By Andi Anderson
Soybean cyst nematode (SCN) remains one of the most damaging pests affecting soybean production. To help farmers protect yields and maintain profitable operations, Iowa State University (ISU) has released an updated list of soybean varieties resistant to SCN for the 2027 growing season. The information is available through ISU Extension and Outreach publication “Soybean Cyst Nematode-resistant Soybean Varieties for Iowa.”
Growing resistant soybean varieties is one of the most effective ways to manage SCN infestations. The annual publication provides farmers, agronomists, and crop advisors with valuable information to support variety selection and improve pest management strategies. The project is supported by soybean checkoff funds from the Iowa Soybean Association.
The updated publication contains a total of 796 SCN-resistant soybean varieties spanning maturity groups 0 through 3. These varieties are offered through 30 seed brands marketed by 22 different companies, giving producers a wide range of choices for different growing conditions and management goals.
Most of the resistant varieties use genetics from two well-known resistance sources, PI 88788 and Peking. Of the 796 varieties listed, 613 contain resistance derived from PI 88788, while 175 varieties contain resistance from Peking. The publication also includes two varieties that combine both resistance sources and six blended products containing varieties with PI 88788 and Peking resistance.
The availability of multiple resistance sources is important because it provides farmers with additional tools for managing SCN populations. Diversifying resistance genetics can help improve long-term effectiveness and reduce pressure on any single source of resistance.
In addition to resistance information, the publication provides several important details to assist in variety selection. These include relative maturity ratings, herbicide resistance or tolerance traits, and iron deficiency chlorosis (IDC) tolerance scores. IDC is a common concern in alkaline soils where SCN infestations are often present. Selecting varieties with strong IDC tolerance can improve crop performance in challenging field conditions.
The largest number of resistant varieties falls within Maturity Group 2, which includes 328 options. Maturity Groups 0 and 1 contain 197 varieties, while Maturity Group 3 includes 271 varieties. This broad selection allows growers to choose varieties well suited to their regional production environments.
Beyond publishing the annual variety list, Iowa State University also conducts extensive field evaluations of SCN-resistant soybean varieties. Researchers test varieties in replicated trials located across all nine USDA Crop Reporting Districts in Iowa. These evaluations measure both soybean yield performance and the ability of varieties to manage SCN populations under field conditions.
Results from these research trials provide valuable information that farmers can use when making planting decisions. Findings from the 2026 variety evaluations will be published in the ISU Extension and Outreach report “Evaluation of Soybean Varieties Resistant to Soybean Cyst Nematode in Iowa.” The report is expected to be available online in December 2026, with printed copies distributed through agricultural publications in early 2027.
By offering updated variety information and performance data, Iowa State University continues to support farmers in managing soybean cyst nematode. The 2027 variety guide provides producers with the knowledge needed to select effective resistant varieties, improve soybean yields, and strengthen long-term pest management efforts across Iowa’s soybean industry.
Photo Credit: gettyimages-zoran-zeremski
Categories: Iowa, Crops, Soybeans