Nozzle type and application pressure govern droplet size (see Nozzles: Selection and Sizing, Virginia Cooperative Extension publication 442-032), which in turn affects system output (application rate), target deposition, uniformity, efficacy, and the risk of drift. Off-target movement in the form of spray drift is a major concern because it diverts the chemical from the intended target, reduces efficacy, and deposits pesticide where it is not needed or wanted. When a pesticide drifts, it may cause both environmental and economic damage, including exposure to people and property, injury to susceptible vegetation, harm to wildlife, deposition of illegal residues on crops, and contamination of water supplies.

Acts of terrorism have heightened our awareness of the need for increased personal and farm security. The greatest security risk to farms, greenhouses and nurseries where plants are grown is the unauthorized access to farm chemicals and application equipment.

Acts of terrorism have heightened our awareness of the need for security, both at home and on the farm or nursery. This publication and the checklist that accompanies it will help you be proactive with regard to farm security.

This fact sheet covers nozzle description, recommended use for common nozzle types, and orifice sizing for agricultural and turf sprayers. Proper selection of a nozzle type and size is essential for correct and accurate pesticide application. The nozzle is a major factor in determining the amount of spray applied to an area, uniformity of application, coverage obtained on the target surface, and amount of potential drift.