freshare.net
Tougher weeds are making Ken Smith’s phone ring.
“I had 50 phone calls the day before yesterday and resistance was the subject of eight of 10 of them,” Smith, an extension weed scientist for the University of Arkansas Division of Agriculture said.
Two of the toughest foes are Palmer amaranth, or pigweed, and horseweed, both of which have developed resistance to glysophate, commonly sold as Roundup. The new weeds don’t discriminate, appearing in wheat, cotton and soybean fields.
“We went around all winter and spring and were painting a pretty grim picture” during our meetings with producers, educators and others in the industry, Smith said. “My colleague in Tennessee thought I was being alarmist, but this has really blown up on us.”
Research is the first line of defense and Smith, crop soil and environmental professors Dick Oliver, Jason Norsworthy and extension weed scientist Bob Scott are all part of the Division of Agriculture team working to find solutions for growers.
“Since 2003, when we first discovered the resistant horseweed coming into the state, we probably looked at 10,000 different treatments,” Smith said. “We have been able to bring new techniques to the market and have been instrumental in getting Reflex labeled for our cotton farmers and showing them how to make it work for them.”
The team has research plots across the state, including plots in farmer’s fields and at the Lon Mann Research Station in Marianna.
The university has been recognized nationally and internationally for its expertise and is the go-to resource for other states battling the same problems.
“We have the only research station in the South dedicated to herbicide resistant weeds,” Smith said.
The researchers have found the best defense is a good offense. A key is showing farmers to recognize the problem before it becomes a major problem.
Smith told the story of a producer who fired his spray rig driver for missing parts of the field.
“It wasn’t that he was missing anything. The weeds were resistant to the herbicide he was spraying,” he said. The grower ended up with hundreds of acres of big pigweed.
Smith said the urgency of the issue has growers seeking solutions now, instead of years from now and are willing to implement those answers quickly.
“We probably have 50 percent of the farmers shifting to some kind of resistance management program,” he said.
Of those farmers, about half are treating fields before the emergence of the weeds and 20 percent to 30 percent have switched herbicides.
The battle will continue on other fronts as well. Smith said Division of Agriculture researchers have noted a trend of herbicide resistance in two other common weeds: barnyardgrass and johnsongrass.
“We’ll work on this model this winter,” he said “By January or February, we’ll have some information that will help us see where we are. “
The Cooperative Extension Service is part of the University of Arkansas Division of Agriculture.