AMES, Iowa — A common tool used to manage a destructive soybean pest is losing its effectiveness, an Iowa State University plant pathologist warned.
“I have observed a slow but steady decrease in effectiveness of PI 88788 resistance against the soybean cyst nematode in Iowa over the past 15 years, and it is becoming a serious concern,” Greg Tylka, professor in the Department of Plant Pathology and Microbiology.
PI 88788 is a common source of genetic resistance to the soybean cyst nematode (SCN) that was introduced into many soybean varieties to counter the pest. The nematodes cost soybean producers across the United States an estimated more than $1 billion each year in lost yields.
“Midwestern soybean farmers desperately need another type or source of resistance against this widespread pest,” Tylka said.
Tylka was one of a group of nematologists from eight Midwestern states and Ontario that discussed the development at a July 7-8 meeting of the North Central Committee on Practical Management of Nematodes on Corn, Soybeans and Other Crops of Regional Importance (NC1197) in Chaska, Minnesota. The committee reviews and coordinates ongoing research on managing nematode parasites of crops, with special emphasis on corn and soybeans.
The scientists concluded that a coordinated approach using multiple management options, such as alternating soybeans with nonhost crops, planting SCN-resistant soybean varieties and using nematode-protectant seed treatments, provide the greatest likelihood of sustained success for producing soybeans profitably in SCN-infested fields.
They also planned coordinated research projects for upcoming years, including work on nematode-resistant varieties, nonhost crops, seed treatments, new nematode detection methods and soil health.