Payload capacities of remotely piloted aerial application systems affect spray pattern and effective swath

Authors: Martin, Daniel - Dan; Latheef, Mohamed - Ab

Submitted to: Drones
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2022
Publication Date: 8/22/2022
Citation: Martin, D.E., Latheef, M.A. 2022. Payload capacities of remotely piloted aerial application systems affect spray pattern and effective swath. Drones. https://doi.org/10.3390/drones6080205.
DOI: https://doi.org/10.3390/drones6080205

Interpretive Summary: Unmanned aerial systems have recently been introduced into the United States agricultural market but little data exist related to their spray application performance. Field studies were conducted to determine the effect of application height and ground speed on spray pattern uniformity, effective swath and droplet spectra for several commercially available unmanned aerial systems of varying payload capacity. The work established that each unmanned aerial system produced an acceptable spray pattern and that by operating the systems at lower ground speeds and application heights, applicators could achieve higher deposition rates and increase coverage on spray targets. Commercial pesticide applicators and researchers will be able to use this information to increase spray deposition and efficacy of aerial applications while reducing off-target spray drift.

Technical Abstract: Recently, production agriculture has witnessed exponential growth in the use of UAS technology to obtain site-specific, real-time spectral reflectance data for the management of spatial and temporal variability in agricultural ecosystems. The integration of this novel technology and remotely piloted aerial application systems (RPAASs) for pest management requires data curation on spray pattern uniformity, droplet distribution and operational factors governing such data. The effects of application height and ground speed on spray pattern uniformity and droplet spectra characteristics for four commercially available RPAAS platforms configured with four different payload capacities (5, 10, 15 and 20 L) and factory-supplied nozzles were investigated. Spray pattern was determined by a cotton string deposition analysis system. Spray droplets captured on water sensitive paper cards were analyzed using a computer-based scanner system. Test results indicated that each RPAAS platform of varying payload capacity was able to produce an acceptable spray pattern. As payload capacity increased, so did effective swath. However, effective swath was comparable between 15 and 20 L units. Theoretical spray application rate decreased with ground speed. Fundamental data reported here may provide guidance to aerial applicators and help in the furtherance of RPAASs as an effective pest management tool.