Genetically modified cotton fields hide herbicide-resistant weeds (Image: Scott Olson/Getty)

THE world’s most popular herbicide is losing its knockout punch. More and more weeds are evolving resistance to glyphosate – originally marketed by Monsanto as Roundup – but the problem could have been forestalled by farming practices enriched by a better understanding of evolution.

This is a serious problem. “Glyphosate is as important to world food production as penicillin is to human health,” says Stephen Powles, a plant scientist at the University of Western Australia in Perth.

In 1996, Monsanto began selling crop varieties genetically modified to contain a gene for glyphosate …