It is impossible to eliminate spray drift, but a new product developed by the U.S. Department of Agriculture and Ohio State University may aid in keeping chemicals within their intended target.

A computer program called DRIFTSIM (Drift Simulator) predicts drift distances of spray droplets under a variety of environmental conditions using variables such as wind speed, droplet size, droplet release height or boom height, temperature and relative humidity. The application program is modeled after FLUENT — the most common fluid dynamics model that calculates movement of particles in the air and their final destination.

“Spray drift is a serious concern for all who apply pesticides. The biggest problem with reducing drift is that conditions are slightly different in every field, so recommendations to reduce drift are not applicable in all field situations,” said Erdal Ozkan, an OSU Extension agricultural engineer.

“Our goal was to develop a user-friendly simulation program that gives us the drift potential of different size droplets under different conditions” said Heping Zhu, a USDA Agricultural Research Service agricultural engineer who led the development of DRIFTSIM, along with Ozkan and Robert Fox, another USDA-ARS engineer.

Drift is the movement of a pesticide through air, during or after application, to a site other than the intended target. It not only wastes expensive pesticides and damages non-target crops nearby, but it also poses a serious health risk to people living in areas where drift is occurring.

Ozkan said that with DRIFTSIM, the user can calculate drift distance before making any applications, and make changes to agricultural practices or equipment to keep drift at a minimum based on the results. DRIFTSIM calculates the droplet distance up to 656 feet from the release point. Most drift problems, said Ozkan, occur within 100 feet of droplet release.

“If a grower knows that there may be a drift problem, several adjustments can be made to reduce drift. One is to readjust the boom height. Each time the boom height is changed, the program will calculate the change in the drift distance of the droplets,” said Ozkan, who is also an Ohio State Ohio Agricultural Research and Development Center researcher. “A grower can also change the nozzles on the sprayer. A slightly larger size droplet produces less drift.”

DRIFTSIM is applicable for Extension educators, regulatory agencies, agricultural industries, farmers, or any pesticide applicator.

The software is available for $10 and can be purchased by calling Ohio State Section of Communications and Technology at (614) 292-1607 or e-mailing pubs@ag.osu.edu. Additional information on DRIFTSIM is available on OSU Extension’s Ohioline, Bulletin 923, at http://ohioline.osu.edu/b923/index.html.