Several different diseases can cause similar symptoms on soybeans. An example of a disease that is easily misdiagnosed as early crop maturity, sudden death syndrome (SDS), Sclerotinia stem rot or charcoal rot in the North Central United States, is soybean stem canker. Symptoms of the disease can include main stem wilting and widespread plant death in areas of a field (Fig. 1). Closer examination of plants often reveals sunken cankers on main stems (Fig. 2). In recent years stem canker and other diseases caused by fungi in the same group, such as pod and stem blight, have become increasingly problematic in the North Central region. Severe stem canker epidemics can occur in wet springs, and...