Submitted to: Ohio Fruit and Vegetable Growers Congress
Publication Type: Proceedings
Publication Acceptance Date: February 7, 2001
Publication Date: N/A
Technical Abstract: Concerns regarding the fate of spray and the efficacious use of pesticides are forcing spray applicators to re-evaluate their existing pesticide delivery techniques and to seek out more efficient application methods. New, low-drift, venturi-type nozzle technology has been shown to significantly reduce spray drift. Manufacturers also claim that these nozzles do not compromise spray quality because of air inclusion within the spray droplets. Coverage emphasis is also leading to the development of electrostatic and air-assisted delivery technology that promises better performance than traditional broadcast sprayers. New double nozzle technology reportedly provides spray delivery benefits that are similar to air-assisted delivery sprayers. The double nozzle sprayers deliver a concentrated spray solution through small droplet nozzles mounted forward of a coarse droplet nozzle. The large water droplets produced by the coarse nozzle produces air currents that can aid in movement of small droplets down into the target area. A new electronic system that controls operation of a solenoid valve promises to provide on-the-go spray delivery and droplet size. This pulsed delivery system allows an operator to change droplet size based on weather and canopy conditions without having to change nozzle tips. Field studies have demonstrated that drift reduction nozzles can reduce drift and keep more material within the target area but coverage is sacrificed. Several field trials have also shown that air currents, produced either by movement of large droplets or by another power source, can significantly aid canopy penetration, increase coverage on the backside of leaves and reduce rates of active ingredients.