With so many Bt trait offerings on the market today, it can be challenging to determine which package best fits your farm. Each package contains different combinations of traits with different levels of effectiveness against specific pests. Understanding best management practices is critical to ensuring control options for years to come.
Factors to Consider
- Crop rotation
- Corn rootworm pressure
- Ability to use soil-applied insecticide
- Above-ground pest pressure
- Traits and insecticides used in previous years
- Planting date records
- Assess your fields and those around you. Gather information to help you predict the level of pest pressure. Keep in mind that continuous corn acres are subject to higher pest populations. Evaluate the rotation of neighboring fields to understand which pests might move to your fields. Planting date history might reveal clues about pest pressure because significantly later plantings can cause the field to act as a trap crop and attract insects.
- Follow best management practices.
• When planting continuous corn, rotate to different insect protection traits each year or use a stacked trait product with multiple modes of action.
• When using a single mode of action against corn rootworm, use a soil-applied insecticide at full rates. High rootworm populations might require trait packages with multiple modes of below-ground control, coupled with a soil insecticide.
• Watch for corn rootworm beetles. If they appear, consider spraying to avoid silk clipping and to reduce next year’s population.
• Avoid using the same trait more than three consecutive years. Follow refuge requirements.
- Evaluate your level of control. Scout your field throughout the growing season to determine the effectiveness of your management practices. High insect pressure situations will call for crop rotation or higher levels of management.
When selecting Bt trait packages for your corn, evaluate your situation and consider crop rotation, field scouting records, state pest data survey, historical insect problems and other factors. Proper management will ensure longevity of control options and greater economic gain. For more information, contact your local Mycogen Seeds customer agronomist or trusted agronomic adviser.
Difonzo, C., and E. Collen. 2013. Handy Bt trait table. http://labs.russell.wisc.edu/cullenlab/files/2013/11/Handy_Bt_Trait_Table.pdf
In cotton-growing regions, refuge requirements are reduced from 50 percent to 20 percent.