At the Oklahoma State University Wheat and Forages Field Day held in Chickasha, Associate Farm Editor Reagan Calk had the chance to talk with OSU’s Dr. Liberty Galvin about herbicide resistance issues. Galvin is the extension weed scientist and precision week management at OSU.
Galvin said when talking with growers around the state, herbicide resistance in Italian ryegrass is a common complaint for wheat producers, especially those growing single-purpose wheat. While some producers plant ryegrass as a forage, Galvin said unwanted growth is an issue in the fields of many of those who are growing wheat only.
“My assumption is that we are seeing some weeds migrate from our dual-purpose fields into our wheat crops and they have become very problematic for wheat growers,” Galvin said.
As producers are seeing resistance against particular herbicides towards weed control, Galvin talked about considering non-chemical control options such as crop rotation, cover crops, and fire.
“I am pretty excited about fire,” Galvin said. “I know a lot of folks are very hesitant because of the safety aspect, which is completely reasonable.”
With her grad students, Galvin said one of the things they are working on is the efficacy of fire when it comes to weed control. Galvin also mentioned the use of a post-harvest seed crusher to control weeds.
“This is basically a grinder,” Galvin said. “You put all of your chaff through this grinder, and it just destroys all of the weed seeds that are left in the field. It is not a short-term option for killing the weeds, but it does prevent long-term deposits of the weed seeds into the seed bank.”
While chemical-free options are not as efficacious as herbicides, Galvin said they will reduce the prevalence of weeds over time.
Galvin said she and a colleague are conducting a statewide survey of herbicide-resistant weeds, so if a grower believes they have a herbicide-resistant weed in their field, they can contact Galvin at 405-334-7676 or lbgalvin@okstate.edu.
“We would be more than delighted to send a grad student over in a truck to come and pick up those weeds,” Galvin said. “We are trying to get growers, researchers, and everybody in the state up to speed on where those herbicide-resistant weeds are, and how diverse those populations are.”
