Use of natural biostimulants to improve the quality of grapevine production: First results

The research was carried out in the 2015 growing season on Vitis vinifera 'Sangiovese' to study the effects of biostimulants supplied by foliar feeding, on the vine's eco-physiological and productive characteristics, to improve the quality in a highly vigorous vineyard. The main goal of this study was to separate the technological maturation, in terms of the berry's sugar and acidity accumulations, from the phenolic one (i.e., its anthocyanin and polyphenol contents). Specifically, three biostimulant products were sprayed: two seaweed extracts and one vegetal protein hydrolyzate; an untreated control was used for comparison. Leaf gas exchanges and chlorophyll content measurements were carried out. From the veraison to harvest, berry samples were collected and sugar content, titratable acidity, pH, extractable anthocyanins and polyphenols were analyzed. In conclusion, all treatments reduced photosynthesis. The balance between technological and phenolic maturities was improved, basically by maintaining the berries' sugar content and by increasing their anthocyanin and polyphenol contents.