Farmers in the Midwest may be concerned about white mold (also called Sclerotinia stem rot) in soybean this year. The disease, caused by the fungus Sclerotinia sclerotiorum, is not common every year, but farmers who have battled the disease in the past will want to assess the risk of white mold development as soybeans approach flowering (growth stage R1 — plants have at least one open flower at any node).