By Janet Raloff
Agriculture’s most effective pesticides are rapidly losing their punch as weeds evolve resistance to the chemicals. With no game-changing alternatives in the pipeline, researchers warn that farmers could soon see crop yields drop and production prices climb.
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“It’s what Chuck Darwin talked about back in 1850. Organisms evolve in response to selection pressures in their environment,” says Micheal Owen, an extension weed scientist at Iowa State University in Ames. “In essence, the better we get at controlling weeds, the more likely those efforts will select for survivors that do not respond to controls.”
In the June 8 Journal of Agricultural and Food Chemistry, Owen and other researchers describe a rapid rise of herbicide-resistant weeds and a particularly threatening trend: an increasing number of weeds that are simultaneously immune to multiple herbicides.