.......I was concerned that farmers on the Missouri and Nemaha river bottoms of southeast Nebraskswere not aware of the presence or absence of soybean cyst nematodes in their fields.
With the help of Monsanto and Pioneer, I sampled 50 fields at random along the Missouri and Nemaha river bottoms between Rulo and Peru. There were 33 samples taken in river bottom fields. More than 70 percent, 24 of these samples, were positive. We estimate a 75 to 80 percent probability of cyst nematode in river bottom fields and about 50 percent in upland fields. The soybean cyst nematode weathered the recent Missouri flood with no problem.
University of Nebraska Extension soybean cyst trials from 2006 to 2011 at 18 locations with cyst nematode present show susceptible varieties yielded 50.7 bu/A while resistant varieties yielded 55.9 bu/A. At today’s soybean price, that is a $75 per acre difference.
Tests were conducted on 8 non-infested sites; susceptible soybeans out yielded resistant varieties by 2.5 bu/A. However, the "yield drag" of resistant varieties is not nearly as significant as it once was.
It is clear that farmers should be including the cyst nematode as a key factor in the selection of varieties and in crop rotation plans. Most farmers in the area use a corn soybean rotation. This helps to keep populations of the nematode in check, but does not rule out damage to soybeans. Farmers in this area should be selecting resistant soybean varieties and even rotating the genetic resistant mechanisms of the varieties.