HOW DO ROOTSTOCKS AFFECT CABERNET SAUVIGNON AROMATIC EXPRESSION?

Abstract

Grape quality potential for wine production is strongly influenced by environmental parameters such as climate and agronomic factors such as rootstock. Several studies underline the effect of rootstock on vegetative growth of the scions [1] and on berry composition [2, 3] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Little is known about the effect of rootstock genetic variability on the aromatic composition in wines; thus further investigations are needed.
The purpose of this communication is to highlight how rootstock influences Cabernet Sauvignon red wine aromatic expression.
This study was conducted in 2021 in the GreffAdapt plot (55 rootstocks × 5 scions × 3 blocks) focusing on Vitis vinifera cv. Cabernet Sauvignon and on 20 rootstocks [4]. Grape samples were collected and fermented in triplicate at laboratory scale under standardized conditions; wines were stabilized and stored at the end of alcoholic fermentation.
Sensory analyses were performed to evaluate rootstock impact on aromatic expression. Conventional sensory profiles were carried out following the methodology used by Pelonnier-Magimel et al. (2020) [5], divided into three main steps: descriptor generation, specific training on the generated vocabulary and final evaluation. A panel with similar wine knowledge and previous sensory training was selected for this purpose.
During the first step of sensory evaluation, the tasters generated a defined number of descriptors on a wine selection and following this session 11 terms were chosen based on with panel agreement.
A specific session was carried out before the start of the training in order to validate the general consensus for the proposed references (or descriptors). A control sensory profile was organized after several weeks of training to verify the consensus of the panel.
Sensory analysis data did not allow to highlight a difference in Cabernet Sauvignon red wine aromatic expression for this specific vintage, characterized by excessive rainfall and mean temperatures below the seasonal average. In conclusion, the exploration of other sensory approaches would be interesting to complete this work, as well as a complementary study of other vintages characterized by contrasting climatic conditions compared to 2021.