There are hundreds of soybean varieties with resistance to the soybean cyst nematode. An updated list of SCN-resistant varieties in maturity groups 0, 1, 2 and 3 for 2021 was published as Iowa State Extension PM 1649 in November.
Of the 849 varieties in the ISU publication, 810 have resistance genes from the same genetic source, a breeding line called PI 88788. Resistance genes from PI 88788 have been used in the vast majority of varieties for most of the last 30 years (see figure in ICM News article).
Continuous use of soybean varieties with this single source of resistance has led to SCN populations developing increased reproduction on varieties with the PI 88788 resistance throughout Iowa and the Midwest.
Yield lift with other varieties
Growing soybean varieties with a source of SCN resistance other than PI 88788 can increase yields as a result of better nematode control. For example, soybean varieties with the Peking source of SCN resistance yielded 22 bushels per acre more than varieties with PI 88788 SCN resistance in an experiment conducted by ISU in southeast Iowa in 2019.
The increased yields correlated with much better control of SCN reproduction. End-of-season SCN egg densities with Peking varieties averaged 800 eggs per 100 cubic centimeters of soil, whereas egg densities with PI 88788 varieties averaged 14,400 eggs per 100 cubic centimeters (see this ICM article ICM article).
It is critical that farmers begin growing soybean varieties with SCN resistance different from PI 88788 in SCN-infested fields. These varieties should be grown in rotation with varieties with PI 88788 resistance, not as a complete substitute for PI 88788 resistance. Below is information about soybean varieties for Iowa with SCN resistance from sources different from PI 88788.
SCN resistance from Peking
The soybean varieties below have the Peking source of SCN resistance. The information was provided by the seed companies offering the varieties. Brands are listed alphabetically and varieties are listed in increasing order of maturity within brand.
Additional soybean varieties with SCN resistance different from PI 88788 and Peking include:
- Golden Harvest brand GH2329X — resistance from PI 89772, relative maturity 2.3.
- IAR2601SCN from ISU — resistance from PI 38489B, in maturity group 2.
- IAR2801SCN from ISU — resistance from PI 437654, in maturity group 2.
- NK brand S23-G5X — resistance from PI 89772, relative maturity 2.3.
Additional information about the soybean varieties mentioned in this article and many other SCN-resistant soybean varieties is available online here.Tylka is a Morrill professor in the Department of Plant Pathology and Microbiology at Iowa State University. Source: Iowa State University Extension and Integrated Crop Management News, which are solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.