ARS | Publication request: Mechanical thinning pillar peach trees

Submitted to: Annual Cumberland Shenandoah Fruit Workers Conference
Publication Type: Proceedings
Publication Acceptance Date: March 15, 2007
Publication Date: April 1, 2007
Citation: Miller, S.S., Peterson, D.L., Scorza, R. 2007. Mechanical thinning pillar peach trees - second year results and observations. Annual Cumberland Shenandoah Fruit Workers Conference.

Technical Abstract: Columnar (pillar) form peach trees were mechanically thinned at 50 days after full bloom during the pit hardening stage of development. A spike-drum mechanical shaker, which showed promise for peach fruit thinning, during preliminary tests in 2005 was used to remove the young fruits. The shaker was driven at 3 km/hr and the spiked-drum was operated at either 180 or 260 cycles/min. Significantly more fruits were removed at the higher operating speed. Mechanical thinning reduced the time required for follow-up hand thinning by 54 percent to 81 percent. Crop load on the trees mechanically thinned at the higher operating speed was reduced by 87 percent compared to the hand-thinned control trees. Fruit diameter at harvest was increased by hand and mechanical thinning. Mechanical thinning with the spiked-drum shaker at 260 cycles/min. resulted in a highly significant reduction in the projected yield per ha. Using the test operating settings employed in this study, yield reductions from the mechanical thinner would probably exceed the level for commercial acceptance. Additional studies are needed to improve the efficacy of the mechanical spiked-drum shaker for thinning upright form peach trees.