Influence of Climate, Soil, and Cultivar on Terroir

Abstract

The three main components of terroir—soil, climate, and cultivar—were studied simultaneously. Vine development and berry composition of nonirrigated Vitis vinifera L. cv. Merlot, Cabernet franc, and Cabernet Sauvignon were compared on a gravelly soil, a soil with a heavy clay subsoil, and a sandy soil with a water table within the reach of the roots. The influence of climate was assessed with year-to-year variations of maximum and minimum temperatures, degree days (base of 10°C), sunshine hours, ET_o, rainfall, and water balance for the period 1996 to 2000. The effects of climate, soil, and cultivar were found to be highly significant with regard to vine behavior and berry composition (an example being anthocyanin concentration). The impacts of climate and soil were greater than that of cultivar. Many of the variables correlated with the intensity of vine water stress. It is likely that the effects of climate and soil on fruit quality are mediated through their influence on vine water status.