By Dusty Post
Global Insect Management Lead
U.S. farmers face many risks each year when they put their seed in the ground, from adverse weather to insects. As we’ve written about in past blog posts, corn rootworm is a devastating pest that can be challenging for farmers to manage. It’s why Monsanto has committed millions of dollars to the Corn Rootworm Knowledge Program, to work with academics to enhance the collective understanding of the corn rootworm.
One of the past recipients of our Knowledge Program grants, Dr. Aaron Gassmann from Iowa State University, recently published a study in Proceedings of the National Academy of Sciences (PNAS), which emphasized both concerns surrounding resistance to Bt corn products, as well as an integration of management practices, such as crop rotation, and a recommendation for increased refuge.
Regarding the effectiveness of our Bt products, since 2002, millions of acres have been planted with the Cry3Bb1 technology in the U.S. While greater than expected corn rootworm damage has occurred in a small portion of those acres, we’ve found that these products continually demonstrate an outstanding level of performance and grower satisfaction on greater than 99.8% of those acres. That percentage has remained steady in recent years.
While much of the study highlights management practice topics we’ve previously discussed at length, both in this blog and our website, the research by Dr. Gassmann and his coauthors underscores the continued importance of and need for adoption of best management practices (BMP) for rootworm control, such as regular crop rotation and practical integrated pest management solutions.
The vast majority of corn rootworm trait performance inquiries occur with continuous corn-on-corn. The most effective cultural practice is rotation to soybeans or another non-host crop – and is also our No. 1 recommended BMP to address fields experiencing unexpected rootworm damage. Based on the 2013 results of our BMPs, those farmers who rotated to soybeans saw both the elimination of high corn rootworm pressure in their fields and also experienced augmented soil fertility and a reduction of residue build-up.
We remain committed to sharing information about what we see and learn about corn rootworm and corn rootworm management with farmers and the academic community. Our combined efforts with researchers such as Dr. Gassmann and other CRW Knowledge recipients is all in the hope of continuing to find practical solutions for farmers and ensuring that Bt traits remain a viable tool for farmers.