Conditions such as mild winters and low moisture are making it likely that many growers should expect the recent rise in corn rootworm (CRW) pressure to continue into next season. For those with affected or at-risk fields, it could mean plants with damaged root systems, poor seed set and yield loss.
That’s why a critical component of any management plan is using defensive CRW trait technology, and according to a recent poll by Pioneer, most growers prefer partnering traits with a combination of best management practices (BMPs) to help maximize and prolong the life of CRW trait technology.
Pioneer polled U.S. corn growers on Instagram and Twitter in late July, asking: “Which of these BMPs is most critical to extending the life of a CRW trait?” The responses from 907 growers had 51% answer “combination of practices,” 35% answer “crop rotation,” 7% answer “in-season insecticide,” and 7% answer “soil-applied insecticide.”
“Corn rootworms have proven over time to be very adaptive, and I’d say there’s no magic bullet – there’s no one trait that can eliminate this pest problem from your field,” said Matt Essick, Pioneer Agronomy Manager. “Trait effectiveness could be anywhere from three to five years to as long as 20 plus years. But if we also implement best management practices, our research shows that can extend the trait life by at least 30%, and up to 50%.”
According to Essick, the data supports growers choosing an integrated approach with multiple tactics to improve the durability and effectiveness of CRW products. Using crop rotation and/or in-season adult insecticides can reduce eggs in the soil for the following season. Altogether, it resets populations to the point where the pest can be managed, while helping to extending the life of today’s advanced CRW traits.
Essick also stresses the importance of accurate measurement of CRW pressure and shares three tips growers can use to identify the presence of corn rootworms, and then measure levels:
1) During tasseling, dig up 10 to 20 plants throughout the field, wash the roots off using a pressure washer or a bucket of water and evaluate for corn rootworm feeding.
2) When adult beetles start to emerge in July and August, go into the field and count the number of beetles you find per plant, doing this at several locations across the field.
3) Utilize yellow sticky traps during beetle emergence. Catching anything less than 20 beetles/trap/week is considered light pressure, anything over 50 beetles/trap/week caught on sticky traps is considered high corn rootworm pressure.
“It all comes back down to understanding what your pressure is and then using multiple methods to minimize build-up, followed by continuously evaluating your management practices over time,” Essick says.
Growers can collaborate with their local Pioneer agronomist to help scout fields and develop integrated management plans. More information on CRW trait technology, such as found in Pioneer brand Qrome products, is available on Pioneer.com or by contacting their local Pioneer sales representative.