Bilan hydrique: une méthode proposée pour l’évaluation des réserves hydriques dans le zonage viticole

A relevant trend in winemaking is to reduce the use of chemical compounds in both the vineyard and winery.

Among the different management techniques in Viticulture, which have
been developed with the purpose of optimizing the interception of sunlight, the photosynthetic capacity of
the plant and the microclimate of the clusters, especially in varieties that show excess vigor, the management of defoliation presents great importance. The defoliation consists of the removal of leaves that cover or that are in direct contact with the curls, which can cause physical damages in the berries, and aims to balance the relation between part area and number of fruits, providing the aeration and insolation in the interior of the vineyard, as well as reduce the incidence of rot in order to achieve greater efficiency in phytosanitary treatments and quality musts.

Ellagitannins are the main oak wood phenolic compounds that contribute to wine and spirits organoleptic quality (color, astringency, bitterness)(1-3). Given the lack of knowledge regarding their composition and evolution in spirits, the objectives were to follow their extraction kinetic in Cognac “eaux-de-vie” matured in barrel representing different toasting and to observe their evolution and structural modifications during aging. METHODS: Eight different toasting levels were used for studying the impact of the toasting on ellagitannins composition. Two verticals (1978-2018) of “eaux-de-vie” samples coming from two terroirs were analyzed in order to observe ellagitannins evolution during aging. The above analyses were conducted using HPLC-Triple Quadrupole mass spectrometer (4) and the unknown compounds were identified by UPLC-Q-TOF, purified by preparative HPLC prior to 1D/2D-NMR analysis.

Vine water status has a significant influence on vineyard yield and berry composition (Williams and Matthews, 1990; Williams et al., 1994). It has been hypothesized that the response of plants to soil water deficits may be due to some sort of “root signal” (Davies and Zhang, 1991). This signal probably arises due to the roots sensing a reduction in soil water content or an increase in the mecanical impedance as the soil dries out.

The indigenous Greek grape varieties Assyrtiko, Malagousia, Moschofilero and Roditis are used to produce white wines that are attracting the interest of wine producers and consumers due to their aromatic characteristics [1]. In addition, the Agiorgitiko and Xinomavro varieties are Greece’s most prominent red grape varieties.