Yield losses from this disease are infrequent, but seed quality can be greatly reduced. The fungus survives in diseased stubble or is seed-borne. At maturity, symptoms appear as vertical rows of small black spots on the stem or pods. Seeds may be cracked, shriveled, or moldy. The disease is favored by high humidity and rainfall, especially late in the season. The disease can be managed using crop rotation, destruction of infested debris, or chemical treatment. Seed treatments can be used on pod and stem blight infested seed. Foliar sprays may be used on soybeans grown for seed at growth stage R6.
Taken from Kansas State University Agricultural Experiment Station and Cooperative Extension Service Publication #C-449. Soybean Diseases, Dr. Douglas J. Jardine, Extension State Leader, Plant Pathology Program.