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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Aerial Application Technology Research » Research » Publications at this Location » Publication #428206
Research Project: Advancing Precision Aerial Application for Sustainable Crop Production and Protection

Location: Aerial Application Technology Research

Title: Updates to the USDA ARS spray nozzle models

Author
item Fritz, Bradley

Submitted to: Agricultural Aviation
Publication Type: Trade Journal
Publication Acceptance Date: 8/15/2025
Publication Date: 9/27/2025
Citation: Fritz, B.K. 2025. Updates to the USDA ARS spray nozzle models. Agricultural Aviation. Fall 2025 pp. 60-65.

Interpretive Summary: Spray nozzle selection and operation is a critical factor in achieving effective and safe aerial pesticide applications. To help applicators meet product label requirements and reduce off-target drift, Spray Nozzle Models for both helicopters and fixed-wing aircraft were updated. These updates include new nozzle types, improved accuracy for existing models, and major changes to the way droplet size classes are defined. The new classification curves align better with real-world droplet behavior and may affect how some nozzles are categorized. A streamlined interface now combines high- and low-speed models into one application. These improvements provide applicators with more accurate and user-friendly tools to plan applications that are both effective and compliant with evolving pesticide labels.

Technical Abstract: The USDA ARS Spray Nozzle Models have undergone significant updates to enhance the accuracy and efficacy of aerial pesticide applications. This paper reviews the importance of droplet size in minimizing spray drift and achieving product efficacy, emphasizing the role of droplet size classes specified on pesticide labels. The foundational work by USDA in the early 2000s led to the development of the first spray nozzle models for helicopters, which were later expanded to include fixed-wing aircraft. Subsequent improvements incorporated new nozzle types and broader operational conditions. The most recent updates include the addition of two new straight stream nozzles, as well as revisions to the droplet size classification curves in collaboration with the International Standards Organization. These updates aim to provide applicators with the most accurate and practical resources for optimizing spray operations, ensuring compliance with label-specified droplet size requirements.