Characterization of Ground Nozzles for Pesticide Applications

Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating pressure) selection while also considering environmental influences such as wind speed and temperature. However, applicators are often limited in guidance on making successful applications, and this can result in off-target movement of the pesticide(s) causing unintentional injury to vegetation, environmental contamination, and/or human exposure. This has prompted several state and federal agencies to monitor pesticide applications and development strategies or programs to reduce off-target movements of pesticides. The objectives of the current research were to 1) incorporate and expand upon the US Environmental Protection Agency (EPA) drift reduction technology (DRT) guidelines using a wind tunnel laboratory, 2) characterize the droplet size, velocity, pattern uniformity, and drift potential of commonly used application nozzles for ground systems in the US, and 3) bridge laboratory and field studies in pesticide application technology using established and new methodologies. The data from this research aided in the development of a robust application technology program within the University of Nebraska and advanced the EPA DRT guidelines for wind tunnel testing of pesticides. Furthermore, the data demonstrated the impacts of ground nozzle selection upon the drift potential of new and existing herbicides in the US. The methods and equipment utilized in this research will be beneficial to researchers in application technology and can serve as a foundation for future experiments. Advisor: Greg R. Kruge