Double-Pruning: preventive technique against spring frost damage

Abstract

The double pruning technique on Sangiovese vines, based on pre-pruning in February and finishing in April, induced a delay of bud break, which is an approach to avoid spring frost damage. The field experiment was conducted on Sangiovese vines mechanically spur-pruned during dormancy in February and manually finished post budburst to test the potential of ‘double-pruning’ approach to prevent the spring frost damage. This technique, associated with the finishing performed when the apical shoots on the mechanically-shortened canes were about 10 cm long, allowed to keep the basal buds in a dormant phase for almost 15 days, extending the resistance period against the spring frosts, particularly important for the cultivars characterized by early bud-break. Yield reduction per vine was -22% due only to the incidence of unsprouted buds, while the grape ripening profile was delayed with an increase of acidity and phenols and a decrease of pH and soluble solids.