Impact of Pruning Methods on Yield Components and Juice and Wine Composition of Cynthiana Grapes

Abstract

Four pruning methods were applied to Cynthiana (Vitis aestivalis Michx.) for four years (2002 to 2005): hand (balanced to 50+10), machine (box cut to 80 nodes), machine + hand (box cut to 110 nodes with hand prune to 80 nodes), and minimal pruning (no pruning). There were only minor differences in vine nutrition and in fruit and wine composition among the pruning methods. Minimal-pruned vines had high yields and less mature fruit in the first year, followed by low yields the second year, with yield stabilization by the third year. Wines produced were similar within year among pruning methods with the exception of wine from minimal-pruned vines in the first year. No sensory differences were found between wines from hand-pruned vines versus other methods in any year (wine from minimal-pruned 2002 excluded). After the first year, all pruning methods produced similar fruit and wine. In the final year, all pruning methods had comparable yields. However, the minimal-pruned vines averaged 38% more clusters over the last two years with a 5- to 10-day delayed harvest as compared with handpruned vines. The use of machine pruning either alone or in conjunction with hand pruning is a viable option for Cynthiana production in regions with a sufficient growing season length. Minimal pruning may also be an acceptable method but additional research is needed.