Orchard Sprayer Design for Precision Pesticide Application

Active agents should be applied at an appropriate level when using sprayers to apply pesticides. Applying pesticides to areas that do not require spraying can result in waste and contamination of the air, water, and environment. With this research, a variable rate tree spraying prototype equipped with Internet of Things (IoT) technology and devices was developed, modelled, and produced. The developed machine was capable of applying pesticide to a camera-detected tree canopy. The sprayer’s nozzles were individually controlled by electrical signals sent from an electronic control unit. Computer simulations and laboratory experiments were used to test and analyze the functions of the prototype sprayer. Using water-sensitive papers positioned at various heights in the tree canopy and between trees, the sprayer’s droplet density and coating rates were assessed. Four different parameters were used in the experiments: electrostatic voltage (10, 15, 20, 25, 30 kV), ground speed (1, 3, 5, 7 and 9 km·h−1), pressure (200, 400, 600, 800, 1000 kPa), nozzle diameter (0.8, 1.1, 1.4, 1.7 and 2.0 mm), and nozzle diameter. The coating rates that were reached were the highest for the following parameters: pressure 600 kPa (31.81%), nozzle hole diameter 1.1 mm (35.01%), electrostatic loading 15 kV (36.39%), and velocity 1.0 km·h−1-1 (68.91%). According to the analysis of variance, there was no discernible difference between the spray coverage rates and spray droplet diameters within the tree canopy.