PERFORMANCE OF ‘CLARA FRIJS’ PEAR ON SEVEN ROOTSTOCKS

A rootstock trial evaluating 7 pear rootstocks for the pear cultivar ‘Clara Frijs’ was established in 1991 at the Research Centre Aarslev in Denmark. The main objective was to test ‘Old Home x Farmingdale’ rootstocks OH x F 333, 217 and 267 against the standards Quince A and Quince Adams. Also included in the trial was Pyrus calleryana (P1170) and a Polish rootstock (P1-16-2A51). The most promising rootstock was Quince Adams, which had high yield efficiency combined with low tree vigour. In spite of a higher yield efficiency Quince Adams trees were less prone to biennial bearing than trees on Quince A. The total yields of all OH x F rootstocks were comparable to the yield of both Quince A and Quince Adams. OH x F rootstocks reduced biennial bearing, but the OH x F 217 and OH x F 267 trees proved too vigorous to handle in a high-density pear orchard. OH x F 333 were moderately larger than Quince A trees and could be of potential interest on sites where frost hardiness is a major concern. Yield on both P. calleryana and P1-16-2A51 was only a third of that of Quince Adams, and P. calleryana affected fruit size negatively.