Organic mulches improve vine vigour, yield and physiological response in a semi-arid region

Recently, the European Commission seems to have inaugurated a new mechanism for regulating the wine sector. Through two communications, articulated in the form of “Questions & Answers”, concerning the new rules for labeling (24.11.2023) and dealcoholization of wine (15.01.2024), the Commission is not simply “explaining” the new rules but, in an approach close to the theory of “Circulaire Normative” established in comparative law, chooses among different interpretations and even adds Praeter Legem constraints.

Un vasto programma si riferisce alla verifica di 28 selezioni clonali di Pinot nero atte a vini base spumante. Gli impianti sono stati realizzati in diversi ambienti delle Langhe e del Monferrato nel periodo 1992-1996, in 57 vigneti diversi e su una superficie complessiva di circa 50 Ha.

Saccharomyces cerevisiae is responsible for alcoholic fermentation (AF) and is widely distributed as active dry yeast (ADY).

Using grapevine genetic diversity is one of the strategies to adapt viticulture to climate change. In this sense, assessing the plasticity of cultivars in their responses to environmental conditions is essential. For this purpose, the drought tolerance of Grenache, Tempranillo and Semillon cultivars grafted onto SO4 was evaluated at two experimental vineyards, one located in Valencia (Spain) and the other in Bordeaux (France). This was done by assessing gas exchange parameters, water relations and leaf hydraulic traits at the end of the season.

In recent decades, the scarcity of water resources in agriculture in certain areas has been aggravated by climate change, which has caused an increase in temperatures, changes in rainfall patterns, as well as an increase in the frequency of extreme phenomena such as droughts and heat waves. Although the vine is considered a drought-tolerant specie, it has to satisfy important water requirements to complete its cycle, which coincides with the hottest and driest months. Achieving sustainable viticulture in this scenario requires high levels of efficiency in the use of water, a scarce resource whose use is expected to be severely restricted in the near future. In this regard, the use of drought-tolerant varieties that are able to maintain grape yield and quality could be an effective strategy to face this change. During three consecutive seasons (2018-2020) the behavior in rainfed regime of 13 traditional red grapevine varieties of the Spain central region was studied. These varieties were cultivated in a collection at Centro de Investigación de la Vid y el Vino de Castilla-La Mancha (IVICAM-IRIAF) located in Tomelloso (Castilla-La Mancha, Spain). Yield components (yield, mean bunch and berry weight, pruning weight), physicochemical parameters of the musts (brix degree, total acidity, pH) and some physiological parameters related with water stress during ripening period (δ13C, δ18O) were analysed. The application of different statistical techniques to the results showed the existence of significant differences between varieties in their response to stressful conditions. A few varieties highlighted for their high ability to adapt to drought, being able to maintain high yields due to their efficiency in the use of water. In addition, it was possible quantify to what extent climate can be a determinant in the δ18O of musts under severe water stress conditions.