Martín Fanzone

Hailstorms cause substantial economic loss in vineyards worldwide by reducing yield and deteriorating grape quality. Although anti-hail nets are extensively used to prevent hail damage, their effects on canopy microclimate, vine water status, vegetative growth, yield, and berry composition have been scarcely studied. Understanding these effects is increasingly important as climate change intensifies the frequency and severity of extreme weather events. We evaluated the effects of net color and installation system on canopy microclimate and midday leaf water potential (Ψmd) of Vitis vinifera L. cv. Malbec over two growing seasons. Treatments consisted of two net colors (Black and Pearl) combined with two systems (Grembiule and Modified), together with an uncovered control. Regardless of net color, the Grembiule system reduced canopy air temperature (Tair) and vapor pressure deficit (VPD), while the Modified system increased both variables. Ψmd was higher under the Grembiule than in the control, whereas the Modified system showed intermediate values. These results demonstrate that the effects of anti-hail nets produce contrasting results depending on net color and installation system. Careful selection of the installation system is therefore essential, particularly in warm, arid winegrowing regions frequently exposed to hailstorms and other environmental stresses. Highlights: Radiation was reduced by all anti-hail nets, mainly under the Black net and the Modified system. The Grembiule system decreased the daily maximum air temperature and VPD at canopy levels. In contrast, the Modified system increased the air temperature when compared with Grembiule and Control plants. The Grembiule system increased midday leaf water potential. Our results could be used to improve the standard practices and installation systems by considering the impact of nets on canopy temperature, VPD, RH and water status.

Shoot density is a key viticultural factor modulating canopy microclimate, berry composition, and wine quality, although yield–quality relationships are strongly influenced by environmental conditions. Saignée, a winemaking technique involving partial juice removal prior to fermentation, increases the skin-to-juice ratio and may enhance phenolic extraction. This study assessed the combined effects of shoot density (33 [T1], 20 [T2], and 15 [T3] shoots/m) and saignée (20% vs. control) on yield, grape composition, and wine chemical and sensory properties in Malbec across two vintages (2021–2022). At harvest, the pruning weight, yield components, general maturity parameters, and phenolic composition were measured. The wines were analysed for their phenolic and elemental composition, polysaccharides and volatile compounds, colour, and sensory attributes. T1 exhibited the highest yields and vegetative imbalance, whereas T2 and T3 achieved optimal Ravaz indices. The general grape maturity parameters were unaffected; however, T3 had increased berry phenolic content in 2022. T2 and T3 had enhanced wine tannins, total phenols, and polymeric pigments, particularly in 2022. Saignée increased the pH, potassium, total phenols, tannins, and acylated anthocyanins. Targeting yields near 4 kg/vine (≈10,500 kg/ha) improved vine balance and phenolic composition, although the responses were strongly modulated by interannual variability.

Climate change is advancing ripening and can impair phenolic maturity in grapes, compromising anthocyanins and stilbenes that affect the wine color and stability. We tested whether exogenous abscisic acid (ABA) mitigates warming-induced shifts in the phenylpropanoid pathway in the ’Malbec’ red wine grape variety. A factorial field experiment compared control temperature (−T) and elevated temperature (+T, +2.5 °C), with and without ABA sprays (three applications after veraison). Berry skin gene expression (ten flavonoid and stilbene genes) was monitored across ripening and summarized using time-course and AUC-based clustering. Anthocyanins were quantified in berry skins at harvest and in the corresponding wines, and stilbenes were quantified in wines. Warming reduced MYBA1 early in ripening and decreased anthocyanins and stilbenes overall. Meanwhile, ABA reinforced a late anthocyanin program under −T (MYBA1, UFGT, MYBC2-L3, F3′5′H), consistent with a shift toward the 3′,5′-hydroxylated/malvidin-type branch. Conversely, stilbenes remained suppressed under +T, with limited recovery under +T/+ABA. Time-integrated expression patterns and Spearman correlations consistently linked CHS2, F3′5′H, UFGT, MYBC2-L3, with variation in berry skin anthocyanins across treatments, while STS AUC tracked wine stilbenes. Overall, ABA partially buffered warming effects on ‘Malbec’ color by reinforcing late anthocyanin regulation but did not prevent warming-driven declines in wine stilbenes.

Malbec, Argentina's emblematic wine, is appreciated worldwide for its unique characteristics and distinctive organoleptic profile. As demand for Malbec wines increases locally in Argentina and international markets, there is a need to better understand the relationship between the price of these wines and their chemical and sensory characteristics. The aim of this study was to describe and quantify the sensory attributes and chemical parameters (in particular, phenolics) of Argentinean Malbec wines of different price segments. In order to observe the differences between each price range, the eight best-selling wines from the low, medium, and high price categories were analysed. Wine general analytical parameters and phenolics composition were determined and a descriptive analysis was performed with a trained panel. The results show that it was only possible to differentiate between the high- and low-price ranges. Both ranges exhibited variability, including different types of wines. Significant differences were identified in several parameters, such as O.D.280, titratable acidity, malic acid, volatile acidity, alcohol, glucose and total sugars. There were also significant differences in anthocyanins, LPP, SPP, TPP and tannins. The high-price range was characterised by higher alcohol content, greater polyphenol concentration and greater colour intensity. Sensorially, they were distinguished by the descriptors wood, astringency and colour. The low-price range was associated with low colour intensity and higher total sugar content. This is the first study to clearly establish the sensory differences among different price ranges of Argentine wines. Our study demonstrated that wine pricing is not determined in a subjective or arbitrary manner; rather, wines produced for a specific segment are intentionally designed to achieve the desired sensory and chemical characteristics.

The growing demand in recent years for sustainable wine production has led to the management of waste and by-products. Among them, vine-shoots could be used as additives comparable to the oak fragments widely employed in enology. This work analyzes the feasibility of applying vine-shoot chips during winemaking and the aging of Malbec and Bonarda wines from Mendoza (Argentina) and evaluates their chemical and sensory impact. Toasted (CHT) and untoasted (CHWT) vine-shoot chips obtained from a Bonarda vineyard were added in Malbec and Bonarda grapes during winemaking (Experiment A): C, control; CHWT, 12 g/L; CHT, 12 g/L. Furthermore, the same treatments were applied during aging (1M, 30 days; 2M, 60 days; 4M, 120 days) to the finished wines under controlled conditions (Experiment B). The impact of vine-shoot chips during winemaking was different between varieties. For Malbec alone, CHT caused a significant decrease in tannins, anthocyanins, and polymeric pigments, and a modification of wine color. During aging, CHWT and CHT had an impact mainly at the sensory level, increasing the wine’s complexity in terms of aromatic attributes and mouthfeel. In conclusion, the proposed technology could be a simple and economical tool for red wine production of high chemical and organoleptic quality.

The climatic conditions in some wine regions imply in many cases the important delay in the harvest date to achieve an appropriate phenolic maturity in red grape varieties, leading to wines with high pH and alcohol content. This problem, associated with low acceptation for some consumers and chemical/microbial instability, can be addressed from a viticultural, oenological, or microbiological level. The present study aimed to provide a technological alternative, combining vintages blending and inoculation of native yeasts, for reducing simultaneously the alcohol content and the pH of Malbec wines without altering the chemical and sensory quality. Sauvignon blanc grapes harvested at the beginning of ripening (2017 season) were employed to obtain a wine with high acidity and low alcohol content (LW), that was blending with Malbec grapes of full phenolic maturity. Malbec grapes were harvested at two different moments (1H, 13.0 % v/v; 2H, 14.5 % v/v, probable alcohol), and elaborated following a standard protocol. From 2H, a part of the grape juice was removed and replaced with LW as a strategy for alcohol reduction (2RW). Consequently, it was obtained nine wines by triplicate combining 1H, 2H, 2RW musts with three fermentative strategies: CI, co-inoculation of Hanseniaspora uvarum BHu9/Saccharomyces cerevisiae BSc114 native yeasts; NS, S. cerevisiae BSc114 native yeast; and CS, S. cerevisiae EC 1118 commercial yeast. We found that 2RW wines, fermented with different yeast strains, showed similar levels of total phenols, tannins, anthocyanins, and polymeric pigments concerning control wines (2H). In all cases, those wines presented greater phenolic potential compared to wines from 1H. At the same time, the pre-fermentative strategy of vintages blending produced wines with 1.4 % v/v less alcohol than 2H wines, also achieving a pH decrease of 0.3 units. Combined treatments with native strains, especially as single inoculum (2RW–NS), were the most efficient in reducing both parameters, showed higher tannins, anthocyanins levels, and colour saturation, without affecting the sensory quality, in terms of aromas and mouthfeel. In conclusion, the strategies proposed could be simple and economic tools, for red wines production with low alcohol content, and high chemical and organoleptic quality, capable of competing and satisfying market needs.