Transgenic corn's suppression of the European corn borer has saved Midwest farmers billions of dollars in the past decade, reports a new study in Science.

 

Research conducted by several Midwest universities shows that suppression of this pest has saved $3.2 billion for corn growers in Illinois, Minnesota and Wisconsin over the past 14 years with more than $2.4 billion of this total benefiting non-Bt corn growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion accruing for non-Bt corn growers.

 

Transgenic corn is engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Bt corn has become widely adopted in U.S. agriculture since its commercialization in 1996. In 2009, Bt corn constituted 63% of the U.S. crop.

 

Corn borer moths can't distinguish between Bt and non-Bt corn, so females lay eggs in both types of fields. Once eggs hatch in Bt corn, young borer larvae feed and die within 24-48 hours.

 

The major benefit of planting Bt corn is reduced yield losses, and Bt acres received this benefit after the growers paid Bt corn technology fees. But as a result of area-wide pest suppression, non-Bt acres also experienced yield savings without the cost of Bt technology fees, and thus received more than half of the benefits from growing Bt corn in the region.

 

"We've assumed for some time that economic benefits were accruing, even among producers who opted not to plant Bt hybrids," says co-author of the study Mike Gray, University of Illinois Extension entomologist and professor in the department of crop sciences. "However, once quantified, the magnitude of this benefit was even more impressive."