Bilan hydrique: une méthode proposée pour l’évaluation des réserves hydriques dans le zonage viticole

Aims: Microscopic bud dissection is a common tool used to assess grapevine bud fertility and therefore to predict the yield of the following season

The use of the term bioprotection in winemaking refers to the use of non-chemical methods to prevent the development of undesirable microorganisms (yeasts and/or bacteria). The reason for studying this method is mainly as a natural alternative to the addition of sulfites during the pre-fermentation stages. In winemaking, the addition of s02 has multiple functions, the main ones being antiseptic and antioxidant power.

Understanding the catabolism of thiol precursors is essential for understanding the revelation of varietal thiols in wine. For many years, knowledge of these precursors has been limited to the S-conjugates of glutathione, cysteine (Cys3SH) and the dipeptides g-GluCys and CysGly, without being able to explain the full origin of 3-sulfanylhexan-1-ol (3SH) in wines

Climate change effects in Languedoc include an expected rise in temperatures, increased evapotranspiration as well as more severe and frequent climatic hazards, such as frost, drought periods and heat waves. For winegrowers theses phenomena impact both yield and quality, resulting in more frequent unbalanced wines. Research on identified mitigation tools for vineyard management is necessary to improve resilience of grapevine agrosystems. Varietal assortment is one of them. This study focuses on agronomic and oenologic potential of 14 foreign varieties grown in Languedoc French region. Fourteen grapevine varieties were monitored during 2021 from June until harvest on eight different sites, some of which occurring on more than one site adding up to 21 different modalities: 7 white varieties Alvarinho B, Assyrtiko B (2), Malvasia Istriana B, Parellada B, Verdejo B, Verdelho B, Xarello B, and 7 black varieties Saperavi N (2), Touriga nacional N, Baga N, Aleatico N, Montepulciano N (2), Primitivo N (3), Calabrese N (3). Varietals were compared through the following parameters: phenology was assessed by using the information collected in the Database Network of French Vine Conservatories (INRAE-SupAgro-IFV, 2005-2015). The number of inflorescences for shoots from secondary buds and bourillons and suckers were observed to assess post-bud break frost tolerance potential. Grapevine water status was studied through stem water potential measurement, observation of foliage symptoms of drought, and 𝛿13C on must. Frequencies and intensities of downy mildew, powdery mildew, and black rot attacks were estimated before harvest on leaves and clusters and botrytis at harvest to assess disease susceptibilities. Berry composition was monitored from end of veraison until harvest. Yield and mean bunch weight were also calculated. Varieties were then ranked on a 1-4 scale for each parameter and compared through PCA. Forty two stations of the Mediterranean basin were compared by PCA with the Multicriteria Climatic Classification indicators in order to confront the collected information during 2021 campaign to the hypothesis that plants coming from dry and hot regions are genetically adapted to such climatic conditions.

Context and purpose of the study. Italy hosts diverse grapevine varieties crucial for viticultural biodiversity. Preserving this biodiversity is essential for maintaining a diversified genetic pool and addressing future challenges such as climate change and emerging plant diseases.