SCN-resistant Soybean Varieties for Iowa in 2022
Growing resistant varieties in rotation with nonhost corn and using nematode-protectant soybean seed treatments is recommended for integrated management of the soybean cyst nematode (SCN). ISU compiles a list of soybean varieties with resistance to SCN each year. This year’s publication was recently completed and is available online. There are 872 varieties in the publication, 96% with resistance from PI 88788, which has been used almost exclusively for 15 years. Due to prolonged widespread use of PI 88788 SCN resistance in Iowa, SCN populations have developed increased reproduction on varieties with PI 88788 resistance and SCN is causing increasing yield losses. This article discusses the situation and gives guidance on how farmers should manage SCN with so few choices of resistance genetics available.