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Wine phenolics are of considerable interest due to their implication in the organoleptic appreciation of wines and due to their bioactive functions as antioxidants. In this work, the effects of sustainable strategies in the vineyard, regulated deficit irrigation treatments (RDI) and crop load level (CL) on Tempranillo grape phenolics over two seasons was studied. Rainfed (T), early (EDI) and late (LDI) regulated deficit irrigation was applied. Cluster thinning (TH) and control (C) without cluster removal were also applied under each irrigation treatment. The effect of CL remained independent of RDI for all compounds, except for phenolic acids. The RDI influence on the grape skin phenolic profile was higher than CL in the dry season (2009); however, in 2010, the effect of CL was greater. In 2009, a tendency to increase anthocyanin and hydroxycinnamic acid content in grape skins was registered in EDI with respect to T. However, significant decreases in hydroxycinnamic and flavanol compounds were found in LDI. In 2010, the wettest year, CL increased all phenolic families’ content. Thus, it can be concluded that the effects of RDI and cluster thinning treatments depend on the family of compounds considered and the meteorological conditions of the year.

“Crop-forcing” is an effective technique to delay grape maturation to a period of lower temperatures, and in this way, improve grape quality. Because of the aggressiveness of this technique (removal of leaves and fruit to reinitiate a second vegetative cycle), it may affect the level of reserves and could provoke progressive vine exhaustion. The aim of the present work is to evaluate the short- and medium-term evolution of carbohydrate reserves in different plant organs and the effect of “crop-forcing” under different irrigation regimes on seasonal biomass production and its distribution. The study was carried out over a four years period (2017–2020), applying “crop-forcing” in three consecutive years (2017–2019) to the same vines on two different dates and using two irrigation strategies. The application of “crop-forcing” did not decrease root reserve levels in either the year of application or the following year, but did modify starch and soluble sugar levels in shoots and leaves in some moments of the vegetative cycle during the years of “crop-forcing” application. Total biomass production in terms of grams per vine was lower in the “crop-forcing” treatments and continued to be so when “crop-forcing” was no longer applied. The percentage of biomass in vegetative organs increased at the expense of productive organs.

Background and Aims. High temperatures during grape ripening have a negative effect on the winemaking characteristics of musts. The crop forcing technique delays ripening to a period when temperatures are lower. The objective of this study is to provide information to winemakers and grape growers on how the delay in ripening caused by crop forcing can affect berry performance. Methods and Results. This study of 3 growing seasons (2017–2019) analyzes the effect of this technique in a vineyard of the Vitis vinifera L. cv. Tempranillo in Extremadura, together with two irrigation strategies. The grapevines were forced 4 and 22 days after anthesis (F1 and F2, respectively), compared to a treatment without crop forcing techniques (NF). Each treatment was subjected to two irrigation strategies: to cover the water needs of the plants (C) and deficit irrigation during preveraison (RI). Crop forcing delayed the harvest between 32 and 56 days on average in relation to NF. Crop forcing and irrigation strategy modified berry composition at harvest: C-F1 and C-F2 had higher total polyphenol and anthocyanin concentrations, total acidity, malic acid content, and lower pH relative to C-NF; RI-NF increased total anthocyanin concentration and pH and decreased titratable acidity value. Conclusions. Crop forcing is able to delay grape ripening to lower temperature periods. This is a promising technique for restoring the coupling between phenolic and technological ripeness. The combination of both crop forcing and deficit irrigation strategy maintains the berry quality while improving water use efficiency. Significance of the Study. The present work shows how the “crop-forcing” technique is effective in modifying the relationship between different parameters that determine the characteristics of berries throughout ripening as a raw material for winemaking, compared to vines with traditional winter pruning, under different irrigation strategies.To the memory of Jordi Marsal

This study aims to analyze the effects of non-limiting irrigation (I) vs. rainfed (R) through two different shoot densities, high-load (H) and low-load (L), on vegetative growth, agronomic parameters, flavonoid and non-flavonoid polyphenol substances of cv. Tempranillo grown in a semi-arid climate during three consecutive seasons (2014–2016). Under these conditions, in the 2015 and 2016 seasons, irrigation showed significant increases in berry weight (14.7% and 13.4% in H and L, respectively, in 2015, and 35.6% and 23.5% in the same treatments in 2016) and yield (66.7% and 48.5 in 2015; 27.9% and 177.5% in 2016). Additionally, a general decreasing trend is observed in anthocyanins with the exception of peonidin derivates, almost all flavonol compounds, cinnamic acid and resveratrol values with different degrees and statistical significance depending on the shoot density of the vines. A slight variation is observed in 2014 in these parameters. On the other hand, no general trends are established either in flavanol compounds or hydroxybenzoic acid. Thus, the effect of irrigation depends on the parameter considered, the shoot density of the vine and the season considered.

The main phenological stages (budburst, flowering, veraison, and ripeness) of 53 Spanish minority varieties were studied to determine their potential to help winegrowers adapt to climate change conditions. In total, 43 varieties were studied in the same location in Spain (Alcalá de Henares, in the Madrid region) and 10 varieties in 5 other regions (Galicia, Navarre, Catalonia, Extremadura, and Andalusia). Other traits of agronomic and oenological interest, such as yield and acidity, were also monitored. The results allow for the grouping of the varieties into several clusters according to the time of ripeness (very early—only for red varieties—and early, intermediate, and late, for both red and white varieties) and yield (high, medium, and low). The total acidity in the grape juice ranged from 3 to 11 g of tartaric acid/L. The average temperatures were higher (up to 3–4 °C during summer) compared to historical averages during the 1957–2021 time period. Advanced phenology phases and reduced acidity are regarded as negative effects of climate change for winegrowing practices. Since some minority varieties showed late or intermediate ripening, high acidity, and high (1 Kg/shoot) or medium (0.5 Kg/shoot) yield, our findings suggest that they may be cultivated in the coming years by winegrowers as an approach to mitigate climate change effects.

One of the effects of climate change in warm areas is the asynchrony between the dates of the technological and the phenolic maturity of grapes. This is important because the quality and color stability of red wines are directly related to the content and distribution of phenolic compounds. A novel alternative that has been proposed to delay grape ripening and make it coincide with a seasonal period more favorable for the formation of phenolic compounds is crop forcing. This consists of severe green pruning after flowering, when the buds of the following year have already differentiated. In this way, the buds formed during the same season are forced to sprout, initiating a new delayed cycle. The aim of the present work is to study the effect on the phenolic composition and color of wines elaborated from vines fully irrigated (C), grown using conventional non-forcing (NF) and forcing (F) techniques (C-NF and C-F), and wines from vines subjected to regulated irrigation (RI), grown using NF and F techniques (RI-NF and RI-F). The trial was carried out in an experimental vineyard of the Tempranillo variety located in a semi-arid area (Badajoz, Spain) in the 2017–2019 seasons. The wines (four by treatment) were elaborated and stabilized according to the classic methodologies for red wine. All wines had the same alcohol content, and malolactic fermentation was not carried out in any of them. Anthocyanin profiles were analyzed by HPLC, and total polyphenolic content, anthocyanin content, catechin content, the contribution to color due to co-pigmented anthocyanins, and various chromatic parameters were also determined. Although a significant effect of year was found for almost all the parameters analyzed, a general increasing trend in F wines was found for most of them. The anthocyanin profile of F wines was found to differ from that of C wines, especially in delphinidin, cyanidin, petunidin, and peonidin content. These results indicate that by using the forcing technique it was possible to increase the polyphenolic content by ensuring that the synthesis and accumulation of these substances occurred at more suitable temperatures.