Location: Application Technology Research
2025 Annual Report
Objectives
Objective 1: Model plant growth responses to environmental conditions, design control systems, and develop automation technologies and decision support tools to optimize production, yield, quality, resource use, and carbon footprint of protected culture crops.
Sub-objective 1.A: Model plant growth responses to environmental conditions.
Sub-objective 1.B: Design and test environmental control algorithms for light, temperature, humidity, and CO2.
Sub-objective 1.C: Develop measurement systems to optimize lighting and airflow in controlled environments.
Sub-objective 1.D: Develop decision support tools that model plant growth and resource usage.
Objective 2: Develop and integrate production and automation technologies in soilless culture that improve physiochemical properties of water and substrates, reduce agrichemicals and contaminants, and improve economic and environmental sustainability of food and ornamental crops.
Subobjective: 2.A: Understand and optimize mineral nutrient inputs in greenhouse crops to enhance crop productivity response and quality.
Sub-objective 2.B: Understand and augment soilless substrate production systems to foster more sustainable protected culture agro-ecosystems that address GHG emissions, sequester carbon, or better utilize inputs.
Sub-objective 2.C: Develop improved water management and treatment technology strategies to extend freshwater resources and increase water quality to protect aquatic ecosystems when producing protected culture crops.
Objective 3: Develop climate-smart and automated strategies for managing insect pests and diseases in horticultural food and ornamental crops through engineered technologies and improved knowledge of pest biology, ecology, and behavior to reduce reliance on synthetic pesticides.
Sub-objective 3.A: Develop recommendations for the use of silicon for management of soilborne and foliar diseases in horticultural food and ornamental crop production.
Sub-objective 3.B: Develop disease management recommendations for hydroponic food crop production.
Sub-objective 3.C: Develop methods to improve plant health in soil-based protected culture systems.
Sub-objective 3.D: Optimize genomoviruses and spray-induced gene silencing as alternative fungicides for the control of Sclerotiniaceae fungi.
Sub-Objective 3.E: Determine the biology, behavior, and ecology of redheaded flea beetles infesting plants in ornamental nurseries to aid in developing a management plan.
Sub-objective 3.F: Optimize monitoring and management options for ambrosia beetles infesting trees in ornamental nurseries.
Approach
Ornamental, nursery, and protected culture crops represent about one-fourth of the farm gate value of all specialty crops, and about 15% of the total value of U.S. crop production (USDA NASS Horticultural Crop Census 2014). This project brings together the expertise of USDA-ARS research scientists with cooperators at other universities to focus on research that advances ornamental, nursery, and horticultural food crops in protected culture. The project is a science-based, outcome-driven, economically motivated program to assist growers in improving the quality of food and ornamental crops. This project will continue to further our knowledge base in protected culture crops by: 1) modeling plant growth responses to environmental conditions, designing control systems, and developing automation technologies and decision support tools to optimize production, yield, quality, resource use, and carbon footprint of protected culture crops, 2) developing and integrating production and automation technologies in soilless culture that improve physiochemical properties of water and substrates, reduce agrichemicals and contaminants, and improve economic and environmental sustainability of food and ornamental crops, and 3) developing climate-smart and automated strategies for managing insect pests and diseases in horticultural food and ornamental crops through engineered technologies and improved knowledge of pest biology, ecology, and behavior to reduce reliance on synthetic pesticides. This project integrates the mission and expertise of the Application Technology Research Unit with other researchers in disciplines critical to the overall success of the project.
Progress Report
This is the first report for this new project which began in January 2025 and continues research from the previous project, 5082-21000-001-000D, “Sustainable Production and Pest Management Practices for Nursery, Greenhouse, and Protected Culture Crops”. Please see the report for the previous project for additional information.
In support of Objective 1, we developed photosynthetic models for five culinary herbs (basil, cilantro, mint, parsley, and sage) in response to light and carbon dioxide (CO2) (Sub-objective 1A).
In support of Objective 2, we evaluated nutrient management strategies to increase strawberry daughter plant production. Optimal strawberry daughter plant production required a higher total fertilizer concentration than is recommended for strawberry fruit production. Initial data on fertilizer nitrogen (N) concentration indicates that increasing the amount of N supplied did not increase daughter plant number but did improve plant quality. Plant size, leaf greenness, and leaf %N all increased as N fertilizer concentration increased. Additionally, we evaluated the effectiveness of supplying silicon (Si) during production to mitigate chilling injury. One aspect was to supply Si to hydroponically grown herbs to alleviate chilling injury after harvest and storage in a cooler. Silicon was beneficial to some, but not all, of the herbs evaluated in delaying the onset and severity of chilling injury. Ongoing research is evaluating the application of Si to potted herbs to alleviate chilling injury during production (Sub-objective 2A).
A high-throughput system was developed for rapidly analyzing the horticultural properties of novel soilless substrates. The basic chemical and physical properties of the novel substrates needed to formulate a fertilization and irrigation regime for production of horticultural crops were documented. The total time needed for this suite of laboratory analyses is 10 days. This is followed by carefully standardized short-term greenhouse experiments to assess the novel substrate’s performance in a production setting. Four substrates have been run through this system, potential problems have been identified, production practices have been standardized, and the schedule has been streamlined to provide a consistent and standardized report for each novel substrate.
A series of experiments were conducted to determine the decomposition rate and route of carbon loss in soilless substrates. Fallow containers (with growing media but no plant) were placed in a greenhouse and fertilized with a nutrient solution commonly used in greenhouse crop production. Leachates (water and solution drained from containers after irrigation) were analyzed for suspended solids and dissolved organic carbon. A separate subset of sample was placed in glass jars used to quantify the concentration of carbon dioxide to determine the mass of organic matter converted to gas. Modifications to the gas loss phase of the experiment were determined necessary to more thoroughly capture all carbon lost by gas.
Objective 3, Goal 3C.2: A research trial was established in a high tunnel at our research station in which soils were infested with tomato soilborne pathogens and anaerobic soil disinfestation and soil steaming treatments were applied.
Sub-objective 3.D: Recent research has shown that small RNAs (RNA of 18~30 nucleotides long) play important roles in gene regulation and potentially pathogenesis of fungal pathogens. We are currently preparing a publication about the first evidence of tRNA-derived small RNAs acting as a virulence effector for a pathogenic fungus, Sclerotinia sclerotiorum, which is a major pathogen world wide affecting all dicotyledon plants, including lettuces, tomatoes, and field crops like sunflower, canola, soybean, and dry beans.
Sub-Objective 3.E, Goal 3.E.1: Feeding by adult red-headed flea beetles causes aesthetic damage and reduces marketability of ornamental plants and reduces yield in cranberry production. A broad range of ornamental plants are damaged by adult feeding, especially Hydrangea, sweetspire (Itea), Weigela, Holley, and Roses. However, knowledge of host preference is lacking, but is important for helping grower target the most vulnerable plants. Furthermore, knowledge of seasonal activity (phenology) is needed for timing insecticide treatments to manage this pest, but even basic information such as the number of generations per year is lacking. Treatments timed too early are wasted and those timed too late allow too much damage to occur. We have started collecting red-headed flea beetles to determine seasonal reproductive maturity for phenology research. We completed one season of research on red-headed flea beetle host preference and are starting a second season this summer (the beetles have not yet emerged this year).
Sub-Objective 3.F: We completed a third season of developing an attractant for ambrosia beetles. Ethanol is a key attractant that wood-boring ambrosia beetles use to locate and tunnel into infested trees. To help growers identify stressed trees at risk of infestation, research was conducted with an ethanol biosensor bracelet designed for humans, which demonstrated that the sensor can also detect ethanol from flood-stressed trees. Subsequent studies demonstrated that the biosensor could detect ethanol emissions from stressed trees within one to two days after initiating flood stress, and before mass infestation by ambrosia beetles.
Trees produce ethanol and acetic acid in response to physiological stress, such as flooding. Research was conducted to assess the influence of ethanol and acetic acid on the tunneling behavior and offspring production of exotic ambrosia beetles. Stems infused with ethanol plus acetic acid were associated with increased tunneling and offspring (i.e., larvae, pupae, and adults) by ambrosia beetles compared to stems infused with ethanol alone or water. By understanding how host tree chemistry benefits colonization by fungus-farming ambrosia beetles, biological weaknesses in this mechanism can be identified for novel management purposes.
Accomplishments
1. Intelligent spray system reduces costs without sacrificing performance. Researchers analyzed field data to understand how weather, especially wind, affects how pesticides drift away from their target. The study showed that the intelligent spray control system, which adjusts the amount of pesticide based on real-time conditions, greatly reduced unwanted drift. Importantly, it provided similar spray deposition and coverage on nursery tree canopy to conventional sprayers, meaning it still protected the plants effectively. This means farmers can use fewer chemicals without losing crop protection. By reducing waste and improving accuracy, this system helps lower production costs while also protecting the environment. Families and communities benefit too, because smarter spraying supports safer, cleaner farming practices.
2. Improved nutrient management guidelines for strawberry production in controlled environments. Strawberry fruit production in greenhouses has rapidly expanded in recent years to extend growing seasons and have better control over environmental conditions. This has increased the need for healthy, disease-free starting plant material. Propagation of strawberry plants in the U.S. typically consists of removing and rooting the “daughter plants” that develop on a plant. ARS researchers in Wooster, Ohio, developed improved nutrient management strategies to optimize health and yield for greenhouse-grown strawberry plants. These strategies increased daughter plant production by up to 50% more than current industry practices. The increased yields will help improve profitability for propagators and increase the supply of rooted plants for the greenhouse strawberry industry.
3. Biosensor for identifying trees at risk of infestation by ambrosia beetles. Non-native ambrosia beetles are destructive wood-boring pests that target horticultural trees. Trees emit ethanol in response to stressors like flooding and freezing, which the beetles use to locate vulnerable hosts. Rapid detection of this ethanol emission can help growers and arborists identify trees at risk of infestation. ARS researchers in Wooster, Ohio demonstrated that a next-generation alcohol biosensor bracelet, designed for human use, can also detect ethanol emissions from flood-stressed trees. The biosensor can detect ethanol emissions in realtime from flood-stressed trees, before mass attacks by invasive ambrosia beetles. This discovery will aid in efforts to develop an ethanol biosensor that alerts pest management specialists to trees at risk of infestation by invasive ambrosia beetles.
4. Unearthing hidden tomato pathogens in covered structures used to extend growing seasons. Fresh, locally grown vegetables are essential for healthy communities, and many farmers are turning to high tunnels or hoophouses to protect their vegetable crops and allow for longer growing seasons. As more farmers use high tunnels, issues are arising that need to be addressed quickly to ensure long term use of high tunnels. One issue is the emergence of unseen soilborne plant diseases that greatly reduce the yield and quality of tomato, the most popular high tunnel vegetable. Soilborne diseases are difficult to detect as they hide in soils and attack unseen plant parts, including roots and stems. ARS researchers in Wooster, Ohio, developed methods to quickly test high tunnel soils for soilborne plant pathogens and surveyed 265 tomato high tunnels on 118 farms from 12 states. This testing revealed four tomato soilborne pathogens in at least half of the high tunnels surveyed, making these hidden diseases incredibly common. Farmers were provided with disease findings from their high tunnels so that they can begin to plant disease management approaches. ARS researchers are proactively studying methods to combat these tomato diseases including anaerobic soil disinfestation and soil steaming.
Review Publications
Criscione, K., Owen Jr, J.S., Fields, J. 2025. Stratified soilless substrates decrease the vertical gravitational water gradient altering Helianthus root morphology. Plant and Soil. https://doi.org/10.1007/s11104-025-07385-8.
Boldt, J.K. 2025. A comparison of photosynthetic light response curves of nine tomato cultuvars. Acta horticulturae. 1423:1-7. https//doi.org/10.17660/ActaHortic.2026.1423.1.
Yafuso, E.J., Boldt, J.K. 2025. Adjusting the percent nitrate in nutrient solution to optimize strawberry stolon and daughter plant production. HortScience. 60(3):435–445. https://doi.org/10.21273/HORTSCI18245-24.
Huang, J., Fisher, P., Argo, W., Jeong, K., Altland, J.E. 2025. Macronutrient solubility in response to the pH of soilless container substrates. Journal of Soil Science and Plant Nutrition. https://doi.org/10.1007/s42729-025-02331-0.
Amrhein, J.J., Rotondo, F., Kubota, C., Miller, S.A., Testen, A.L. 2025. Diagnostic guide for Pythium root rot in hydroponic leafy green and herb production. Plant Health Progress. 26(1):87-95. https://doi.org/10.1094/PHP-07-24-0070-DG.
Abdi, D., Owen Jr, J.S., Wilson, P.C., Hinz, F.O., Cregg, B.M., Fernandez, R.T. 2025. Pesticide mobility in surface and subsurface irrigation return flow in a container plant production system. Water. 17(7) Article #953. https://doi.org/10.3390/W17070953.
Meng, Q., Ranger, C.M., Boldt, J.K., Runkle, E. 2025. A sufficiently high blue photon flux density can promote accumulation of phenolic compounds in hydroponic lettuce. Acta horticulturae. 1423:211-218. https://doi.org/10.17660.ActaHortic.2025.1423.28.
Chowdhury, M., Samarakoon, U., Altland, J.E. 2025. Analysis of nutrient composition of liquid organic fertilizer for optimizing fertilizer dosing for hydroponic crop production. Acta horticulturae. Article 1428. https://doi.org/10.17660/actahortic.2025.1428.3.
Tobin, K., Peeler, S., Yilmaz, A., Baniszewski, J.A., Krawczyk, G., Ranger, C.M., Rivera, M. 2025. Evaluating the push-pull strategy in eastern apple orchards: verbenone effectively reduces ambrosia beetle populations without the need for a pull factor in a species-specific manner. Pest Management Science. Article ps.8755. https://doi.org/10.1002/ps.8755.
Poudel, A., Oliver, J., Perkovich, C., Ranger, C.M., Addesso, K. 2025. An approach for ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)management: can low-cost ethanol detectors effectively identify ethanol emissions in flood-stressed trees? Journal of Insect Science. 25(3): Article 10. https://doi.org/10.1093/jisesa/ieaf056.
Kelsey, D., Lee-Rodriguez, J., Michel, A., Ranger, C.M., Canas, L., Leach, A. 2025. eDNA sampling detects early colonization of spotted lanternfly Lycorma delicatula better than in-person scouting in an urban landscape. Environmental DNA. 7 Article e70123. https://doi.org/10.1002/edn3.70123.
Patiluna, V., Owen Jr, J.S., Maja, J.M., Neupane, J., Behmann, J., Bohnenkamp, D., Borra-Serrano, I., Pena, J., Robbins, J., De Castro, A. 2025. Using hyperspectral imaging and principal component analysis to detect and monitor water stress in ornamental plants. Remote Sensing. 17. Article 285. https://doi.org/10.3390/rs17020285.
Lamm, A.J., Owen Jr, J.S., Altland, J.E., White, S.A. 2025. A survey analysis comparing perceptions of plastic use in nurseries and greenhouses in the United States. Land. 14. Article 1383. https://doi.org/10.3390/land14071383.
Clade, D., Veazie, P., Boldt, J.K., Hicks, K., Currey, C., Flax, N., Walters, K., Whipker, B. 2025. Establishing leaf tissue nutrient standards and documenting nutrient disorder symptomology of greenhouse-grown cilantro (Coriandrum sativum). Applied Sciences. 15. Article 9266. https://doi.org/10.3390/app15179266.
Veazie, P., Chen, H., Hicks, K., Boldt, J.K., Whipker, B. 2025. A data-driven approach for generating foliar nutrient interpretation ranges and machine learning-based interpretation for petunia. HortScience. 60(6): 878-888. https://doi.org/10.21273/hortsci18508-25.