Rootworms, which have cost corn farmers excessive crop losses, are showing resistance to genetically modified Bt corn, leading to a rise in pesticide use and not the decline promised by biotech companies.
Genetically engineered Bt corn contains the Bacillus thuringiensis bacteria, which makes the corn a pesticide, technically. The Bt bacteria kills insects like the adaptable rootworm, by essentially exploding its stomach. And according to Food Safety News, after Bt corn began hitting the market, pesticide use initially decreased. "Bt crops reduced insecticide use by 10-12 million pounds annually in the period from 1996 to 2011." But for Bt corn farmers today, things have changed.
The rootworm has begun fighting back against Bt corn and glyphosate (best known as Monsanto's Roundup herbicide) and sales of pesticides are now climbing in order to fend off the crop destroying insects. "More pesticides bought to control another break-out of the western corn rootworm is seen by most growers as just a little more insurance," says Food Safety News. "Corn growers[…]are “covering their bets” by upping their pesticide use while sticking with a Bt hybrid for corn rootworm.”
According to Food Safety News, the plight of struggling farmers elicited a response from Monsanto, which advised farmers to rotate their crops and use the company's "dual of mode action products."
Experts including Charles Benbrook of Washington State University’s Center for Sustaining Agriculture and Natural Resources and University of Illinois entomologist Michael Gray say that 2013 will see more acres planted with GMO corn than ever before, and with the use of more pesticides than ever. The cost of pesticides is driving up corn prices, too. USDA predicts $4.50 a bushel at harvest time.
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