Aerial Sprays 1.4

The Aerial Application Technology team operates within the United States Department of Agriculture’s (USDA) Agricultural Research Service (ARS). Their core mission involves conducting and disseminating research aimed at optimizing aerial application techniques to support the country’s aerial applicators, who collaborate with farmers and producers to safeguard and enhance food and fiber crop production.

To achieve precise and effective applications, aerial applicators select specific operational parameters—such as spray nozzle type, spray pressure, and airspeed—to generate spray droplet sizes that maximize on-target deposition while minimizing off-target drift. The team has developed a set of computer models designed to assist applicators in predicting spray droplet size distributions based on selected operational settings.

Currently, there are 19 nozzle models available—comprising 10 for fixed-wing aircraft and 9 for rotary-wing operations. The fixed-wing models are calibrated for airspeeds ranging from 100 to 160 mph, whereas the helicopter models are applicable for speeds between 30 and 100 mph. These models have been accessible for several years through downloadable spreadsheets. The introduction of this application enhances functionality by offering increased mobility and a streamlined user interface.

The nozzle models enable users to estimate spray droplet sizes based on four key input parameters:

• Nozzle Orifice Size
• Nozzle Orientation
• Spray Pressure
• Airspeed

Utilizing these inputs, the models generate the following outputs:

• DV0.1, DV0.5, and DV0.9: These values indicate the droplet diameters (in micrometers) below which 10%, 50%, or 90% of the spray volume resides.
• %Vol<100µm and %Vol<200µm: The percentage of total spray volume composed of droplets smaller than 100 or 200 micrometers, respectively.
• Droplet Size Classification: The classification of the spray's droplet size distribution according to standard engineering classifications (ASABE S572).

The generated results, along with the initial parameters, are timestamped and can be saved locally or shared via email by the user.

This application is offered as a public service by the USDA-ARS. While the information provided is considered public and may be redistributed or copied, proper attribution to USDA-ARS is requested. Although efforts are made to ensure data accuracy, users are encouraged to report any errors encountered so that they can be addressed promptly. References to specific commercial products or services do not imply endorsement by the United States Government or USDA-ARS.