Callery Pear Cultivars Tested as Street Trees: Second Report

Abstract

Nine Callery pear (Pyrus calleryana) cultivars were planted under utility wires in 11 communities for evaluation as street trees. In most communities, 2 cultivars were alternated within each of several plots. Cooperators in the Municipal Tree Restoration Program used standardized methods to measure them annually at the end of the growing period for 3 years, and periodically afterwards until the ninth year in some cases. Significant differences were found in growth rate, height, crown width, and trunk diameter, but growth patterns and dimensions of most cultivars that were evaluated for 9 years were similar, with some notable exceptions. The height growth of 'Autumn Blaze' seems to have stalled at 5.6 m (18.5 ft) 9 years after transplanting, whereas most other cultivars exceeded 7.2 m (23.7 ft) and were still growing about 0.4 m (1.3 ft) per year. 'Cleveland Select' and 'Whitehouse' had narrower crowns and smaller trunks than others. All cultivars were in very good health except 'Whitehouse', whose foliage and twigs were injured somewhat in most years by unidentified insects and disease, possibly anthracnose or fireblight.