This disease occurs in most fields, but rarely is moisture consistent enough for losses to occur. Bacteria are seed-borne and survive in crop residue. Bacteria are commonly spread during storms containing high winds and heavy rains. Symptoms include small, water-soaked leaf spots that turn brown and have a yellow border. As spots coalesce, the tissue falls out giving the leaves a torn and ragged appearance. Do not save seed from severely infected fields. Crop rotation and avoiding field operations when the foliage is wet are important management tools.
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.