Modified Corn Aids Nearby Farmers, and Vice Versa

A long-term study of corn production in the Midwest has found that the widespread use of varieties engineered with a bacterial gene that kills insect pests has had big benefits in adjacent fields of conventional corn — cutting infestations there and boosting farmers’ income by billions of dollars. The paper, “Areawide Suppression of European Corn Borer with Bt Maize Reaps Savings to Non-Bt Maize Growers,” is being published in the Oct. 8 edition of the journal Science. The genetically modified variety, known as Bt corn, debuted in the Midwest in 1996 as a means of cutting losses from the European corn borer, a pest that spread to the United States in 1917. It now accounts for more than 60 percent of the American corn crop. A press release from the research team, led by scientists at the University of Minnesota and the Department of Agriculture, summarized the financial findings: The researchers estimate that farmers in Iowa, Illinois, Minnesota, Nebraska and Wisconsin received cumulative economic benefits of nearly $7 billion between 1996-2009, with benefits of more than $4 billion for non-Bt corn farmers alone. The scientists estimated that in Minnesota, Illinois and Wisconsin, borer populations in adjacent non-Bt fields declined by 28 to 73 percent, with similar reductions recorded in Iowa and Nebraska. According to the paper, maintaining “refuges” of conventional corn varieties helps prevent the corn borer from developing resistance to the engineered variety, and the yields in such areas — because of a combination of reduced insect damage and lower costs of the non-engineered seed — ensure that such plantings are profitable...more