Whenever you buy insurance, it’s helpful to weigh the cost versus the benefit. In other words, does the inherent risk justify the premium being paid? The same should be true whenever a grower makes the decision of whether or not to plant a Bt corn hybrid.

“Bt corn is really a form of crop insurance that comes in the seed bag. The presence of one or more Bt genes in a corn hybrid will not increase yield potential. Instead, the gene(s) prevent yield losses from certain insects,” according to a recent evaluation of Bt corn hybrids conducted by researchers at Auburn University, including Kathy Flanders, Extension entomologist; Brenda Ortiz, Extension agronomist; Austin Hagan, Extension plant pathologist; and other cooperators.

The most important thing to remember, states the report, is that if the population of the target insect in your field or area is high enough, Bt corn will pay off. If the insect pressure is not there, then you won’t get your money back. So it is a matter of deciding if the risk is high enough to warrant purchasing “insurance.”

There are different kinds of Bt corn, depending on which Bt genes have been inserted. Some Bt genes protect against stalk borers and others help prevent leaf and ear damage from various caterpillars, including corn earworm and fall armyworm. Still other genes protect the roots from Western corn rootworm.

These genes are bundled together in various combinations, with or without herbicide tolerance genes.

According to the researchers, the cost of Bt technology that protects against corn borers and other caterpillars is about $3.70 per acre for older products such as YieldGard Corn Borer, Agrisure CB/LL, and Herculex I. The cost of Genuity VT Triple Pro is about $10.50 per acre. Genuity VT Triple Pro contains two genes for above-ground caterpillar resistance, in addition to protection from Western corn rootworm.