Performing Department
(N/A)
Non Technical Summary
Crop pathogens that disperse through the soil are a significant problem for organic farmers, especially when theyinfect vegetables during high tunnel production in the Northeastern and Midwestern United States. Steaming the soil to high temperatures and Anaerobic Soil Disinfestation (ASD) are two disease management methods that have the potential to kill problematic plant pathogens without using synthetic fungicides or fertilizers. This project will 1) compare the efficacy of soil steaming and ASD for suppressing soilborne diseases of vegetables including a focus on high tunnel tomatoes, 2) determine soil microbial community recovery (composition/diversity) after steaming and/or ASD and impacts on plant health, and 3) understand the factors that affect farmers' willingness to adopt sustainable soilborne disease management practices. We aim to share best practices with organic growersfrom these two promising, innovative organic farming practices. Results will be disseminated at farmer conferences and meetings, through peer-reviewed publications, extension materials, factsheets, and webinars. The target audiences will include partnering organically certified farmers, those who are interested in or who are in transition to organic production, industry partners, federal and academic scientists, and the public at large.
Animal Health Component
40%
Research Effort Categories
Basic
40%
Applied
40%
Developmental
20%
Goals / Objectives
Crop diseases are a significant problem for organic vegetable farmers in the US with up to 75% yield loss due to soilborne plant pathogens. Steaming the soil and Anaerobic Soil Disinfestation (ASD) are two promising management approaches that can help organic growers suppress pathogens without using synthetic fungicides or fertilizers. However, there is little science-based research on the efficacy of soil steaming and ASD methods or data on the recovery of the microbiome and nutrients post-steaming and ASD treatments. In order for these pathogen management approaches to be effective, it is paramount to understand the underlying biological mechanisms behind these approaches and to capture the willingness of farmers to adopt such technologies. Our goal is toconduct management trials and in-person/online surveys to help organic and transitioning to organic farmers reduce high tunnel soilborne diseases.Objective 1. What Works? To compare the efficacy of ASD and soil steaming for suppressing soilborne diseases of vegetables with a focus on high tunnel tomatoes (Research).Objective 2. Who Survives? To determine soil microbial community recovery (composition/diversity) after steaming and/or ASD and impacts on plant and soil health.Objective 3. Why Adopt These Methods? Is it Worth it? To understand the factors that affect farmers' willingness to adopt sustainable soilborne disease management practices and educate growers on the management practices.Plans/Milestones: We will conduct controlled high tunnel experiments at an USDA-ARS research station in Ohio, efficacy trials on organic farms in Pennsylvania and Ohio over the duration of the grant, and address farmers' needs for adoption with interviews, surveys and conduct a cost benefit analysis.Relevance to Program Goals: Two research priorities of the National Organic Standards board are addressed in this proposal: "Development of systems-based plant disease management strategies are needed to address existing and emerging plant disease threats," and "More research is needed to fully understand the relationship between on-farm biodiversity and pathogen presence and abundance."
Project Methods
Objective 1. What Works? To compare the efficacy of ASD and soil steaming for suppressing soilborne diseases of vegetables with a focus on high tunnel tomatoes.At total of 7 experiments will be conducted in vegetable high tunnels located on the USDA-ARS research station in Wooster, OH in order to assess the timing of application and efficacy of steaming and ASD to suppress target pathogens under organic vegetable management conditions. These trials will be carried out in a controlled setting where pathogens can be easily manipulated. High tunnel soils on station will be uniformly inoculated with vermiculite inoculum of the common of the target soilborne pathogens of tomato: Pseudopyrenochaeta lycopersici, C. coccodes, V. dahliae, Fusarium oxysporium f. sp. lycopersici, Phytophthora spp. and eggs of the nematode M. hapla. Soil samples cores ~ 15cm in depth will be collected an analyzed for nutrient analyses and qPCR will be conducted to detect pathogen levels in the soil for each treatment. Tomato 'Red Deuce' will be planted according to organic farming standards and will be measured for nutrient uptake, root rot severity, and root-knot nematode galling.Evaluation of Outputs: Because the efficacy trials are located on-station at ARS, we will be able to monitor and evaluate their progress closely using data loggers for soil and ambient temperature, moisture etc.The most effective timings for ASD, steaming, and combination treatments will be recorded by hand in spread sheets and with data loggers; these results will be analyzed and communicated to stakeholders. Specifically, trial results will be incorporated into scientific journals which are peer-reviewed, posters,extension factsheets, and we will monitor the number of factsheet downloads.Objective 2. Who Survives? To determine soil microbial community recovery (composition/diversity) after steaming and/or ASD and impacts on plant and soil health.We will conduct on-farm trials where the goal will be to research soilborne pathogens microbial communities in the soil and the effect of treatments on tomato health in organic systems.We will sample soil from 4 treatments: (1) pre-post soil steaming, (2) pre-post ASD, (3) a combined treatment (steaming + ASD) and (4) a control (no treatment). The rationale for conducting these trials is that we can assess the environmental and management variability found in organic farms as opposed to conditions in aresearch station high tunnel (Objective 1). We will screen soils for the presence ofpathogens that already exist in the high tunnel systems, soil and plant beneficial microbes, and we will measure the recovery of the soil over time to examine changes in the soil health (nutrients, soil texture, etc.) and tomato plant health (macronutrients such as nitrogen). We use a novel mixed-methods approach to understand the efficacy of our organic management approaches by using: soil microbiome analyses, soil and plant nutrient analyses,plant health data such as chlorophyll content, root rot severity, soil pathogen populations within roots, RKN damage, photosynthetic efficiency, and fruit yield and biomass at tomato harvest.Evaluation of Outputs: Because these efficacy trials are located on-farm with collaborating farmers, we will monitor and evaluate our trial progress at each visit during the growing season during years 2 and 3 (Post-docs and Graduate Student). Trial results will be incorporated into a peer-reviewed articles, posters, and factsheets and will be presented at grower meetings and conferences.Objective 3. Why Adopt These Methods? Is it Worth it? To understand the factors that affect farmers' willingness to adopt sustainable soilborne disease management practices and educate growers on the management practices.Our approach will be to (1) research conceptual models related to the theory of Adoption of Innovation, (2) determine the factors affecting the adoption of sustainable soilborne disease management practices, and (3) identify opportunities for organic farmers to use steaming and ASD for disease suppression. We will review existing literature that points to models and outcomes from other agroecosystemsfor the willingness of farmers to adopt new production methods. Next, we will assess farmers' perceptions about the proposed new management practices in relation to the existing ones, factors affecting adopting new management practices, and incentives for farmers that will influence their attitudes toward the new management practices. A mixture of farmer surveys, interviews, and a cost-benefit analysis will help us gauge how and why organic farmers are or would be willing to adopt soil steaming disinfection and ASD into their high tunnel management practices.Evaluation of Outputs: Through various milestones, we will evaluate our outputs. Specifically, we will recruit a graduate student in year 1. This student will develop socio-economic research methodologies for their thesis and will form a committee of faculty who will evaluate their progress through the gradudate program at Penn State. After gaining IRB approval, the student will conduct in-depth farmer interviews, collect qualitative data (years 2), and complete data analysis of qualitative data and survey instruments (year 3). PSU and ARS extension products will be created such as articles and research presentations to disseminate results to stakeholders.