香蕉冠层结构特征下无人机施药雾滴沉积规律研究

Deposition Law of UAV Spraying Droplets under Canopy Structural Characteristics of Banana

摘要:

随着植保无人机在热带果树施药中普及，香蕉叶片宽大、层叠等结构特点导致的雾滴沉积不均、药剂利用率低等问题凸显。为优化施药参数，以营养生长期至生殖生长期香蕉为研究对象，采用多旋翼无人机开展正交设计田间试验，以飞行高度、速度及雾滴粒径为关键因素，结合冠层垂直分层与叶片水平分区，解析参数对雾滴沉积的影响规律。结果显示：3个因素对香蕉冠层上、中、下3层叶片正面沉积量均有显著影响（P<0.05），对反面沉积的影响随冠层层次差异明显，且对正面调控作用强于反面；同时3个因素对地面流失率影响极显著（P<0.001）。基于流失率分级控制目标，提出两类优化参数：30%~45%流失率对应较低飞行高度（2m）、中低速飞行速度（1.5、2.5m/s）及中到大粒径雾滴（230、310μm）；10%~30%流失率则选用较高飞行高度（3、4m）。本研究明确了施药参数与雾滴沉积、药剂流失的关联规律，为香蕉无人机精准施药提供量化依据，也为热带大叶果树雾滴分布机理研究提供技术支撑。

Abstract:

With the popularization of plant protection unmanned aerial vehicles (UAVs) in tropical fruit tree spraying, problems such as uneven droplet deposition and low pesticide utilization caused by banana’s structural characteristics (e.g., large, overlapping leaves) have become prominent. To optimize spraying parameters, the orthogonal design field tests were conducted by using multi-rotor UAVs on bananas from vegetative to reproductive growth stages. Taking flight height, speed, and droplet size as key factors, combined with vertical canopy stratification and horizontal leaf zoning, the influence of parameters on droplet deposition was analyzed. Results showed that the three factors significantly affected droplet deposition on the adaxial surface of upper, middle, and lower canopy leaves (P<0.05), with distinct differences in their impact on abaxial deposition across canopy layers and stronger regulatory effects on the adaxial surface. Meanwhile, the three factors exerted an extremely significant influence on ground loss ratio (P<0.001). Based on hierarchical loss ratio control goals, two optimized parameter combinations were proposed: 30%~45% loss ratio corresponded to lower flight height (2m), medium-low speed (1.5m/s and 2.5m/s), and medium-to-large droplets (230μm and 310μm);10%~30% loss ratio can use higher flight height (3m and 4m). The correlation between spraying parameters, droplet deposition, and pesticide loss was clarified, providing quantitative basis for precise banana UAV spraying and support for droplet distribution mechanism research on tropical large-leaf fruit trees.