Spraying quality using unmanned aerial vehicle in citrus

This study aimed to evaluate the effect of the operating flight height of an unmanned aerial vehicle with different spray tip rotations on the parameters of droplet coverage, density and volumetric median diameter of the sprayed droplets, in acid lime culture ´Tahiti’. The experiment was performed in randomized blocks design, with repetition within the block, in a factorial system (3x2), with four repetitions. Three planting lines were selected for each treatment. The two outer lines were used as borders and the central one for evaluation. In each treatment, one plant was selected from the planting line and four water-sensitive papers were fixed in the middle third of the outermost portion of the canopy.A solution containing water and a drift reducing adjuvant was prepared to analyze the quality of the spray. A significant difference was found for the variables of spray tip rotation and flight height with no interaction between them. This result indicates that these variables act independently on the volumetric median diameter values. Furthermore, the spray heights of 3.0 m and 4.0 m have a notable effect on the amount of deposition. However, their influence on droplet size is negligible.