Terroir 1996 banner
IVES 9 IVES Conference Series 9 A viticultural perspective of Meso-scale atmospheric modelling in the Stellenbosch wine growing area, South Africa

A viticultural perspective of Meso-scale atmospheric modelling in the Stellenbosch wine growing area, South Africa

Abstract

La brise de mer et les facteurs climatiques qu’elle entraîne (accélération de la vitesse du vent au cours de l’après midi, augmentation de l’humidité et baisse de la temperature) sont d’un intérêt particulier pour la viticulture. La configuration climatique de la région, comprenant l’effect de la brise de mer, en parallèle avec des donnés pédologiques, viticoles et oenologiques sont étudiés afin de determiner les implications sur la croissance et le fonctionnement de la vigne et potentiellement sur la composition du raisin et le caractère du vin et de bien comprendre les interactions terroir/vigne/vin.
Le modèle atmosphérique RAMS (Regional Atmospheric Modelling System) a été utilisé afin d’étudier le degré de pénétration de la brise de mer et les caractéristiques climatiques (température, humidité relative et vent) qui en résultent, en parallèle avec des données en surface enregistrées par des stations agroclimatiques situées dans le vignoble. Des parcelles expérimentales de Sauvignon blanc situées dans les vignes commerciales sont associées à chaque station météorologique automatique. Les mesures viticoles et oenologiques de ces parcelles sont utilisées comme base pour étudier l’impact de la pénétration de la brise de mer et du topoclimat, en conjonction avec d’autres composantes du terroir, sur la viticulture de la région d’étude. Les résultats des analyses statistiques soulignent l’importance du climat, particulièrement les caractéristiques liées à la brise de mer.

The sea breeze and induced climatic patterns (increase in wind velocity in. the afternoon with a concomitant increase in relative humidity and reduction in temperature) are of particular interest for viticulture. The climatic patterns of the area, including the sea breeze effect, along with soil, viticultural and oenological data were studied in order determine the implications for vine growth and functioning, and, potentially, berry composition and wine character and to fully understand the terroir/vine/wine interactions.
The Regional Atmospheric Modelling System (RAMS) was used to study the degree of penetration by the sea breeze and the resulting climatic characteristics (temperature, relative humidity and wind) along with surface data recorded at agroclimatic stations situated in the vineyards. Associated with the automatic weather stations are experimental plots of Sauvignon blanc within commercial vineyards. The measured viticultural and oenological attributes of these plots were used as a basis to assess the impact of the sea breeze penetration and topoclimate, in conjunction with other terroir components, on viticulture in the study area. Results of statistical analyses emphasized the importance of the climate, especially sea breeze related characteristics.

DOI:

Publication date: February 15, 2022

Issue: Terroir 2002

Type: Article

Authors

V.A. CAREY (1) and V.M.F. BONNARDOT (2)

(1) ARC Infruitec-Nietvoorbij, (Present address: Department of Viticulture and Oenology, Stellenbosch University, Private Bag Xl, 7602 Matieland, South Africa)
(2) ARC Institute for Soil, Climate and Water, Private Bag X5026, 7599 Stellenbosch, South Africa

Keywords

Modélisation Atmosphérique, brise de mer, humidité relative, température, Sauvignon blanc
Atmospheric Modelling, sea breeze, relative humidity, temperature, Sauvignon blanc

Tags

IVES Conference Series | Terroir 2002

Citation

Related articles…

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.

Impact of glutathione-rich inactivated yeast on wine chemical diversity

Glutathione-rich inactivated dry yeasts (GSH-IDY) are claimed to accumulate intracellularly and then release glutathione in the must.

Influence of grape withering on corvina and corvinone aroma composition

AIM:Valpolicella is a wine region located in Italy north-east, famous for the production of dry and sweet red wines from withered grapes, including Amarone and Recioto. The aim of this study is to understand the influence of the withering process on Corvina and Corvinone wines aroma profiles. METHODS:Wines were produced with a standard red wine winemaking protocol with Corvina and Corvinone grapes from different Valpolicella vineyards and vintages. In consideration of the local traditional practice of post-harvest withering of the grapes, wines from each vineyard were obtained from either fresh and withered grapes. Wines were analysed by Solid Phase Extraction and Solid Phase Micro Extraction gas chromatography coupled to mass spectrometry.

“Garrigues”, part of the mediterranean vine terroirs

Les paysages viticoles méditerranéens présentent une originalité qui ne se retrouve nulle part ailleurs : ils associent des garrigues très odoriférantes à des parcelles de vignes souvent qualitatives. La connaissance empirique des vins du Languedoc par leurs dégustateurs a conduit la Chambre d’Agriculture de l’Hérault à supposer que les arômes de la garrigue environnante peuvent se retrouver dans les vins (arômes de ciste, de genévrier, … )

Amino nitrogen content in grapes: the impact of crop limitation

As an essential element for grapevine development and yield, nitrogen is also involved in the winemaking process and largely affects wine composition. Grape must amino nitrogen deficiency affects the alcoholic fermentation kinetics and alters the development of wine aroma precursors. It is therefore essential to control and optimize nitrogen use efficiency by the plant to guarantee suitable grape nitrogen composition at harvest. Understanding the impact of environmental conditions and cultural practices on the plant nitrogen metabolism would allow us to better orientate our technical choices with the objective of quality and sustainability (less inputs, higher efficiency). This trial focuses on the impact of crop limitation – that is a common practice in European viticulture – on nitrogen distribution in the plant and particularly on grape nitrogen composition. A wide gradient of crop load was set up in a homogeneous plot of Chasselas (Vitis vinifera) in the experimental vineyard of Agroscope, Switzerland. Dry weight and nitrogen dynamics were monitored in the roots, trunk, canopy and grapes, during two consecutive years, using a 15N-labeling method. Grape amino nitrogen content was assessed in both years, at veraison and at harvest. The close relationship between fruits and roots in the maintenance of plant nitrogen balance was highlighted. Interestingly, grape nitrogen concentration remained unchanged regardless of crop load to the detriment of the growth and nitrogen content of the roots. Meanwhile, the size and the nitrogen concentration of the canopy were not affected. Leaf gas exchange rates were reduced in response to lower yield conditions, reducing carbon and nitrogen assimilation and increasing intrinsic water use efficiency. The must amino nitrogen profiles could be discriminated as a function of crop load. These findings demonstrate the impact of plant balance on grape nitrogen composition and contribute to the improvement of predictive models and sustainable cultural practices in perennial crops.