Exploring diversity of grapevine responses to Flavescence dorée infection

Climate has a predominant role on growth and development of grapevines. Therefore, climate change represents an important challenge to the winemaking sector.

The characterization of « the soil effect » in vine growing is often limited to the description of the physical components of the terroir. Many works were done in this direction and corresponded to geological, pedological or agronomical approaches. However, if the physical environment influences the vine and its grapes, its effect becomes limited at the scale of exploitation. Thus, it could be important to consider how the viticulturist « translated » the potential.

Marselan (Cabernet-Sauvignon x Grenache), has been planted for more than 20 years now in Uruguay. Due to its good agronomic and oenological aptitudes under uruguayan conditions, it is currently the red variety with highest plantation rate. The objective of the study was to identify management practices, aimed at improving quality in highly productive vineyards, different fruit/leaf regulation methods were tested in southern Uruguay.

he main goal of this research was to identify key aroma compounds linked with the maturity of grapes (ripe and overripe) and involved in grapes and wines with an intense dried fruits aroma. Odoriferous zones reminiscent of these aromas were detected by gas chromatography coupled with olfactometry (GC-O).

Champagne or sparkling wines elaborated through the same traditional method, which consists in two major yeast-fermented steps, typically hold about 10 to 12 g/L of dissolved CO2 after the second fermentation in a closed bottle. Hundreds of molecules and macromolecules originating from grape and yeast cohabit with dissolved CO2; they are essential compounds contributing to many organoleptic characteristics (effervescence, foam, aroma, taste, colour…). Indeed, the second alcoholic fermentation and the maturation on lees (which may last from 12 months up to several years) both induce various quantitative and qualitative changes in the wine through the action of yeast, as listed hereafter: development of aromas during aging on lees, release of nitrogen compounds during autolysis and release of macromolecules (polysaccharides, lipids, nucleic acids) in wine.