Spray drift is when a sprayed pesticide, herbicide, or fungicide reaches areas beyond the targeted crop — and it has a number of undesirable effects. Spray drift can cause damage to nontargeted crops and wildlife areas, kill beneficial insects like pollinators, waste product, pose a danger to humans and animals, and more! Your “Best Practices” toolkit should always include efforts to reduce spray drift, both for the environment and for your operation’s bottom line. See our compilation of the best ways from UF/IFAS to reduce spray drift in your Florida citrus grove.
Ways to Reduce Spray Drift
Reading and following the product’s label is the first step in getting any spray right. The experts at UF/IFAS recommend these additional options for reducing spray drift:
Equipment. The equipment you’re using to apply herbicides or other chemicals can affect the chances of the spray drifting outside the application zone.
- Utilize drift reduction nozzles on your spray equipment.
- Equip your spray equipment with wide-angle nozzles.
- Lower spray boom heights and ensure that the spray boom remains stable.
- Stop the spray during application for missing trees in the row if possible. Spraying empty spaces means that the spray does not enter the tree canopy, allowing it to drift. This wastes the product and allows it to drift outside of your application zone.
- Set your equipment to as coarse a spray as possible to still obtain good coverage and control; the higher the spray pressure, the finer the droplets.
- Herbicides have the greatest potential for damaging nontargeted crops, but they can be applied with a coarser spray; pesticides, including insecticides and fungicides, generally must be applied with a finer droplet at a higher spray pressure.
- Service and calibrate your equipment regularly to ensure your equipment is delivering the right spray deposition pattern.
Conditions
- Do not apply products if it is windy or gusty outside; a good rule of thumb is to avoid spraying in winds over 10 miles per hour.
- Avoid spraying during thermal inversions; this is when air closest to the ground is warmer than the air above it. Spraying under these conditions will cause drift when your product is moved upwards as the warm air rises.
- Try to avoid spraying when the temperature is 90° F or higher.
- Aim to apply pesticides early in the morning or late in the evening as conditions are usually more ideal; for example, temperatures are generally cooler and wind is usually more still in the morning or late evening than in the rest of the day.
Products
- Choose application methods and formulations that have a lower chance of spray drift.
- Utilize drift control/drift reduction agents designed to minimize the formation of droplets smaller than 150 microns. While they help produce a more consistent spray pattern and aid in deposition, drift control additives do not completely eliminate drift, so you still need to take additional steps to avoid spray drift.
General
- Identify areas around your grove that are more sensitive to the products being applied, especially nontargeted crops that are sensitive to herbicides.
- Utilize adequate buffer zones to keep spray drift from reaching nontargeted areas.
- Keep records of each spray application, including an evaluation of the spray results and areas for improvement.