Use a wind meter to determine speed and direction. There is no magic wind speed at which applications must cease. Each field and situation is different, depending on the sensitive areas nearby. Many labels provide information about maximum wind speed and some, such as Command 3ME, have mandatory setback restrictions. Use nozzles that produce large spray droplets Droplet size is the major factor influencing herbicide drift.
Small droplets take more time to fall to the ground and can thus drift farther.
It is desirable to use a nozzle that produces large, uniform droplets. Droplet size can have a negative effect on herbicide performance when coverage is reduced. The droplet size produced by these nozzles should have no effect on performance for systemic herbicides, including burndown applications involving growth regulators or glyphosate. Contact herbicides, such as Buctril, Cobra, and Reflex, require adequate target coverage for maximum effectiveness and may have required nozzle and pressure combinations that produce smaller droplets. Always consult the herbicide label for specific recommendations or restrictions on equipment selection.