By Blake Jackson
Soybean Cyst Nematode (SCN) has long influenced soybean production in Missouri, gradually reducing yields and stressing crops over time. While its effects may not always be obvious in a single season, the cumulative impact has kept farmers and researchers searching for better solutions.
“Much of the genetic discovery, pretty much started at the Delta Research Center in Southeast Missouri back in the early 1980s,” University of Missouri professor of plant genetics and biotechnology Henry Nguyen says.
For decades, growers have relied on resistant soybean varieties developed from a limited number of genetic sources. However, this heavy dependence has allowed SCN populations to adapt.
“SCN populations in Missouri have been exposed to the same resistance source for decades,” says University of Missouri research scientist Sushil Chhapekar. “That has allowed SCN populations to gradually adapt, with about 50% of Missouri SCN populations now showing high virulence on it.”
This shift often goes unnoticed in the field.
“As a result, farmers may not always see obvious symptoms yet still experience steady and hidden yield losses year after year,” Chhapekar says. “With tight margins and increasing production costs, Missouri growers cannot afford these hidden yield losses.”
Researchers are now exploring new genetic options. By studying more than 1,100 soybean genomes, scientists have identified alternative resistance sources that function differently from those commonly used today.
“As SCN populations in Missouri continue to evolve, relying on a single resistance source is becoming increasingly risky,” Chhapekar says. “Our current research focuses on identifying and combining multiple resistance genes from diverse genetic sources beyond PI 88788 and Peking.”
“With advanced genomics and biotechnology tools, we can now pinpoint resistance regions more precisely and stack them more efficiently in elite breeding lines,” Nguyen says. “This approach helps slow nematode adaptation and creates varieties with durable, sustainable resistance.”
In the meantime, farmers must focus on integrated management strategies.
“SCN management still requires an integrated approach,” Nguyen says.
“Rotating resistance sources using crop rotation, including Peking-based varieties, non-host plants like corn, sorghum, and wheat, and PI 88788-based varieties, is essential,” Chhapekar says.
“Selecting varieties based on local trial data is critical,” Nguyen says.
“Regular soil testing and seed treatments can play a supplementary role,” Chhapekar says.
“It’s always good to stack up along with the known source of resistance,” Nguyen says.
Photo Credit: istock-sandramatic
Categories: Missouri, Crops, Soybeans