Really tough morningglory problems can cause season-long headaches. Let them get away from you and you'll pay for it at cotton harvesting time.
Bill Elliott, Lake Village, Ark., knows the morningglory woes all too well in his mostly furrow-irrigated fields. “It's a big problem, the toughest weed to control here. We've spent more time and money trying to control it than any other species,” he says.
That's why he turned to BXN varieties. Tolerant to Buctril herbicide, they provide a wide application window for morningglory.
“It is exceptionally good on morningglory. You can draw a line under that and put a double exclamation point after it,” Elliott says.
“With stacked gene BXN, we can work on morningglory and get Bt to help control worms. In the old days, we didn't have much choice on what to do about these problems. The chemistry just wasn't available. We knew we were going to have to put the money into worm control if we were even going to begin to get a handle on them. And morningglory control then could be pretty difficult if the vines got much growth on them.”
Many other growers planting BXN varieties do so to help out with morningglory control, says Bob Scott, Arkansas Extension weed specialist. “They're able to use it at wider intervals than the other options available. Buctril is a contact herbicide and is rated very good on morningglory,” he says.
Still, getting started early is key to getting good morningglory control. “If you let them get a foot-and-a-half long, no program is going to do a fantastic job. Get on them early and you have a much better shot at good control,” Scott says.
Morningglory tends to cause the biggest problems in southeast Arkansas, where Elliott farms, says Ken Smith, Arkansas Extension weed specialist. “In the northeast, pigweed is kind of running over us. It's still morningglory in the southeast, though. BXN is still a good system for it there,” he says.
In 2002, Elliott planted two BXN varieties: BXN49B, stacked with the Bt gene for worm control, and BXN47, a non-Bt variety.
For weed control, he starts out with a preplant application of Prowl or Treflan. “We have to do that to take care of pigweed and a little teaweed problem,” Elliott says.
If pigweed escapes that preplant shot, he may come back over-the-top with an application of Staple. All the while, though, he's watching for morningglory. Though he prefers attacking morningglory while it's small with BXN and Buctril, he has a little extra leeway on application timing.
“The wide window of application helps a lot. If morningglory is out there, Buctril is going to pretty well take care of those vines. Then we don't have the problem they would create for us at harvest,” Elliott says.