ASHS 2025 Conference

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.

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

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.

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.

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.

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.

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.

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.

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 summer squash (Cucurbita pepo ‘Multipik’) 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 summer squash served as the control treatment. Control beds were 6.7m long. All treatments were replicated three times. Summer Squash was transplanted on May 31, 2024 at 0.6m spacing, single row. HOBO soil temperature, air temperature, and light intensity sensors were installed on the same day. Mustang MAXX® AND PyGanic® were sprayed to manage spotted cucumber beetles and squash bugs. A total of 31 harvests occurred throughout the season every 2 to 3 days between July 1 and September 20. Plants between the solar panels yielded 49.5 kg per row while the open-field yielded 36.5 kg, a 26% increase in the solar treatment. Between June, July, and August, the air temperature was cooler than the control on average by 3 degrees Fahrenheit while the soil temperature was 2 degrees Fahrenheit cooler. Light intensity decreased by 34% under the solar panels. Based on first year results, summer squash shows 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 summer squash.

Solar energy production has been rapidly expanding in the Southeast; in Georgia alone, acreage has increased from under 500 to over 25,000 acres in the last decade. Agrivoltaics and ecovoltaics have emerged as strategies to ease land competition between Large-Scale Solar (LSS), agriculture, and natural resources. Agrivoltaic systems co-locate solar panels with row crops or livestock agriculture, thereby “stacking” the production of energy and agricultural products on the same land. LSS sites are typically seeded with Bahia and Bermuda grasses to control erosion while vegetation height is maintained by mechanical mowing. However, one of the most common and successful agrivoltaic applications is grazing livestock – typically sheep, which benefit from a high-protein diet, such as a legume. Rhizoma Perennial Peanut (RPP) is an emerging forage crop grown predominantly in southern areas with sandy soils and permissive winter temperatures. Most LSS are located in mid- and South Georgia where soils may have higher clay content. We set out to explore feasibility of RPP as a land cover under solar system in South Georgia. RPP ‘EcoTurf’ was planted between solar panels and outside the solar array. We implemented two experimental treatments: three seeding rates (100, 140, or 160 bushels/acre), and fertilization at planting or at mid-season. We measured canopy spread, leaf chlorophyll content and fluorescence. We also counted blooms and made aerial sweeps to assess arthropod abundance and diversity. In addition to being a potential grazing source, RPP matures well below the leading edge of the solar panels, thus eliminating the need for mowing even without livestock. If left uncut, RPP produces attractive yellow blooms which may serve as floral resources for pollinators and other beneficial insects. In this way, RPP can provide ecosystem services, including biodiversity and wildlife habitat, a potential win-win opportunity for LSS development and natural ecosystems in the Southeast USA. Given the selection of low growing ground cover that requires less frequent mowing (or no mowing), the implementation of RPP could also lead to lower inputs and reduced operation costs of the LSS in the long term.

Artichoke (Cynara cardunculus var. scolymus) belongs to the sunflower family and is cultivated for its edible flower buds. Being adapted to Mediterranean climates, artichoke requires adequate winter chilling for flower bud induction but is susceptible to freeze damage, limiting its commercial production in the United States almost exclusively to California. In tropical and subtropical climates, despite minimal freeze risk, insufficient winter chilling presents a major constraint to artichoke production. This study was initiated in 2015 to evaluate the potential for establishing artichoke as a viable winter crop in Florida. First, we developed a protocol for artificial bud induction using the plant hormone gibberellic acid (GA₃). When applied at the optimal rate and developmental stage, GA₃ effectively promotes bud formation independently of natural winter chilling. From 2016 to 2020, we evaluated seven cultivars based on earliness, yield, and bud quality and selected two promising cultivars, ‘Imperial Star’ and ‘Green Queen’. We also evaluated planting dates from early September to early December and determined that early to mid-October is the optimum planting window, yielding up to 17.3 and 11.8 t ha–1 for ‘Imperial Star’ and ‘Green Queen’, respectively. From 2022 to 2025, we tested additional 16 hybrids and identified three promising cultivars, ‘20-063’, ‘22-017’ and ‘23-057’. Our current artichoke production guide includes recommendations on GA3 application, cultivars, planting configurations, plastic mulch, and basic pest management. In 2023, artichoke was grown on about 12 hectares in Florida using this production guide. Ongoing research focuses on assessing nutritional values and postharvest quality to enhance the viability of artichoke as Florida’s new winter crop.

Vegetable production is highly susceptible to yield and quality loss due to insect pests leading to increased management intensity. Use of conservation biological control practices such as intercropping offers potential benefits to environmental sustainability while also maintaining economic profitability. This study was conducted to evaluate the impact of intercropping bell pepper (Capsicum annuum ‘King Arthur’) with cut flowers including zinnia (Zinnia elegans ‘Benary’s Giant White’), sunflower (Helianthus annus ‘Soraya’) and dianthus (Dianthus caryophyllus ‘Chabaud Benigna’). Data collected included insect and disease pressure ratings, marketable and unmarketable yield, economic return, and insect population diversity. Pepper yield was positively impacted in treatments including dianthus, while economic return was greatest where bell pepper was intercropped with zinnia.

Regenerative farming practices focus on improving soil health and creating resilient agricultural systems, offering long-term sustainability and environmental benefits compared to conventional organic methods. This study investigated the effects of an in-season cover cropping practice on insect and weed density and crop yield on California’s Central Coast. Two field trials compared regenerative and standard organic systems. Weed populations were assessed biweekly using 50cm x 50cm quadrats, while insect populations were monitored with yellow sticky cards and direct counts. Yields were measured in kilograms per hectare and categorized as fresh marketable, processed marketable, and unmarketable. Both treatments were planted on 80-inch beds using certified organic inputs and methods. The regenerative treatment featured a cereal cover crop in the bed center, with two rows of transplants on either side. The first trial took place at Cal Poly San Luis Obispo Organic Farm (Jan–May 2024) with cabbage and sudan grass (three replicates). The second was at a grower’s field near San Ardo, CA (Feb–June 2025) with sweet baby broccoli and ryegrass (four replicates). In Trial 1, weed coverage was not significantly different between treatments (19.6 ± 5.3% for standard organic, 14.9 ± 0.7% for regenerative). Flea beetles were the most common pests, with no significant differences in pest densities (370.67 ± 24.17 vs. 403.11 ± 23.27). Predator and parasitoid insect counts were similar, and no pollinators were observed. Total yields were 5730.91 ± 5688.32 kg/ha for standard organic and 4929.50 ± 4890.27 kg/ha for regenerative. Fresh marketable yields were comparable (3169.77 ± 3139.50 vs. 3237.02 ± 3204.51). Although both treatments experienced high weed pressure, regenerative plots had fewer weeds, suggesting the grass cover crop may aid suppression. Insect density was numerically higher in regenerative plots, which also had slightly lower yields—possibly due to the grass strip. In the second trial, effective weed management led to no observed weeds. Higher insect densities were found in regenerative plots. These findings indicate that regenerative practices, such as incorporating a grass cover crop, may influence weed suppression and insect activity, though they may also slightly reduce yields. Continued research is needed to better understand these trade-offs and optimize regenerative system design for both productivity and ecological benefits.

The current marketing of humic acid products to potato growers indicates that incorporating these materials at planting will lead to improved nutrient uptake, increased soil health, vigorous growth, and increase in yields. Humic acids are composed of long chained, organic molecules that can be naturally or industrially made. In 2024, the in-furrow application of humic acid was evaluated in Pennsylvania on the cultivar ‘Lehigh’. Plots were evaluated for nutrient uptake and photosynthetic capacity as impacted by use of Black Label Zn, Duo Maxx, Fertiactyl, Humi-Flex FA, Hydra-Hume, and Monty's Carbon. Preliminary data show no statistically significant difference between applied products and an untreated control for macro and micronutrients analyzed by plant tissue sampling. No statistically significant differences were observed for stomatal conductance, chlorophyll fluorescence, or electron transport rate. These preliminary data suggest that there is no positive return on investment with using humic acid products in-furrow at the time of planting. As part of a three-year study, data from 2023 supported a similar conclusion.

Organic farming systems face inherent limitations in nutrient management, particularly when plant nutrient demand exceeds available supply. This multi-year study examined the effectiveness of various soil amendment strategies and cover cropping systems on soil health indicators and pepper yields across three Purdue Agriculture Research Centers in Indiana (Wanatah, Lafayette, and Vincennes). Our experimental design compared conventional, organic, and mixed soil amendment approaches using standardized nutrient targets across treatments. Soil amendments included conventional and organic nutrient sources, plant and manure-based, or mixed (leaf mold and manure) compost applications. Summer cover crops (mustard for biofumigation, sunn hemp for nitrogen fixation, and sorghum-sudangrass for biomass production) were planted in Year 1, while a mix of cereal rye and hairy vetch served as fall/winter cover crops throughout the study. Buckwheat was seeded in bed row middles during Years 3 and 4. Soil health was assessed using the Haney test on composite samples from fifteen 15 cm deep soil cores per experimental unit. Initial challenges from nutrient losses due to heavy rainfall and significant weed pressure in 2021 necessitated management adaptations, including preplant herbicide application and plastic mulch protection of soil amendments. Soil health metrics improved dramatically at the Lafayette location in 2022 (67-202% increase) but showed minimal improvement at Wanatah and Vincennes. By 2023, average soil health declined by 14% across sites, primarily due to decreased water-extractable organic nitrogen (WEON) and slight reductions in water-extractable organic carbon (WEOC), resulting in reduced microbial activity. Our findings demonstrate that summer cover crops combined with fall/winter cover crops produced comparable benefits to high-rate compost applications for both crop yield and soil health improvements. However, high compost applications, particularly at Lafayette, led to extremely high P₂O₅ levels that required adjustment of fertility management. Soil respiration emerged as a reliable predictor of overall soil health, with statistical analysis indicating that a 10-point increase in soil respiration corresponded to soil health improvements of 1.0, 1.1, and 1.3 units at Wanatah, Lafayette, and Vincennes, respectively. This research provides evidence-based guidance for integrated soil fertility management that balances immediate crop nutrient needs with long-term soil health objectives, offering sustainable strategies for both organic and conventional production systems.

The Colca River Valley is an important agricultural and touristic region in southern Peru ranging from 2,500 to 4,000 meters above sea level. Many of the challenges associated with farming in this hyper-arid region were overcome through the establishment of unique terraces on the steep hillsides centuries ago, which have improved soils and help retain water and heat. However, the cold temperatures in this region prevent farmers from growing many warm-season crops such as tomatoes and zapallo, which bring high returns in larger cities like Arequipa. Fitotoldos are temporary greenhouse like structures created using earthen bricks and a plastic covering. Much like high tunnels or polyhouses in the U.S., these structures can help extend the growing season and allow farmers to grow new warm season crops that bring higher returns. In the past five years, many initiatives from the Peruvian government and several non-governmental organizations have provided funds to establish fitotoldos in the Colca River Valley. However, the farmers recieved little guidance on how to effectively manage soils and crops in these structures. This has led to poor quality crops and the abandoment of many of these structures. To help overcome this challenge, we conducted a survey of soils and farming practices in these structures. Soil samples were subject to several tests to quanitify soil physical, chemical, and biological properties and determine how these properties were impacted by the farmer’s management practices. Results were shared with farmers and used to design training programs that will help local farmers better manage these structures and their crops over the long-term.

Edamame [Glycine max (L.) Merr.] is a specialty crop with untapped potential in the Midwest. Adoption of edamame in the Midwest has potential due to similarities in production practices to grain soybean and the potential for higher return per acre. Additionally, USA is experiencing expanding market opportunities and rising consumer interest in locally grown edamame. Despite these benefits, limited research exists on suitable edamame varieties for this region, and effective weed control remains crucial for Midwest edamame adoption. Our research aimed to identify currently available varieties of edamame with rapid germination response, with and without weed competition. Six readily available varieties of edamame (Chiba green, Sayamusume, BeSweet 292, Midori Giant, Tohya, and Karikachi) were grown with and without velvet leaf (Abutilon theophrasti Medik.) competition. Weed seeds were planted using three timing treatments: two weeks before edamame planting (PRE), simultaneously with edamame (SIM), and two weeks after edamame planting (POST). Two control treatments without weeds (‘Control 1’ and ‘Control 2’) were also incorporated. This study was designed as an RCBD split-plot design with three replications, with variety as the main plot and timing of weed competition as the split-plot under greenhouse conditions. Edamame emergence rate, plant height, LA (leaf area), and dry weight for both edamame and weed were measured. At 5 and 9 DAS (days after seeding), edamame emergence was significantly higher without weed competition (71.76% and 95.37% in ‘Control 2’ treatment) compared to when weeds had a head start (46.53% and 72.69% in ‘PRE’ treatment). At 9 DAS, edamame emergence was significantly higher when edamame had a head start (93.06% in ‘POST’ treatment) compared to when weeds emerged first (72.69% in ‘PRE’ treatment). In terms of emergence rate, Karikachi showed superiority (78.89%) compared to Midori Giant (39.17%) at 5 DAS, but there was no difference among varieties at 9 DAS. Timing of weed planting affected edamame height, LA, and edamame dry weight. Edamame height and dry weight were reduced by 11.67% and 5.71 % by weed competition when weeds were planted two weeks earlier than edamame. Edamame competition significantly reduced weed dry weight by 93.94% when weeds were planted two weeks later and by 84.85% when planted the same day, compared to weeds established two weeks before edamame. Weed competition reduced edamame LA by 29.189 cm² when weeds were planted simultaneously with edamame compared to two weeks after edamame planting (241.582 cm² in ‘SIM’ vs 270.771 cm² in ‘POST’).