EVALUATION OF THE GROWTH AND PHENOLOGICAL TRAITS OF TEN ROOTSTOCKS IN COMBINATION WITH PEAR CULTIVARS 'HOSUI', 'YALI' AND 'CONFERENCE'

We conducted a field experiment in the South Moravia region of the Czech Republic with ten rootstock cultivars and three pear cultivars (two Asian and one European) from 2009 and 2013, and evaluated the following traits: rootstock suckering, trunk suckering, and growth intensity of grafted cultivars, phenological traits and yield. Pear rootstocks such as Pyrodwarf, Pyriam, FOX 11, OH×F 333, BET (P. betulifolia), pear seedling and ‘Conference’ seedling were evaluated as well as quince rootstocks such as MA, S1 and BA29. The results identified the pear seedling as the most sucker prone rootstock (3.4 suckers per tree on average) while Pyriam rootstock had the least suckers (0 tree^-1). The Japanese pear cultivar ‘Hosui’ on the pear seedling rootstock produced the most secondary suckers on the trunk (1.8 tree^-1), followed by the European pear cultivar ‘Conference’ on Pyrodwarf (1.7 tree^-1). Conversely, in the first three years after planting on a permanent site the least number of suckers was observed in the trunk of the Chinese pear cultivar ‘Yali’ and ‘Conference’ seedling rootstock. ‘Hosui’ was the most vigorous cultivar (an average increment of 48.3 cm) unlike ‘Yali’ which had the least growth (an average increment of 41 cm). There were no significant differences in phonological characteristics due to rootstock but ‘Yali’ and ‘Hosui’ started to bloom 3.5 days earlier than ‘Conference’ (irrespective of rootstock). Fruit yield at the start of the fruit-bearing stage was highest with ‘Conference’ on the quince rootstocks BA29, MA and S1 (average 11.8 kg tree^-1), followed by ‘Hosui’ on pear seedling (8.7 kg tree^-1) and ‘Yali’ on pear seedling (7.9 kg tree^-1).