Cotton farmers could get some help on late-season and other problem weeds with three new herbicides that Syngenta Crop Protection, Inc., expects to have available for 2004.
The products are:
- Envoke, a new broad-spectrum, postemergence herbicide that can be applied over-the-top or post-directed in cotton to control morningglory, pigweed, nutsedge, cocklebur, hemp sesbania, sicklepod and others;
- Suprend, a premix of trifloxysulfuron sodium (the active ingredient in Envoke) and prometryn that could provide contact and extended residual control of many problem weeds at layby;
- Sequence, a premix of Touchdown and Dual Magnum that can be applied over-the-top in Roundup Ready cotton and pre-emergence in conventional cotton to provide contact and residual control of many broadleaf weeds and nutsedge. Registration is also being sought for Roundup Ready soybeans.
Speaking at a Syngenta media event near Leland, Miss., weed scientists said they expect the products, which generally would be applied in reverse order to this listing, could help address several issues in cotton weed control
“Envoke could fill a gap in a place where we need some help,” said Charles Ed Snipes, Extension area cotton specialist at the Delta Research and Extension Center in Stoneville, Miss. “We need a little something else to help get us from early-season weed control to layby.”
Snipes, who worked with Envoke for several years while it was under development, said north Delta farmers battled more morningglory and pigweed than usual this year because of the unusually wet June 2003.
“Envoke or Suprend or Sequence would have been helpful in that situation,” he noted. “Anything we can do to get some residual control out there could make a difference during that time.”
Syngenta representatives said they believe that applying the Sequence premix of Touchdown and Dual Magnum could help growers “shift” their weed control programs to later in the season.
“Applying Sequence could delay the follow-up treatments in cotton a few days to a few weeks,” said Chuck Foresman, product manager for Envoke. “Sequence would provide control of most of the weeds except for morningglory, sicklepod and hemp sesbania. That's where Envoke would come in.”
“Envoke appears to have increased activity on morningglory and hemp sesbania, which are serious weeds in the Delta,” said Dan Reynolds, weed scientist with Mississippi State University. “In the hills, where sicklepod is more of a problem, Envoke has excellent activity on that species, as well.”
Many growers have been tank-mixing Touchdown and Dual Magnum to provide residual control of weeds like nutsedge and pigweed in early season,” said Ken Smith, weed scientist with the University of Arkansas.
“We're already seeing it being accepted in many parts of our state,” he noted. “Of course, the three biggest weeds in Arkansas are pigweed, pigweed and pigweed, and Suprend will fit there very well.”
Besides excellent control of pigweed, Suprend's active ingredients of trifloxysulfuron sodium, an ALS-inhibitor, and prometryn (Caparol) will also provide an alternate mode of action on pigweed, something that Smith believes is greatly needed in cotton weed control in the Mid-South.
“Pigweed is very susceptible to glyphosate at this point, but pigweed has a history of becoming resistant when it is sprayed with one class of chemistry over and over again,” he noted. “Suprend will be a good tool for helping avoid resistance in pigweed.”
“We believe that a program approach of Sequence followed by Envoke followed by Suprend at layby could carry farmers through the season,” said James Holloway, weed scientist at Syngenta's Southern Regional Technical Center near Leland, pointing to a test plot treated with that sequence of herbicides.
“You have residual control and four modes of action between the glyphosate, Dual, Envoke and Suprend. It will allow farmers to be good stewards of their herbicides and cover a broad range of weeds under often difficult conditions.”
Syngenta expects to receive a Section 3 registration for Envoke in October, followed by a federal label for Suprend 30 to 60 days later, said Foresman. Registration for Sequence could come in January 2004.
It is also seeking state registration of Suprend in Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, the Missouri Bootheel, North Carolina, South Carolina, Tennessee, Virginia and portions of Texas and Oklahoma. Neither Envoke or Suprend will be labeled for stripper cotton.