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The damage of the 2012 drought to the corn crop in the U.S. wouldn't be so bad if it weren't for GMO Bt corn and the lack of crop rotation, according to corn crop and pesticide management experts.
Findings by the farmers such as Charlie Sandager and pest experts like Dr. Bruce Potter, a University of Minnesota professor, have concluded that the primary corn pest rootworm has developed resistance to the proteins in the GMO Bt corn that was designed to kill the pests.
Apparently, this resistance is resulting in the widespread growth of rootworm among America's corn crop. And since one of the rootworm's effects is that it prevents corn roots from absorbing water, the rootworm-infested GMO corn crop has magnified the crop damage produced by one of the worst U.S. droughts in decades.
The pest experts suggest that the primary reason for the rootworm outbreak is due to the fact that rootworm has become resistant to the Bt protein, producing stronger and larger rootworm populations.
Adding to the problem is the fact that GMO corn growers are not rotating their crops. When the farmer rotates corn with another crop that does not attract the rootworm, the rootworms and their eggs will typically die off, creating less exposure to the next corn crop. Traditionally, Midwest corn growers would alternate corn with soybeans, which would allow the rootworms to die off.
But this strategy has largely been abandoned by GMO corn farmers. GMO seed producers and their distributors have suggested to growers that when they plant GMO seeds, they do not need to rotate their crops because the proteins in Bt corn were supposed to kill the rootworm. This strategy has apparently backfired.
Farm and pest experts are now indicating that rootworms in many fields have now become resistant to those proteins. "We're not going to make this go away," Dr. Potter told Minnesota Public Radio. "We're stuck with managing this problem."
As the roots become weakened by the rootworm outbreak, they not only cannot absorb water adequately: They also become unstable and can topple over easily.
"Strong wind came up and it just tipped the corn plants over like a big old tree," corn farmer Charlie Sandager told MPR.
The U.S. Environmental Protection Agency is investigating the rootworm outbreak.
Outside of crop rotation strategies, organic farmers utilize natural strategies to combat pests. These include adding beneficial insects to the fields, such as nematodes, ladybugs, pirate bugs and others. Naturally-derived substances such as neem and rotenone are also used to combat different pests.
By fertilizing with nutrient-rich compost and other natural fertilizers, organically-grown crops also tend to have stronger immunity against fungus and other pests. For example, better nourished plants will attract more nematodes, which help protect roots from pests such as rootworms. Researchers have also found that other pests, such as wolf spiders, directly attack rootworms.
Research has also established that organic crops also tend to be more drought resistant. In a recent study of grain and legume crops by researchers from Cyprus' Agricultural Research Institute, organic practices including crop rotations were compared with conventional monoculture, finding that the rotated organic crops had better production during drought seasons. Multiple crop years confirmed their findings.
A 2008 report by the United Nations concluded that organic farming practices among African farmers could substantially increase that region's ability to feed its people.
Written by Case Adams, Naturopath
- Steil, M. Corn farmers struggle to cope with rootworm resistance. Minnesota Public Radio. August 3, 2012.
- Dalias P. Increased yield surplus of vetch-wheat rotations under drought in a Mediterranean environment. ScientificWorldJournal. 2012;2012:658518. May 2, 2012.
- UNEP-UNCTAD. Organic Agriculture and Food Security in Africa. United Nations. 2008.
- Science Daily. Predatory Bugs Can Save Cornfields. Dec. 1, 2010.