As farmers try to make up for lost time from this winter's wet conditions, they may want to look at a new herbicide that can hasten and enhance the burndown of winter and spring weeds.
The new herbicide is Valor, a product from Valent U.S.A. Corp. Valent specialists note that while the glyphosate herbicides can take two weeks to eliminate destructive weeds, winter and spring broadleaf species treated with glyphosate plus Valor can be controlled in three or four days.
Valor can also help growers rid their fields of tough weeds that the glyphosate herbicides alone can't kill, weeds prevalent in no-till settings such as cutleaf eveningprimrose and Florida beggarweed, the specialists say.
“Valor is a new herbicide that delivers the quick preplant burndown and the residual control growers need, with little to no carryover concerns to rotated crops,” said John McClendon, southern row crop product manager with Valent.
“This is one of the first products developed for a Roundup Ready world,” he says. “It complements the Roundup Ready system by enhancing the burndown of tough-to-kill winter weeds and providing residual control for species that tend to emerge after the burndown application.”
Labeled for pre-emergence weed control in peanuts and soybeans, it can be applied within 30 days of planting cotton, field corn, rice, sorghum, sugarcane, sunflowers, tobacco and wheat.
Valent specialists say that Valor provides consistent pre-emergence control of some of the most troublesome weeds, including morningglory, Palmer pigweed, prickly sida, lambsquarter, Florida pusley, common ragweed, eclipta, black nightshade, waterhemp, spotted spurge, hemp sesbania and Florida beggarweed.
“Valor has flexible timing and can be used as part of a burndown program, as a stale seedbed application or in an early preplant or pre-emergence application,” says McClendon. “It also offers reliable control of ALS- and triazine-resistant weeds including waterhemp, lambsquarter and pigweeds.”
But it's on some of the problem no-till weeds that Valor may be of the most help initially, according to weed scientists.
“We have five very troublesome weeds,” says Stanley Culpepper, weed scientist with the University of Georgia. “No. 1 is primrose, No. 2 is primrose, No. 3 is primrose…. If we get 50 percent control with a pound of glyphosate and we add 1 to 2 ounces of Valor, we'll go from 50 to 85 percent control.”
“I decided to change my herbicide program this year because we had a lot of Florida beggarweed to get by us every year,” said Scott Moore, a crop consultant from Elko, Ga., noting that Valor provides four to six weeks of residual control of Florida beggarweed.
The increased flexibility from Valor has not been lost on farmers and crop consultants in the southeastern United States.
“We don't want to have a herbicide that we put on our peanuts that locks us in to where we cannot plant cotton or some other crop 18 months later,” said Danny Bennett, a crop consultant from Cochran, Ga.
The application rate of Valor for pre-emergence soybeans ranges from 2 to 3 ounces per acre, depending on the weed spectrum and soil characteristics. Valent says growers should see their dealers for recommendations.
For peanuts, the application rate is 3 ounces per acre when targeting Florida beggarweed, except in North Carolina, Virginia and Oklahoma. The maximum use rate in peanuts in those states is 2 ounces per acre. For both crops, the product requires a quarter inch of rain or irrigation for activation and soil residual activity. Once activated, Valor remains as a weed control barrier for the crop.
For fast preplant burndown when little to no residual control is needed, Valor may be applied at rates as low as 1 ounce per acre to improve glyphosate control of cutleaf eveningprimrose, Carolina geranium, henbit, chickweed and wild mustard, according to Valent.
Valor, which is sold in a bag of four 10-ounce water-soluble packs, is a protoporphyrinogen oxidase or ppo inhibitor, which means that it has a different mode of action than the glyphosate herbicides. Thus, it could aid in control of glyphosate-resistant weeds such as horseweed. Valor offers excellent residual control of horseweed, according to Valent.
The EPA currently is reviewing Valent's application for a Valor cotton layby label, but such use has not been approved. Louisiana has requested a Section 18 emergency exemption for Valor as a replacement for Bladex. “It will be a great product for providing contact activity on weeds and residual control in cotton at layby,” says McClendon. “It's a little more active than Bladex so that it will control more and bigger weeds. However, growers should not use Valor as a layby treatment unless and until is approved by the EPA.”