Foliar application of yeast derivatives at veraison to grapevines and their effects on the chemical composition. A bibliographic review

Abstract

Mestrado em Engenharia de Viticultura e Enologia / Instituto Superior de Agronomia. Universidade de Lisboa / Faculdade de Ciências. Universidade do PortoThe present work was aimed to elaborate a bibliographic review about the importance and effects, in a viticultural and enological point of view, of a new and innovating product, the LalVigneâ, that consists in inactive dry yeast (Saccharomyces cerevisiae) derivatives. It was discussed the ongoing challenges of climate change in wine industry, as the alterations of flowering, veraison and harvest, emphasizing the changes in the ripening process, the metabolism of the vine and also at sensorial level. It was referred in this work, some adaptation measures, being the application of LalVigneâ the most important and the one which was developed throughout the work. Elicitation topic went deeper, being referred what elicitor is and its mode of action. Bridging the gap between elicitors and its mode of action in vines, it was possible to develop the work about LalVigneâ. The LalVigneâ is an elicitor, consisting in inactive dry yeast derivatives, with foliar application. The characteristics of LalVigneâ, it’s mode of action, the advantages and disadvantages for viticulture and enology, as well as their side effects, were described. There are two types of LalVigneâ, Mature and Aroma, whose application is made in red and white grapes, respectively. Regarding the side effects, the use of LalVigneâ AROMA had: improvements in the skin thickness; developments in the aroma precursors; no impact in berry weight, Brix, pH or Tartaric acid; enhancements in the glutathione concentration; increases in thiolic varieties as 3MH and 3MHA; and reduction of herbaceous or aggressive character. The use of LalVigneâ MATURE had: improvements in the skin thickness; no impact in berry weight, Brix, pH or tartaric acid; a reduction of herbaceous or aggressive character; improvements in the concentration of extractable anthocyanins; improvements in the skin tannins; and developments in the degree of polymerization. Several trials were compared in this regardN/