Leaf area reduction by trimming, a growing technique to restore the anthocyanins: Sugars ratio decoupled by the warming climate

The aim of this work is the evaluation of the leaf area reduction by trimming, as a growing technique to restore the anthocyanins: sugars ratio decoupled by the warming climate. A 3-year period (2010-2012) severe shoot trimming treatment was done after berryset (berry diameter 3-4 mm) and the veraison date was delayed around 20 days. The grapes were picked at the same level of soluble solids in all the treatments. However, for every year, the trim treatment significatively increased the total anthocyanin content between 8 % and 21 % compared to control. Therefore, delaying the berry ripening process trough the decrease of the leaf area to fruit ratio, could partially restore the anthocyanins: sugars ratio disrupted by elevated temperatures. Although it is necessary to study other trimmings intensities as well as other times of intervention, the shoot trimming treatment could be a very simple technique to delay berry ripening and compensate the effects of climate warming.Peer Reviewe