Postveraison shoot trimming in Tannat and Merlot: preliminary results on yield components, plant balance and berry composition

The aim of this work was to analyze the variability in grape composition of the Tempranillo cultivar related to climatic conditions, in La Mancha Designation of Origin. Grape composition (sugar content, total acidity, pH, malic acid, and total and extractable anthocyanins) recorded during ripening, were analysed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The relationships between grape parameters with climatic variables related to temperature and to water deficits, referring different periods between phenological events along the growing cycle, were evaluated using regression analysis. High variability in grape composition was observed in the period analysed. Total acidity varied between 3.7 and 7.3 gL-1 while malic acid varied between 1.2 and 4 gL-1. The extractable anthocyanins ranged between 526 and 972 mgL-1, and total anthocyanins ranged between 922 and 1388 mgL-1, being the lowest values recorded in the hottest year (2017). Total acidity decreased 0.77 gL-1 for an increase of 100 GDD, while malic acid decrease in 0.42 gL-1 for the same GDD increase, being the period between veraison and harvest the one that seemed to have higher influence on acidity. In addition, it was confirmed that increasing water deficits decreased acidity. Total and extractable anthocyanins increased in about 210 and 105 mgL-1, respectively, with an increase of 100 GDD from veraison to harvest, and the increase in water deficits favour the increase of anthocyanins, both total and extractable anthocyanins. Total and extractable anthocyanins concentration increased in 35 and 22 mgL-1 per an increase of 10 mm in the water deficit. These results can be of interest to understand the potential changes that grapes composition may suffer under future warmer climates.

AIM: To investigate chemical and sensory drivers of regional typicity of Cabernet Sauvignon from different geographical regions of Australia.

In recent years, the consumption of fine wines in Brazil has increased significantly, a phenomenon that is also reflected in the expansion of production to new regions. In the brazilian southeast for example, the so-called “winter wines” are being produced, through management in two cycles, one of formation and one of production, with two prunings and one harvest per year, a technique known as double pruning, with vineyards established at altitudes close to or above 1,000 m above sea level.

Color is one of the key elements for the marketing of rosé wines due to their packaging in transparent bottles. Their broad color range is due to the presence of pigments belonging to phenolic compounds extracted from grapes or formed during the wine-making process. However, the mechanisms responsible for such diversity are poorly understood. The few investigations performed on rosé wines showed that their phenolic composition is highly variable, close to that of red wines for the darkest rosés but very different for light ones [1]. Moreover, large variations in the extent of color loss taking place during fermentation have been reported but the mechanisms involved and causes of such variability are unknown.

The Grapevine Red Blotch Virus (GRBV) poses a critical challenge to the wine sector, lacking a uniquely identified vector. Current control methods involve costly and labor-intensive vine removal, emphasizing the urgency for targeted alternatives. The limited understanding of intricate host-virus interactions underscores the need for foundational knowledge to develop innovative disease control strategies. These include efforts to boost the plant’s RNA interference (RNAi) response, including RNA-based topical applications.