Evaluating the use of unmanned aerial vehicles for spray applications in mountain Nanguo pear orchards

Abstract

BACKGROUNDNanguo pear is a distinctive pear variety in northeast China, grown mainly in mountainous areas. Due to terrain limitations, ground‐based pesticide application equipment is difficult to use. This limitations could be overcome by using unmanned aerial vehicles (UAV) for pesticide application in Nanguo pear orchards. This study evaluated the spraying performance of two UAVs in the Nanguo pear orchards and compared them with a manually used backpack electric sprayer (BES). The study also analysed the effect of canopy size on droplet deposition and ground loss and evaluated two sampling methods, leaf sampling and telescopic rod sampling.RESULTSCompared to BES, droplet deposition is lower for UAVs, but the actual pesticide active ingredient deposition is not necessarily lower given the solution concentration. The droplet deposition varies among different UAVs due to structural differences. Under the same UAV operating parameters, droplet deposition on trees with smaller canopy sizes is typically greater than that on trees with larger canopy sizes, and the ground loss was also more severe. Although telescopic rod sampling is a quick and convenient method, it can only reflect the trend of droplet deposition, and the data error is greater compared with leaf sampling.CONCLUSIONUAVs can achieve better droplet deposition in mountainous Nanguo pear orchards and almost has no harm to the operators compared with the BES. However, canopy size needs to be considered to adjust the application volume rate. Telescopic rods can be used for qualitative analyses only, but are not recommended for quantitative analyses.

Dynamic Slicing and Reconstruction Algorithm for Precise Canopy Volume Estimation in 3D Citrus Tree Point Clouds

“…It is vital in citrus tree production, breeding, and management, as it is inextricably associated with orchard precision management projects such as irrigation and fertilization practices, moisture detection techniques, fruit crop breeding, and yield assessment methods [8]. At the same time, accurate canopy volume measurements can serve as a foundation for determining crop pesticide doses and making decisions [9,10], as well as providing technical assistance for pruning robots [11] and assisting managers in making sound agricultural production decisions [12][13][14]. Therefore, the rapid and accurate estimation of canopy features plays a crucial role in monitoring fruit tree growth dynamics and enhancing orchard management optimization [15].…”