Variabilité spatiale du gel printanier dans le vignoble champenois : application au zonage climatique

Industry and regulatory agencies have developed regulations to ensure authenticity and compliance with wine composition limits. However, this can be truncated by the absence of simple and robust analytical methodologies, uninfluenced by the environment, different oenological techniques and cultural practices. Genetic fingerprinting is the most powerful tool for unequivocal varietal identification; it is not affected by the environment or agronomic practices; however, its usefulness in musts and wines has been controversial and there is currently no routine certification of varietal origin based on DNA analysis.

Today in the wine industry, a lot of alternatives are available for reducing phytosanitary inputs. Among these, prophylaxis, the use of biocontrol products and the deployment of pathogen-resistant vines are the most promising. eugenol (2-methoxy-4-(2-propenyl)-phenol), a molecule with recognised antifungal properties, can contribute to the last two alternatives. This molecule has been identified as an endogenous compound in the baco blanc hybrid variety used in armagnac pdo, which is at least tolerant to botrytis cinerea.

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin and epicatechin are slowly exchanged in D2O to the corresponding deuterated analogues; even quercetin, a relevant flavonol representative, shows the same behaviour in a D2O/DMSOd6 1:1 solution. Detailed kinetic measurements of these H/D scrambling processes are here reported by exploiting the time-dependent changes of their peak areas in the 1H-NMR spectra taken at different temperatures. A unifying reaction mechanism is also proposed based on our detailed kinetic observations, even taking into account pH and solvent effects. Molecular modelling and QM calculations were also carried out to shed more light on several molecular details of the proposed mechanism.

Vine water status is a crucial determinant of vine growth, productivity, fruit composition and terroir or wine style; therefore, regulating water stress is of great importance. Since vine water status depends on both soil moisture and aerial environment and is very temporally dynamic, direct measurement of vine water potential is highly preferable. Current methods only provide limited data. To regulate vine water status it is critical to monitor vine water status to be able to: (1) measure vine water status to predict the effect of water stress on the overall vineyard performance and fruit quality and optimize harvest management and wine-making (2) properly regulate the water status to impose for a desired fruit quality or style (3) determine if water management has reached the desired stress level.

The first white settlers arrived in Australia in 1788 and brought grape vine cuttings with them. As migration to Australia continued to grow during the XIX Century more and more vine cuttings, viticulturists and winemakers from Britain, France, Germany, ltaly, Switzerland and Yugoslavia founded their businesses.