The introduction of hybrids containing the Bt gene gave no-tillers a new management tool to reduce European corn borer losses, but how long this tool will remain effective is the responsibility of growers.

“If Bt is taken for granted and not properly protected, the Bt advantage could prove short lived,” says Steve Butzen, Pioneer agronomy information specialist.

University of Illinois entomologist Kevin Steffey agrees that Bt resistance will happen if growers don’t treat the technology with respect. Steffey’s concern stems from past experience with resistant insects.

“After insects have developed resistance to insecticides, for example, they often come back with a vengeance,” says Steffey. “They are more aggressive, so you end up with a tougher animal to deal with. If we get a worm resistant to Bt corn, we’ll probably have to resort to insecticides more so than in the past.”

Steffey believes every no-tiller who grows Bt corn must realize the following three assumptions:

• If Bt corn is planted on too many acres, European corn borer will become resistant to Bt corn.

• The long-term benefits of Bt corn will not be realized if resistance develops.

• If European corn borer resistance to Bt occurs, the chances for developing other transgenic crops become slim.

Management…