Cultivars and rootstocks of grapevines for the production of fine winter wines in a subtropical climate

ABSTRACT Excessive summer rainfall can impair grape ripening and wine quality in subtropical regions. Double pruning management offers an alternative by enabling grape production in the first half of the year, with harvest during drier months. This study evaluated the performance of five Vitis vinifera cultivars (‘Marsanne,’ ‘Marselan,’ ‘Touriga Nacional,’ ‘Muscat Petit Grain,’ and ‘Syrah’) grafted onto the rootstocks IAC 766 and 1103 Paulsen for the production of fine winter wines under a subtropical climate. Vines were trained using a vertical shoot positioning system without irrigation, and assessments were conducted over two growing seasons. Productive and chemical parameters of the grapes were measured. Data were analyzed using analysis of variance, and means were compared with the Scott-Knott’s test (p < 0.05). The IAC 766 rootstock promoted higher vigor without reducing must quality. ‘Touriga Nacional’ showed excessive vigor and low bud fertility, highlighting the need for careful canopy management. Overall, ‘Marselan,’ ‘Syrah,’ ‘Marsanne,’ and ‘Muscat Petit Grain’ demonstrated good potential for winter wine production.