Researchers have been updating the map of known soybean cyst nematode distribution regularly since 2000, and with each update, the threat spreads. The latest update, spearheaded by Greg Tylka, a nematologist from Iowa State University, reveals 31 counties in ten states reporting SCN for the first time between 2020 and 2023. In Canada, ten rural municipalities in Quebec and three counties across Manitoba and Ontario reported SCN for the first time during that three-year span. In the U.S., SCN is in every county across Illinois and Iowa, the top two soybean-producing states. Just because an area doesn’t report any SCN doesn’t mean fields are free from infestation. “Fields may be infested for many years before the infestations are discovered,” Tylka added. The SCN Coalition encourages producers to develop a plan that includes testing their fields to know the numbers, rotating resistant varieties, rotating to non-host crops, and using a nematode-protectant seed treatment.
SCN continuing spread renews focus on the threat
