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ARS Home » Research » Publications at this Location » Publication #122612


item Kirk, Ivan

Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Labels for crop protection products often specify that the material must be applied in a certain droplet size spray. Aerial applicators need to know the droplet size from their system to comply with these label requirements. Computer spreadsheet models were developed for fixed-wing aircraft spray nozzles to meet these needs. Aerial applicators can input their operating conditions into the model for their nozzles and the model predicts droplet size and percentage of sprayed material that is expected to drift. This information will permit aerial applicators to comply with product label requirements and to optimize applications for controlling spray drift. Aerial applicators will be more responsible applicators of crop production and protection products through use of these spray nozzle models.

Technical Abstract: Pesticide applicators should be knowledgeable about droplet spectra classification and compliance with crop protection product labels. Some pesticide product labels already specify application with a certain droplet spectra classification and labels for many new and reregistered products are expected to require application within a specified range of the spray droplet spectrum (e.g., Medium or Coarse). Applicators of pesticides will need to know how to achieve the specified droplet spectra classification with their application. Spray nozzle parameters, pressure, and airspeed are primary factors that influence droplet spectra classification from aerial spray nozzles. Computer spreadsheet models for spray nozzles commonly used on fixed-wing aircraft were developed that will permit applicators to select their spray nozzle, input operational conditions for an application, and predict the expected droplet spectra classification. Atomization models are presented for eight of the most commonly used spray nozzles on fixed-wing aircraft as determined from aerial applicator surveys. The models are available on diskette and web pages for applicator use. These models provide a tool that applicators can use to mitigate spray drift and ensure compliance with crop protection product label requirements for applying sprays with a specific droplet spectra classification.