Promising Early Results with Four New Apple Rootstocks from Quebec

Four cold-hardy apple ( Malusx domesticaBorkh.) rootstocks developed in Quebec, Canada (SJM-15, SJM-189, SJP84-5198, SJP84-5218) were tested for over seven seasons for their horticultural performance under Pacific Northwestern growing conditions in Summerland, British Columbia, Canada. Malling 9 (M.9, strain NAKBT337) and Budagovsky 9 (B.9) were included in the trial as standards of comparison. All trees were budded with ‘Royal Gala’, trained as slender spindles, and drip-irrigated. Tree survival was good for all the rootstocks. After seven years, trees on SJP84-5198 and SJP84-5218 were slightly larger than those on M.9 or B.9, while trees on SJM-189 and SJM-15 were similar to the standards in vigor. All the rootstocks had low amounts of root suckering, particularly SJM-189. Cumulative yield efficiency of the Quebec rootstocks equaled that of B.9 or M.9 after five cropping years. Fruit size was acceptable for all trees, but smallest on B.9 and largest on SJP84-5218. Fruit red color development was especially good for trees propagated on SJM-189. Further testing of these rootstocks is recommended.