Sclerotinia stem rot (SSR) or white mold of soybean is caused by the fungus Sclerotinia sclerotiorum. Sclerotinia sclerotiorum has a diverse host range, infecting many weedy plant hosts and crop plants. In the Northern U.S. SSR is a major disease of soybean. In years when average temperatures are cool (70° F) and there is frequent rains or high humidity, SSR can cause significant damage to soybean crops resulting in yield loss. For every 10% increase in plant death at the R7 growth stage, yield can be reduced 2 to 5 bu/a. This presentation will highlight recent research conducted to understand how SSR epidemics move in soybean fields, cause damage on soybeans, and how to manage the disease. The research presented here is partially funded by the soybean check off though the North Central Soybean Research Program and several state soybean associations including the Wisconsin Soybean Marketing Board.
