Soybean varieties that are resistant to the soybean cyst nematode (SCN), Heterodera glycines, allow farmers to produce the crop profitably in fields infested with the nematode. SCN-resistant soybean varieties allow less nematode reproduction than what occurs on non-resistant (susceptible) varieties. Most (>95%) SCN-resistant soybean varieties have SCN resistance from the soybean breeding line called PI 88788, and the continued use of soybean varieties with such a narrow genetic base of SCN resistance has resulted in selection of SCN populations with increased reproduction on resistant varieties in fields. This presentation discusses the role and nature of SCN-resistant soybean varieties and the effects of elevated SCN reproduction on the yield of SCN-resistant soybeans.
