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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 #368366
Research Project: Aerial Application Technology for Sustainable Crop Production

Location: Aerial Application Technology Research

Title: Effect of application height and ground speed on spray pattern and droplet spectra from remotely piloted aerial application systems

Author
item Martin, Daniel - Dan
item WOLDT, WAYNE - University Of Nebraska
item Latheef, Mohamed - Ab
item KRUGER, GREG - University Of Nebraska

Submitted to: Drones
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2019
Publication Date: 12/4/2019
Citation: Martin, D.E., Woldt, W., Latheef, M.A., Kruger, G. 2019. Effect of application height and ground speed on spray pattern and droplet spectra from remotely piloted aerial application systems. Drones. 3:83. https://doi.org/10.3390/drones3040083.
DOI: https://doi.org/10.3390/drones3040083

Interpretive Summary: Unmanned aerial application systems are an emerging technology that provide a new platform for the application of crop protection and production products in unique agricultural environments. However, little research currently exists examining the effects of application height and ground speed on the deposition characteristics at the target site of interest and cumulatively across a larger area of concern. Field studies were conducted that examined the uniformity and deposition characteristics of the deposits from two commercially available units. Neither ground speed nor application height were found to significantly impact the effective spray swath width due to the overwhelming influence resulting from the natural variable nature of the wind. Spray patterns within the same operational conditions showed significantly different shapes, many with highly concentrated peak deposits under the system. Consecutive multiple passes with these highly variable deposit patterns can result in non-uniform applications across a field and lead to ineffective control of the target pest and chemical wastage. This results of this work will provide direction and cautionary guidance for users of unmanned aerial spray systems and focus for future research efforts seeking to optimize operational guidelines.

Technical Abstract: The objectives of this study were to characterize the effects of operational factors on important spray application parameters for remotely piloted aerial application systems (RPAAS). The effects of application height and ground speed on spray pattern uniformity and droplet spectra characteristics were investigated for two RPAAS (DJI model MG-1 and HSE V6A) delivery vehicles equipped with original equipment manufacturer (OEM) nozzles. A spray mixture of tap water and fluorescent dye was applied at three different application heights in conjunction with four different ground speeds over the center line of a cotton string, suspended 1 m above ground. Fluorometric assessment of spray deposits on cotton strings and spray droplets captured on water sensitive paper samplers described spray pattern and droplet spectra, respectively. Effective swath was determined based on the widest spray swath with a coefficient of variation (CV) = 25%. Regardless of ground speed, application heights of 2 and 3 m yielded the largest effective swath for the MG-1. Neither application height nor ground speed significantly influenced effective swath for the V6A. These test results may provide guidance to remote aerial applicators as to the best application height and ground speed to use for their RPAAS for efficacious application of pest control products.