Performance of 'Gala' apple on eight dwarf rootstocks: Ten-year summary of the 1990 NC-140 rootstock trial

In 1990, trees of 'Gala' apple (Malus x domestica Borkh.) on 8 dwarfing rootstocks were planted at 8 locations in North America according to the guidelines established for cooperative testing by the North Central regional cooperative project (NC-140). Rootstocks in this trial included MAC.39, P.1, O.3, M.27, B.9, Mark, M.9 EMLA, and M.26 EMLA. Tree survival was not affected by rootstock. P.1 produced trees with the largest trunk cross-sectional areas, lowest yield and yield efficiency, and smallest fruit. O.3 and M.26 EMLA produced trees with similar TCSA, but M.26 EMLA was the least productive. Mark, MAC.39, B.9 and M.9 EMLA produced trees with similar TCSA, yields and yield efficiencies. M.27 produced trees with the smallest TCSA and relatively low yields.