Farmers taking action against glyphosate resistance

Nearly 60 percent of farmers who responded to a recent national poll said they are changing their weed management plans to deal with growing glyphosate resistance.

The poll, conducted by BASF crop protection, showed that a similar percent of farmers are adding a preemergent herbicide with residual control to battle stubborn weeds such as ragweed, marestail, lambsquarters, and waterhemp.

"Lambsquarters are coming through higher rates of glyphosate, leaving weed pressure and competition in fields later in the season," says one grower in the national poll.

While only 23 percent of respondents believe glyphosate resistance will impact their yield this growing season, the poll confirms that many farmers believe they need to take action now to overcome the threat of yield-robbing glyphosate resistant weeds in the future.

A Purdue University study conducted in 2005-2006 found 40 to 47 percent of growers indicated that tank-mixing glyphosate with residual herbicides, or including alternate herbicides with different modes of actions would be effective management practices for minimizing weed resistance. Five years later the BASF poll confirms that a majority of farmers are putting those ideas into practice.

"Growers are looking for new herbicide chemistry to fill in the gap where glyphosate is falling short," says Dr. Dan Westberg, technical market manager for BASF.

BASF offers resistance solutions with new chemistries like Kixor herbicide technology, Westberg says.

Despite widespread acknowledgement among agricultural experts about herbicide resistance, 40 percent of farmers who answered the poll plan to increase the use rate of glyphosate or the number of post-emergent applications from last year, creating conditions that are ripe for development of resistance.

"Relying too heavily on one mode of action, like glyphosate, will build up resistant weed populations," Westberg says. "If growers keep applying glyphosate over and over at higher and higher rates, they will eventually hit a wall. Growers can fight resistance by employing a diversity of tools in their weed management system."

(Source: BASF crop protection)