How we can fight back against herbicide-resistant superweeds

A field dominated by palmer amaranth, or pigweedDelaware Agriculture

A field dominated by palmer amaranth, or pigweed, one of the plants that has gained glyphosate resistance.

There’s a clear scientific consensus that heavy use of glyphosate — the active ingredient in Roundup and other brands of herbicide — has sped up the evolution of glyphosate-resistant weeds. And it’s reasonable to assume that crops genetically engineered to work hand in glove with glyphosate (like Roundup-resistant soy) are part of the problem, contributing to the popularity of the weed killer.

Now crops genetically engineered to work with other herbicides — such as dicamba and 2,4-D — look like they will soon come on line. The seed companies’ answer to the Roundup-resistance problem is: Let’s just fall back on older herbicides. An editorial published by the journal Nature recently criticized this plan. If we do the same thing with dicamba and 2,4-D that we did with glyphosate, the editorial argued, history is likely to repeat itself.

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