Scientists Found a Magic Bullet for Weeds. Now, 'Big Problems'

Weeds that were once curtailed by herbicides have quickly adapted to withstand them, raising concerns for farmers who are already seeing lower yields in their crops. Reuters breaks down the issue in a thorough investigation with the scientists, farmers, and herbicide companies involved. Weeds like kochia, waterhemp, and giant ragweed are overtaking farmland as one of the most common active herbicide ingredients, glyphosate, loses effectiveness more each year. In the US, glyphosate and other chemicals such as dicamba are used to control 180 weed species, and waning effectiveness puts crops like corn, soy, and sugar beets at risk. This is bad news for farmers, who are already facing obstacles such as inflation and extreme weather.

"We're in for big problems over the next 10 years for sure," Ian Heap, director of the International Survey of Herbicide Resistant Weeds, tells the outlet. "We are in for a real shake-up." His group maintains a global database that tracks how weeds interact with herbicides in over 80 countries. They found that the most common modes of action—how a chemical kills weeds—in glyphosate and dicamba are on a rapid decline. Developing new modes of action has slowed down as companies have invested less in R&D, coupled with strict environmental regulations that can slow down introducing new chemicals. Companies FMC and Bayer plan to launch new products in 2026 and 2028, but researchers warn against using the same playbook to solve the problem.

"Let's imagine a company says they have the next silver bullet," says researcher Aaron Hager of the University of Illinois, per EurekaAlert. "It's going to enjoy a huge market share almost instantaneously. But it needs to come with a stewardship plan to better preserve that chemistry over time." A paper he co-authored in PNAS Nexus found that weeds were 32% less responsive to glyphosate within a decade of administering it. The Center for Food Safety, meanwhile, warns farmers against using crops genetically engineered to withstand herbicides given the chemical-resistant plants that result. "It's like this toxic spiral," says scientific director Bill Freese. "There's no end in sight." (Is the future of farming on the water?)