Palmer amaranth

A new study reveals how weeds develop resistance to glyphosate herbicide. Researchers specifically looked at Palmer amaranth, one of the most difficult-to-control weeds in row crops.

Resistant weeds differ genetically from other weeds. Researchers found that in glyphosate-resistant weeds, the chromosomes containing the target gene form a separate, self-replicating DNA structure. This altered DNA then continuously produces the enzyme that glyphosate targets. The abundance of this enzyme negates the impact of the glyphosate application on the weed, making the herbicide ineffective.

Scientists also found this self-replicating DNA can be passed to a weed’s offspring and other related weed species. Resistance can happen as quickly as one generation, which means timing is crucial when fighting resistant weeds.

Researchers encourage growers to reduce weed pressure by using good weed management practices, like rotating herbicides and crops. Glyphosate has several good characteristics as a herbicide, so it’s important not to abuse it. If glyphosate is over-used, resistance will only continue to spread to other weeds.

Visit ResistanceFighter.com to learn more about weed resistance management in corn, soybeans and wheat.

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