Il monitoraggio meteorologico come strumento per la gestione della variabilità climatica in Franciacorta

A worrying drop in the acidity of wines has been observed in many wine regions, such as Bordeaux (Merlot), Burgundy (Pinot Noir), Côtes-du-Rhône (Grenache) or Rioja (Tempranillo). This lack of acidity is particularly marked in the Midi-Pyrenean vineyards of the Côtes du Frontonnais (Tournier, 1993). However, the acidity of a wine is one of the main factors of its quality, in fact, a low acidity combined with an insufficient tannic structure leads to rapid oxidation of wines and makes them age prematurely.

Late spring frost is a major challenge for various winegrowing regions across the world, its occurrence often leading to important yield losses and/or plant failure. Despite a significant increase in minimum temperatures worldwide, the spatial and temporal evolution of spring frost risk under a warmer climate remains largely uncertain. Recent projections of spring frost risk for viticulture in Europe throughout the 21st century show that its evolution strongly depends on the model approach used to simulate budburst. Furthermore, the frost damage modelling methods used in these projections are usually not assessed through comparison to field observations and/or frost damage reports.
The present study aims at comparing frost risk projections simulated using six spring frost models based on two approaches: a) models considering a fixed damage threshold after the predicted budburst date (e.g BRIN, Smoothed-Utah, Growing Degree Days, Fenovitis) and b) models considering a dynamic frost sensitivity threshold based on the predicted grapevine winter/spring dehardening process (e.g. Ferguson model). The capability of each model to simulate an actual frost event for the Vitis vinifera cv. Chadonnay B was previously assessed by comparing simulated cold thermal stress to reports of events with frost damage in Chablis, the northernmost winegrowing region of Burgundy. Models exhibited scores of κ > 0.65 when reproducing the frost/non-frost damage years and an accuracy ranging from 0.82 to 0.90.
Spring frost risk projections throughout the 21st century were performed for all winegrowing subregions of Bourgogne-Franche-Comté under two CMIP5 concentration pathways (4.5 and 8.5) using statistically downscaled 8×8 km daily air temperature and humidity of 13 climate models. Contrasting results with region-specific spring frost risk trends were observed. Three out of five models show a decrease in the frequency of frost years across the whole study area while the other two show an increase that is more or less pronounced depending on winegrowing subregion. Our findings indicate that the lack of accuracy in grapevine budburst and dehardening models makes climate projections of spring frost risk highly uncertain for grapevine cultivation regions.

Un grand nombre de travaux ont été consacrés à la mise en éyidence et à la quantification de l’effet du climat sur la qualité de la production viticole. IIs ont permis de caractériser les grands types de production à une large échelle géographique, et d’en évaluer les variations interannuelles au niveau des millésimes.

Agri-photovoltaics (apv) describes the dual use of an agricultural area for food production and solar power generation. There are already a number of systems in operation around the world with various crops and under a wide range of different set-ups. In large parts, they still allow mechanical cultivation and other positive side effects of an APV system were observed in addition to the increase in utilization in the form of electricity and food: effects on the water balance and passive protection against extreme weather events.

Ovalbumin (ova), a natural clarifying protein, is particularly suitable for clarifying red wines. It helps improve the tannic and polyphenolic stability of the wine by removing the most astringent tannins and contributing to soften and refine the structure. Ova binds to suspended particles, proteins, polysaccharides, and, to a lesser extent, tannins through electrostatic and hydrophobic interactions, forming large complexes that can be removed from the wine through fining and/or filtration before bottling.