Convenience of Applying of Viticulture Technique as a Function of the Water Status of the Vine-Stock

Abstract

This study determined the effect that the irrigation dosage and cluster thinning showed over the antioxidant activities and total phenols in grapes, and phenolic profile and chromatic characteristics of cv. Tempranillo wines. The experiment was carried out over two consecutive seasons at an experimental vineyard in Extremadura (Spain). The plants were subjected to two post-véraison irrigation treatments, one at 100% (R100) and the other at 25% (R25) of crop evapotranspiration (ETc). Two crop loads (C and T) were additionally established for each irrigation treatment by cluster thinning at véraison. The winemaking process involved separate use of the grapes from each of the four resulting treatment groups (R100C, R100T, R25C and R25T) and followed a common protocol. In grapes, the effect of thinning enhanced when combined with water deficit, resulting in increases phenylpropanoids and flavonoids at the harvest, while leaving the polyphenol oxidase´s activity unaffected. In wines, the higher post-véraison water stress of the R25 treatments resulted in higher values of dimeric flavonol and flavanol concentrations. The wine hue was affected by water status. The cluster thinning caused additional increases in the concentrations of monomeric flavanols and anthocyanins, as well as resulting in stronger wine colour intensity.

Vine Irrigation through Two Shoot Densities in Flavonoid and Non-Flavonoid Compounds in ‘Tempranillo’ Grapes

“…Graciano grown in plastic pots, irrigated with sustained deficit irrigation (SDI), Niculcea et al found registered decreases in FLAVO and increases in CA in respect to non-irrigated grapes [ 40 ]. In Tempranillo vines grown in the same edaphoclimatic conditions as the present work, Gamero et al [ 83 ] found increases in Pro B1 and Pro B3 dimers in irrigated grapes. When regulated deficit irrigation (RDI) was applied to ‘Monastrell’ grapevines grown in eastern Spain under semiarid conditions, the content of EC in these grapes was mainly flavanol, and epicatechin-3-gallate decreased [ 108 ].…”

“…Touriga Nacional during three seasons in the Douro region, they observed increases in KpG, My-hexoside, QcG, KpR and QcGR in two of the three vintages, while MyG decreased only in two of them. Gamero et al [ 83 ], in wines elaborated from vines grown in similar edaphology and climatic conditions to those in the present work, reported a different irrigation effect depending on whether the wines were created from thinned or control vines. However, little or no change was noticed for other flavonoid compounds.…”

“…Of the different classes of polyphenols present in grape berries, the most important are flavonoids (anthocyanins, flavonols and proanthocyanidins (also called condensed tannins)) and stilbenes. Previous works analyzing the effect of water stress on polyphenols report that their effect depends on the season, weather conditions, grapevine variety, magnitude and timing of water deficit and cultivar techniques applied in the vineyard [ 53 , 79 , 80 , 81 , 82 , 83 ].…”

“…While a short drought effect was observed in the tR concentration in grape berry skins in the Barbera cultivar [ 115 ] and no significant differences were found by [ 108 ] in ‘Monastrell’ grapes, a substantial increase in STS was observed in the Cabernet Sauvignon cultivar [ 100 ]. According to the work of Molero, PCAs demonstrated that seasons had a great effect on polyphenol values under our conditions [ 83 , 116 ]. The season effect was even greater than treatment effect.…”

Accelerating Aging of White and Red Wines by the Application of Hydrostatic High Pressure and Maceration with Holm Oak (Quercus ilex) Chips. Influence on Physicochemical and Sensory Characteristics

“…Therefore, anthocyanins are the main agents responsible for the red wine color. These substances are able to react with compounds extracted from wood but also with other compounds formed by redox potential changes, induced by wood components [ 60 ].…”