The herbicide well runs dry

Abstract

Since the 1980s, crop protection companies have introduced only one herbicide with a new weed-killing mechanism. During this period, many weeds have evolved to survive the modes of action used by existing herbicides, creating huge problems for farmers. In response, crop protection companies are increasing R&D efforts to discover new modes of action. They’re using new tools, often borrowed from the pharmaceutical industry, to speed up that process. But even if new products do emerge, many experts warn that farmers should moderate their use of herbicides to avoid the evolution of resistance going forward. The first herbicide-resistant weeds started showing up on Keith Miller’s farm about 18 years ago. He grows sorghum, wheat, alfalfa, and soybeans on 4,000 hectares in western Kansas. Amaranthus , often called pigweed, is his biggest problem. Spraying weeds with the workhorse herbicide glyphosate does virtually nothing these days, Miller says. A combination of dicamba, 2,4-D,