Impact of the Parameters of Spraying with a Small Unmanned Aerial Vehicle on the Distribution of Liquid on Young Cherry Trees

Research was carried out concerning spraying young cherry trees with a multirotor drone: a hexacopter. The aim of the study was to evaluate the impact of the following: the nozzle type, the air stream from the drone rotors and the size of spacing between the trees on the distribution of the liquid sprayed in the crown of the trees being sprayed. Experimental trials were conducted on a laboratory test stand. Air-injector spray nozzles: single and a twin flat were used interchangeably to spray the liquid. The travelling speed of the drone was 1.0 m∙s−1. A drone of 106.7 N weight was accepted in the study. The value of the spray liquid deposited and the uniformity of the liquid deposition in the crowns of the trees as well as the transverse distribution of the liquid under the nozzles were evaluated. It was found that the air stream from the drone rotors increased the distribution of the liquid on the trees sprayed, mainly at the middle and lower levels of the crown. A higher deposition value of the liquid was sprayed from the twin flat nozzle than from the single flat nozzle. There was no significant effect of the difference in the distance between the trees, of 0.5 and 1.0 m, on the liquid distribution. Under the influence of the air jet, the uniformity of the liquid distribution in the crowns of the trees also improved.