Corn Rootworms

Western corn rootworms are reported to overcome our trait resistance in Cry3Bb1, when used in a continuous corn rotation.  Entomologists were surprised at how quickly (6 yrs.) this insect adapted to overcome this transgenic rootworm technology.

You might ask “What can be done?”  Rotate to soybeans.  Even in continuous corn rotation, every 4-6 years soybeans should be grown.  This management step will dramatically improve the performance of your corn rootworm management.

Secondly, add a pyramided corn rootworm transgenic trait, such as Smart Stax (Cry3Bb1 and Cry34/35Ab1) or Agrisure 3122 (Cry34/35Ab1 and mCry3A) to your corn rotation.  These pyramided traits should be rotated every 2-3 years.

Third, as a soil insecticide on non-rootworm Bt corn. 

Fourth, rotate single Bt corn rootworm traits.  Start with the Cry3Bb1 (Genuity VT Triple Pro) or mCry3A (Agrisure RW) then switch to Cry34/35Ab1 (Herculex Xtra).  Generally, rotate single Bt traits annually or every two years.