Soybean foliar diseases in July
As we head into the mid-season of crop growth, some foliar soybean diseases are visible. Based on my observations and reports from growers and agronomists, the following foliar diseases are relatively common in Iowa soybean fields. Bacterial blight has been observed in some soybean fields. The disease is caused by the bacterium Pseudomonas syringae. Lesions associated with this disease are normally first observed on younger, top leaves of soybean plants. The lesions are small, angular, water-soaked, yellow-to-brown spots. The angular lesions enlarge in rainy weather and merge to produce large, irregular dead areas. The bacteria also can infect pods and seed quality may be affected when this disease is severe.