Field measurement of spray drift from a spray application by UAV

To use unmanned aerial vehicles (UAVs) to deliver pesticides, new data are needed to allow regulators to conduct risk assessments. A field trial was conducted to obtain spray drift data relating to ground deposits and airborne spray resulting from a spray application delivered by a small UAV.

A 12 m width area was sprayed with four passes of the UAV and spray deposits were collected within the sprayed area and up to 50 m downwind. Airborne spray was collected at 5 and 10 m downwind. Ground deposits of spray drift were similar to other data produced by orchard airblast sprayers; airborne spray was generally lower than other data produced by boom sprayers.

Drift data was obtained to allow regulators to conduct a risk assessment for a pesticide application delivered by the UAV configuration used in this study. The ability to control the operation and to record applied doses was inadequate and the distribution within the sprayed area was poor. © 2025 Society of Chemical Industry.