The disease Phomopsis seed decay of soybeans is considered to be the major cause of low quality, poorly germinating seeds in most areas where this crop is grown. This disease is caused by a complex of fungi consisting of Diaporthe phaseolorum var. sojae (Dps), D. phaseolorum var. caulivora (Dpc), and Phomopsis longicolla (Pl). In addition, Dps and Pl cause pod and stem blight and Dpc causes stem canker of soybeans.