Donnie Miller’s list of weeds that could be found in the Roundup Ready Xtend and Enlist test plots at the Northeast Research Station near St. Joseph, La., reads like a rogue’s gallery of problem weeds in the Deep South.
Dr. Miller, weed scientist with the LSU AgCenter and resident director of the Northeast Research Station, was showing participants in the station’s annual field day how applying residual herbicides pre-emergence or early postemergence with the new technologies was helping provide good weed control in the plots.
“You can see the weed control,” he said. “We have yellow nutsedge in here, but we also had crabgrass in here, we had barnyardgrass in here, we had signalgrass in here, we had browntop millet in here, we had some goosegrass in here, we have sesbania, sickelpod, pitted morningglory, entireleaf morningglory and redroot pigweed. So we had a pretty good population.
“So you can see what these programs are bringing to the table.”
Miller said the use of selected herbicides in the test plots at the station did not imply an endorsement of any of those materials.
“Anything out there will work just as good,” he said, referring to the residual herbicides researchers are recommending for use with the new dicamba and 2,4-D formulations that are expected to be available for crops resistant to those materials in 2016.
“Just as long as you have a good foundation residual at planting followed up by these technologies – all of them have looked good for us. Where we didn’t have a pre herbicide, then we came back early with the technology mixed with a residual herbicide.”
In one plot with Enlist soybeans, the researchers applied Valor pre-emergence and followed it with a tank mix of Enlist herbicide and Warrant, another residual herbicide. “So we have two residuals here along with Enlist Duo,” said Miller. “We’re always trying to keep something else in there, trying to keep a different mode of action.”
For more on herbicide-resistant crops, visit http://agron-www.agron.iastate.edu/Courses/Agron317/2005/readings/HRCresistance.pdf