In order to make a comparison of viticultural and oenological behaviour between old or young vines, a study of six grape varieties was set up by the Agroscope Changins-Wädenswil ACW research station. The comparison was made between old vines of more than thirty years and young vines between four and eight years, these coming from the same vegetative material as the old vines. The influence of the vinestock age on the physiological behaviour (water usage, vegetative expression), agronomic characteristics (yield components, leaf-fruit ratio) and grape berry and wine quality, were studied between 2002 to 2006. In this article only the physiological behaviour of the vinestocks relative to the vine age is discussed. A second article will present the agronomic results, as well as the grape and wine quality aspects.