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Genetically Modified Crops (April 30, 2014)
One of the most recent advances in chemical weed control involves the oldest of all selective herbicides. Crops that are resistant to 2,4D have recently been developed by Dow Agro sciences. Corn and soybean varieties that are resistant to 2,4D were grown commercially for the first time in Canada in 2014 and have been under review by the USDA for four years. Dow calls this trait Enlist Weed Control Systems and it will first be available in the U.S. on corn and soybeans.

2,4D was discovered independently in both the US and UK in 1941. Both countries were developing this chemistry as Chemical warfare agents for use in World War II and it’s value for weed control was discovered by accident. It was first released commercially as a herbicide in 1946 and was the first selective herbicide for use in wheat, corn, rice and other grass crops.

The development of genetically modified crops is not new and have been around for many years. It is estimated that today 70% of all processed food in the supermarket is genetically modified. Estimates for last year were 88% of the corn grown was genetically modified, soybeans 93%, Cotton 94%, canola 90% and sugar beets 90%. Genetically modified alfalfa, papaya, tomato, potato, squash, cantaloupe, rice, flax, and reddicchio are also available. Roundup Ready lettuce was successfully tested here several years ago but has never been registered. Work has been underway by University of Idaho, University of California and USDA researchers in recent years to develop lettuce varieties that are tolerant to sulfonylurea herbicides like thifensulfuron (Harmony, Affinity).
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For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.

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