No-Till soybean growers who don’t feel soybean cyst nematode (SCN) is causing significant yield losses now have a clearer picture of its impact on yields.

On-farm, field-sized trials done by Ohio State University researchers indicate SCN-resistant varieties offer a 10 to 15 bushel-per-acre yield advantage in areas where infestation levels run as high as 3,000 to 5,000 SCN eggs per 200 cubic centimeters (cc) of soil.

Mac Riedel, an Ohio plant pathologist, says the field-sized plot data is crystal clear. “These results will visualize for growers the damage this nematode causes in a way that small plot results never could. “It also clearly illustrates the value of genetic resistance,” he says.

Using the split-planter comparison method developed by agronomy researchers at Pioneer Hi-Bred International, the Ohio plant pathologists compared a SCN-resistant soybean variety to a non-resistant variety by planting in alternating strips.

The study indicates susceptible soybeans out-yielded resistant beans by as much as 5 bushels per acre when soil populations were below 2,000 eggs per 200 cc of soil. When the populations were between 2,000 and 6,000 eggs per 200 cc of soil, resistant varieties had a 5 to 10 bushel per acre advantage over susceptible varieties. With over 10,000 eggs per 200 cc of soil, resistant varieties had a yield advantage of more than 10 bushels per acre.

“The results show a strong correlation between SCN populations, varietal resistance and yield,” says Riedel. “Based on our work, we recommend that producers plant resistant varieties if soil tests indicate…