Development of an envisioned total vineyard mechanization system required evaluation of shoot positioning in conjunction with pruning methods. Shoot positioning and pruning regimes were established in an irrigated Geneva double curtain-trained Concord (Vitis labruscana B.) vineyard for eight years. Shoot positioning (SP) (none, center, machine, and hand) and dormant pruning (hand balanced 30+10 or 50+10), machine-pruned with hand adjustment to 60 nodes (MP60) or 80 nodes (MP80), machine-pruned with fruit thinning (MPFT), and machine-pruned with no adjustment (MPNA) were applied. Machine- and hand-SP produced comparable results with increased yield, lower pruning weights, and lower juice pH as compared with no SP. Center-SP had little to no effect on yield and MPNA vines were only slightly affected by SP. Yield increased from 2.7 to 6.7 kg/vine for machine- and hand-SP as compared with non-SP vines for the remaining pruning methods. Vine morphology affected the mechanism behind yield increase. Yield/node increased 56% with hand-SP on 30+10 and 50+10 vines, while MP60 and MP80 increased 30 to 38%. Yield increases on hand-SP MPFT were due to more nodes and clusters. The effects of machine- and hand-SP were most apparent following a year with light fruit load and high pruning weight with yield/node increases of 60 to 115% on node-adjusted vines. Shoot positioning had little effect on juice soluble solids or color but reduced juice pH. Hand-SP reduced pruning weight by 30 to 60% on node-adjusted vines as compared with no SP. Machine-SP benefited yield and/or quality on all pruning methods tested, was superior to center-SP, and can be implemented into the total vineyard mechanization system.
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