La hiérarchisation des Coteaux du Languedoc: une application concrète du zonage vitivinicole

Today, there is need to design, produce and label terroir wines, with unique organoleptic properties and more “attractive to consumers”. For this purpose, two Saccharomyces cerevisiae yeast strains (Sa and Sb) isolated during spontaneous fermentations were used for white wine production from the Assyrtiko grape of Santorini. A third commercial strain was used as control.

Grape phenolic compounds are very important constituents of red wine because, in addition to their antioxidant properties, they contribute to color, astringency and bitterness, oxidation reactions, interactions with proteins and ageing behavior of wines. The aim of our study was to assess the structural characteristics of grape and wine proanthocyanidins of Agiorgitiko variety and to evaluate the influence of the vintage year. Twelve vineyard locations were designated in the Nemea wine region. For three consecutive years (2012-2014), the grapes were harvested at technological maturity and the method of phloroglucinolysis was employed to determine the mean degree of polymerization (mDP) and subunit composition of the samples.

Plant water status of grapevine plays a critical role in affecting berry and final wine chemical composition. The environmental variabilities existing in vineyard system have significant impacts on plant water status, but it is challenging to individualize environmental factors from the temporal and spatial variabilities in vineyard. Therefore, there is need to monitor the ecophysical variation through utilizing precision viticulture tools in order to minimize the separation in berry composition. This study aims at delineating vineyard into different management zones based on plant water status explained by soil texture, and utilize differential harvest to equilibrate the final berry and wine composition.

Alteration of sap pH is one of the first chemical changes that occurs within the xylem vessels of plants exposed to drought. Xylem sap acidification accompanied by the accumulation of soluble sugars has been recently documented in several species (Sharp and Davis, 2009; Secchi and Zwieniecki, 2016). Here, Vitis vinifera plants of the anysohydric cultivar Barbera were exposed to either short (no irrigation; SD) or to prolonged drought (continual reduction of 10% water; PD). When comparable severe stress was reached, the potted grapes were re-watered. SD was characterized by fast (2–3 days) stomatal closure and high abscisic acid (ABA) accumulation in xylem sap (>400 μg L−1) and in leaf. In PD plants, the rise in ABA levels was considerably diminished.

Chitosan has been shown to enhance grapevine tolerance toward downy mildew while reducing the environmental impact of traditional protection products.