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    Droplet Velocity from Broadcast Agricultural Nozzles as Influenced by Pulse-Width Modulation

    Published: 2018

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    The recognition of agricultural pesticide application complexity has increased in recent years due to pesticide drift concerns and increasingly difficult-to-control pests. Spray application optimization is necessary to maximize pesticide efficacy while reducing environmental impact. Pulse-width modulation (PWM) spray application systems can be a vital precision agricultural tool by providing quick and accurate variable rate application changes and creating an opportunity for a site-specific pest management strategy. Research was conducted to identify the impact of PWM duty cycle, nozzle type, application pressure, and spray solution on spray droplet velocity to develop potential PWM optimization practices. Spray droplet velocity increased as pressure and duty cycle increased across nozzles. Greater variability in droplet velocities was observed across nozzles when pulsed at a 20 % duty cycle. Venturi nozzles created greater reductions in droplet velocity as duty cycle decreased and had greater variability in droplet velocity measurements than non-venturi nozzles. Based on present research, if PWM sprayers are to be used in site-specific pest management strategies, it is recommended that non-venturi nozzles coupled with greater than 40 % duty cycle be used to reduce spray droplet velocity variability, mitigate changes in drift potential, and assist pesticide applicators in optimizing site-specific pest management strategies.


    application parameters, duty cycle, non-venturi nozzle, precision agriculture, venturi nozzle

    Author Information:

    Butts, Thomas R.
    University of Nebraska–Lincoln, Dept. of Agronomy and Horticulture, North Platte, NE

    Hoffmann, W. Clint
    U.S. Dept. of Agriculture, Agricultural Research Service, Aerial Application Technology Research Unit, College Station, TX

    Luck, Joe D.
    University of Nebraska–Lincoln, Dept. of Biological Systems Engineering, Lincoln, NE

    Kruger, Greg R.
    University of Nebraska–Lincoln, Dept. of Agronomy and Horticulture, North Platte, NE

    Committee/Subcommittee: E35.22

    DOI: 10.1520/STP161020170192