Performance of Pear Rootstocks in North America

The adoption of high-density orchards during the last decades has resulted in a significant improvement in yield and fruit quality. However, the late full production achievement is still one of the main challenges when planting a pear orchard. In addition, winter damage and fire blight can also compromise viability, especially in cool humid areas like North America. For instance, quince rootstocks in North America have not been used due to the possibility of winter damage, fire blight and pear decline.

In 2004, a field trial was planted at three locations: Geneva, New York, USA; Rockland, Nova Scotia, Canada; and Kentville, Nova Scotia, Canada. The trials compared three Pyrus rootstocks: Old Home x Farmingdale (OHF) 97, OHF87 and Pyrodwarf with ‘Taylor's Gold Comice’ and ‘Concorde’ pear as the scion cultivars. Trees were trained as central leaders with 2 tiers of branches, with branches spread to 70-90° from vertical in the third year. Tree spacing was 2.5 m x 4.5 m. The trial at Geneva and the trial at Rockland were managed with conventional pesticides and fertilizers while the trial at Kentville was managed using organic strategies.

After 12 years of growth, trees with OHF97 and OHF87 were the most vigorous under conventional management, whereas Pyrodwarf and OHF87 performed better than OHF97 under organic strategies. Cumulative yields were highest from ‘Concorde’ compared with ‘Taylor’s Gold Comice’. There were no significant differences in yield efficiency among the three rootstocks, and fruit size was generally smaller with Pyrodwarf, which also had the most suckers. Results from this study show that Pyrodwarf does not offer any significant advantage over the OHF stocks.