Ripening of Mencía grape cultivar in different edaphoclimatic situations (D.O. Ribeira Sacra, Spain)

Da anni la ricerca viticola sta orientando le sue attenzioni verso lo studio della vocazionalità degli ecosistemi viticoli, perché fulcro della produttività della vite e qualità dei suoi frutti.

Aromatic characteristics of wines are strongly influenced by agronomical and enological factors, depending of the climate, cultivar and winemaking process. Tropical wines are a new concept of vitiviniculture that is being developped in the Northeast of Brazil since the 80’s, located between 8-9º latitude of the South Hemisphere, where the second most important cultivar used for reds is Tempranillo. In this condition, vines produce grapes and enologists elaborate wines twice a year, because high temperatures, solar radiation and water availability for irrigation.

Agro-ecological transition and adaptation to climate change are the two major challenges facing modern agriculture.

The effects of climate change are seriously affecting the quality of wine grapes. High temperatures and drought cause imbalances in the chemical composition of grapes. The result is overripe grapes with low acidity and high sugar content, which produce wines with excessive alcohol content, lacking in freshness and not very aromatic. As a consequence, the search of varieties with capacity of produce quality grapes in adverse climate conditions is a good alternative to preserve the sustainability of vineyards. In this work, quality parameters of seven Vitis vinifera L. cultivars (five whites and two reds) recently recovered from extinction and grown under two different hydric regimes (rainfed and irrigated) were analyzed during the 2020 vintage. At harvest time, weight of 100 berries, must physicochemical parameters (brix degree, total acidity, malic acid, pH), and carbon and oxygen isotope ratios (δ13C, δ18O) were determined. Subsequently, varietal aroma potential index (IPAv) and total polyphenol index (TPI) were analyzed. Quality parameters, IPAv and TPI, showed significant differences between varieties and water regimes. Both red varieties, Moribel and Tinto Fragoso, stood out for their high aromatic and phenolic potential, which was higher under rainfed regime. Regarding to white varieties, Montonera del Casar and Jarrosuelto stood out in terms of varietal aroma potential. Montonera del Casar high acidity in its musts and Jarrosuelto showed the highest berry weights.

Galicia, a region sited in the northwest of Spain, is one of the most important wine production area, with five Appellations of Origin Controlled (AOC).