During a planting season, there are four fungal diseases that may be a concern. Infections by the fungi that cause these diseases occur at early stages of soybean development, and understanding the biology of these diseases helps in properly assessing and consequently effectively managing the risk of these diseases. A simple way to assess disease risk for fields that had disease problems previously is to use soil conditions after planting. A pathogen attacks soybean within a range of soil temperatures, and severe damage occurs only when soil temperature and moisture are optimum for infection.