Terroir 1996 banner
IVES 9 IVES Conference Series 9 Influence de la nutrition potassique sur le manque d’acidité des vins issus du cépage Negrette

Influence de la nutrition potassique sur le manque d’acidité des vins issus du cépage Negrette

Abstract

Une baisse préoccupante de l’acidité des vins est observée dans beaucoup de régions viticoles, comme le Bordelais (Merlot), la Bourgogne (Pinot Noir), les Côtes-du-Rhône (Grenache) ou la Rioja (Tempranillo). Ce manque d’acidité est particulièrement marqué dans le vignoble Midi-Pyrénéen des Côtes du Frontonnais (Tournier, 1993). Or, l’acidité d’un vin est un des principaux facteurs de sa qualité, en effet, une faible acidité combinée à une structure tannique insuffisante entraîne une oxydation rapide des vins et les fait vieillir prématurément. De multiples travaux font état de la liaison étroite entre la faible acidité d’un moût ou d’un vin grande richesse en potassium (Boulton, 1980 ; Delas et al., 1989 ; Falcetti et al., 1993 ; Champagnol, 1988; Soyer et Molot, 1993).

D’autre part, la teneur en potassium des moûts est corrélée à celle des feuilles (Mattick, 1972 ; Champagnol, 1990) et une corrélation a été mise en évidence entre cette dernière et la fertilisation potassique (Morris et al., 1983 ; Champagnol, 1988, 1990 ; Soyer et Molot, 1993 ; Jourdan, 1993). Cependant, ces liaisons sont discutées par d’autres auteurs comme Dundon et al. (1984), Conradie et Saayman (1989) ou Matthews et al. (1993).
Pour contribuer à résoudre ce problème, nous avons choisi comme matériel d’étude la Négrette, cépage principal des Côtes du Frontonnais et cépage donnant des vins particulièrement peu acides.

Une double expérimentation a été mise en place. La première a été effectuée en culture hors-sol, sous serre. Elle a pour but de déterminer, grâce à l’application de solutions nutritives ayant des équilibres potassium-calcium différents, les relations existant entre les teneurs en potassium du milieu nutritif et celles des feuilles et des moûts, ainsi que leurs répercussions sur l’acidité des vins. La seconde est une expérimentation en champ qui a pour objectif d’étudier les interactions précédentes in situ. Le suivi de l’état nutritionnel de la vigne a été réalisé selon un protocole mis au point par Garcia et al. (1984) et Doux et al. (1985). La sélection des parcelles a été effectuée en s’inspirant de la méthode mise au point par Morlat et Asselin (1992).

DOI:

Publication date: March 25, 2022

Type: Poster

Issue: Terroir 1996

Authors

M. GARCIA (1), C. DAVEREDE (1), P. GALLEGO (1), D. VIGNES (2), J.L. FAVAREL (3), F. DEDIEU (4)

(1) Institut National Polytechnique-ENSAT, 145 av de Muret 31076 Toulouse
(2) CESBIO, 18 av Edouard Belin 31055 Toulouse
(3) Institut Technique de la Vigne et du vin-Gaillac, 52 Place Jean Moulin 81300 Gaillac
(4) Faculté de pharmacie, Chemin des Maraîchers 31062 Toulouse Cédex

Tags

IVES Conference Series | Terroir 1996

Citation

Related articles…

The wine microbial ecosystem: Molecular interactions between yeast species and evidence for higher order interactions

Fermenting grape juice represents one of the oldest continuously maintained anthropogenic microbial environments and supports a well-mapped microbial ecosystem. Several yeast and bacterial species dominate this ecosystem, and some of these species are part of the globally most studied and best understood individual organisms. Detailed physiological, cellular and molecular data have been generated on these individual species and have helped elucidate complex evolutionary processes such as the domestication of wine yeast strains of the species Saccharomyces cerevisiae. These data support the notion that the wine making environment represents an ecological niche of significant evolutionary relevance. Taken together, the data suggest that the wine fermentation ecosystem is an excellent model to study fundamental questions about the working of microbial ecosystems and on the impact of biotic selection pressures on microbial ecosystem functioning. Indeed, and although well mapped, the rules and molecular mechanisms that govern the interactions between microbial species within this, and other, ecosystems remain underexplored. Here we present data derived from several converging approaches, including microbiome data of spontaneous fermentations, the population dynamics of constructed consortia, the application of biotic selection pressures in directed laboratory evolution, and the physiological and molecular analysis of pairwise and higher order interactions between yeast species. The data reveal the importance of cell wall-related elements in interspecies interactions and in evolutionary adaptation and suggest that predictive modelling and biotechnological control of the wine ecosystem during fermentation are promising strategies for wine making in future.

Terroir and sustainability: an analysis of brazilian vineyards from a territorial perspective

In the concept of sustainable viticulture proposed by the OIV, it can be noted that enhancing terroir is also one measure of sustainability. Thus, the territorial approach may offer an interesting viewpoint from which to consider this issue in a multi-perspective way.

Use of ultrasounds to accelerate aging on lees of red wines

Aging on lees (AOL) is a powerful technique to protect varietal aroma and color. Simultaneously, helps to soften tannins and increase and improve wine body and structure. AOL is complementary to barrel aging modulating the wood impact and protecting wine from oxidative conditions.

French wine sector facing climate change (part. 2) : the implementation of the national strategy

This summary follows this made by Hervé Hannin et al. Entitled “French wine sector facing climate change (part. 1) : a national strategy built on a foresight and participatory approach “. The french wine sector has taken a collective approach to the issue of climate change, and has officially submitted its strategy to the minister of agriculture in 2021. This industry policy is the result of multidisciplinary work carried out through the “laccave” project (metaprogramme accaf, inrae) and its prospective study designed to anticipate climate change in the french wine industry (aigrain p. Et al., 2016). French wine professionals decided to structure a strategy to deal with climate change du in particular to the presentation made at the 2016 OIV congress in Brazil.

WINE SWIRLING: A FIRST STEP TOWARDS THE UNLOCKING OF THE WINE’STASTER GESTURE

Right after the pouring of wine in a glass, a myriad of volatile organic compounds, including ethanol, overwhelm the glass headspace, thus causing the so-called wine’s bouquet [1]. Otherwise, it is worth noting that during wine tasting, most people automatically swirl their glass to enhance the release of aromas in the glass headspace [1]. About a decade ago, Swiss researchers revealed the complex fluid mechanics underlying wine swirling [2]. However, despite mechanically repeated throughout wine tasting, the consequences of glass swirling on the chemical space found in the headspace of wine glasses are still barely known.