Droplet Distribution And Control Against Citrus Leafminer With Uav Spraying

To explore the applicability of unmanned aerial vehicle (UAV) in the citrus orchard, this study was initiated to evaluate the droplet distribution by the UAV spraying, the difference of control effect against the citrus leafminer (Phyllocnistis citrella Stainton) (CLM) and the economic benefits between UAV spraying and manual spraying under the condition of different citrus tree shapes. These experiments were conducted at the sprouting-growing period of citrus autumn shoots with five-year-old Tarocco blood orange. The results presented that hedgerow-shaped plants have the best performance of droplet distribution and shoots' protective effect (SPE) under the conditions of UAV spraying. The CLM leaf damage index (LDI) by manual spraying was lower than that by the UAV spraying, especially for open centre shape. Overall, the CLM control effect by the UAV spraying is about 65-75% of that by the manual spraying. These results indicated that the droplet distribution and the CLM control effect of the hedgerow-shaped and the open-centreshaped canopy by the UAV spraying achieved a better performance than that of the round-head-shaped plants. The results of droplet distribution and CLM control effect demonstrated that open-centreshaped canopy has relatively satisfactory performance. Compared with the manual spraying, UAV spraying got high efficiency and low cost performance.