Influence of flight pattern on the effectiveness of unmanned aerial vehicles application in a mountain Nanguo pear orchard

Introduction: The application of unmanned aerial vehicles (UAVs) in orchards has been gradually emerging. Due to the complex architecture of tree canopies and the planting environment, choosing a reasonable UAV flight pattern to effectively enhance droplet deposition on critical target areas remains a challenge. Methods: This study employed Nanguo pear trees as the application target, with an electric multi-rotor UAV, the EA-30X, chosen as the spraying platform. Through comprehensive droplet assessment methodologies, five different flight patterns (intra-row, intra-row-high-speed, intra-row-half-rate, inter-row, verti-row) were analyzed and compared to assess droplet deposition in the tree canopy. Results: ² range. The results also showed that there was no statistically significant difference in droplet deposition between the inner and outer zones of the fruit tree canopy in the horizontal direction among the treatments (p > 0.05). Discussion: The results indicate that, under the conditions of constant spray volume rate (60 L/ha) and flight height (2.5 m), particularly when natural wind speeds are excessive, using a UAV for two-pass spraying patterns (intra-row-high-speed, intra-row-half-rate) is not recommended. Intra-row, inter-row and verti-row are viable options, but the selection should be made flexibly based on operational requirements. Different flight patterns lead to changes in the droplet deposition distribution trends across vertical layers and between inner and outer zones. This study provides scientific and precise operational guidance and reference for pest and disease control in Nanguo pear orchards.