The soybean cyst nematode (SCN) continues to be an extremely damaging and widespread pest of soybean in Iowa and many other Midwestern states. The nematode infests more than 70 percent of the fields in Iowa and more than 80 percent of the fields in Illinois. Often there is no obvious stunting or yellowing of soybean plants in infested fields. Consequently, many SCN-infested fields in Iowa have not been diagnosed.
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