Many growers who are shifting acreage out of corn in 2009 will be looking to put that land into soybeans. That could cause some problems for growers who planted soybeans in the same fields last year, says North Carolina State University soybean specialist Jim Dunphy.
"I have two concerns about getting away from rotation," Dunphy says. "There is a 3 to 5 bushel per acre price tag for soybeans behind soybeans and, sooner or later, a pest problem will get out of hand."
Dunphy says the yield reduction will hit growers who plant soybeans behind soybeans right away. It is uncertain how quickly losing rotation as a pest control management practice will cause pest problems to develop in the field, however.
Dunphy says nematodes are the most likely pest problem to develop in the North Carolina Blacklands or Coastal Plains regions, particularly soybean cyst nematode.
"Unfortunately, the races of cyst nematode that most of our Roundup-Ready varieties are resistant to are races that we haven't identified very often in North Carolina," says Dunphy. "In the Piedmont, I'd be harder pressed to predict which pest will become a problem, but I'm confident it will happen sooner or later. The better job a farmer does of finding, and managing, pest problems, the less risky soybeans behind soybeans becomes."