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, Czech Republic) using scion cultivars Golden Delicious, Melrose, Jonagold, Rubin, and Florina. The 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 the original rootstock M.9. The 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. The rootstock J-TE-H was semi-vigorous and grafted trees had low yield efficiency. The clone Pajam 1 had the similar growth vigour as M.9. Trees on Jork 9 grew significantly weaklier 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.