PERFORMANCE OF 'COMICE' PEAR ON QUINCE ROOTSTOCKS IN OREGON, USA

‘Comice’ pear trees on ‘Quince H’ (also known as ‘Quince 193-16’ and ‘EMH’), ‘Quince C’, and ‘Quince BA-29C’ rootstocks were planted in 2001 in a sandy loam soil at the Southern Oregon Research and Extension Center near Medford, Oregon. Trees were planted in a completely randomized design with 18 single-tree replicates of each rootstock at a spacing of 1.3×4.5 m and trained to a central leader. Fruit production data were collected annually 2004-2010. The number of flower clusters and fruit per tree, fruit weight, and trunk diameter were measured, from which fruit set, yield per hectare, trunk cross-sectional area and yield efficiency were calculated. Overall, ‘Comice’ pear trees on ‘Quince H’ rootstock were similar in fruit set, tree size, and yield efficiency to trees on ‘Quince C’ while yield and fruit size were similar to trees on ‘Quince BA-29C’. The average trunk cross-sectional area at the end of the 10^th year was 157.4 cm² on ‘Quince BA-29C’, 91.3 cm² on ‘Quince H’, and 73.5 cm² on ‘Quince C’. The cumulative average individual fruit weight was 231 g on ‘Quince BA-29C’, 214 g on ‘Quince H’, and 167 g on ‘Quince C’. The cumulative yield efficiency (kg/cm²) was 0.56 on ‘Quince BA-29C’, 1.04 on ‘Quince H’, and 0.98 on ‘Quince C’. Through the 10^th year, ‘Comice’ pears on ‘Quince H’ rootstock appear to be better suited to the tree density of this plot (1690 trees per ha) than those on ‘Quince BA-29C’, with tree size moderately larger than ‘Quince C’ while achieving fruit size and yield characteristics similar to trees on ‘Quince BA-29C’.