Since the flood of 1993, soybean cyst nematode infestations are common in many river and creek bottom fields.
Eggs can survive in the soil for many years even when a host plant is absent.
It is often difficult to identify fields with SCN, because lower yield at harvest may be the only above-ground symptom. Yields may decrease for a number of years before the reduction becomes obvious. Yield loss of 30 percent is possible without any obvious problem until harvest. When SCN is present and plants are under stress, symptoms such as leaf margin or general chlorosis, plant stunting, or under extreme cases, plant death can occur. The most accurate way of determining whether SCN is present in a field is to have the soil tested in a nematology lab for the presence of SCN eggs.