Aerial spraying application of multi-rotor unmanned aerial vehicle on areca trees

Abstract

In order to illustrate the effects of droplet deposition on the canopy and the stem of the areca nut sprayed by the multi-rotor Unmanned Aerial Vehicle (UAV), for providing the operation parameter basis for the application of aerial spray in Hainan Province. The effects of MG-1p multi-rotor UAV on different leaf area index (LAI) areca under different operation heights and nozzle types were mainly studied. Eight treatments were carried out in the experiment. Instead of pesticides, seduction red stain agent was selected and prepared into an aqueous solution with a mass fraction of 5‰, with a quantity of 75 L/ha and a flight speed of about 1.3 m/s. The droplets were collected on coated paper and analyzed by DepositScan. The canopy droplet deposition ranged from 0.355 to 0.747 μL/cm, and the deposition level was from 47.32% to 99.55%. The stem layer droplet deposition amount was 0.049-0.304 μL/cm, the deposition level was 6.47%-40.51%. The droplet volume medium (DV50) test results showed that, the effect on the stem layer DV50 was very significant when only the type of nozzle was changed or all operating parameters were changed, and the DV50 range of droplet volume was 240-525 μm. The test results showed that the deposition amount of ground loss droplets was larger with the lower LAI under the same flight altitude and nozzle type, the deposition amount of ground loss droplets was the smallest when the flight altitude was 7 m, and the deposition amount of ground loss droplets was the largest when the operation height was about 13 m, which was about 2.53 times of height of 7 m. The results of the drift region droplets test showed that 90% of the total spray drift volume distance ranged within 4.5-17.40 m. The test results in this study can provide theoretical and data support for multi-rotor UAV of the areca nut aerial spray operation.