 IVES 9 IVES Conference Series 9 Methodology to assess vine cultivation suitability using climatic ranges for key physiological processes: results for three South African regions

Methodology to assess vine cultivation suitability using climatic ranges for key physiological processes: results for three South African regions

Abstract

Le climat a de fortes implications sur le bon fonctionnement physiologique de la vigne et a besoin d’être quantifié afin de déterminer l’aptitude des régions à la culture de la vigne. Une méthode, qui pourrait éventuellement servir à prévoir l’aptitude des régions à la culture de la vigne, est proposée. Les seuils climatiques (température, vitesse du vent et humidité relative) pour les processus physiologiques (aussi bien photosynthèse des feuilles qu’accumulation des sucres et potassium et formation d’acide organique et respiration) ont été étudiés dans trois régions viticoles d’Afrique du Sud (Stellenbosch, Roberston et Upington) pendant les périodes de pré-et post-véraison. Sont considérés à la fois les seuils climatiques optimum et extrêmes. Une variation importante dans le nombre d’heures disponibles pour le fonctionnement physiologique optimal (selon les paramètres étudiés) apparait entre les régions. En considérant tous les facteurs, la région de Stellenbosch semblerait être la plus appropiée aux besoins physiologiques étudiés pour la culture de la vigne.

Climate has serious implications on proper physiological functioning of grapevines and needs to be quantified in order to determine the vine cultivation suitability of grape growing regions. Methodology is proposed that may eventually be used to predict the suitability of regions/terroirs for grapevine cultivation. Climatic ranges of temperature, wind speed and relative humidity for key physiological processes (photosynthesis of the leaves as well as sugar and potassium accumulation, organic acid formation and respiration, and colour and flavour development in the grapes) were studied in three wine producing regions of South Africa (Stellenbosch, Robertson and Upington) during the pre- and post-véraison growth periods. Both optimum and extreme climatic ranges were considered. Marked variation in the number of hours available for optimal physiological functioning (according to the parameters studied) occurred between the regions. All factors considered, the Stellenbosch region would seem to be best suited to the studied physiological requirements for grapevine cultivation.

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Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

J.J. Hunter (1) and V. Bonnardot (2)

1) Infruitec/Nietvoorbij-Institute for Fruit, Vine and Wine of the Agricultural Research Council (ARC) Private Bag X5026, 7599 Stellenbosch, South Africa
2) ARC-Institute for Soil, Climate and Water (ISCW), Private Bag X5026, 7599 Stellenbosch, South Africa

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