Pragati Dahal, a graduate student from Nepal, is undertaking a master’s thesis in applied economics under the guidance of Chris McIntosh, head of the Department of Agricultural Economics and Rural Sociology (AERS). Supported by the Joe and Terri Guenthner Graduate Scholarship, Dahal’s research is poised to address a critical gap in understanding how U.S. potato growers tolerate diseases in seed potatoes and whether their practices align with certification standards.
Dahal’s project is motivated by the need to reduce seed wastage and offer practical solutions during seed shortages. “If we better understood farmers’ preferences for seed potato quality, we would have a much clearer understanding of the seed potato market,” Dahal explained. The research will focus on major diseases, including Potato Virus Y (PVY), which significantly impacts seed quality.
Survey and Data Collection
To gather comprehensive data, Dahal and her team will develop a survey targeting potato growers. This survey will be distributed at prominent industry events such as Potato Expo 2025 in Orlando, Florida, and the 57th Annual Idaho Potato Conference in Pocatello. The survey will also reach growers through trade magazines, aiming to capture a broad range of opinions and practices related to seed quality and disease tolerance.
Current Standards and Practices
In Idaho, potato seed certification is managed by the Idaho Crop Improvement Association (ICIA), which ensures that seed meets specific standards. From 2008 to 2023, about 1.05% of seed acres were rejected during field inspections. Notably, if PVY levels exceed 1%, ICIA prohibits the recertification of seed. However, Idaho does not restrict commercial growers from planting seed with high PVY levels, unlike states such as Wisconsin and Michigan, which impose a 5% threshold.
The discrepancy between certification standards and actual grower practices raises important questions. As Chris McIntosh notes, “Everyone assumes that commercial growers don’t care up to about 10 percent PVY, but nobody has actually measured that.” Dahal’s research seeks to address this assumption by providing empirical data on growers’ tolerance levels and their impact on seed quality and yields.
Economic Impact and Grower Perspectives
Previous research by Dahal’s team indicated that low levels of PVY had minimal economic impact, although the effect varied with potato variety. American Falls farmer Klaren Koompin highlighted the importance of variety and PVY strain in assessing losses. Koompin’s experience demonstrates that different PVY strains can have varying impacts on crop yields, underscoring the need for more detailed research on strain-specific effects.
Additionally, Alan Westra of ICIA pointed out that market conditions, such as seed shortages, influence growers’ tolerance levels. “Two springs ago when seed was short, there wasn’t much discussion about virus,” Westra said. “This year there’s too much seed, and commercial growers are asking about disease ratings because they can pick and choose.”
Pragati Dahal’s research promises to provide valuable insights into U.S. potato growers’ tolerance of seed-borne diseases and the alignment of these practices with certification standards. By addressing the gap between theoretical standards and practical preferences, this study could lead to improved seed management strategies and better alignment with market needs. Ultimately, this research will contribute to more efficient seed use, reduced waste, and enhanced disease management practices in the potato industry.
