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ISU researcher: SCN buildup is ‘train wreck in slow motion’

The buildup of soybean cyst nematode (SCN) on SCN-resistant soybean varieties is a growing concern across the Midwest.

“I liken it to the cliché ‘a train wreck in slow motion’,” says nematologist Dr. Greg Tylka, director of the Iowa Soybean Research Center.

Tylka says the most common source of SCN-resistance, PI 88788, is losing its effectiveness due to overuse.

“We’re already continuing down a path that eventually could mean that common PI 88788 resistance might not be resistant at all,” Tylka says. “I don’t mean that we’re single-digit years away from that, but another 10 to 15 years of this and it could very well be.”

Tylka says some seed companies are starting to incorporate a different source of SCN-resistance, called Peking, into their soybeans.

“But by and large, well over 90 percent of the varieties available for growth in Iowa and surrounding states are still going to have the 88788 resistance,” he says.

Tylka says yield loss on non-SCN resistant varieties can range as high as 50 percent. He says his studies on seed treatments that promise protection against SCN have produced inconsistent results. He is also studying the effects of cover crops on SCN biology and management.

AUDIO: Dr. Greg Tylka