Credit – Craig Grau, Bugwood.org

Results from a winter round of free soybean cyst nematode (SCN) testing show that while most Illinois soybean fields are managing the pest well, a few locations may be at risk for significant yield loss. Often called the billion-dollar pest, SCN is estimated to cost North American growers $1.5 billion annually in lost yield. 

 Between December and February, Dr. Nathan Schroeder’s lab at the University of Illinois processed 424 soil samples. While the average egg count was nearly 1,000 eggs per 100 cm³ of soil, the median was just 120—largely due to a high number of zero egg count results. However, a small number of samples showed extremely high SCN populations. 

 “These hotspots suggest that SCN is still a threat in certain fields,” said Schroeder. “We don’t yet know if those high counts are tied to management decisions, soil type, or the nematode developing resistance to commonly used varieties.” 

 SCN testing is part of a larger checkoff-funded effort to better understand how SCN populations are changing and how resistant soybean varieties are holding up across the state. Although testing has wrapped up for the winter season, farmers can still request a free kit for future sampling by emailing freeSCNtesting@illinois.edu or visiting fieldadvisor.org/scntesting. 

 To explore more Illinois Soybean Checkoff-funded research, visit the Field Advisor Research Hub.