Balearic varieties of grapevine: study of genetic variability in the response to water stress

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.

Variegation, a frequently observed trait in plants, is characterized by the occurrence of white or discoloured plant tissue. This phenomenon is attributed to genetic mosaicism or chimerism, potentially impacting the epidermal (L1) and subepidermal (L2) cell layers. In grapevine, variegation manifests as white or paler leaf, flower, or berry tissues, often leading to stunted growth and impeded development. Despite its prevalence, variegation in grapevines remains understudied.

Vigor declines in older vineyards and poor vine establishment in replant situations have been attributed to plant-parasitic nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent plant-parasitic nematode species found in Washington wine grape vineyards. Management for nematodes in established vineyards is limited to the application of post-plant nematicides. We are evaluating new nematicides that are currently not registered in grape for their efficacy in controlling M. hapla and a part of that evaluation includes improving the alignment of nematicide application timing with the vulnerable second-stage juvenile (J2) life stage of M. hapla.

In 2010, the OIV adopted a resolution that defines ‘terroir’. The OIV definition understands terroir as the result of the interactions between the physical specificities of a space and human labor, with an emphasis on the subsequently produced collective knowledge (OIV-VITI 333-2010); by doing so, it alludes to the social and cultural dimensions of terroir.

This study explored the responses of Chardonnay and Sauvignon blanc grapevine cultivars to water deficit across four years, uncovering their shared patterns and distinctive coping mechanisms. The research was conducted in a commercial vineyard located in Isla de Maipo, Chile. Various characterization approaches were employed including plant water potentials (), gas exchange measurements, shoot vulnerability curves, productivity assessments, and leaf cell water relations. Linear mixed models and sensitivity analyses were performed using various statistical methods to evaluate cultivar responses to water deficit. As the water deficit progressed, both cultivars displayed a parallel reduction in stomatal conductance, leaf turgor, and increased shoot embolism.