To control yield-robbing weeds, experts recommend a multi-pronged strategy, starting with a clean, weed-free field and keeping weeds at bay with timely applications of preemergence and postemergence herbicides. These herbicides should feature multiple modes of action — generally, the more the better.
With the Enlist weed control system, cotton farmers can adopt a program approach to weed control. The Enlist system features Enlist Duo herbicide, a combination of new 2,4-D choline and glyphosate. Growers who plant PhytoGen cottonseed with the Enlist trait can also apply glufosinate postemergence, providing more flexibility to broaden their weed control options.
Seen and unseen costs
Weed pressure costs cotton growers across the South by limiting yield.
“It’s difficult to appreciate the total cost of weed pressure,” says Dr. Alan York, professor of crop science at North Carolina State University.
“We know how much herbicide costs and how much application costs,” York says. “We have programs that can estimate the weed-related yield loss we see at harvest. However, we can’t measure the future costs of allowing the weed seedbank to grow. Those weeds will require control — or will limit yield — in the coming years.”
Ralph Lassiter, Enlist field specialist for Southeastern states, suggests a program approach that brings multiple modes of action to bear on tough weeds.
Many growers have begun weed control efforts this spring with a burndown and, at planting, use of residual herbicide products. However, to start at the beginning, here’s a step-by-step rundown of a program approach.
WEED MANAGEMENT STEPS FOR COTTON
- Start clean with an effective burndown.
- Apply residual herbicides with varied modes of action.
- Scout fields to identify problem weeds and time postemergence applications.
- Apply postemergence herbicides with additional modes of action.
- Consider a lay-by application with an additional residual product to handle troublesome weeds.
- If necessary, manually remove weeds to reduce the weed seedbank.