AMES, IOWA (RFD-TV) — Corn rootworm continues to cost U.S. farmers more than $1 billion annually in combined yield losses and management expenses, making pest control an important consideration as producers plan for the 2027 growing season.
Bruce Battles, head of technical agronomy with Syngenta, joined Market Day Report to discuss this year’s rootworm pressure, management challenges, and how newer trait technologies could help protect yield potential.
Rootworm Damage Can Sneak Up on Growers
Battles said corn rootworm damage remains a persistent risk, particularly in continuous corn and fields where growers may not expect significant pressure.
He said he personally encountered unexpected damage in some second-year corn fields this season, while long-term continuous corn acres continued to show the risks associated with repeated planting.
Although some growers have described increasing rootworm pressure, Battles said he does not see a major change in overall pressure across the Corn Belt over the past several years.
Instead, he said the biggest differences often occur at the field level, depending on management practices and weather conditions.
Multiple Tools Needed for Management
Crop rotation remains one of the most effective tools for managing corn rootworm, Battles said, but it is not always a complete solution.
Extended diapause, in which rootworm eggs remain in the soil and hatch in a later season, can make rotation less effective in certain areas.
Insecticides, either alone or in combination with trait technologies, are another option. However, Battles cautioned against choosing products based solely on price.
He said lower-cost generic products may work in lower-pressure situations, but growers dealing with significant rootworm pressure could see better results from newer, more effective products.
He encouraged farmers to understand the risks in their individual fields and select management tools accordingly.
Trait Technologies Show Differences in Performance
Battles said trait technologies can play a significant role in reducing corn rootworm damage, particularly when they are selected and used as part of a broader management program.
In Syngenta’s trials this year, insecticide treatments reduced rootworm damage by more than two-thirds. Effective trait technology provided closer to a 90% reduction, he said.
He also highlighted the company’s newer Durastak trait technology, which adds a third Bt protein for corn rootworm protection.
Battles said adding that third protein improved the level of control by approximately two times compared with the previous trait technology in the company’s comparisons.
In one comparison using the same hybrid, changing the trait package resulted in an approximately 9.7-bushel-per-acre yield advantage.
He also emphasized that traits are not a silver bullet. Rotating technologies and combining appropriate management practices remain important as growers work to preserve trait effectiveness and manage changing resistance.
Planning for 2027 Starts Now
Battles encouraged growers to evaluate rootworm pressure field by field as they make seed and management decisions for next season.
Continuous corn acres, fields with a history of rootworm damage and areas with extended diapause may require additional attention.
He said producers should consider crop rotation, insecticide options and trait selection together rather than relying on a single management tool.
With more technology choices available, understanding what has happened in each field and selecting the appropriate combination of tools will be important to protecting yield potential.
LEARN MORE: www.syngenta-us.com/seeds/corn-traits/durastak
