To optimize yield potential, soybean farmers in Iowa are planting earlier in the growing season. Together with reduced tillage practices, this often means that seed germinate in cold, wet soils and are at risk for seed rot and damping off due to soil borne pathogens such as Pythium spp., Phytophthora sojae, Fusarium spp. and Rhizoctonia spp. Limited research has been done on the basic biology, and epidemiology of these important seedling pathogens of soybean.
In collaboration with Dr Martin Chilvers at Michigan State University, and soybean pathologists across the North Central region, we are currently determining which are the predominant Pythium spp. affecting soybean stands in the region. Our goal is to improve our understanding of the pathogenicity, aggressiveness, optimum conditions required for infection and disease development and sensitivity to fungicides used in seed treatments of each of these species. These data will enable more effective disease management practices to be implemented.
Seedling disease has also become an issue for corn farmers in southern Iowa. Oftentimes, the same pathogens that infect soybean seedlings will also infect corn. Once again there is limited research that has been done on the corn-Pythium pathosystem. In Spring 2012, we conducted a survey to identify the Pythium spp. responsible for stand loss and determine the sensitivity of these isolates to commercial seed treatment fungicides.