Over the past 12 years, corn growers have enjoyed lower populations of once troublesome insects and lower yield losses thanks to Bt corn, said Ric Bessin, entomologist in the University of Kentucky College of Agriculture.

Bt corn is a genetically modified organism, which means a small amount of genetic material from a different, naturally occurring organism was added to its genetic makeup. The modified gene can control a pest or a group of pests, thus preventing potentially significant yield losses. One of the most common pests Bt corn protects against is the European corn borer.

"Bt corn has been safely distributed, grown and consumed since its introduction into the agricultural sector," Bessin said. "And since it controls pest populations, it's even helping farmers that do not grow Bt corn."

Producers may find Bt corn extremely useful in today's grain market. With current corn prices around $5.50 a bushel, any damage to the crop is more costly than in past years. Bt corn can help producers keep crop loss at a minimum and retain higher profit margins. It also saves producers the time and money associated with scouting for pests and spraying pesticides on infected crops.

Bessin, Jim Herbek, UK grain crops specialist, and Doug Johnson, UK entomologist, completed a seven-year study on Bt corn and found it is most beneficial to growers that are forced to plant behind schedule because late planted crops are the most susceptible to pests.

"We found that Bt corn can prevent as much as a 22 bushel per acre yield loss," Bessin said.

The crop became available to growers in 1996, and in 2008 makes up over half of all corn acreage in the United States. Most of the crop is used for livestock feed or ethanol.

As technology has advanced, varieties that protect against different pests were developed. Varieties are now available to control a single pest or group of pests. At UK, researchers are studying corn that has as many as five modified genes.

 "There is always the potential for pests to become resistant or tolerant to the genes," Bessin said. "We want to be proactive and continue to work to anticipate pest resistances and make improvements to the genes so plants can keep pests at bay before they develop a resistance to previous varieties."