Monitoring vineyard canopy structure by aerial and ground-based RGB and multispectral imagery analysis

Natural factors of the production (“terroir” and vintage) are known as an important element for identifying wines by their genuine typicité and their authenticity. The program “Terroirs d’Anjou” (1994-1999) aims at bringing the necessary scientific basis for a rational and reasoned exploitation of the terroir.

Nous savons tous très bien qu’on a assisté au cours de ces dix dernières années à une éclosion soudaine de recherches sur le zonage viti-vinicole qui, à partir par exemple du modèle du concept de “terroir”, se sont de plus en plus enrichies en passant aux “Unités ou Systèmes de Transformation” (UTTE) et “Valorisation” (UTCE) pour terminer avec les “Systèmes productifs globaux du Territoire” (UTB) comprenant en filière les aspects existentiels (UTBES), sociaux (UTBSO) et économiques (UTBEC) hypothisés dans le “GRANDE ZONAZIONE: Grand zonage” (MORLAT R., 1996, CARBONNEAU A., 1996, TOUZARD J.M. 1998, CARBONNEAU A., CARGNELLO G., 1996, 1998, CARGNELLO G., 1994, 1995, 1996, 1998, 1999, 2001, -MILOTIC A., CARGNELLO G., PERSURIC G., 1999, PERSURIC G., STAYER M., CARGNELLO G., 2000, MILOTIC A., OPLANIC M., CARGNELLO G., PERSURIC G., 2000).

Varietal thiols 3-sulfanylhexan-1-ol (3SH), 3-sulfanylhexyl acetate (3SHA) and 4-methyl-4-sulfanylpentan-2-one (4SMP) are essential for fruity aromas of Sauvignon Blanc wines. The concentration of varietal thiols in wines was thought to be related to the concentration of their precursors in grapes, however only a small proportion of precursors are released to varietal thiols during fermentation. New findings suggested that specific grape juice metabolites could significantly impact on the development of three major varietal thiols and other aroma compounds of Sauvignon Blanc wines.

Global warming has enhanced the frequency and severity of drought events, hence calling for a better management of water resources in the vineyard and for an improvement of breeding platforms. Somatic embryogenesis (SE) (i.e. the initiation of embryos from somatic tissues) can spontaneously generate new genetic variability, which results from genetic mutations, changes in epigenetic marks, or phenotypic alterations.
This study was tailored to test whether vines in vitro regenerated through SE (i.e. somaclones), can tolerate water deprivation better than the mother plant.

Vegetative growth and yield are reported to affect grape and wine quality. They can be controlled through different techniques linked to vine management. The objective of this research was to determine the effect of vine vigour and number of clusters per vine on physicochemical composition and phenolic profile of red wines. The experiment was carried out during two vegetative cycles, with cv. Cabernet Sauvignon grafted onto Paulsen 1103. Three vine vigour were defined, according to shoot weight at previous harvests, being low, medium and high. Five treatments of number of clusters were used for each vigour, with 15, 22, 29, 36, and 45 clusters per vine. Grapes from all treatments were harvested in the same day from Brix and total acidity criteria. Thirty days after bottling, classical analyzes and phenolic compounds were performed. As results, different responses were obtained from each vintage. In 2020, a dry season from veraison to harvest, grapes and wines obtained from low vigour treatment and 45 clusters per vine was the highest in sugar and alcohol content respectively, while grapes and wines from high vigour and 15 clusters presented the lowest sugar and alcohol content. Total anthocyanins were higher in treatment with low vigour and 15 clusters, while the lowest amounts were found in low vigour with 45 clusters, as well as medium and high vigour with 36 clusters per vine. Total tannins were higher in high vigour with 22 clusters and medium vigour with 29 clusters, while were lower in low vigour with 36 clusters. In 2021, a wet season at harvest, responses were different, and great variations were observed between treatments. As conclusions, yield and vine vigour had strong influence on grape and wine quality, promoting different enological potentials on which can be indicated/used for aging strategies of red and even rosé wines.