PERFORMANCES OF ELEVEN GRAPEVINE VARIETIES IN TWO DIFFERENT VITICULTURAL AREAS OF TUSCANY

Four-year observations on eleven white wine grape varieties ('Canaiolo bianco', 'Chardonnay', 'Malvasia bianca del Chianti', 'Pinot grigio', 'Riesling italico', 'Roussanne', 'Sauvignon,' 'Semillon', 'Trebbiano toscano', 'Verdicchio' and 'Vermentino') grafted on 140Ru and trained according to the Guyot system were carried out in two different "Chianti" zones of the provinces of Siena and Pisa. Varieties tested showed good adaptability in both areas. Noteworthy differences in date of bud break, earliness of ripening, yielding performance and wine quality were observed. 'Trebbiano toscano' was the most productive variety while Pinot g. and 'Chardonnay' showed the lowest yield and the earliest ripening. In general, all varieties except 'Malvasia bianca' showed a lower heliothermic index (HI) in the Province of Siena than in Pisa. Most of the varieties not originating from Tuscany were characterized by higher quality than those such as 'Canaiolo bianco,' 'Malvasia bianca' and 'Trebbiano toscano' typically grown in this area. More specifically, 'Chardonnay', 'Pinot g.' 'Sauvignon' and 'Semillon' (and in addition 'Vermentino' in the Pisa zone) showed the possibility of improving the quality of white wine traditionally produced in both areas.