Preliminary results of hedge mechanical pruning performed with Nero di Troia winegrape cultivar

Traditional winter pruning is labor consuming and has a high cost for grape-growing farms. In order to reduce this cost, mechanical pruning was experimented at a commercial farm located in a Controlled Appellation of Origin area (D.O.C.) of Southern Italy, on the local winegrape variety ‘Nero di Troia’. Vines were trained to spur pruned VSP, with 7 two-bud spurs and thus 14 buds per vine. In winter, a plot was mechanical pruned by cutting the stems below the first couple of wires that maintain their vertical position. As a result, each spur had 8 buds in the first year, thus the bud number per vine was 56. In the second year the spur number increased, and the average bud number per vine rose to 73. The aim of the present work was to study the effect of this alternative pruning method on Nero di Troia canopy geometry and structure, grape yield, berry composition and wine phenol content of winegrape grown in Southern Italy, in comparison to the traditional pruning. Data collected during the second year of treatment showed that the mechanical pruning method experimented in this trial increased the canopy density and the grape yield, without inducing a sensible penalization of the grape and wine composition. ‘Nero di Troia’ produced a higher number of small berries per cluster that proved to have a greater content of several phenol compounds.