Handy Bt Trait Table Updates
Eileen Cullen, Extension Entomologist
More corn hybrids contain multiple transgenic traits, and cost of this seed is steadily rising. Meanwhile, refuge requirements are changing for stacked trait and pyramided trait corn. Planting the correct refuge with knowledge of the insect spectrum controlled and suppressed is critical to insect resistance management.
Some refuges remain 20% and ‘structured’, planted in a block or series of rows. Others are reduced to 5% or 10%, in a block or ‘in the bag’ mixed with the Bt seed itself. This fact sheet from Michigan State University and University of Wisconsin Extension (click here), updated May 2013, provides a quick reference to the currently available Bt traits, spectrum of insect control, and refuge percentage and location requirements.