The yield potential of juice grape cultivars, namely Concord, Isabel and Seibel 2, grafted on 'IAC 313', 'IAC 571-6', 'IAC 572' and 'IAC 766' rootstocks was studied in an experiment conducted for six years at Mococa Experimental Station (21º28'S, 47º01'W). Regarding Concord cultivar, the greatest mean yields were achieved when grafted on 'IAC 313', 'IAC 571-6' and 'IAC 572'rootstocks, respectively 3.86kg/plant, 3.81 kg/plant and 3.65 kg/plant. 'Isabel' gave the largest grape productions when grafted on 'IAC 572' (3.85kg/plant), 'IAC 571-6' (3.63kg/plant) and 'IAC 313' (3.26kg/plant). The best grape yields of 'Seibel-2' were obtained when it was grafted on 'IAC 313', 'IAC 572' and 'IAC 571-6', being respectively 2.61kg/plant, 2.40 kg/plant and 2.10 kg/plant. Regardless the variety used as scion, the rootstock with the worst performance in grape production was 'IAC 766'. Vigor, measured through the weight of pruned stems along the period of the experiment, was higher when 'IAC 572' and 'IAC 313' were used for 'Concord', 'IAC 766' and 'IAC 313' for 'Isabel' and 'IAC 766' and 'IAC 572' for 'Seibel-2'.
grape juice; cultivars; rootstocks; Vitis spp
