Reducing Spray Drift

Spray drift is the movement of a pesticide through the air, during or after application, to a site other than the intended target. Drift is considered to be the most challenging problem facing applicators and pesticide manufacturers. Although drift may occur as vaporized active pesticide from the application site, it is usually the physical movement of very small drops from the target area at the time of application. Spray drift started with the invention and use of pesticides. Spray drift has become a serious concern because the pesticides used today are more active and many are non-selective. Usually, only a small amount of pesticide is needed to cause injury to nontarget plants and animals that are susceptible to the pesticide. The use of genetically altered crops that are resistant to non-selective herbicides is growing. When crops produced from conventional seeds are grown next to a field of a genetically altered crop, only a small amount of a non-selective herbicide may be needed to cause damage in the field with a conventional crop. Drift is likely to occur where liquid sprays are applied. However, under favorable weather conditions, the problem associated with drift can be reduced to a minimum if chemicals are applied with the proper selection and operation of equipment. Spray drift is becoming an increasingly important part of every spraying operation. More diversification of crops, more active and non-selective herbicides, and a greater awareness of pesticides in the environment has caused spray drift management to become every applicator’s business. Nozzles play an extremely important part in drift management by having a major affect on determining spray droplet size. They are inexpensive but can be the most important sprayer part regarding spray drift. The spray nozzle and operating pressure determines how effective the spray deposit is and how much spray may drift. While elimination of all drift is impossible, new nozzle technology is extremely effective in reducing it. Drift can also be kept within reasonable amounts by avoiding spraying at times and places when drift potential is high and by using proven drift-reducing procedures and equipment.