-assisted selection (MAS) and genomic selection (GS), thereby accelerating the development of spinach lines with desired leaf textures.

Speakers

Renjie Du

university of arkansas

Co-authors

Ainong Shi

University of Arkasnas

Beiquan Mou

Sam Farr U.S. Crop Improvement and Protection Research Center, U.S. Dept. of Agriculture, Agricultural Research Service (USDA-ARS)

Derrick Harrison

university of arkansas

Haizheng Xiong

Wenzhou Academy of Agricultural Sciences

Hanan Alkabkabi

university of arkansas

Ibtisam Alatawi

university of arkansas

Kenani Chiwina

University of Arkansas

Muhammad Ullah

university of arkansas

Qun Luo

university of arkansas

YUEJUN QU

University of Arkansas

Friday August 1, 2025 2:30pm - 2:45pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv

2:45pm CDT

CE 8 - Controlled Environment Production of Snow Peas (Pisum sativum) in the Northeast US

Friday August 1, 2025 2:45pm - 3:00pm CDT

Strand 10

Snow peas (Pisum sativum) are a flavorful crop that can be eaten raw or cooked. Diversified farmers often grow them to provide diverse crops for local markets. Controlled environment agriculture allows for fresh harvest and sale in markets that may not otherwise have access to them, such as early or late in the season. This research aims to increase crop diversity for growers. In this research, three cultivars of snow pea were grown including, Oregon Giant, Royal Snow, and Golden Sweet. These varieties were grown using a high (200 mg/L N) or low rate (100 mg/L N) of fertilizer in three different systems. The systems were drip irrigated 3:1 coconut coir: parboiled rice husks, drip irrigated 3:1 sphagnum peat: parboiled rice husks, and hydroponic nutrient film technique (NFT). The pods were harvested every two days for two weeks. Data collected included germination rate, number and weight of pods, and dry weight of shoot biomass per experimental unit. Two trials occurred, the first in winter 2024-2025 and the second in spring 2025. Golden Sweet and Royal Snow had the highest germination rate at over 80% in both trials and Oregon Giant performed poorly at less than 60%. In total harvestable yield, there was no significance in rate of fertilizer by itself, but the interaction between system and fertilizer was significant. In NFT, plants produced more peas with a high rate of fertilizer while in sphagnum peat, they produced more peas with a low rate of fertilizer. Regardless of fertilizer, plants in coconut coir produced very little and experienced a high rate of fruit abortion. In the interaction between system and cultivar, Golden Sweet in NFT produced more than any other combination. In this comparison, when grown in coconut coir, all three cultivars produced significantly less than all other combinations. The production cycle from seed to final harvest was approximately 80 days in both trials. It is feasible to produce a marketable crop of snow peas in controlled environment agriculture. NFT systems with 200 mg/L N of fertilizer produced the highest yield and biomass and could offer hydroponic growers a new crop option.

Speakers

Jacob Schwab

University of Maine

Co-authors

Stephanie Burnett

University of Maine

Friday August 1, 2025 2:45pm - 3:00pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Funding Source Maine Space Grant Consortium (MSGC) Ideas Lab

2:45pm CDT

CITR 4 - Brassinosteroid-Induced Physiological Adaptations Improve Freezing Tolerance in Grapefruit (cv. Ray Ruby)

Friday August 1, 2025 2:45pm - 3:00pm CDT

Strand 11A

Brassinosteroids (BRs) are essential plant steroid hormones that regulate a wide range of developmental and physiological processes. In addition, these hormones play a significant role in helping plants cope with stress by modulating responses to various stressors, including heat, cold, drought, and heavy metals. Freezing temperatures during winter and spring pose a serious threat to citrus production, putting the sustainability of this newly emerging citrus industry in north Florida. Based on the protective effects of BRs, we hypothesized that exogenous application of BRs could enhance the basal tolerance of citrus plants exposed to freezing temperatures. To test this hypothesis, we evaluated the photosynthetic performance and cellular damage of cold sensitive grapefruit (cv. Ray Ruby) plants sprayed with BRs (6 ppm) under freezing stress. Plants were treated with BRs (0 and 6 ppm) at 12, 24, and 48 hours before freezing stress (hbfs). Plants maintained at 20°C and sprayed with BRs (0 and 6 ppm) served as controls. Following treatment, the plants were placed in a freezing chamber and subjected to a gradual temperature decrease until reaching -6°C, where they were maintained for 1.5 hours. Freezing stress induced greater cellular damage in exposed plants compared to those kept at 20°C. However, BRs-treated plants at 12, 24, and 48 hbfs showed approximately 30% less cellular damage compared to water-sprayed plants. Photosynthetic parameters were affected by freezing stress, leading to reductions in CO₂ assimilation (

Speakers

Carlos Aucique

Postdoctoral Associate, University of Florida

Co-authors

Charles Nauck

University of Florida

Fernando Alferez

UF-IFAS

KeAndre Leaks

University of Florida

Muhammad Shahid

University of Florida

Shahid Iqbal

University of Florida

Friday August 1, 2025 2:45pm - 3:00pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops
Poster # csv

2:45pm CDT

NUR - The Challenges and Opportunities of Using Colored Shade Materials for Nursery Production

Friday August 1, 2025 2:45pm - 3:00pm CDT

Foster 1

Hydrangea (Hydrangea macrophylla) is a widely cultivated ornamental nursery crop, but its vigorous shoot growth often necessitates labor-intensive pruning or repeated applications of plant growth regulators (PGRs) to achieve saleable quality. As a result, methods to reduce reliance on pruning or PGRs are highly desirable to growers. One potential alternative is the use of shade netting, which is commonly used in nursery production to protect sensitive plants from excessive solar radiation. This includes hydrangeas which are frequently grown under 30–50% black shade netting. Beyond reducing light intensity, shade nets can also alter the light spectrum, adjusting the relative quantities of blue (400–499 nm), green (500–599 nm), and red (600–699 nm) light, which may affect plant morphology. Blue shade nets, which primarily absorb green and red light, are often marketed as tools to produce more compact shoot growth and thus could serve as an alternative to pruning or PGRs. However, little information exists on the use of blue shade netting to control hydrangea shoot growth. This study evaluated the effects of shade color (black, blue, red, and grey) and blue shade percentage (40–75%) on the growth of hydrangea ‘Twist and Shout’ in a nursery and a greenhouse trial. In the nursery trial, hoop houses were covered with either 30% black, 30% blue, 30% red, or 45% grey shade netting. In the greenhouse trial, chambers were covered with either 40% blue, 50% blue, 75% blue, or 50% black shade netting. Growth parameters including canopy height, width, volume, projected canopy area, leaf length, and chlorophyll concentration were measured repeatedly over a 49-day growth period. Results from the nursery and greenhouse trial showed that shade percentage, not shade color, was the dominant factor influencing shoot growth. Thus, colored shade netting did not suppress plant vigor or reduce the need for pruning or PGRs. These findings suggest that 30% black shade was ideal for hydrangea production, and altering the color of shade netting provided no additive benefits. While ineffective for hydrangea production, nursery crops that benefit from higher percentages of shade such as Hosta plantaginea, may benefit more from colored shade netting.

Speakers

Eric Stallknecht

Virginia Tech

Friday August 1, 2025 2:45pm - 3:00pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source Virginia Nursery & Landscape Horticulture Research Foundation

2:45pm CDT

PNM 4 - Effects of Nutrient Management on Nutrient Leaching in Cut-and-Come-Again Collards Production

Friday August 1, 2025 2:45pm - 3:00pm CDT

Strand 11B

Cut-and-come-again, or repeat harvesting, is a practice in which a single planting of greens is harvested on multiple occasions. This is a common practice among small-scale, urban, and home producers in which the outermost leaves are removed, leaving the growing center of the plant intact enabling multiple harvests without compromising plant health. As this practice is not common among large-scale and commercial producers, there are currently no research-based fertilizer recommendations for cut-and-come-again greens. General guidance simply suggests continued, nitrogen-heavy fertilizer applications to ensure repeated harvests. This type of guidance is not easy to follow and could lead to overapplications and nutrient leaching. An experiment was designed to examine eight different fertilizer application strategies to determine which provided better growth and nutritional quality in later collard harvests while limiting nutrient leaching. Fertilizer applications for the cut-and-come-again treatments (CC) ranged from an initial fertilizer application matching local nutrient recommendations, to repeated applications either the initial complete application or a nitrogen side dressing at every third, every other, or at each harvest. A single harvest control grown to maturity (ODM) was also monitored for nutrient leaching. Leachate from collards was collected weekly and the volume measured. Leachate was then tested for pH, conductivity, color, and turbidity using bench top instruments. A portion of the leachate was also filtered and tested for nitrate-nitrogen, ammonia-nitrogen, and phosphate using microplate spectroscopy. Another filtered portion was acidified and tested for mineral nutrient content using ICP-OES. Nutrient management treatment had no effect on leachate volume, which was affected by sample collection time, season, and year, likely due to weather variation and plant growth factors. Nutrient management treatment did have an effect on water quality metrics; however, no metric displayed a dose response. Differences between nutrient management treatments were seen during the spring of 2024 more often than any other growing season. Most metrics were higher in the spring than in the fall, which could be due to poor growth and fewer harvests in the fall, and therefore lower nutrient additions. While the two fall growing seasons were very similar to each other, there were some differences between the spring of 2023 and the spring of 2024, although which had higher nutrient content depending on the nutrient measured. Leachate pH, color, and increased with the number of days after planting in most cases. Leachate conductivity, turbidity, potassium, magnesium, total phosphorus, and sodium decreased with number of days after planting.

Speakers

Leigh Whittinghill

The Connecticut Agricultural Expeirment Station

Co-authors

Meghan Cahill

The Connecticut Agricultural Experiment Station

Sofia Shubin

Southern Connecticut State University

Friday August 1, 2025 2:45pm - 3:00pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv
Funding Source U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service grant AM22SCBPCT1132

2:45pm CDT

POM 4 - Fruit Doubling in Montmorency Tart Cherry (Prunus cerasus)

Friday August 1, 2025 2:45pm - 3:00pm CDT

Foster 2

Heat or drought stress during critical stages of bud differentiation can result in the formation of double pistils in many stone fruits. If these flowers are pollinated, the resulting malformed “double” or “twin” fruit are not marketable. The frequency of double fruit in Utah tart cherry orchards has increased in recent years. To determine the critical time of flower bud formation for doubling, whole-tree treatments of induced heat stress were imposed for one-week intervals from July to September in 2022 and 2023. The resulting doubling incidence was observed in the following spring and at harvest. There were seasonal differences in the frequency of doubled fruit between years, but the highest incidence of doubling in both years resulted from induced heat stress at 4 to 6 weeks after harvest. Understanding this timing is important in targeting alleviation strategies such as evaporative cooling or spray-on orchard protectants.

Speakers

Brent Black

Utah State University

Co-authors

Josette Moon

Utah State University

Friday August 1, 2025 2:45pm - 3:00pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv
Funding Source Utah Department of Agriculture and Food Specialty Crop Block Grant

2:45pm CDT

VGBR 3 - Evaluation of Salt Tolerance in USDA Spinach (Spinacia oleracea L.) Germplasm at the Seedling Stage

Friday August 1, 2025 2:45pm - 3:00pm CDT

Strand 12B

Soil salinity is a critical abiotic stress that severely limits spinach (Spinacia oleracea L.) growth and productivity, particularly in salt-affected agricultural regions. Developing salt-tolerant cultivars and identifying genetically diverse germplasm are essential strategies to improve spinach resilience under saline conditions. In this study, 150 spinach accessions from the United States Department of Agriculture (USDA) germplasm collection are evaluated under control and salt stress (300 mM NaCl) conditions in a controlled greenhouse environment. The experiment was conducted using a randomized complete block design with three replications. Seedlings were assessed for chlorophyll content (SPAD value), leaf injury score (1–7 scale; 1 representing no visible injury and 7 representing completely necrotic leaves), and seedling height (cm). Substantial genetic variation was observed among the accessions. Five accessions were identified as salt-tolerant based on trait performance, including higher chlorophyll content, lower leaf injury scores, and greater seedling height under salt stress. These included CPPSIH 3 04, PI 171860, PI 177082, PI 171859, and PI 174387. Broad-sense heritability was high for chlorophyll content, leaf injury score, and seedling height, indicating that these traits are largely controlled by genetic factors under salinity stress. A negative correlation was detected between chlorophyll content and leaf injury score, suggesting that accessions maintaining higher chlorophyll content tended to exhibit less foliar damage under salt stress. These findings highlight valuable genetic resources for spinach breeding programs focused on improving salinity tolerance. Future studies will expand the evaluation to a broader collection of spinach accessions and implement genome-wide association studies (GWAS) to identify single nucleotide polymorphism (SNP) markers that can facilitate molecular breeding for salt tolerance.

Speakers

Hanan Alkabkabi

University of Arkansas

Co-authors

Ainong Shi

University of Arkasnas

Derrick Harrison

university of arkansas

haizheng xiong

University of Arkansas

Ibtisam Alatawi

university of arkansas

Kenani Chiwina

University of Arkansas

Muhammad Ullah

university of arkansas

Qun Luo

university of arkansas

Renjie Du

university of arkansas

YUEJUN QU

University of Arkansas

Friday August 1, 2025 2:45pm - 3:00pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv

3:00pm CDT

CE 8 - Manipulation of Light Spectrum Enhances Seed Yield and Plant Compactness in Soybean Cultivated in Controlled Environment

Friday August 1, 2025 3:00pm - 3:15pm CDT

Strand 10

Soybeans play a crucial role in global agriculture, serving as a primary source of protein and oil, which supports food security, livestock feed, and renewable energy worldwide. The growing demand for food and fuel has intensified the need for soybean production, driving research into soybean cultivation in controlled environments. Manipulating light conditions using specialized LED lights in soybean production is particularly promising, as soybeans are highly responsive to light variations, including changes in the light spectrum. Our objective was to develop compact soybean plants optimized for controlled environments and enhance seed yield by exposing them to various light spectra. Soybean plants (varieties CZ 75 70LL and S16-14801C) were cultivated from seeds in growth chambers (27 °C/26 °C, day/night; 68% relative humidity; 590 µmol mol⁻1 CO₂) in 11 L plastic pots containing peat-moss substrate. One week after germination, the plants were exposed to one of four light spectrum treatments with 700 μmol m−2 s−1 photon flux density. These treatments had different percentages of photon flux ratios of blue (B: 400–500 nm), green (G: 500–600 nm), red (R: 600–700 nm), and far-red (FR: 700–750 nm) wavelengths: 1) 22B:50G:26R:2FR (White light), 2) 20B:80R, 3) 50B:50R, and 4) 40B:40R:20FR. Seed yield evaluations showed that the 40B:40R:20FR treatment resulted in a 10% higher 100-seed weight compared with the other treatments for both varieties. The number of seeds per plant increased by 21% in S16-14801C and 11% in CZ 75 70LL under the same treatment. Seed weight per plant was also higher in both varieties under this treatment, with increases of 26% for S16-14801C and 19% for CZ 75 70LL. Morphological evaluations revealed that the shortest plants were in the 50B:50R treatment, with a 2.4-fold reduction in height for S16-14801C and a 1.7-fold reduction for CZ 75 70LL compared to White light. Plants under the 40B:40R:20FR treatment were 33% shorter than those in the white light treatment for both varieties. Additionally, plants exposed to 40B:40R:20FR had 27% fewer branches but exhibited a 19% thicker stem diameter and a 29% higher shoot dry weight than other treatments. These findings confirm that the light spectrum can be adjusted to meet specific goals and enhance soybean cultivation in controlled environments, particularly by increasing seed yield and promoting plant compactness.

Speakers

Cristiane da Silva

Postdoctoral Research Scholar, North Carolina State University

I'm Cristiane, a plant physiologist with experience in plant biochemistry and plant responses to abiotic stress. Currently, I'm a post-doc at NCSU studying the effects of light on plant life cycles to expedite breeding purposes in crop and tree species. When I'm not working, I enjoy... Read More →

Co-authors

Cristian Collado

North Carolina State University

Jan Van Butsele

BASF

Ricardo Hernandez

North Carolina State University

Friday August 1, 2025 3:00pm - 3:15pm CDT
Strand 10

Oral presentation, Growth Chambers and Controlled Environments 8

Subject Growth Chambers and Controlled Environments
Poster # csv

3:00pm CDT

CITR 4 - Extending the Satsuma Harvest Window Through a Single Gibberellic Acid Application

Friday August 1, 2025 3:00pm - 3:15pm CDT

Strand 11A

The Georgia citrus industry is rapidly growing. The citrus farmgate value increased by ~70% from 2022 ($22.4M) to 2021 ($13.2M). More acres of citrus are put in every year and, as of 2024, there are nearly 5,000 acres of citrus across the southern half of the state. Of this acreage approximately 60% are satsumas. This has generated a bottleneck for packinghouses as a majority of the citrus grown in the state reach an acceptable maturity at the same time. Georgia citrus growers have expressed an interest in expanding the harvest window of their existing plantings so more fruit can reach the market. The plant growth regulator, gibberellic acid (GA), has historically been used to delay color break in Florida citrus. Unfortunately, the existing recommendations from Florida are not applicable to the citrus varieties grown in Georgia. The present works aims to develop GA recommendations for Georgia satsumas. GA was applied at a rate of 0, 8, 10, 15, 20 ppm (n = 4) prior to color break in August 2024. The 15 and 20 ppm concentrations saw significantly less red and yellow color development by mid-December (p

Speakers

Mary Sutton

University of Georgia

Co-authors

Jacob Kalina

University of Georgia

Friday August 1, 2025 3:00pm - 3:15pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops
Funding Source Georgia Farm Bureau

3:00pm CDT

NUR - Mapping Water Risk for US Nursery and Greenhouse Growers

Friday August 1, 2025 3:00pm - 3:15pm CDT

Foster 1

Nursery and greenhouse growers and dealers in the United States contribute significantly to the economy, environment, and food systems. Nursery and greenhouse operations provide a wide range of plants critical to residential and commercial landscaping, habitat creation for pollinators, and essential planting materials for fruit, vegetable, and ornamental crop production. The sustainability of these operations, as with other agricultural productions, highly relies on water availability, making it significant to evaluate the future of water and climatic risks throughout the United States. This study focuses on the critical part of this evaluation, developing a map of licensed greenhouse and nursery growers and dealers throughout the United States, using information received directly from state officials and agency websites. Texas, Florida and California were revealed to have the most HRI operations (growers and dealers), but the latter two states have the most growers. Region-wise, the Southeast and Northeast regions have the most nursery growers, with the Northern Rockies and Plains and the Southwest regions having the lowest numbers, although states like Utah, Arizona, and Idaho are currently missing in our analysis due to data unavailability and complexity. This mapping exercise will be followed by overlaying climatic indices such as precipitation, temperature and drought forecasts, to evaluate growers' state and regional vulnerability to water and climatic risks. This will aid in assessing climate-related risks, guide adaptive strategies, and support sustainable nursery management across diverse environmental zones.

Speakers

Ibrahim Busari

Clemson University

Co-authors

Debabrata Sahoo

Clemson University

Lydia Alford

Clemson University

Sarah White

Clemson University

Friday August 1, 2025 3:00pm - 3:15pm CDT
Foster 1

Oral presentation, Nursery Crops

Subject Nursery Crops
Poster # csv
Funding Source Horticulture Research Institute

3:00pm CDT

PNM 4 - Effect of Selenium Fertilization on Carotenoid and Glucosinolate Accumulation in Two Cress Varieties Grown Hydroponicall

Friday August 1, 2025 3:00pm - 3:15pm CDT

Strand 11B

Nutrient biofortification in leafy vegetables is a promising strategy to enhance dietary health benefits, improve crop nutritional quality, and promote sustainable agricultural practices. Advanced plant cultivation techniques, such as hydroponic production and targeted micronutrient fertilization, provide a controlled environment for optimizing nutrient uptake and secondary metabolite synthesis. Selenium (Se), an essential micronutrient, has been shown to influence plant metabolism, particularly the synthesis of bioactive compounds such as carotenoids and glucosinolates. However, its role in modulating these phytochemicals in hydroponically grown Nasturtium officinale (watercress) and Barbarea verna (upland cress) remains underexplored. This ongoing study investigates the effects of selenium fertilization at varying concentrations (0, 1.0, 2.0, and 4.0 mg Se·L⁻¹) on carotenoid and glucosinolate accumulation in two cress varieties cultivated under controlled hydroponic conditions. The hydroponic system provides a consistent environment for plant growth, allowing precise manipulation of nutrient levels, pH, temperature, and light intensity. Selenium treatments follow a randomized complete block design to ensure replication and statistical rigor. Growth parameters, biomass accumulation, and biochemical analyses of carotenoid and glucosinolate levels are being monitored to determine the interactions between selenium uptake and secondary metabolite biosynthesis. Carotenoid content in plant tissues will be quantified using high-performance liquid chromatography (HPLC), while glucosinolate concentrations will be determined through chromatographic and spectrophotometric methods, ensuring precise assessment of bioactive compound accumulation. Preliminary observations suggest that selenium supplementation may modulate plant physiological responses, potentially enhancing carotenoid and glucosinolate synthesis. Differences in metabolite accumulation between the two cress varieties indicate potential genotype-specific responses to selenium fertilization. Understanding these interactions will contribute to optimizing hydroponic production systems, improving the nutritional and functional quality of leafy greens, and informing sustainable agricultural practices. Findings from this study could advance nutrient-fortification strategies, enhance functional food development, and address micronutrient deficiencies, thereby supporting both horticultural innovation and public health. Keywords: Selenium fertilization, Beta-carotene, Hydroponic, Watercress varieties, Agricultural sustainability, Crop yields, Environmental impact, Spectrophotometric analysis,

Speakers

Adekunle Adeyeye

Kentucky State University, Frankfort, KY

Co-authors

Theoneste Nzaramyimana

Kentucky State University, Frankfort, KY

Friday August 1, 2025 3:00pm - 3:15pm CDT
Strand 11B

Oral presentation, Plant Nutrient Management 4

Subject Plant Nutrient Management
Poster # csv

3:00pm CDT

POM 4 - Diversity and Abundance of Insect Pollinators in Pawpaw (Asimina triloba), an Emerging Commercial Fruit Crop

Friday August 1, 2025 3:00pm - 3:15pm CDT

Foster 2

Pawpaw (Asimina triloba) is a temperate, deciduous fruit tree native to North America and a member of the custard apple family (Annonaceae). It produces unique, flavorful fruit with a taste resembling mango, banana, and pineapple, making it valuable for various value-added products such as jams, bread, ice cream, and brandy. Pawpaw fruits are also rich in nutrients, vitamins, and antioxidants, contributing to their increasing commercial potential. However, fruit sets in some cultivars may be limited due to the protogynous and self-incompatible nature of pawpaw flowers, which require external pollinators for successful fertilization. Unlike many fruit-bearing species, pawpaw has been thought to be pollinated by beetles and flies rather than bees. However, their abundance and role in pollination remain understudied. This study aims to identify and quantify insect visitors to flowering and non-flowering branches of two pawpaw cultivars, ‘Sunflower’ and ‘Susquehanna’. Ten trees of each cultivar were selected, and a completely randomized design was implemented setting up 20 wire cage traps coated with tangle-trap adhesive (The ORTHO Group, Marysville, OH 43040) on flowering and 20 on non-flowering branches. After an 18-day flowering period, the traps were collected, and captured insects were identified to the level of order and their abundance recorded. In 2024, 20 traps were placed at control sites outside the orchard (roadsides and fields), and nine days of direct observations were conducted to document insect activity on male and female flower stages. Data were analyzed using RStudio v.2023.09.1 (Posit, PBC, Boston, MA) and subjected to an ANOVA, with flowers, cultivars, and years as treatment factors, followed by Least Significant Difference (LSD) means separation. Results from 2023 indicate a significantly higher abundance (p-value< 0.0001***) of Coleopteran insects on both flowering and non-flowering branches of ‘Sunflower’ and ‘Susquehanna’ compared to 2024. In 2023 Coleoptera was significantly higher in the flowering branch (p-value 0.0255*) and had an interaction of cultivar and flowers (p-value 0.04767*) while in 2024 Diptera was substantially higher in the non-flowering branches (p-value 0.04009 *) This study provides valuable insights into the pollination ecology of pawpaw, aiding in the development of strategies to enhance fruit set and improve commercial production as the species transitions into broader commercialization.

Speakers

Subas Thapa Magar

Kentucky State University

A major change happened when the tragedy of Corona hit the world. Hi, I am Subas Thapa Magar, a graduate research assistant under the supervisor Dr. Kirk Pomper. I am currently working on Pawpaw (Asimina Triloba), the native fruit tree of the United States of America, and my research... Read More →

Co-authors

Jeremy Lowe

Kentucky State University

Kirk Pomper

Kentucky State University

Sheri Crabtree

Kentucky State University

Friday August 1, 2025 3:00pm - 3:15pm CDT
Foster 2

Oral presentation, Pomology 4

Subject Pomology
Poster # csv

3:00pm CDT

VGBR 3 - Response Of Sweet Potato Genotypes To Drought Stress

Friday August 1, 2025 3:00pm - 3:15pm CDT

Strand 12B

Sweet potato (SP) is a staple in many countries, primarily used for human consumption, but also showing potential for animal feed, ethanol production, ornamental use, and industrial applications. SP is mistakenly considered tolerant to drought, but water shortage can significantly compromise the yield and quality of this crop. It is frequently cropped in drought-prone environments, characterized by sandy soil and high temperatures. Identifying drought-tolerant genotypes is essential for the development of future-ready cultivars. This study aimed to evaluate physiological, biochemical, and morphological responses of sweet potato genotypes to water deficit conditions. A completely randomized experimental design was adopted in a 2 x 20 factorial scheme with four replicates. The first factor consisted of two water regimes, 20 and 100% of pot capacity. The second factor included 20 genotypes. Plants were grown in 12L-pots filled with a 2:1 soil-to-sand mixture. All plants were irrigated at full pot capacity for five weeks to ensure establishment. Subsequently, water regimes were imposed employing time-domain reflectometry (TDR) sensors, and evaluations were conducted four weeks later. Parameters assessed included chlorophyll fluorescence, biomass, water potential, gas exchange, biochemical parameters, and secondary metabolites. Genotypes responded differently to water regimes, revealing considerable genetic variability for drought tolerance. Water deficit negatively affected the performance of several genotypes, particularly in relation to the variation of minimum fluorescence (Fv/F0), leaf water potential, and electron transport rate. Correlation analysis showed strong associations among traits of stressed plants. There was a high positive correlation between leaf water potential and fresh mass of the aerial part, as well as the photosynthetic rate with the chlorophyll fluorescence parameters Fm and Fv/F0. Genotypes ‘Luiza’, ‘Canadense’, ‘CIP-420717', ‘Maria Isabel’, and ‘CIP-440186' exhibited superior performance under drought conditions and are promising candidates for breeding programs targeting drought tolerance.

Speakers

Edgard Silva

Western Sao Paulo University

Co-authors

Ana Claudia Pacheco

Western Sao Paulo University

Beatriz Viezel Moraes

Western Sao Paulo University

Dario Sousa da Silva

Western Sao Paulo University

Elisa Patricia Ramos de Melo

Western Sao Paulo University

Joao Lucas Pires Leal

Western Sao Paulo University

Maria Albertina Monteiro dos Reis

Western Sao Paulo University

Friday August 1, 2025 3:00pm - 3:15pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv
Funding Source Sao Paulo Research Foundation

3:15pm CDT

CITR 4 - Insights into Pre-Harvest Rind Disorder in Mandarins Under California Growing Conditions

Friday August 1, 2025 3:15pm - 3:30pm CDT

Strand 11A

The citrus industry experiences considerable losses due to a physiological rind disorder that compromises mandarin fruit quality and marketability—particularly in cultivars like Satsuma Owari. This disorder, characterized by water-soaked areas that progress to brown lesions, is likely triggered by multiple factors, including environmental conditions such as high relative humidity and rainfall. It typically appears after fall rain events and is more prevalent in fruit from the outer canopy. Our study, conducted in a commercial orchard in California’s San Joaquin Valley, explored the role of environmental conditions, rind water status, and potential management strategies. We found that treatments applied at the color break stage, 2,4-dichlorophenoxyacetic acid (2,4-D, 16 mg/L), gibberellic acid (GA₃, 20 mg/L), and Vapor Gard® (0.5% v/v)—significantly reduced rind damage. However, GA₃ delayed external color development by approximately four weeks. Susceptibility to rind disorder varied by cultivar, with Kishu being the most susceptible, followed by Satsuma Owari and Gold Nugget, while Page, Tango, and W. Murcott exhibited greater tolerance. We also investigated biochemical, hormonal, and molecular changes associated with the disorder. Damaged tissues showed reduced cellulose concentrations but similar levels of pectin and hemicellulose compared to healthy tissue. Additionally, damaged rinds had higher hydrogen peroxide (H₂O₂) content and increased peroxidase (POD) and polyphenol oxidase (PPO) activities. Metabolomic and hormonal profiling identified 76 metabolites, with 43 differing significantly between healthy and damaged tissues, highlighting the involvement of jasmonic acid and related compounds in the disorder’s development. Transcriptomic analysis further revealed differential expression of genes involved in stress responses, cell wall degradation, and hormone signaling between healthy and affected tissues. These findings suggest that delaying rind senescence using targeted treatments may reduce the incidence of this disorder. This research provides new insights into the physiological, biochemical, and molecular basis of mandarin rind disorder and offers practical management strategies to mitigate fruit losses across different varieties.

Speakers

Ashraf El-kereamy

University of California Riverside

Co-authors

Ahmed Ismail

University of California Riverside

Alaaeldin Rezk

University of California Riverside, Riverside

David Obenland

USDA

Greg Douhan

University of California Riverside

Manhoi Hur

University of California, Riverside

Mary Lu Arpaia

University of California Riverside

Suejin Park

Jeonbuk National University

Tariq Pervaiz

University of California Riverside, Riverside

Friday August 1, 2025 3:15pm - 3:30pm CDT
Strand 11A

Oral presentation, Citrus Crops 4

Subject Citrus Crops
Funding Source California Citrus Research Board

3:15pm CDT

VGBR 3 - Impact of seasonal variability and soil types on Phosphorus Use Efficiency in Lettuce.

Friday August 1, 2025 3:15pm - 3:30pm CDT

Strand 12B

In Florida, lettuce is cultivated in the southern region in wintertime, a period marked by environmental fluctuations. The dominant Histosols in this area are prone to subsidence and exhibit an increased pH due to the incorporation of calcium carbonate, leading to a reduction in phosphorus (P) availability. In the northern part of Florida, lettuce has the potential to be cultivated in sandy soil to supply the high demand of lettuce, however this type of soils naturally exhibits low P availability. To sustainably produce lettuce in these soils, P efficient cultivars should be bred. Prior, lettuce genotypes were identified as P-efficient and P-inefficient across types. The objective of this study was to determine the influence of Genotype × Environment (G×E) interaction on lettuce cultivated under low P inputs. A multi-environment trial was conducted using 22 P-efficient or P-inefficient genotypes in eight experiments distributed across the lettuce season (Fall, Winter, and Spring) at two locations and distributed in a randomized complete block design with four replicates. Five experiments were conducted in histosol soils, and three in sandy soils. Each experiment was cultivated under a standard and a reduced P fertilizer rate . Data collected included head weight, and marketability. The analysis of the G×E for these traits under low P conditions utilized three methodologies: the Finlay-Wilkinson approach, that determines the stability of each genotype across environments independently; the Genotype Genotype × Environment biplots, that discerns the 'which-won-where' patterns for mega-environments and identifies the most stable genotype(s) across environments; and the Bayesian AMMI, that aims to understand genotype stability across environmental factors. The results demonstrated that both crossover and non-crossover G×E interactions are statistically significant, accounting for 16% of the variance for season and for soil types in head weight. These interactions explained 27% of the variance for marketability for P fertilizer treatments, accounting 15% and 9% for season and soil types, respectively. The romaine breeding line 60183 and cultivar Tall Guzmaine were identified as P-efficient, exhibiting non-crossover interaction and stability across P rates, seasons, and soil types. Iceberg cultivars Honcho II, and Cibola, and the loose-leaf RSX743 were P-efficient and exhibited crossover interactions. The analysis revealed that winter planting in both soil types is the most stable and productive environment, with histosol soils achieving higher yields under low P input. Results of this study highlight the importance of G×E interactions to be considered when breeding lettuce cultivars for low P inputs.

Speakers

Jairo Antonio Arcos Jaramillo

University of Florida

Co-authors

Byron Manzanero

Horticultural Sciences Department, University of Florida

My name is Byron Manzanero a Ph.D. Candidate in plant breeding.

Diego Jarquin

University of Florida

German Sandoya Miranda

University of Florida EREC

Jesse Murray

University of Florida

Julian Garcia Abadillo

University of Florida

Friday August 1, 2025 3:15pm - 3:30pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv
Funding Source Specialty Crop Research Initiative Project “Enhancing Resource Utilization for Sustainable Lettuce Production in Changing Climates”

3:30pm CDT

VGBR 3 - Host Range and Epiphytic Potential of Xanthomonas hortorum pv. vitians in Lettuce-Associated Plant Species

Friday August 1, 2025 3:30pm - 3:45pm CDT

Strand 12B

Bacterial leaf spot (BLS) of lettuce, caused by Xanthomonas hortorum pv. vitians (Xhv), is a major disease limiting lettuce production worldwide, particularly in tropical environments such as the Everglades Agricultural Area (EAA) in Florida. The pathogen is highly aggressive, rapidly dispersing under favorable conditions, and its sporadic outbreaks make disease prediction and management challenging. While Xhv is primarily known to infect lettuce (Lactuca sativa L.), its potential to colonize alternative hosts, including crops and weeds in lettuce-growing regions, remains poorly understood. This study aimed to evaluate the host range and epiphytic capabilities of Xhv by inoculating two isolates (‘L7’ and ‘SC8B’) onto common leafy vegetable crops and weeds frequently found in or around lettuce fields. A total of 26 plant species were tested, including weeds from Malvaceae (n=1), Portulacaceae (n=1), Amaranthaceae (n=2), Asteraceae (n=3), Brassicaceae (n=1), and Poaceae (n=1), along with vegetable crops from Asteraceae (n=6), Brassicaceae (n=7), and Apiaceae (n=5). Disease severity was assessed 12 days post-inoculation (DPI) using a 0–5 rating scale based on symptomatic foliage area. Initial water-soaked lesions were observed on susceptible lettuce (‘Okeechobee’) at 2 DPI, progressing to necrotic lesions and severe infection with an average disease severity score of 4 at 12 DPI. Notably, symptomatic responses were also observed in endive (Cichorium endivia L.), escarole (C. endivia var. latifolium), and coriander (Coriandrum sativum L.), with median disease severity scores of 3, 3, and 2, respectively. Symptoms in these crops were consistent with BLS in lettuce, including water soaking, chlorosis, and necrosis. In contrast, Brassicaceae species and all tested weeds remained asymptomatic. Bacterial isolations from symptomatic and asymptomatic leaves revealed colonies morphologically consistent with Xhv, displaying yellow pigmentation on nutrient agar. To confirm pathogenicity, hypersensitivity and compatibility response assays were conducted by infiltrating recovered bacterial isolates into resistant (‘PI 358001-1') and susceptible (‘Okeechobee’) lettuce cultivars. Typical disease symptoms developed on susceptible lettuce, confirming Koch’s postulates. The asymptomatic nature of weed species suggests they may serve as reservoirs, potentially contributing to pathogen persistence and dissemination in lettuce fields. These findings provide new insights into Xhv epidemiology and highlight alternative host species that may play a role in disease outbreaks. Understanding the pathogen’s ecological interactions is critical for developing effective disease management strategies and mitigating economic losses in lettuce production systems.

Speakers

Byron Manzanero

Horticultural Sciences Department, University of Florida

My name is Byron Manzanero a Ph.D. Candidate in plant breeding.

Co-authors

Calvin Odero

University of Florida

German Sandoya Miranda

University of Florida EREC

Friday August 1, 2025 3:30pm - 3:45pm CDT
Strand 12B

Oral presentation, Vegetable Breeding 3

Subject vegetable Breeding
Poster # csv