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…

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

Effects of graft quality on growth and grapevine-water relations

Climate change is challenging viticulture worldwide compromising its sustainability due to warmer temperatures and the increased frequency of extreme events. Grafting Vitis vinifera L.

Assessment of the impact of actions in the vineyard and its surrounding environment on biodiversity in Rioja Alavesa (Spain)

Traditional viticulture areas have experienced in the last decades an intensification of field practices, linked to an increased use of fertilisers and phytosanitary products, and to a more intensive mechanization and uniformization of the landscape. This change in management has sometimes led to higher rates of soil erosion andloss of soil structure, fertility decline, groundwater contamination, and to an increased pressure of pests and diseases. Additionally, intensification usually leads to a simplification of landscapes, of particular concern in prestigious wine grape regions where the economical revenue encourages the conversion of land use from natural habitats to high value wine grape production. To revert this trend, it is necessary that growers implement actions that promote biodiversity in their vineyards. The aim of this study is to assess the impact of the implementation of cover crops, vegetational corridors, dry stone walls and vineyard biodiversity hotspots estimated through the study of arthropods. The work has been carried out in four vineyards in Rioja Alavesa belonging to Ostatu winery, where these infrastructures were implemented in 2020. The presence and diversity of arthropods was studied by capturing them at different times in the season and at different distances from the infrastructure using pit-fall traps in the soil and yellow, white and blue chromatic traps at the canopy level. This is a preliminary study in which all adult insects were sorted to the taxonomic level of order and Coleoptera were classified to morphospecies. The results obtained show that there is a relationship between the basic characteristics of the vineyard and the arthropods captured, with a positive effect, although also dependent on the vineyard, of the presence of infrastructure.

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares