Influence of rootstocks on different sweet cherry cultivars and accumulation of heavy metals in leaves and fruit

Two seedling rootstocks of Mahaleb cherry (Prunus mahaleb L.) from a German type cv. Alpruna marked as No. 2 and No. 6 were selected for their semi-dwarfing properties from biotypes growing at the Rural Experimental Station in Baranowo belonging to the University of Life Sciences in Poznan, Poland. In an orchard experiment in 2012-2013, growth and yield of eight- and nine-year old trees of the cvs Regina, Summit and Vanda were studied. These cultivars were grafted on Mahaleb cherry No. 2 and No. 6 and were compared to the control rootstock Mazzard (Prunus avium L.) cv. Alkavo. The Mahaleb cherry biotypes significantly decreased the trunk cross-sectional area and the crown volume of the trees. The cultivars grafted on Mahaleb cherry biotypes No. 2 and No. 6 had more flowers and they gave a higher yield. The yield efficiency for cultivars grafted on these rootstocks was higher than for rootstock Mazzard. Significant differences of the concentration of the elements were found for Fe, Cu, Zn in fruit and for Fe, Cu and Cr in leaves. Presence of Pb and Cr was not detected in sweet cherry fruit.