The eff ect of foliar treatment on phenolic maturity of grapes and qualitative characteristics of wines materials

Abstract

Wine materials quality characteristics evolve at fruit ripening stage. Grapes must be harvested at their maximum ripeness stage in order to obtain wine with a deep red colour, full body, soft tannins and fruit aroma. One way to evaluate the degree of fruit ripeness is the Glories method, the principle of which is based on determination of the total and extractable anthocyanin potential of grapes. In 2018 reseachs were conducted to study the eff ect of grapevine foliar fertilizing with organo-mineral fertilizers (“Siamino Pro 500” preparation) on productivity and enological characteristics of the vines, as well as the qualitative characteristics of respective wine materials. The studies demonstrated a positive eff ect of the experimental foliar dressing scheme on the grape yield – the increase made 18,1 % as compared to the means over the past 3 years. The experimental treatment scheme proved to stimulate earlier technical maturity of grapes, characterized by a high anthocyanin percentage extracted from peel, reduced by 20 % must enrichment with seed tannin, as compared to control. The oxidative enzymes activity of monophenol monooxygenase and peroxidase in the test sample was by 14 and 37 % lower than in the control. Base wines obtained from grapes treated by the organo-mineral fertilizer demonstrated intense colour, balanced aroma and taste.