However, wind velocity is usually the most critical factor of all meteorological conditions affecting drift. The greater the wind speed, the farther off-target a droplet of a given size will be carried. The larger the droplet, the less it is affected by the wind and the faster it falls. High winds, however, can cause even larger droplets to move off-target. Therefore, spraying operations should be stopped if wind speeds are excessively high.
Wind direction is as important as wind velocity in reducing the damage caused by drift.
The presence of sensitive vegetation near the spray site, particularly downwind, is one of the first things that should be evaluated, but is often overlooked when beginning a spray application. Check in all directions from a spray site for sensitive vegetation, and be alert to changes in wind direction during application. Spray the buffer strip later, when the wind has shifted away from sensitive crops. Buffer strips can reduce drift famages to sensitive crops. While they generally are not as critical as wind velocity, they are a strong influence in some geographic regions or under certain meteorological conditions.