For rice growers, there’s nothing more feared than barnyardgrass in their fields — unless it’s waterhemp, Palmer amaranth or pigweed. They all are top of mind for rice growers.
In a recent “The Root of the Matter” podcast episode, Dr. Jason Norsworthy, University of Arkansas Distinguished Professor and Elms Farming Chair of Weed Science, shared how his research centers on evaluating herbicide resistance and testing new chemistries in rice fields.
“I've spent the majority of my career dealing with herbicide-resistant weeds, and you know, rice is not different than any other crop that we've dealt with,” Norsworthy said. Many rice farmers use a rotation strategy with soybeans, wheat or corn to be able to control the weed populations year to year.
“For those of your listeners that are familiar with other commodities, we talk about pigweed or Palmer amaranth in the Mid-South. Other crops, we talk about waterhemp in the Midwest,” he explains. “But when it comes to rice, the global weed of importance is barnyardgrass. And it's, we're getting to the point today, where we have very few options.”
There are even some fields in the state where growers might not have a post-emergence option for the control of barnyardgrass due to the fact that it has evolved resistance to five or possibly six different modes of action, he says.
Weeds are much more effective at production and reproduction than crops. Weeds can produce an astronomical amount of seed in just one growing season.
“We actually collected a Palmer amaranth plant from a soybean field,” Norsworthy says during the podcast. “This was actual soybean production field in eastern Arkansas. I think this was back in 2008/2009. We took that plant, we ground the plant up, we collected the seed off of it, made some estimates to count the seed, and that plant had 1.87 million seed on a single plant.”
How can growers manage resistant weed populations with the industry’s limited number of new active ingredients?
“When you think about resistance to herbicides…if we're going to be effective in managing these weeds, it all starts with a good sound residual,” Norsworthy counsels.
It’s important to start the year by planting into a clean field — meaning no weeds at planting, he says. Start by applying a residual herbicide and then layer herbicides with multiple modes of action to maintain that clean field early in the growing season. Learn about the best products to control the specific weed pressures in your fields.
What other topics did Norsworthy cover?
Norsworthy also discussed the shift in the past five to six years to furrow-irrigated rice (row rice) to address water shortages and increase water conservation, as well as the importance of the rice export market. Listen to the March 28, 2022 episode here.
Learn more about the herbicide portfolio for rice: RICEONE CS, RICEBEAUX®, RICESHOT®, STAM® 80 EDF, STORM®, ULTRA BLAZER®, UP-STAGE™ 3CS.
For more information, contact your local UPL representative or visit www.UPLRicePortfolio.com.
