Potential evaluation of different climatic regions for vine cultivation by using temperature ranges for key physiological processes
Hunter, J J
This aim of this project is to determine the physiological acceptability of the temperature profile (and wind profile) of a given region/locality for quality grapes and wine, to contribute to the choice of a specific region/locality for vine cultivation, to estimate the potential of a given region/locality for top quality production, and to improve grape and wine quality and increase cost efficiency.
The relationship between seasonal temperature profiles of different climatic regions/localities and the temperature ranges for viticultural and enological important processes/compounds will be determined. Minimum and maximum temperature data from weather stations in different climatic regions [Robertson and Le Chasseur (hot), Vinkrivier (cool); Stellenbosch and Klein Waterval (hot), Jacobsdal (cool); Upington and Augrabies (hot), Kakamas (cool)] will be used. Focus will be placed on favourable temperatures for photosynthesis, sugar increase and delay of sugar accumulation, organic acid formation and catabolism (with effect on pH), potassium, colour formation and flavour formation. Temperatures with impact on water loss from the berries will also be considered. The importance of high and low temperatures during different periods (e.g. before véraision and after veraison) will be highlighted. Few studies that apply existing temperature ranges to viticultural and enological important physiological processes exist. Although emphasis is currently on the choice of the correct terrain (locality) for new plantings, focus is placed on the relationship between climate, soil, and cultivar adaptation without really accommodating the physiological requirements for optimal functioning of the grapevine and high grape and wine quality. In this project it is endeavoured to add a physiological basis to the quality production potential evaluation of the different wine regions (climatic regions) and localities for quality production by determining the relationship between the temperature ranges of some physiological processes and the macro-temperature profiles of some cultivation regions.
Bonnardot, V M F. 1999. Climate and Sauvignon blanc performance in Stellenbosch area for the 1995 – 1999 period. Paper presented at the 24th National Congress of the South African Society for Enology and Viticulture. 18-19 November, Somerset West, South Africa.
Hunter, J J and Bonnardot, V. 2002. Climatic requirements for optimal physiological processes: A factor in viticultural zoning. Paper presented at the 4th International Symposium on Viticultural Zoning. 17-20 June, Avignon, France.
Hunter, J J. 2002. Viticultural research aimed at the growth conditions in Stellenbosch. Presentation at the Winetech and VinPro Information Day, 13 August, Stellenbosch.
Hunter, J J. 2004. Methodology to assess vine cultivation suitability using climatic ranges for key physiological processes: Results for three South African regions. Paper presented at the Joint International Symposium on Viticultural Zoning, November, Cape Town.