Skip to main content Skip to navigation

New Resources for Sprayers

Written by Gwen-Alyn Hoheisel, WSU Regional Extension Specialist, Benton County Director, Jan 2021.

The goal for all pesticide applications should be to get every drop to the crop. Calibration ensures that the appropriate product rate is applied by the sprayer, while optimization ensures that the product is delivered onto the intended target. Calibrating and optimizing the sprayer are essential to sustainability, as they affect the environment, farm workers, and economic impact through fruit quality and pesticide costs. In six steps, this new extension publication (PNW749 Six Steps to Calibrate and Optimize Airblast Sprayers) explains how to measure ground speed and nozzle output, check and adjust airflow and nozzle alignment, and verify coverage for an airblast sprayer. Methods are outlined for manual completion of the steps, and simplified formulas and suggestions for tools that can make the process faster are included.

Nozzle selection is an important part of calibration. The nozzles on your sprayer can significantly influence the efficacy of your pest management program. They influence how much product is delivered (application rate), the spray pattern on the target crop, and droplet size. Sprayers with interchangeable nozzles, such as Rear’s air blast, Turbo-mist, or Quantum Mist, require the operator to select, or change, the type of nozzle that is installed based on the canopy or field parameters. An explanation on how to choose a nozzle from a catalog is available in PNW749.  However, there are several different attributes that commercial nozzles have that can make the selection of a nozzle daunting. Such attributes include nozzle resistance to abrasion, nozzle body design, droplet size produced, and nozzle spray pattern. A more in-depth explanation on nozzle attributes is available in a new Extension publication (FS352E Common Interchangeable Nozzles for Perennial Crop Canopy Sprayers).

Nozzles and calibration are just a start to understanding the operation and optimization of your airblast sprayer. Experts Jason Deveau (OMAFRA Fruit Crop Specialist) and Mark Ledebuhr (Application Insight LLC) teamed up with contributions by David Manktelow (NZ sprayer specialist) to write version 2 of Airblast 101.  The 300+ page resource does not disappoint for the sprayer enthusiast, but is written in a manner applicable and understandable to anyone farming with an air-assisted sprayer.  It strives to comprehensively intertwine the concepts of sprayer characteristics, canopy architecture, and general farm operations to achieve optimal spray coverage.

All of these resources are supported by Extension programs and have free downloads.

representative image of the front and back cover, and a chapter page from the new Airblast 101 publication.

*Parts of this newsletter article are directly from the new publications with permission from authors.

Gwen-Alyn Hoheisel
WSU Regional Extension Specialist,
Benton County Director articles may only be republished with prior author permission © Washington State University. Republished articles with permission must include: “Originally published by Washington State Tree Fruit Extension at” along with author(s) name, and a link to the original article.

Washington State University