ASHS 2025 Conference

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.

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

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

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.

Overview of Workshop: Horticultural crop production depends on plastic mulch film to suppress weeds, optimize the soil microclimate, and overall improve economic and efficient production of crops within both conventional and organic systems. Unfortunately, the benefits of plastic mulch are often overshadowed by its poor end-of life outcomes with growers frequently landfilling, stockpiling, burying, or burning mulch waste at the end of a production season. Some of this mulch waste can become pollutants of soil and water. The horticultural industry needs new technologies that reduce persistent plastic waste generation with the expansion of extended producer responsibility, circularity, and sustainability initiatives. This interactive workshop will educate participants on promising solutions that preserve the essential functions of plastic mulch while reducing waste generation with an emphasis on soil-biodegradable plastic mulch and new collection, retrieval, and recycling technologies for non-biodegradable plastic mulch.  
The workshop is divided into three interactive sessions that will provide participants with a balance of academic and private industry perspectives. The sessions include: 1) Identifying the problem and possible solutions; 2) Lessons learned and recommendations from industry; and 3) Socioeconomic considerations and future prospects. Each session will have a panel of experts that will provide a brief presentation on a targeted topic. Invited industry speakers will share lessons learned and experience-shaped strategies to reduce plastic mulch waste generation. At the end of each session, samples of materials (e.g., soil-biodegradable mulch, mulch made with recycled resin) will be circulated and questions will be asked from the audience. The moderator will also poll the audience to promote engagement and to gather information about shared experiences related to sustainable mulch management. This information will be leveraged to discuss and design participant-tailored recommendations for sustainable end-of-life mulch management within their regions and communities at the end of the workshop. 
Moderators: Lisa W. DeVetter and Carol Miles

Session 1: Identifying the Problem and Possible Solutions (40 minutes total)
Speakers:

• Lisa DeVetter / Washington State University / Associate Professor of Horticulture
• Carol Miles / Washington State University / Professor of Horticulture
• Gene Jones / Southern Waste Information eXchange/ CEO

Session 2: Lessons learned from Industry (40 min total)
Speakers:

• Shuresh Ghimire/ Vegetable Assistant Extension Educator / University of Connecticut
• Ben Andros / Andros Engineering Cooperation / President
• Hillary Thomas / Naturipe Berry Growers, Inc. / Research and Technical Director  

Session 3: Socioeconomic Considerations and Future Prospects (40 min total)
Speakers:

• Jessica Goldberger / Washington State University / Professor of Crop and Soil Sciences
• Sam Wortman / Associate Professor and Environmental Horticulturist / University of Nebraska-Lincoln
• Pierre Sarazin / Polyexpert / Vice President of R&D and Sustainability

This session is being co-sponsored by Viticulture and Small Fruits (VSF) and American Pomological Society (APS)

As climate conditions continue to shift, heat stress poses a significant challenge to fruit production, affecting both yield and quality. This session will explore the physiological and biochemical responses of fruit crops to extreme temperatures, highlighting the key impacts on growth, composition, and overall marketability. Experts will discuss innovative mitigation strategies, including vineyard, berry, and orchard management techniques aimed at reducing heat stress impacts. Attendees will gain insights into practical, science-based approaches to safeguard fruit production in the face of increasing heat stress.

Speakers:

• Lee Kalcsits Associate Professor, Tree Fruit Physiology Endowed Chair of Tree Fruit Environmental Physiology and Management Programmatic Lead, Wenatchee Tree Fruit Research and Extension Center Washington State University, Department of Horticulture 
• Lisa Wasko DeVetter Associate Professor, Small Fruit Horticulture Department of Horticulture College of Agricultural, Human, and Natural Resource Sciences Washington State University NWREC
•  Everett P. Layton Ashmore, Ph.D. Postdoctoral Researcher Department of Viticulture and Enology College of Agricultural, Human, and Natural Resource Sciences Dave Bryla Research Horticulturist USDA-ARS Horticultural Crops Production and Genetic Improvement Research Unit, Corvallis, OR

Everyone working at the university level is expected to evaluate the impact of their programs. The knowledge and practice of evaluation is assumed to be among the skill sets of staff, including early career staff, without the provision of professional development or analysis support. This is not the case. In 2024, Rutgers conducted statewide and national surveys of Master Gardener programs. Of staff and faculty responding to Rutgers national survey, 73% said that they either did not have the time or the knowledge of evaluation processes to successfully evaluate their programs.

This workshop will explore the process and outcome of this research followed by a hands-on activity illustrating the pitfalls of survey creation and how to avoid them. This opportunity to learn about survey data collection and analysis while using data that is current and relative to the Master Gardener program is invaluable. The participants of this workshop will experience designing research surveys, evaluating data and using sound research processes while exploring data collected via the Rutgers study from over 2,000 participants ranging from volunteers to national stakeholders. Unexpected vs. invalid outcomes will be included. The data presented as examples is as important as the learning process. For example, 97% of staff respondents, regardless of organization, did not see the Master Gardener volunteers as “masters of horticulture”. Participants will attempt to determine if this is an indication of survey bias or process issues or is the data valid, revealing training deficiencies, performance issues, or bias toward volunteers as non-professionals. Participants will leave with a better understanding of how to evaluate their Master Gardener programs and with foundation data on which to build future analysis.

Moderator: Ruth Carll, State Leader, Consumer Horitculture, Rutgers

Speakers:

• Ruth Carll, State Leader, Consumer Horticulture, Rutgers
• Belinda Chester, Senior Program Coordinator, Rutgers

Overview Goal:
The goal of this workshop is to bring together professionals who manage Master Gardener programs and, through guided discussion, identify methods for implementing surveys that deliver valid data by examining a current survey project’s development process and outcomes.

Format:

1. Pre-test
2. Group introduction and orientation to the topic
3. Small group activities with real-time reporting
4. Post-discussion assessment
5. Partnership creation
6. Wrap-up and distribution of notes

Ethylene-releasing and ethylene-inhibiting materials are essential tools to manage different aspects of horticultural crop production such as plant growth and development, flowering, stress response, thinning and harvesting. This workshop will focus on two topics related to promoting ethylene and two topics related to inhibiting ethylene in horticultural crop production highlighting aspects of 1-aminocyclopropane-1-carboxilic acid (ACC), Ethephon, aminoethoxyvinylglycine (AVG) and 1-Methylcyclopropene (1-MCP) applications in horticulture. Following each of these two broad categories of ethylene related materials, time will be provided for discussion and questions with the speakers and participants. The overall goal of this interactive workshop is to bring together speakers working on methods to influence ethylene related processes in different horticultural commodities to provide an environment for the exchange of information on new uses and management tools of ethylene-releasing and ethylene-inhibiting plant growth regulators.

Speakers:

• Dr. Esmaeil Fallahi – ACC Use on Tree Fruits University of Idaho
• Dr. Garrett Owen – Use of the Ethylene Generating PGR Collate in the Ornamental Industry Ohio State University
• Dr. Shinsuke Agehara – 1-MCP as it Relates to Suppressing Ethylene-Induced Stress Responses in Vegetable Transplants University of Florida Dr.
•  Dr. Jimmy Larson – AVG/Tools to Manage Apple Harvest Utah State University

Workshop Summary for Conference Program
Huanglongbing (HLB), commonly known as citrus greening disease, continues to challenge citrus growers and researchers worldwide. Its devastating impact on tree health, fruit quality, and overall orchard longevity makes it essential to explore adaptive horticultural strategies that can sustain production in affected regions. This workshop provides an in-depth exploration of the horticultural approaches being used to mitigate the effects of HLB, with a focus on real-world applications and current research. The content is designed to equip participants with actionable insights into how orchard management can be adjusted to maintain tree vigor and maximize productivity despite HLB pressure. Topics will include:

Physiological impacts of HLB on citrus growth and development: Understanding how the disease disrupts water, nutrient, and carbohydrate transport, and its implications for tree management.
Nutritional and irrigation strategies: Optimizing inputs to support trees with compromised root systems and reduce stress.

Soil amendments and root health: Exploring the role of organic matter, compost, biochar, soil conditioners, and microbial inoculants in enhancing soil health and nutrient availability to support stressed trees.
Canopy and crop load management: Best practices for pruning, thinning, and canopy maintenance to enhance light interception, reduce disease severity, and promote new growth.
Rootstock and scion selection: Insights into tolerant or better-performing combinations under HLB pressure, and how rootstock choice can influence disease expression.
Replant and tree replacement strategies: Managing orchard renewal while dealing with persistent disease pressure.
Cultural practices integration: How horticultural management intersects with pest control (e.g., Asian citrus psyllid suppression), disease diagnostics, and emerging technologies.

Workshop Format:
This workshop will include:
-Expert presentations from researchers, university extension specialists, and industry professionals sharing the latest findings and innovations.
-Grower case studies detailing the successful implementation of horticultural practices in HLB-endemic orchards.
-Interactive Q&A sessions and moderated discussions to encourage knowledge exchange and problem-solving tailored to regional conditions.
Learning Objectives:

By the end of the workshop, participants will be able to:

• Identify the key horticultural impacts of HLB on citrus trees.
• Apply practical orchard management techniques including soil amendments and nutrient strategies to mitigate disease effects.
• Make informed decisions about rootstock, scion, canopy, and irrigation strategies.
• Integrate horticultural practices with broader HLB management approaches for sustainable production.

Speakers:

• Chater, John M. jchater@ufl.edu “Cultivar selection, OTC trunk injection, and nutrition are important horticultural strategies under observation for HLB mitigation in Florida”
• Wang,Nian nianwang@ufl.edu  “Genetic determinants underneath the Candidatus Liberibacter-triggered immune disease development of citrus Huanglongbing and its control”
• Killiny,Nabil nabilkilliny@ufl.edu  “Achieving the traditional control strategies through biotechnological approaches for sustainability: Attract-and-Kill and Repellency to control Asian citrus Psyllid”
• Albrecht,Ute ualbrecht@ufl.edu “Integrating trunk injection of oxytetracycline with other practices to sustain tree health and productivity under HLB-endemic conditions”
• Chandrika Ramadugu chandram@ucr.edu “Citrus Huanglongbing - use of disease tolerant and resistant varieties for sustainable cultivation.”
• Vincent,Christopher I civince@ufl.edu “Mitigating the physiological impact of huanglongbing by shading.”
• Dutt, Manjul manjul@ufl.edu “Rooted in Resistance: Breeding the Next Generation of HLB-Resilient Citrus rootstocks”
• Ashraf El-kereamy (ashrafe@ucr.edu) “Cultural practices to control HLB in California”

This workshop will focus on the educational (University) and Technical Programs geared towards Organic Horticulture. Universities vary greatly in their organic programs, student interest in organic programs, and facilities. Similarly, the technical assistance provided from growers varies from state to state. Recent Transition to Organic Partnership Program (TOPP) programming, has created more interest in providing this assistance. This workshop will focus on discussing the challenges to organic education both at the undergraduate and farmer level.

Speakers:

• Kate Cassity-Duffey, University of Georgia
• Mary Rogers, University of Georgia
• Christian Stephenson University of Nebraska-Lincoln
• Christine Coker University of Mississippi

The horticultural industry has been moving towards sustainable practices, and industry is no exception! Come to this Interest Group session to learn about how industry is assessing and implementing sustainability practices, and how you can partner with industry in these initiatives.

Roundtable discussion following with Q&A.

The goal of this workshop is to bring together Master Gardener stakeholders working to create impactful programs in unique and efficient models and to provide a forum for the exchange of ideas for achieving greater impact through effective program operation. The participants will leave the workshop with partnerships identified between programs of similar needs and change status. The panel for the workshop represents 4 programs that have successfully restructured their programs and serve as models for those considering making a change. Through discussion, we will identify how to build a case for change, present the case to the leadership, manage change, and measure the outcome. Those active in any role of their Master Gardener program are encouraged to attend. Creating impactful programming in this field is directly influenced by the efficiency through which we operate. To achieve greater success, more effort must be invested in advancing purposeful and effective management. However, many of the programs throughout the country have grown into their current forms organically and through grassroots process which are now less effective for larger, statewide programs. Making large-scale changes in a university system can be difficult. Participants of this workshop will leave with a better understanding of the change process and learned about different Master Gardener program models that have successfully implemented change.

Speakers:

• Missy Gable, Director, UC Master Gardener Program, University of California Agriculture and Natural Resources, mjgable@ucanr.edu
• Jennifer Marquis, Director, WSU Extension Master Gardener Program, Washington State University, jgmarquis@wsu.edu
• Mary Ortiz Castro, Colorado Master Gardener State Education Specialist, Interim Extension Programs Manager, Colorado State University Extension, mary.ortiz_castro@colostate.edu
•  Ruth Carll, State Leader, Consumer Horticulture, Rutgers, ruth.carll@rutgers.edu

This interactive workshop will introduce attendees to the history, science, and industry opportunities related to grafting perennial tree fruits, nuts, and vines. It will be accompanied by a hands-on demonstration and time for attendees to practice with real-time feedback. A liability waiver will be required for participants who wish to handle grafting knives.

Speakers:

• Dr. Rachel Spaeth, post doc Research Horticulturist currently serving as the Interim Curator of Prunus, National Clonal Germplasm Repository, UC Davis, CA
• Dr. John Preece, Supervisory Research Leader of the USDA-ARS National Clonal Germplasm Repository Davis, CA 

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.

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.

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.

WORKSHOP OBJECTIVES
The primary goal of this workshop is to bring together a diverse network of professionals from academia, industry, extension services, and government agencies who are working to enhance the performance, sustainability, and resilience of Latin American horticultural supply chains to the U.S.
Participants will:

• Share knowledge on how to improve quality, minimize postharvest losses, and meet regulatory and market demands.
• Highlight opportunities for supporting Latin American growers, exporters, and logistics providers.
• Explore cross-cutting themes including climate resilience, labor, sustainability, and technology adoption.
• Foster collaboration and lay the groundwork for future events focused on Latin America and horticulture.

Speakers:

• Jorge Vanegas – jvenegas@pairwise.com
• Juan Rodriguez – jc@foginfo.org

WORKSHOP FORMAT
I. Expert Presentations (35 minutes total)
 Three panelists (15 minutes each) will present on the following themes:

• Production and Sustainability: Emerging challenges and innovations in Latin American fruit, vegetable, and ornamental production systems.
• Postharvest and Quality Management: Best practices to preserve quality and extend shelf life during export, focusing on compliance with U.S. standards.
• Trade and Market Access: Navigating U.S. regulations, phytosanitary requirements, and certification systems, with insights into logistics and cold chain management.

II. Experience Sharing from the Field (15 minutes)
 A moderated session where 5–6 attendees will briefly (2–3 minutes each) share their field experiences working in or with Latin American horticultural systems. This segment will offer valuable context and grassroots perspectives to enrich the subsequent discussions.
III. Breakout Group Discussions (25 minutes)
 Participants will join focused roundtables based on key crops or sectors (e.g., tropical fruits, temperate fruits, vegetables, ornamentals). Each group will explore:

• Specific supply chain challenges
• Opportunities for innovation and collaboration
• Regional production and trade differences

IV. Group Reporting & Strategy Sharing (15 minutes)
 Groups will reconvene to summarize key insights and report out barriers and proposed solutions (e.g., cold chain infrastructure gaps, pest and disease pressures, labor constraints, traceability needs). A shared whiteboard will capture these points to inform follow-up actions.

V. Building Toward Future Collaboration (15 minutes)
 The workshop will conclude with an open discussion to identify opportunities for future collaboration. This may include organizing a follow-up workshop or proposing a broader symposium or conference focused on Latin American Horticulture—bringing together academic, industry, and government stakeholders to build long-term partnerships and shared research agendas.

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.

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.

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.

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.

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.

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.