Sclerotinia stem rot (SSR) or white mold of soybean is caused by the fungus Sclerotinia sclerotiorum (Grau and Hartman, 1999). In the temperate north central soybean production areas of the United States, SSR can be a significant yield limiting disease. In seven growing seasons between 1996 and 2009, yield losses as a result of SSR where greater than 10 million bushels (270 million kg) per year (Peltier et al., 2012). Yield can be reduced 2-5 bushels per acre (133-333 kg/ha) for every 10% increment increase in SSR incidence in soybeans at the R7 growth stage (Peltier et al., 2012). These impacts on yield are significant and make SSR one of the most important diseases of soybean in the North Central U.S.