Site-specific orchard sprayer equipped with machine vision for chemical usage management

•An orchard sprayer with bent vertical booms was designed to conform to the shape of the trees.•A machine vision system was designed to locate the trees.•Vision system governs the sprayer to run the spraying on the trees and stop it between the trees.•Results showed a reduction of up to 54% in pesticide usage. The considerable spacing between trees along orchard rows causes a lot of pesticides to be wasted by conventional continuous spraying which is not targeted to the tree canopy and therefore releases a lot of toxic chemicals to the environment. In order to solve this problem, a site-specific orchard sprayer was designed and developed by using machine vision technology which applies a precise amount of pesticide based on the tree green canopy and improves chemical application efficiency in orchards. Laboratory and field tests were conducted to evaluate its performance. During laboratory tests, green and white papers were mounted along a line at 2.70 m above the ground, while a camera was used to record the on and off time of the spraying nozzles. During the field tests, the sprayer performance and deposition of pesticide on tree branches and the empty spaces between the trees were evaluated by placing water sensitive papers at different locations. Field performance of the sprayer in an olive orchard was evaluated in two conditions of continuous and discrete-targeted spraying both at three forward speeds and four replications. The results showed that discrete-targeted spraying resulted in 54% less chemical consumption compared with conventional continuous spraying. Further reduction of pesticide usage is expected in newly established orchards with younger trees and larger intra-row spacing.