Farmers relying on Roundup lose some of its benefit

WEST LAFAYETTE, Ind. – Roundup Ready crops have made weed control much easier for farmers, but a new study shows their reliance on the technology may be weakening the herbicide’s ability to control weeds.

Bill Johnson, a Purdue University associate professor of weed science, said farmers who plant Roundup Ready crops and spray Roundup or glyphosate-based herbicides almost exclusively are finding that weeds have developed resistance. It is only a matter of time, Johnson said, before there are so many resistant weeds that the use of glyphosate products would become much less effective in some places.

“We have weeds that have developed resistance, including giant ragweed, which is one of the weeds that drove the adoption of Roundup,” Johnson said. “It’s a pretty major issue in the Eastern Corn Belt. That weed can cause up to 100 percent yield loss.”

…”Farmers do not think resistance is a problem until they actually have it,” Johnson said. “And they think the chemical companies can turn on the spigots and produce a new herbicide whenever they want. The problem is, since Roundup is so effective, there’s not been any money for new herbicide discovery.”

Purdue