The microscopic, soil-borne soybean cyst nematode (SCN) is considered the most serious biological threat to the U.S. soybean industry. In North America, it causes yield losses worth more than $1 billion annually.
The SCN Coalition helps farmers combat this relentless pathogen in a variety of ways. Established by Professor Greg Tylka, director of the Iowa Soybean Research Center, with several colleagues at other universities, the coalition was launched in 2018 and now includes university scientists from 28 states and Ontario, Canada, grower checkoff organizations and corporate partners.
Each year, Tylka and his team develop an updated list of commercially available SCN-resistant varieties for Iowa that the Coalition helps promote. ISU Extension and Outreach publishes the list in the fall. A preliminary version of the list for 2026 is available online.