The Halo Effect: Modified Corn Kills Pests for All Crops

By John Hendel

Regardless of planting choices, few farmers escape genetically modified crops. More than four-fifths of U.S. soybean, corn, and cotton acres are planted with them, according to The Associated Press, but the remaining acres may also be affected. New research published in Science suggests there is a "halo effect" for modified corn crops. Their special, modified traits kill off pests like the European corn borer, but in doing so they also help the "refuge" acres of non-modified crops and have allegedly saved farmers billions. The finding illustrates the side effects of modified crops--in this case, profitable ones. But the "halo effect" is also a sign of how agribusiness's innovations in recent decades can cause unexpected changes:

Corn that's been genetically engineered to resist attacking borers produces a "halo effect" that provides huge benefits to other corn planted nearby, a new study finds. Since the borers that attack the genetically modified crops die, there are fewer of them to go after the non-modified version.

Given that the corn borer has cost U.S. farmers $1 billion a year, the economic benefits are dramatic, according to the report in Friday's edition of the journal Science.

The genetically modified plants, called Bt corn, have had an economic benefit of $6.9 billion during the past 14 years in the five Upper Midwest corn-producing states studied, concluded the researchers. They were led by William Hutchison, head of the entomology department at the University of Minnesota, and Paul Mitchell, an agricultural economist at the University of Wisconsin.

They said they were surprised to find that non-Bt corn acres actually reaped 62 percent of the benefit, or $4.3 billion. That's because of the pest-control effect and because non-Bt seed is cheaper.

"We knew there was a benefit but we didn't realize it was going to be that high," Hutchison said in an interview.

Read the full story at The Associated Press.

This article available online at:

http://www.theatlantic.com/health/archive/2010/10/the-halo-effect-modified-corn-kills-pests-for-all-crops/64320/