IFCA’s Best Management Practices (BMP) to Reduce Spray Drift This Spring Season
Spray drift accounts for most of all misuse pesticide cases investigated by the Illinois Department of Agriculture. Drift can never be eliminated; however, it can be minimized if pesticides are applied under favorable weather conditions and by adopting proven drift reduction strategies. Drift reduction strategies include:
- Always read and follow label directions.
- Use nozzles that produce coarser droplets when applying pesticides on targets that do not require small, uniformly sized droplets.
- When feasible, increase application volume (gpa) and use nozzles with larger orifices.
- Switch to "low-drift" nozzles when buying new ones.
- Have more than one size and type of nozzle on the boom ready to switch when the need arises.
- Consider using air-assisted or electrostatic sprayers, which were developed for drift reduction.
- Use nozzles with a wider spray angle so you can keep the boom closer to the spray target.
- Make sure pressure gauges are accurate and keep spray pressure down.
- Avoid spraying on extremely hot, low humidity, or windy days, especially if sensitive areas are nearby.
- Spray during moderately unstable atmospheric conditions (very slight vertical updraft). Avoid spraying in stable atmospheric conditions or when inversions trap upward movement of very small spray droplets and result in drift fallout. Spraying during early morning, late afternoons, or night often avoids high winds and may be suitable, although these times have greater propensity for stable atmospheric conditions.
- Because wind speed is a major factor in drift, avoid spraying near sensitive crops that are downwind. Leave a buffer strip of effective width and spray the strip later when the wind shifts or dies down. New label requirements may use a drift model to determine the required buffer width. By exercising various drift-reduction techniques, this buffer zone may be kept to a minimum.
- Use a reliable wind speed meter to accurately determine wind speed and make spraying decisions accordingly.