Among the typical species of rootstock for grafting pear trees, Pyrus calleryana Decne is
one of the most used for producing young plants asiatic cultivars. The use of seedlings from seeds have
been preferred by fruit growers, and this fact requires research in order to obtain the best method to overcome
the dormancy and to get the best germination value in the shortest possible time. The following factors were
evaluated in seeds of Taiwan Nashi-C: stratification under cold (5°C) moist conditions from zero to 40
days; constant germinating temperatures of 20, 25, 30 and 35°C, and alternated temperatures of 20-30 and
20-35°C; germination substrates (on paper, rolled paper, soil, vermiculite, cotton, sand and no substrate);
KNO3 effect when applied on the substrate; and light effect during the germinative process. High germination
indices were obtained at 30 days of stratification. In stratified seeds, for 20 days at 5°C several germination
conditions were evaluated, and so it was possible to conclude that 20°C constant temperature and the presence
of light promoted the germination very strongly. Different kinds of substrate caused little germination
effects, while the application of KNO3 0,2% showed no effect.