Development of a semi-controlled setup for manipulating drought and heat stress in open field trials

Grapevine downy mildew, caused by the oomycete Plasmopara viticola, is responsible for significant economic losses each year and for a large proportion of the fungicides used in viticulture.

After Champagne popping, the first consumer’s observation is the shape of the cork stopper. Consumers expect a “mushroom shape”. Nevertheless, we sometimes observe a “barrel” shape due to inappropriate cork’s elastic properties. The aim of this study was to follow the loss of cork stopper resiliency during 26 months according to the density (d) of the cork in contact with the wine. 1680 disks were weighed + measured and divided in 6 density classes: High (H1 d= 0,19 g/cm3 – H2 d= 0,21 g/cm3), Medium (M, not studied) and Low (L1 d= 0,13 g/cm3 – L2 d= 0,14 g/cm3). Then, 138 technical cork stoppers were produced for each of the 4 studied groups. These corks consisted of an agglomerated natural cork granule body to which two natural cork disks were glued. A total of 552 bottles of sparkling wine were closed with these corks and open after 13, 19 and 26 months to follow cork resiliencies. Wine bottles were stored horizontally; thus, the external natural cork disks were in contact to the wine. During the 26 months of the study, highly significant differences (ANOVA) were observed between the resiliencies of H-corks and those of L-corks, whatever the time studied. The diameters of the L-corks were statistically higher than those of the H-corks. No significant differences were observed between L1 and L2 corks. At the opposite, differences were noted between H1 and H2 at 19 and 26 months. This could be explained by the heterogeneity of the resiliency that was higher for H-corks than for L-corks. Finally, the corks were visually (12 judges) divided in 3 classes corresponding to high (expected mushroom shape, i.e high resiliency), medium (irregular shape of the disk in contact with the wine and/or low premature deterioration of the expected resiliency) and low qualities (barrel shape = premature deterioration of the resiliency). The corks were also divided in 3 categories corresponding to 0-33%, 34-66% and 67-100% resiliency. A strong correlation was noted between the visual and the instrumental categorizations. This study strongly evidenced 1) the importance of the cork density on the cork stopper behaviour when opening the bottle and 2) the interest of an instrumental approach reflecting the consumer’s perception.

Massif and the first sedimentary formations of the western aureole of the Paris Basin. If it is found all over the world (California, Israel, South Africa), it is in this region that it best asserts its identity. It is one of the most interesting grape varieties due to the variety and complexity of the wines it can produce. It can give very dry or very sweet, still or sparkling wines, fresh when young and sublime when ageing, expressing the characteristics of each vintage as much as those of the terroir. The Chenin is a faithful witness of its geographical, geological, pedological and climatic environment; he is the foil of the land. It has strong aptitudes for the production of sweet wines conditioned by overripe grapes often botrytised in the AOC Coteaux du Layon.Massif and the first sedimentary formations of the western aureole of the Paris Basin. If it is found all over the world (California, Israel, South Africa), it is in this region that it best asserts its identity. It is one of the most interesting grape varieties due to the variety and complexity of the wines it can produce. It can give very dry or very sweet, still or sparkling wines, fresh when young and sublime when ageing, expressing the characteristics of each vintage as much as those of the terroir. The Chenin is a faithful witness of its geographical, geological, pedological and climatic environment; he is the foil of the land. It has strong aptitudes for the production of sweet wines conditioned by overripe grapes often botrytised in the AOC Coteaux du Layon.

Grapevine interspecific hybrids (PIWIs, from German “pilzwiderstandsfähige Rebsorten” meaning fungus tolerant grapevine cultivars), offer a promising alternative to traditional cultivars in many wine regions due to their tolerance to certain fungal diseases. This makes them a potential solution for sustainable wine production, particularly under organic systems. Despite extensive research on certain agronomic traits and susceptibility to biotic diseases, such as powdery and downy mildews, the response of these cultivars to abiotic stressors, such as drought, remains unclear. Our study aims to investigate the eco-physiological traits of two commercial PIWI cultivars, Muscaris and Souvignier gris, at the leaf level to evaluate their response to drought stress.

Volatile Organic Compounds (VOCs) are responsible for the flavor and aroma of a wine. The sensory qualities of the wines depend not only on grape intrinsic characteristics, but also on extrinsic factors including the soil composition. Previous studies have shown that the application of pyrogenic carbon (biochar) can lead to a change in soil parameters. For that reason, one of the goals of the ERDF funded project «WoodUp» is the characterization and reutilization of the locally produced biochar for agricultural purposes.