Methyl jasmonate versus nano methyl jasmonate: effects on anthocyanins mature evolution in monastrell grapes

The French viticultural appellation areas are the result of an empirical, historical and evolutionary selection which, generally, has consecrated a match between natural factors, grape varieties and viti-vinicultural practices. The notion of terroir is the main basis of the Appellation d’Origine Contrôlée in viticulture. It is based on the one hand on privileged natural factors and on the other hand on the know-how of the winegrowers; the whole allowing the production of a wine endowed with an authenticity and a sensory typicity. Wine-growing practices evolve according to progress in viticulture and oenology, while the natural factors of the terroir are much more stable, with the exception of the vintage. They therefore represent a fundamental pillar of the identity of an appellation vineyard.

Decrease of chemical inputs during vine management and winemaking is of great importance from a political and societal point of view. In our ongoing project we propose alternative tools to chemicals in the vineyard and the cellar. We have compared a conventional vineyard protection strategy to an alternative strategy using copper and biocontrol products (Biocontrol) against downy

The disruptive effect exerted by high-power ultrasound (US) on plant cell walls, natural barriers to the diffusion of compounds of interest during the maceration of red wines, is established as the reason behind the chromatic improvement that its treatment causes. However, sometimes this improvement is not observed, especially with short maceration times. The presence of a high quantity of suspended cell wall material, which formation is favored by the sonication, could be the cause of this lack of positive results since this cell wall material has a high affinity for phenolic compounds.

Expression of sensory attributes that reflect the varietal and geographical origin of wines (aka terroir) is central to perceived wine quality and reputation of wine producing regions.

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to compare the effects of three strategies of water and minerals supply on grapes and wines qualities. Two fertigation practices were compared to a rainfed control which is the current standard of the local grape growing production. The fertilizers (nitrogen and potassium) were (i) fully brought by irrigation pipe during the season, (ii) partially brought by irrigation pipe and partially on the soil or (iii) fully brought on the soil at the beginning of the season for the non-irrigated control (local standard). The trial was run on cv. Colombard trained on spur pruned with vertical shoot positioning system on a sandy-silty-clay soil over the 2020 vintage which was particularly hot for the region. Moderate to strong water deficit appeared during the growing period of the berries and held on after veraison. Irrigation strategies allowed for maintaining grapevine without water deficit and being significantly different from the control water status. Grapevine with fully or partial fertigation strategies produced 25% more yield mainly due to the increase of the bunch weight. Also, the fully fertigation showed the best ratio between yield and maturity and brought 30% less of fertilizers (both nitrogen and potassium) than the two other strategies. Finally, the analysis of aromatic compounds in Colombard wines, varietal thiols family, showed the same level of concentrations for the 3 treatments, confirming that the yield performance did not impact the aromatic potential in this trial.