When Greg Tylka talks with Iowa soybean growers about soybean cyst nematode (SCN), he provides a sobering perspective.
His data indicates SCN is found in every county of the state, and 70% to 75% of Iowa fields harbor the pest.
“I tell my farmers there’s a three out of four chance any field they grow soybeans in has SCN,” says Tylka, director of the Iowa Soybean Research Center at Iowa State University.
“Probably only Illinois has more widespread numbers of the pest,” he adds.
Only One State Is SCN-Free
Researchers have been updating the map of known SCN distribution regularly since 2000, and with each update, the threat spreads. The latest update, spearheaded by Tylka, reveals 31 counties in 10 U.S. states reporting SCN for the first time during the 2020 through 2023 timeframe, according to a press release from the Coalition.
In Canada, 10 rural municipalities in Quebec and three counties across Manitoba and Ontario reported SCN for the first time over that three-year span.
In the U.S., every soybean producing state in the country has some level of SCN, with one exception. So far, it hasn’t been found in West Virginia, according to the The SCN Coalition.
The organization is a public/checkoff/private partnership formed to increase the number of soybean growers who are actively managing SCN.
No. 1 Contributor To Yield Loss
The Soybean Coalition says SCN is the No. 1 contributor to yield loss in soybean crops nationwide, causing an estimated $1.2 billion dollars in damage.
At the grower level, those dollar losses commonly translate into a yield reduction of 10 bushels to 30 bushels per acre or more, depending on the soybean variety grown and the weather conditions during the growing season.
Even so, Tylka says many U.S. soybean growers still don’t test their fields for the pest.
“I’ve heard lots of excuses about not looking for it, lots of rationalizations, more often than I like to think,” he told AgriTalk Host Chip Flory on Tuesday. “Farmers are way better off to know they’ve got it, because they can then adopt management practices to keep it under control to minimize yield losses and prevent further spread.”
To address SCN, the Coalition encourages farmers to work with their agronomic adviser to develop a plan, including:
- Test fields to know your numbers.
- Rotate resistant varieties with PI 88788 and Peking genetics.
- Rotate to non-host crops.
- Consider using a nematode-protectant seed treatment.
Farmers interested in knowing what SCN could be costing them in yield can learn that information with the SCN Profit Checker tool available online from the Coalition. Powered by data collected from 25,000+ university research plots, the tool defines that economic toll, field by field.
Hear the complete discussion between Tylka and Flory on AgriTalk at the link below.
