Effects of operation height and tree shape on droplet deposition in citrus trees using an unmanned aerial vehicle

Abstract The effects of operation height and tree shape on droplet deposition in citrus trees using an unmanned aerial vehicle (UAV) were investigated in this study. When the operation height was 1.2 m and the flight speed was 3.5 m s−1, the droplet density and droplet coverage rate were maximized in all the canopies. The droplets exhibited the most uniform distribution (CV  = 32.44%) in the lower layer of inverted triangle-shaped trees. The droplet density in the lower layer of inverted triangle-shaped trees was 48.04% higher than that in triangle-shaped trees. There was no statistically significant difference between the middle and lower layers of inverted triangle-shaped trees. The uniformity of the droplet deposition distribution was studied in six parts of the citrus trees at an operation height of 1.2 m. The results indicated that the front, middle, rear, left and centre parts displayed uniform distributions, but the right part of the inverted triangle-shaped trees did not. This difference might have been caused by a deviated flight route due to manual control error or by droplet drift from the wind originating from the right.

[1]  Chun Chang,et al.  Develop an unmanned aerial vehicle based automatic aerial spraying system , 2016, Comput. Electron. Agric..

[2]  Tan Yu,et al.  Modelling operation parameters of UAV on spray effects at different growth stages of corns , 2017 .

[3]  Masoud Salyani,et al.  Spray Drift From Ground and Aerial Applications , 1992 .

[4]  Avic Xi.  Primary Studies on Spray Droplets Distribution and Control Effects of Aerial Spraying Using Unmanned Aerial Vehicle(UAV) against Wheat Midge , 2013 .

[5]  Robert D. Grisso,et al.  Nozzles: Selection and Sizing , 2019 .

[6]  Deng Lie,et al.  Effects of citrus tree-shape and spraying height of small unmanned aerial vehicle on droplet distribution , 2016 .

[7]  Zhang Huihui,et al.  Drift and deposition of ultra-low altitude and low volume application in paddy field , 2014 .

[8]  He Xiongkui,et al.  Recent development of unmanned aerial vehicle for plant protection in East Asia , 2017 .

[9]  Xin-Yu Xue,et al.  Droplet deposition and control effect of insecticides sprayed with an unmanned aerial vehicle against plant hoppers , 2016 .

[10]  Yong He,et al.  Simulation and optimization of multi spray factors in UAV , 2016 .

[11]  R. D. Brazee,et al.  Effect of application variables on spray deposition, coverage, and ground losses in nursery tree applications , 2006 .

[12]  Xiang-ming Xu,et al.  Variability in initial spray deposit in apple trees in space and time. , 2006, Pest management science.

[13]  Raffaele Casa,et al.  Operational unmanned aerial vehicle assisted post-emergence herbicide patch spraying in maize: a field study , 2015 .

[14]  Y. A. Pederi,et al.  Unmanned Aerial Vehicles and new technological methods of monitoring and crop protection in precision agriculture , 2015, 2015 IEEE International Conference Actual Problems of Unmanned Aerial Vehicles Developments (APUAVD).

[15]  Durham K. Giles,et al.  Deployment and Performance of a Uav for Crop Spraying , 2015 .

[16]  Vern Hofman,et al.  Reducing Spray Drift , 2001 .

[17]  André Carlos Ponce de Leon Ferreira de Carvalho,et al.  Fine-Tuning of UAV Control Rules for Spraying Pesticides on Crop Fields , 2014, 2014 IEEE 26th International Conference on Tools with Artificial Intelligence.

[18]  Andrew J. Hewitt.  DROPLET SIZE AND AGRICULTURAL SPRAYING, PART I: ATOMIZATION, SPRAY TRANSPORT, DEPOSITION, DRIFT, AND DROPLET SIZE MEASUREMENT TECHNIQUES , 1997 .

[19]  Shulin Yang,et al.  The application of unmanned aircraft systems to plant protection in China , 2018, Precision Agriculture.

[20]  Masoud Salyani,et al.  A portable scanning system for evaluation of spray deposit distribution , 2011 .

[21]  Yubin Lan,et al.  Effect of wind field below unmanned helicopter on droplet deposition distribution of aerial spraying , 2017 .