P-149 - Services, soil, and survival: the influence of fall cover crops on Rhizoctonia solani and Sclerotinia sclerotiorum in soybean and dry bean production

Cover crops are widely recognized for their positive impact on crop production and soil health, with ongoing research exploring effects on soilborne pathogens. The pathogens Sclerotinia sclerotiorum and Rhizoctonia solani, which cause Sclerotinia stem rot and seedling blight respectively, reduce soybean and dry bean yields in Minnesota. Management is challenging due to their persistence as sclerotia and broad host range. However, cover crops may help control these pathogens by influencing soil microbial communities and their chemical properties. This study examined how fall cover cropping in dry bean and soybean systems affects disease occurrence, viability of S. sclerotiorum and R. solani sclerotia, soil health, and agronomics. Field trials were established in Crookston and St. Paul, MN and planted to brown mustard and winter rye in 2023. Sclerotia of three isolates of S. sclerotiorum (WI47, MNSS2, SSPotter) and three AG groups of R. solani (2-2, 4, 5) were incubated under each cover crop. Viability tests were conducted at planting for R. solani and at early flowering for S. sclerotiorum. Sclerotia viability varied between isolates in both St. Paul (p = 0.04) and Crookston (p < 0.001). Disease incidence was low in both locations for both diseases. Soil aggregation, ACE protein concentrations, yield, and seed protein and oil contents were evaluated to understand the impact of cover crops on soil health and soybean and dry bean agronomics. This research will provide insights into the interaction of cover crops, plant health, and soil health, including inoculum persistence.