Effect of dwarfing and semi dwarfing apple rootstocks on growth and productivity of selected apple cultivars

Fourteen clonal apple rootstocks (M.9, M.26, M.27, MM.106, J-TE-E, J-TE-F, J-TE-G, J-TE-H, J-OH-A, Jork 9, Pajam 1, Pajam 2, Burgmer M.9-751, and Burgmer M.9-984) were tested in two experimental orchards established in the Research and Breeding Institute of Pomology Holovousy using scion cultivars Golden Delicious, Melrose, Jonagold, Rubin, and Florina. Following characteristics were recorded: yield, trunk circumference, suckering. Rootstocks Jork 9, Pajam 1, Pajam 2, M.9-751, and M.9-984 produced better results than original rootstock M.9. Clone J-TE-E favourably affected fruit-bearing of the Rubin cultivar. The growth vigour of trees grafted on Pajam 2, M.9-751, and M.9-984 was somewhat larger than those on M.9. Rootstock J-TE-H was semi-vigorous and grafted trees had low yield efficiency. Clone Pajam 1 had the similar growth vigour as M.9. Trees on Jork 9 grew significantly weakly in comparison with M.9. The rootstocks J-OH-A and J-TE-F produced a lot of suckers. The following rootstocks were recommended for growing in commercial plantations: Jork 9, Pajam 1, Pajam 2, M.9-751, and M.9-984.