Since launching insect-protected corn rootworm traits in 2003, Monsanto has seen pockets of heavy corn rootworm infestation, especially in geographies where there’s a long history of corn-on-corn plantings. Farmers in these areas may see intense rootworm pressure that can overwhelm rootworm-protected corn plants, leading to performance inquiries.
As in years past and similar to 2011, we anticipate the number of corn rootworm performance claims in 2012 will constitute a tiny fraction of the total number of acres planted to this technology. We are working with academics, the Environmental Protection Agency, and other key stakeholders to understand why trait performance is less than expected on these fields and to provide sound agronomic solutions for growers.
For the 2012 field season, growers were encouraged to follow recommended Integrated Pest Management (IPM) practices, including cultural control tactics, scouting and the appropriate use of pest thresholds and sampling. For those fields where performance inquiries with YieldGard VT Triple and Genuity VT Triple Pro corn were filed in 2011, we instructed growers to implement certain Best Management Practices (BMPs).
The BMPs provided practical solutions to reduce rootworm populations, limit rootworm damage and enable insect resistance management. These BMPs were as follows:
- Our lead BMP practice is rotating the field to a non-host crop such as soybeans, which breaks the corn rootworm cycle.
- Another strong option is for growers to use Genuity SmartStax corn hybrids that provide dual mode-of-action (pyramided) Bt traits and deliver excellent performance.
- If rotation or Genuity SmartStax corn is not an option for growers, using soil- or foliar-applied insecticides with YieldGard VT Triple and Genuity VT Triple Pro to manage larvae and adults is a viable option.
In addition, growers always have the option of rotating to a non-Cry3Bb1 corn product, such as a corn rootworm-protected trait from another technology provider or a non-Bt corn hybrid with soil- or foliar-applied insecticides.
Monsanto agronomists and dealers worked with each farmer who had a performance inquiry in 2011 to identify the appropriate BMPs for each affected field. These farmers have overwhelmingly adopted the 2012 BMPs to manage corn rootworm in these fields this season. Throughout the summer, our Technology and Agronomy teams have evaluated the performance of these fields to understand the effectiveness of each BMP.
The chart pictured here highlights that nearly two thirds of the growers with a 2011 performance inquiry adopted a soy rotation or a Genuity SmartStax hybrid. For the fields that rotated to soybeans, the agronomic benefits include not only eliminating the high corn rootworm density but also augmenting soil fertility and reducing residue build up, among others. In the fields where Genuity SmartStax corn hybrids were planted, we continue to see the technology demonstrating excellent control of corn rootworm.
The remaining growers chose to use either a YieldGard VT Triple or Genuity VT Triple Pro hybrid with an insecticide, or to use a non CryBb1 product. In the case of those choosing YieldGard VT Triple or Genuity VT Triple Pro hybrids with insecticides, there have been a few cases where the insecticides were not effective due to the lack of moisture, and thus activation of the insecticides after planting. For these growers in particular, we are strongly encouraging that these fields move to a soy rotation or Genuity SmartStax hybrid for the 2013 growing season. Overall, the BMPs provided effective management of corn rootworm on a field-by-field basis.
Farmers make decisions every day to be successful in the farming business. By fine-tuning product selections and rotations, farmers have effectively changed behaviors to adopt the best agronomic practice for their farms. We are committed to working with farmers to understand the circumstances and the history of their fields to provide agronomic solutions for the current and future growing seasons that maximize productivity, are practical and sustainable. We believe the BMPs we have taken to the field will continue to contribute to farmer success, choice and the long-term durability of corn-trait technologies.
Managing Corn Rootworm in 2012: Kansas, Colorado, and Nebraska
Managing Corn Rootworm in 2012: Wisconsin, Illinois, Iowa
2012 Genuity Corn-on-Corn Clinics
Hot, Dry Weather Causes Root Concerns
Looking Ahead to the 2012 Corn Planting Season
Managing Corn Rootworm Populations Requires Increased Diligence in Weather Stressed Environments
2012 Best Management Practices Helping Growers Effectively Control Corn Rootworm Populations