Many farmers report glyphosate resistance
As a sign farmers are responding to the threat of glyphosate resistance, as many as four out of five farmers plan to alter their weed control programs in 2012, according to results from a recent national BASF survey.
More than 50 percent of farmers surveyed acknowledged the existence of glyphosate-resistant weeds in their fields, and many of them blamed resistance for hurting their yields. In addition, even farmers who have not seen glyphosate resistance in their fields said they would make changes to their weed control programs.
These results encouraged weed experts such as Dan Westberg, Ph.D., Technical Market Manager, BASF.
“It indicates that farmers understand that today’s weed control challenges demand the use of a more comprehensive management approach,” Westberg said. “For a long time, farmers relied almost solely on glyphosate to control their weed problems, but those days are over. The repeated use of a single chemistry is the number one reason many have developed resistant weed populations.”
A majority of survey respondents acknowledged the need to do more, with more than 80 percent saying they would be willing to invest additional dollars to control resistant weeds.
More than one-third of survey respondents plan on adding multiple herbicide sites of action this year, which experts say is a critical element in controlling glyphosate-resistant weed populations. The Weed Science Society of America (WSSA) already has confirmed 13 different species of profit-robbing glyphosate-resistant weeds across 28 states.1
“Once a weed evolves resistance to a particular herbicide and is able to seed, that problem now exists in that field pretty much forever,” said Mike Owen, Ph.D., Iowa State University weed scientist.
Many survey respondents also said they would apply a preemergence herbicide before or at planting for a foundation of weed control, as well as add tank mixes to their post applications. About one-third of respondents said they would work with a consultant to plan out their programs.
Not all are on board
In 2010, a BASF survey asked customers if they thought herbicide resistance impacts yield. Twenty-three percent responded “yes.”
By comparison, the recent farmer survey asked how much yield impact resistant weeds had on their yields in 2011. Seventy-three percent responded that there was at least some yield impact.
Still, not every farmer agrees resistance is an immediate concern, as 16 percent of survey respondents said they would not spend anything more to control resistant weeds. One-third of respondents said they don’t believe resistant weeds even impact their return on investment, going against what weed scientists say.