What is in this article?:
- Herbicides probed for place in Georgia peanut weed control
- Pigweed control programs
- Still looking at Classic
• While there are no new herbicide products for use on peanuts, researchers are looking at products like Warrant and Fierce to see if they have a potential fit in peanuts.
UNIVERSITY OF GEORGIA Extension weed scientist Eric Protsko, right, discusses peanut weed control at the recent Georgia Peanut Farm Show held in Tifton.
Pigweed control programs
The University of Georgia Peanut Team recommends a couple of programs for controlling pigweed, says Protsko.
“One is the Valor/Strongarm program, where we’ve got Prowl, Valor and Strongarm at planting.
“Then, at about 40 days after planting, we apply Cadre. I would suggest you consider adding Dual with Cadre for longer-season control. If for some reason you choose not to use Cadre, you can substitute with Blazer or Cobra in that particular program.
“We know we get great pigweed control with Valor, but we have a lot of issues whenever we get a lot of rainfall around the time of peanut emergence. And there’s no way around that, although we can do some things to help.
“But if we get a lot of rainfall at emergence, we’ll probably see some injury. I would say that probably 95 percent of the time, peanuts will grow out of it and it won’t be a significant problem.”
Because of this injury, some growers choose not to use Valor, he says.
“I think we can still get pretty good control of pigweed with a Dual/Magnum program. With this program, we use Prowl at planting. Then, we go back at 21 days after planting with Gramoxone, Storm and Dual.
“Then, about 18 days later, we spray Cadre and Dual. This provides excellent control which pretty much lasts until August. With this program, we’re using two shots of Dual to help us with pigweed.”
Protsko says the University of Georgia recognizes the state’s top producers each year in the Georgia Peanut Achievement Club, and it’s interesting to take a look at what those growers are doing to control pigweed.
“In 2011, there were 10 growers averaging more than 6,200 pounds per acre. Ten out of 10 of these growers were irrigated, so they could make their residual herbicides work very effectively.
“Seven out of 10 of these top producers bottom-plowed. Nine out of 10 planted in twin rows, and the four herbicides used most by these growers included Sonalan, Valor, Cadre and 2,4-DB. That’s what they’re using to get high yields.”
Most peanut herbicides, with the exception of Strongarm and Valor, were labeled before 2000, and things have changed in the last 13 years, says Protsko.
“We’ve looked at paraquat, sold as Gramoxone or several generics. As growers, you might have sprayed paraquat on your peanuts, and a few hours later you wonder what you’ve done.
“In our trials, we plant a crop, keep out the weeds, and then spray different herbicide treatments. The only effect we’re looking at are the herbicide treatments we impose on the plots.
“In trials conducted in the past three years, we’ve seen no negative yield effects from Gramoxone, Gramoxone/Storm or Gramoxone/Basagran treatments. Most of these plots were planted in GA-06G variety, our most popular peanut cultivar.”
Dual Magnum has been available for more than 20 years, and when it first hit the market there were concerns about injury, especially when there were moisture issues, says Protsko.
“Dual can cause j-rooting in peanuts, but so do other factors. In trials we’ve conducted, we’ve seen no negative yield effects from Dual, PPI, pre, early-post, post, or tank-mixed with Cadre.
“I’m confident that if we use Dual according to the label, unless we have a crazy weather pattern or it’s used at an excessive rate, you should feel comfortable with Dual on peanuts.