Dr. Chris DiFonzo, Entomologist at Michigan State University and author of the Handy Bt Trait Table, and I got a note from a corn seed dealer a couple of weeks ago concerning the removal of some single toxin Bt corn hybrids from the market after 2019. Apparently there was a letter circulating from one of the seed companies to this effect, and he wanted to know whether it was true and, if so, why it was being done - some of his customers really like their single toxin hybrids. It is true, and it is a good and necessary thing. Back when Bt corn was first introduced, most hybrids had only a single toxin for caterpillar pests, and, a few years later, if there was a corn rootworm toxin it was single as well. A few more years down the road, seed companies began selling �pyramids� of toxins; a combination of two or more toxins targeted at a pest. Not only did this improve efficacy, but it also slowed the rate of resistance development as explained in the following scenario. If inse...
Comments
Post a Comment