Nov 8, 2023
Penn State studies soilborne pathogens in organic vegetable crops

A Penn State plant pathologist has received support from the USDA’s National Institute of Food and Agriculture to study plant diseases in organic vegetable operations.

Sharifa Crandall, assistant professor of soilborne disease dynamics and management in Penn State’s College of Agricultural Sciences, will use the $800,000 grant from the agency’s Organic Transitions initiative to investigate methods to suppress soilborne pathogens in vegetable high tunnels.

Sharifa Crandall will study soilborne pathogens and the diseases they spread to organic vegetables crops. Photo courtesy of Penn State.

She explained that crop pathogens that disperse through the soil are a significant problem for farmers — mainly when they infect vegetables during high tunnel production in the Northeast and Midwest — and especially for organic farmers for whom fumigants and other chemicals aren’t an option.

Steaming the soil to high temperatures and anaerobic soil disinfestation are two disease management methods that potentially can kill problematic plant pathogens without synthetic fungicides or fertilizers and could be used in combination to suppress soilborne diseases.

“However, there is little science-based research on the efficacy of these methods or data on the recovery of the microbiome and nutrients after steaming and anaerobic soil disinfestation,” Crandall said. “For these pathogen management approaches to be effective, it is paramount to understand the underlying ecological mechanisms behind these approaches and to capture the willingness of farmers to adopt such technologies.”

This project has three components: comparing the efficacy of soil steaming and anaerobic soil disinfestation for suppressing soilborne diseases of vegetables, including a focus on high tunnel tomatoes; determining soil microbial community recovery after steaming or anaerobic soil disinfestation and impacts on plant health; understanding the factors that affect farmers’ willingness to adopt sustainable soilborne disease management practices.

The team will conduct its experiments at a USDA Agricultural Research Service facility in Ohio and on organic farms in Pennsylvania and Ohio.

Results will be shared through peer-reviewed publications, extension materials, factsheets, webinars and farmer conferences. The target audiences include partnering organically certified farmers, those interested in or transitioning to organic production, industry partners, federal and academic scientists, and the public.

Crandall will be joined by Penn State colleagues Mihail Kantor, assistant research professor in the Department of Plant Pathology and Environmental Microbiology, and Suzanna Windon, assistant professor in the Department of Agricultural Economics, Sociology, and Education.

Anna Testen, research plant pathologist with the USDA Agricultural Research Service in Wooster, Ohio, also will support the study.

Penn State Agricultural Sciences

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