Vine water status as a parameter of the « terroir » effect under the non-irrigated conditions of the Vaud viticultural area (Switzerland)

Abstract

<p style="text-align: justify;"><strong>Aims</strong>: The aim of the study was to assess whether, for vineyards in Vaud (Switzerland), vine water status might be a major natural factor in determining wine sensory characteristics, i.e., responsible for the so-called « terroir » effect.</p><p style="text-align: justify;"><strong>Methods and Results</strong>: The impact of vine water status on fruit and wine characteristics was examined for 23 non-irrigated locations with different soil water holding capacities during three seasons (2007-2009). In 2009, a close relationship was observed between δ¹³C and soil water holding capacity. Furthermore, the level of vine water status influenced both fruit and wine composition. Berry weight was strongly correlated to vine water status. The highest grape soluble solids content (SSC) at harvest was reached when water deficit was mild. Wine colour was related to vine water status: wine made from grapevines with low water status showed a significantly higher colour density. However, sensory analysis did not discriminate between wines from different water conditions.</p><p style="text-align: justify;"><strong>Conclusion</strong>: In a dry year like 2009, vine water status was related to soil water holding capacity and determined grape and wine characteristics. However, no clear relationship was observed between wine sensory characteristics and vine water status.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This study confirms the importance of soil in determining grape and wine characteristics through its effect on vine water status.</p>