What is in this article?:
- Be sure you have a reason to treat corn insects at tassel stage
- No yield improvement
• There is some potential downside to spraying insecticides unnecessarily, besides the added cost, including selecting for resistance and flaring populations of secondary pests.
CORN earworm larva
No yield improvement
I have had one experiment where a single insecticide application reduced kernel injury in non-Bt corn. Even in this case it did not improve yield.
Many other experiences suggest that a single insecticide application has NO effect on kernel injury or yield, and the higher the corn earworm pressure, the less likely they are to work!
The newer Bt technologies such as SmartStax, VT3Pro and Viptera are better at reducing kernel injury by corn earworm and fall armyworm. Even then, I cannot show you one example in Tennessee where the new Bt corn technologies yielded significantly better than the older Bt traits with the same genetic background.
Never say never, but the long and short of it is, kernel damage by corn earworm is worse than it looks and hard to prevent.
There is some potential downside to spraying insecticides unnecessarily, besides the added cost, including selecting for resistance and flaring populations of secondary pests. Spider mites in particular are far more likely following applications of pyrethroid insecticides. Enough said?
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