Rotating Traits Key to Controlling Volunteer Corn

Crop experts recommend trait rotations as corn-on-corn acres rise to meet ethanol demand.

Apr. 18, 2026 at 5:24am

Got story updates? Submit your updates here. ›

A bold, abstract painting in soft greens, browns, and blues depicting interlocking geometric shapes and organic spirals, representing the complex interplay of corn traits, herbicide resistance, and volunteer corn competition.Rotating herbicide-tolerant traits is essential for controlling volunteer corn and maintaining yields as farmers plant more corn-on-corn to meet ethanol demand.DeKalb Today

As no-till farmers plant more corn-on-corn to keep up with growing ethanol demand, crop specialists are advising the use of rotating herbicide-tolerant traits to control volunteer corn and maintain yield potential. A University of Illinois study found that uncontrolled volunteer corn can reduce yields in glyphosate-tolerant and LibertyLink corn by up to 60%.

Why it matters

Volunteer corn from previous seasons can significantly impact yields in corn-on-corn systems, making trait rotation a critical management practice. As more marginal acres are brought into production to meet ethanol needs, controlling this weed will be essential for maintaining profitability.

The details

The study found that complete control of volunteer corn with glyphosate in glyphosate-tolerant corn plots yielded 219 bushels per acre, while 90-92% control with glufosinate in LibertyLink corn plots yielded 205 bushels per acre. While the test plots were uniformly seeded with volunteer corn, which may not reflect real-world conditions, the results still highlight the importance of controlling this weed.

  • Corn acreage increased by nearly 20% over 2006 levels.

The players

Tracy Mader

Marketing manager for Syngenta's Agrisure Corn Traits.

Aaron Hager

University of Illinois Extension weed specialist and coordinator of the volunteer corn study.

Got photos? Submit your photos here. ›

What they’re saying

“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.”

— Tracy Mader, Marketing manager, Syngenta's Agrisure Corn Traits

“Because the test plots were uniformly seeded with volunteer corn, these yield losses may be higher than what you might see under field conditions. 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.”

— Aaron Hager, University of Illinois Extension weed specialist

The takeaway

As farmers plant more corn-on-corn to meet ethanol demand, rotating herbicide-tolerant traits will be crucial to controlling volunteer corn and maintaining yields. Uncontrolled volunteer corn can significantly reduce yields, making this weed management practice essential for profitability in intensified corn production systems.