Terroir 1996 banner
IVES 9 IVES Conference Series 9 The developement of vineyard zonation and demarcation in South Africa

The developement of vineyard zonation and demarcation in South Africa

Abstract

[English version below]

L’histoire de viticulture de l’Afrique du Sud embrasse 340 ans, et a commencé, à la province du Cap, où les colonisateurs hollandais ont planté les premières vignes. L’arrivée des Huguenots français en 1688 a avancé, le développement. Les vins de Constantia deviennent renommés, et ainsi ils sont les premiers “vins d’origine” de l’Afrique du Sud. Pendant l’occupation britannique de la province du Cap en 1806, la viticulture a développé, davantage, dû à l’inaccessibilité, de l’Europe et ses vins pendant cette période. On a plant, la plupart des vignobles à la région côtière du sud-ouest, aux environs de la province du Cap, et aux vallées limitrophes. Ces régions sont toujours productrices principales de vin. Vers 1850, les exportations de vin étaient très limitées, dû à la détérioration de la qualité de vin. Ce fait a résulté du manque de contrôle d’origine et de qualité. L’industrie a reconnu ce problème, ce qui mène à la fondation d’un système de contrôle de Vin d’Origine en 1973. Des experts techniques font la démarcation des secteurs de vin, en employant quatre catégories. Ces sont: (1) Régions, (2) Districts, (3) Circonscriptions (‘Wards’), et (4) Domaines. Faute d’assez de traditions, d’expérience et des données expérimentales (contrasté avec les pays européens de viticulture), la philosophie sud-africaine de démarcation embrasse l’identification des unités de terrain naturel, en employant des données techniques qui sont disponibles.

The 340 year old history of viticulture in South Africa started with the first planting of vines by the Commander of the first Dutch settlers at the Cape. Further expansion was encouraged by succeeding Governors and also stimulated by the arrival of the French Huguenots in 1688. Constantia wines became internationally famous and thus were the first ‘wines of origin’ from South Africa. After the British occupation of the Cape in 1806, viticulture was further stimulated due to the inaccessibility of Europe and its wines to Britain at that stage. Vineyards were mainly established in the south-western coastal zone around the Cape and in adjacent Inland River valleys were irrigation water was available. These areas, characterized by a Mediterranean climate, are still the main wine producing regions today. Towards 1850, wine exports reached an ail time low because of the deterioration in wine quality, mainly as result of the absence of control over origin and quality. This problem was realized by the industry and resulted in a Wine of Origin Control system since 1973. Demarcation of existing vineyards was, and still is, done by technical experts, using four categories, viz. (1) Regions, based on broad geographical features and administrative boundaries; (2) Districts, based on geographical and macro climatic features; (3) Wards, essentially based on uniform soil, climatic and ecological patterns; and (4) Estates, based on the concept of singular ownership of vineyards and wine being produced on the estate. To demarcate Wards, land type maps are used. Land types are a concept unique to South Africa and are defined as a class of land over which the macro climate, the terrain form and soil pattern each displays a marked uniformity. Land types differ from each other in terms of macro climate, terrain form or soil pattern, or combinations of these natural factors. Lacking sufficient tradition, experience and experimental information, compared to the old word wine countries, the philosophy behind demarcation in South Africa is to identify natural terrain units, using available technical information, and then allowing such units to develop and demonstrate particular wine styles and character, rather than demanding proof of uniqueness before demarcation is done.

DOI:

Publication date: March 2, 2022

Issue: Terroir 1998

Type: Article

Authors

D. SAAYMAN

Dept. Of Soil Science, University of Stellenbosch, P/Bag X1, Matieland, 7602, RSA

Tags

IVES Conference Series | Terroir 1998

Citation

Related articles…

The modification of cultural practices in grapevine cv. Syrah, does it modify the characteristics of the musts?

The work shows the results of a year of experimentation (2020) in a Syrah variety vineyard in La Roda (Castilla-La Mancha, Spain). The trial approach was on a randomized block design with two factors: Irrigation (I) and Pruning (P).
Irrigation schedules were adjusted to apply amounts close to 1,500 m3/ha. With this provision, 2 different irrigation treatments were proposed: I1) Start of irrigation from pea-sized grape to post-harvest (providing at least 20 % of the total amount of irrigation water to be provided post-harvest); I2) Start of irrigation from pea-sized grape to harvest (usual irrigation practice in the study area). Pruning was proposed with two treatments, one at the end of January (P1), which is pruning on a conventional date; and P2) pruning carried out at the beginning of budding. In total, 4 repetitions were designed with 4 elementary plots, each one of them representing one of the proposed treatments (I1P1; I1P2; I2P1; I2P2). In total, 16 plots were worked on and each elementary plot consisted of 30 strains, distributed in 3 lines.
The productive response was evaluated with the yield results of the harvest harvested at 23 ºBrix. The qualitative response was measured in the musts through the indices of technological (acidity, pH and potassium) and phenolic maturity and aromatic compounds in free and glycosylated fractions. The treatments tested had, in general, an effect on the different variables analyzed.

Investigating the impact of grape exposure and UV radiations on rotundone in Vitis vinifera L. Tardif grapes under field trial conditions

Rotundone is the main aroma compound responsible for peppery notes in wines whose biosynthesis is negatively affected by heat and drought. Through the alteration of precipitation regime and the increase in temperature during maturation, climate change is expected to affect wine peppery typicality. In this context there is a demand for developing sustainable viticultural strategies to enhance rotundone accumulation or limit its degradation. It was recently proposed that ultraviolet (UV) radiations could stimulate rotundone production. The aim of this study was to investigate under field trial conditions the impact of grape exposure and UV treatments on rotundone in Vitis vinifera L. Tardif, an almost extinct grape variety from south-west France that can express particularly high rotundone levels. Four different treatments were compared in 2021 to a control treatment using a randomised complete block design with three replications per treatment. Grape exposure was manipulated through early or late defoliation. Leaf and laterals shoots were removed at Eichorn Lorenz growth stages 32 or 34 on the morning-sun side of the canopy. During grape maturation, UV radiations were either reduced by 99% by installing UV radiation-shielding sheets, or applied four times using the Boxilumix™ non thermal device (Asclepios Tech, Tournefeuille) with the aim of activating plant signalling pathway. Loggers displayed in solar radiation shields were used to assess the effect of such shielding sheets on air temperature within the bunch zone. The composition of grapes subjected to these treatments will be soon analysed for their rotundone content and basic classical laboratory analyses. Grapes will be harvested to elaborate wines under standardized small-scale vinification conditions (60kg) that will be assessed by a trained sensory panel.

Influence of weather and climatic conditions on the viticultural production in Croatia

The research includes an analysis of the impact of weather conditions on phenological development of the vine and grape quality, through monitoring of four experimental cultivars (Chardonnay, Graševina, Merlot and Plavac mali) over two production years. In each experimental vineyard, which were evenly distributed throughout the regions of Slavonia and The Croatian Danube, Croatian Uplands,

‘Cabernet Sauvignon’ (Vitis vinifera L.) berry skin flavonol and anthocyanin composition is affected by trellis systems and applied water amounts

Trellis systems are selected in wine grape vineyards to mainly maximize vineyard yield and maintain berry quality. This study was conducted in 2020 and 2021 to evaluate six commonly utilized trellis systems including a vertical shoot positioning (VSP), two relaxed VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a guyot (GY), combined with three levels of irrigation regimes based on different crop evapotranspiration (ETc) replacements, including a 25% ETc, 50% ETc, and 100% ETc. The results indicated SH yielded the most fruits and accumulated the most total soluble solids (TSS) at harvest in 2020, however, it showed the lowest TSS in the second season. In 2020, SH and HQ showed higher concentrations in most of the anthocyanin derivatives compared to the VSPs. Similar comparisons were noticed in 2021 as well. SH and HQ also accumulated more flavonols in both years compared to other trellis systems. Overall, this study provides information on the efficacy of trellis systems on grapevine yield and berry flavonoid accumulation in a currently warming climate.

Effect of partial net shading on the temperature and radiation in the grapevine canopy, consequences on the grape quality of cv. Gros Manseng in PDO Pacherenc-du-vic-Bilh

As elsewhere, southwestern France vineyards face more recurrent summer heat waves these last years. Among the possibilities of adaptation to this climate changing parameter, the use of net shading is a technique that allow for limiting canopy exposure to radiations. In this trial, we tested net shading installed on one face of the canopy, on a north-south row-oriented plot of cv. Gros Manseng trained on VSP system in the PDO Pacherenc-du-Vic-Bilh. The purpose was to characterize the effects on the ambient canopy temperatures and radiations during the season and to observe the consequences on the composition of grapes and wines. Two sorts of net were used with two levels of obstruction (50% and 75%) of the photosynthesis active radiation (PAR). They have been installed on the west side of the canopy and compared to a netless control. Temperature and PAR sensors registered hourly data during the season. On specific summer day (hot and sunny) manual measurements took also place on bunches (temperature) and in different spots of the canopy (PAR). The results showed that, on clear days, the radiation is lowered by the shade nets respecting the supplier criteria. The effects on the ambient canopy temperature were inconstant on this plot when we observed the data from the global period of shading between fruit set and harvest. However, during hot days (>30°C), the temperature in the canopy was reduced during afternoon and the temperature of the bunch surface was reduced as well comparing to the control. A decrease of the maturity parameters of the berries, sugar and acidity, was also observed. Concerning the wine aromatic potential, no differences clearly appeared.