MANHATTAN, Kan. – Kansas farmers are following a recent trend and planting more acres to cotton this year than last. But a Kansas State University scientist reminded growers of all crops to be careful with 2,4-D herbicide, which can damage cotton.

Kansas farmers intend to plant 44,000 acres to cotton this year – up 10 percent from the 40,000 acres planted last year, according to government data gathered in March. Overall, U.S. cotton plantings for 2001 are expected to total 15.6 million acres, up less than 1 percent from last year.

"Certain crops like cotton are very susceptible to 2,4-D drift damage if the herbicide moves from the target area to adjacent fields," said Dallas Peterson, weed science specialist with K-State Research and Extension. "Drift damage to cotton can even occur from applications made several miles away, especially if applied in the wrong manner and under the wrong conditions."

The herbicide is commonly used in wheat, corn, sorghum, pastures, fallow and non-crop land areas for broadleaf weed control.

Peterson said some states ban the use of 2,4-D during certain times of the season to avoid the drift problem. Currently there are no such laws or regulations in Kansas.

"Herbicide drift can be reduced by spraying at lower pressures and with the proper spray tips to reduce the number of fine droplets," he said. "Small spray droplets are most susceptible to particle drift."

The formulation of 2,4-D can also make a difference in drift potential. The ester formulations of 2,4-D are volatile, and can move as a vapor in addition to particle drift. The amine formulations of 2,4-D are relatively nonvolatile, and will not form a vapor. For that reason, amine formulations pose less drift concern than do esters, though damage still may occur from particle drift.

Common sense should come into play when spraying near fields with susceptible crops, Peterson said. "Only spray when wind speeds are low and when the wind direction is away from susceptible sites." "These precautions apply not only to cotton growers, but also to other area farmers and commercial applicators who will be making herbicide applications in the general vicinity of cotton fields. It is the legal responsibility of the applicator to use pesticides properly and avoid herbicide drift."

"Communication is the key," Peterson said. He suggests cotton growers alert neighbors and local commercial applicators about the location of cotton fields and urges those who apply 2,4-D herbicide to consider the locations of those fields and use proper procedures to minimize offsite movement.