Specialty Crop Research Initiative

This project was funded by the USDA with matching support from fruit growers, fruit industry associations, and academic institutions. It is a multi-disciplinary, inter-regional effort that combines research and outreach to help the tree fruit industry improve efficiency and sustainability.

Tree fruit are thinned at the blossom or early fruit development stages to ensure larger, higher quality product. This management practice, typically performed by hand, is a labor-intensive and expensive activity. Development of methods to mechanize thinning is a top priority for the tree fruit industry. This project will develop and test new mechanical thinners. A new string thinner will be developed with capability to operate in both vertical and horizontal orientation and evaluated in both traditional and high density training systems. A new drum shaker prototype for green fruit thinning with design features based on previous testing of mechanical harvester prototypes will be evaluated for thinning efficacy, ease of operation, and reduced potential for tree damage. Tree canopy parameters will be studied to enhance machine access to the target blossoms or fruit, and to facilitate machine vision for use with precision end effectors for selective fruit thinning. Sensors will be used to detect the trees and control the position of the thinner relative to the canopy for maximum efficacy and tree safety. Machine vision combined with novel precision end effectors will be developed and tested for selective thinning. The trans-disciplinary project team includes engineers, horticulturists, economists, sociologists, and extension educators. This team will work closely with stakeholders in the tree fruit industry, and results of the effort will immediately be available to commercial operations for implementation. The importance of the work to the tree fruit industry is indicated by the strong financial support being provided by the industry.