Since the identification of phylloxera in Brazil, the search for adequate rootstocks became important in viticultural research activities in the State of São Paulo. Increased actions on breeding and selection, led to a reasonable number of grape rootstocks combining a number of advantageous characteristics. From these, however, only a few are used in the major areas of grape production. The expansion of viticulture to different regions has increased the need of new rootstocks to attend diversification. The aim of this research was to evaluate grapevine hybrids growing at the Centro Experimental de Campinas (Instituto Agronômico - IAC, 23o08'S and 46o55'W), with respect to their potential as new rootstocks. Twenty nine hybrids were selected for vigor and vegetative exuberance. These were compared with four rootstocks commonly used in vineyards of São Paulo: IAC 766, IAC 572, Ripária do Traviú and Kober 5BB. Cuttings were planted in outdoor conditions, in plastic bags with a mixture of soil, superphosphate and castor bean meal. Five trials were carried out to study the initial budding velocity, rooting (percentage of rooted cuttings, root length and dry weight), and vegetative development (shoot dry weight). The following groups of hybrids were selected: a) quick-budding and best rooting: 183-16 (Black July X IAC 21-14), 204-5 (Niagara Rosada X IAC 544-14) and 202-2 (Niagara Rosada X Vitis rupestris S. George); b) best rooting and best vegetative development: 202-21, 202-12 (Niagara Rosada X Vitis rupestris S. George), and 224-10 (Niagara Rosada X IAC 584-53); c) best performance in the three characteristics: 237-24 (Niagara Rosada X Seibel 1077), 202-6, 202-18, 202-1, 202-10, 202-7 e 202-9, (Niagara Rosada X Vitis rupestris S. George).
breeding; selection; cultivars; grapevine; hybrids