Eleven Year Evaluation of American (Geneva^®) and Polish Rootstocks with ‘Golden Delicious Reinders’ Apple in Poland

A field study of dwarf apple rootstock performance using ‘Golden Delicious Reinders’ as scion cultivar was conducted during the year 2001-2011. The study included 6 rootstocks from Cornell Geneva rootstock breeding program (G.11, G.16, G.41, G.202, CG.3007 and CG.4013) 4 rootstocks from the Polish rootstock breeding program (P 14, P 16, P 59 and P 60) and 3 Malling rootstocks as control (M.9 T337, M.9 Pajam 2 and M.26). During the eleven years of growth (2001-2011), there was no tree loss due to root system or cultivar damage caused by frost or diseases including fire blight (Ervinia amylovora Burr. Winsl.) infestation on the rootstock. Trees growing on P 59 and P 16 had the weakest growth while the strongest growing trees were on P 14, M.26, P 60, G.202 and CG.4013. The size of the trees on M.9 Pajam 2, G.16, G.41, CG3007 and CG.4013 were similar to that of the trees growing on the standard rootstock M.9 T337, while the trees on P 59, P 16 and G.11 were significantly smaller from standard trees on M.9 T337. After eleven years of the growth, the cumulative yield varied from 56.7 kg (on P 59) to 237.8 kg (on CG.4013). High yields were also obtained from vigorously growing trees on: G.202, P 14, G.41 and M.26. The cumulative yield expressed as yield per cm2 of trunk cross-sectional area was highest for trees on G.11, P 16, M.9 Pajam 2 and G.41 and lowest for vigorously growing trees on P 60, P 14 and M.26. In 2009, a year of good cropping, the mean mass of fruits varied from 140 g on G.16 to 213 g on P 60. The fruit size from trees on P 14, M.26 and P 16 was statistically similar to fruits from trees on M.9 T337. The results of the eleven-year study lead to the conclusion that the rootstocks G.11 and G.41, which are highly resistant to fire blight, can be recommended for growing ‘Golden Delicious Reinders’ apple in the Polish climate, similarly to trees on M.9 T337, P 16 and M.9 Pajam 2. For orchards located on light soils the following rootstocks are also promising: G.202, CG.3007, CG.4013 and P 14 and P 60 rootstocks of polish selection.