Assessment of plant hydraulics in grapevine on various "terroirs" in the Canton of Vaud (Switzerland)

Aims: The aim of this paper is to study the relevance of different physiological indicators concerning vines hydraulic in relation to estimations of the soil water reservoir on various « terroirs » in Switzerland. Methods and results: Different physiological indicators like leaf and stem water potentials, carbon isotope discrimination and a model of transpirable soil water were used. A close relationship was observed between pre-dawn leaf water potential and the soil water holding capacity (SWHC) from about thirty study sites over a period of three years. Conclusion: The different assessments of plant hydraulics (leaf water potential, carbon isotope discrimination technique, model of transpirable soil water) were in good agreement with the soil water holding capacity. Significance and impact of study:The results confirm the importance and the possibilities to estimate plant water ability in relation with soil water holding capacity and climatic factors