Crop specialist are recommending trait rotations as no-tillers plant more corn-on-corn to keep up with the growing ethanol demand.

Total corn acreage increased by nearly 20 percent over 2006, according to Tracy Mader, marketing manager for Syngenta’s Agrisure Corn Traits. “Many of these new corn acres were planted into last year’s corn crop, which raises the importance of trait rotation to maintain yield potential while optimizing weed and insect control,” he says.

Like soybeans, corn can suffer significant yield loss through competition from volunteer corn, he notes. In a University of Illinois study, volunteer corn infestation reduced yields of glyphosate-tolerant and LibertyLink corn by 42 percent and 60 percent at Illinois test locations in Urbana and DeKalb compared to glyphosate-tolerant corn plots treated with glyphosate and Liberty Link corn plots treated with glufosinate.

“Because the test plots were uniformly seeded with volunteer corn, these yield losses may be higher than what you might see under field conditions,” points out Aaron Hager, University of Illinois Extension weed specialist and coordinator of the study. “In the field, volunteer corn infestations usually include some combination of clump corn, which is not as competitive. But that doesn’t change the take-home message, which is that volunteer corn must be controlled to prevent yield loss in corn-on-corn.”

At the DeKalb facility, glyphosate provided complete control of volunteer corn in GT corn plots and yielded 219 bushels per acre. Glufosinate provided 90 to 92 percent control of volunteer corn in LL corn plots and yielded 205 bushels…