SCN responsible for yellow soybean fields

During the past few weeks, areas of many soybean fields throughout Iowa have turned yellow. In several of these fields, the yellowing is due to feeding by the soybean cyst nematode (SCN). SCN usually is present in fields for many years before population densities increase to a level that causes visible stunting or yellowing. When yellowing occurs, it generally appears in late July or early August. The yellowing often fades after rainfall