Sponsor Agency: WTFRC
Lewis*, K.M.; Musacchi, S.; Whiting, M.
This project is designed to evaluate tree response, equipment and orchard requirements for mechanical pruning in apple, sweet cherry and pear. Trials in apple and sweet cherry were established in 2014. The equipment used in the 2014 trials was a Gillison center mount hedger (Benzonia, MI) with the capacity to run horizontal for top working trees and vertical for hedging. Treatments included mechanical thinning and thinning done by hand at different tree growth stages. Tree measurements include wood and leaf removal, regrowth, and return bloom. Fruit quality measurements include fruit number, fruit weight, fruit damage, and fruit color. Time to complete tasks and resulting economic impact will be reported. Preliminary results indicate that mechanical pruning is 23X faster than hand pruning in cherry and 2-4X faster in apple. Wood and leaves removed at dormant timing using hand pruning is 2X greater in cherry and 3X greater in apple when compared to mechanical treatments. 2014 trials indicated that use of the Gillison Hedger can result in dirty cuts on wood that is not secure and 6.5% of apple fruit was damaged in the summer 12-20 leaf stage treatments. The fruit could easily be identified and removed during the green fruit thinning operation. In ‘Cripps Pink’ the dormant timing for mechanical pruning resulted in significantly fewer number of fruit, lower pounds of fruit per tree and lower yield efficiency when compared to hand pruning at dormant timing. Mechanical pruning at dormant timing also resulted in significantly fewer number of fruit per tree, lower pounds of fruit per tree, lower TCSA and yield efficiency when compared to mechanical pruning at summer timing. Fruit color, hue, and maturity showed a response to pruning method and timing. The Gillison is a center mount but is still a challenge for narrow orchard tractors. 2015 trials will include additional apple and cherry trials and a pear trial. Mechanically pruning treatments in apple and pear will be done with a new hedger manufactured by Lagasse Works Inc. (Lyons, NY).