Bob Scott has read about soybean cyst nematodes (SCN) in Soybean Digest and elsewhere. But he didn't think he had it. So he didn't soil test for it.
Big mistake — big, he admits.
Scott, an Avoca, IA, farmer and independent seed dealer for Kruger, Garst and Syngenta companies, got the message this past fall.
He had a cyst-resistant variety in a test plot in one field. And when he combined that variety, the yield monitor took an 8- to 10-bu/acre yield jump.
“I took about a 10-bu/acre yield hit on 33 acres. That's 330 bu of beans times $5, or about $1,500,” Scott explains. “That would pay for a lot of testing.”
On advice from Clarke McGrath, an Iowa State University area crop specialist, he took samples for nematode testing on all of his fields. Tests were positive on about 40%, with cyst levels running from zero up to 13,000 per 100 cc of soil. Scott became a convert.
“It's a no-brainer,” he says. “Testing for nematodes is a must. Anybody who is soil testing for P and K should seriously consider splitting the sample and sending one in for nematode testing.”
Gary Schmitz, a Sumner, IA, soybean grower, had never soil tested for SCN. But he previously suspected cyst nematodes in a low area of a 100-acre field that had stunted, yellow plants. He saw nothing the next time the field was in soybeans.
Then in 2001, with very dry weather, the spot was back and had spread significantly. Beans were short with fewer pods. It showed up on the yield monitor. Schmitz mentioned it to Brian Meyer, a certified crop adviser with Quality Distributors, Readlyn, IA, who suggested he test for nematodes. Tests confirmed SCN.
“I saw a 13-bu yield hit in that impacted area compared to the rest of the field,” Schmitz says. “In the future, I definitely plan to plant cyst-resistant varieties there, and monitor all my other fields for cyst nematodes.”
Despite significant progress made with the intense educational effort of the SCN Coalition, nematologists and other crop professionals nearly go bonkers over the fact that too many growers still don't test for SCN.
“I have yet to be at a field day where 50% of the producers present have sampled their fields for SCN, and that's unfortunate,” says Tracy Blackmer, director of production technologies for the Iowa Soybean Association.
Hunt Wiley, research director for Dairyland Seeds, sums it up best: “The most important message I can convey to farmers is that they have to get cyst counts on ground going into beans — period.”