Interaction among grapevine cultivars (Sangiovese, Cabernet-Sauvignon and Merlot) and site of cultivation in Bolgheri (Tuscany)

Different “landscape unit” have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in the 1992-1993 period. In all cultivar (Sangiovese, Cabernet Sauvignon and Merlot) x landscape unit combinations, experimental plots were chosen in homogeneous vineyards, single cordon trained (about 3300-4500 vines/hectare). Grape maturation was studied by weekly samples of berries from veraison to vintage in the 1992-1995 period. At harvest yield and must composition traits were measured and, from the most représentative plots, sixty kilograms of grapes were harvested each year and vinified according to a standardised scheme. Wines were evaluated by standard chemical and sensory analyses.

Nutritional status of vines at veraison, surveyed by leaf analysis, assessed the peculiar status of Bolgheri vineyards as concern potassium and iron content in leaves. The influence of site of cultivation (or landscape unit) on crop level, vine vegetative growth, grape composition and wine quality was the result of the combination of mesoclimatic conditions, soil characteristics, water and mineral nutrients availability. The technique of descriptive analyses assessed the peculiarities of the sensory profiles of wines obtained in some landscape units in Bolgheri appellation. In these cases landscape units might be considered as “terroirs”.