Delaying berry ripening through manipulating leaf area to fruit ratio

Abstract

The viticulture practices have always been focused on the production of grapes with higher sugar level, and this tendency has been pronounced by the climate change. The objective consists on delaying berry ripeness by decreasing the ratio between the leaf area and yield, performing intense trimming treatments after berry set and establishing the consequences on grapevine productivity in the following years. Severe shoot trimming with two different intensity treatments were done during a 3-year period (2010-2012). Phenological, vegetative and productive parameters were examined. Veraison date was delayed around twenty days. Regarding the same harvesting date, the trim treatments had lower soluble solids level (15 % reduction), lower pH (0.1-0.3) and less total anthocyanin content (10-27 % reduction). The trim effect was also reflected in berry weight; as a consequence of that, bunch size and yield were also reduced by around 9 and 15 %. Overall, single trim treatment was superior to double trim treatment because it can achieve the same results in delayed ripening, reduced °Brix, pH and production but with a smaller reduction in anthocyanin content and without having any negative impact on following years.