Potentiel des sols viticoles et qualité des vins

Botrytis cinerea is one of the most widespread host-specific fungal pathogens, causing significant yield losses and economic damage to vineyards every year.

In April 2024, the French official catalog includes 449 grape varieties and rootstocks. In 10 years it has been enriched with 70 varieties. It is an indisputable marker of the interest of professionals in genetic resources of all origins and the expectations they have to prepare the viticulture of the future. The scientific community has now put all irons in the fire and is not neglecting any avenue of adaptation. The regular decline in the use of phytosanitary products and the already marked effects of climate change are the targets of varietal improvement.

The dynamic changes of non-structural carbohydrates (NSC) in grapevines during the growing season is driven by phenological events and environmental factors.

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.

In this work, an innovative analytical method has been proposed for fast and reliable in-line analysis of tannins in wines; the method is fast, does not require sample preparation and is based on the selective reactivity of tannins in a mixture containing proteinaceous matter (i.e. gelatin), under pH 3.5, resulting in the formation of white cloudiness.