Regulation of Yield, Fruit Size, and Leaf Mineral Nutrients of the ‘Šumadinka’ Sour Cherry Cultivar with Help of Rootstocks

The impact of seven clonal rootstocks (Colt, MaxMa 14, Krymsk 6, Adara, Cigančica, Gisela 5, and Gisela 6) and one local plum (Myrobalan seedlings) on yield, fruit weight, leaf mineral content at 120 days after full bloom (DAFB), and deviation from optimum percentage (DOP) for macro- and microelements of the ‘Šumadinka’ sour cherry cultivar was evaluated in orchard conditions for two consecutive years. Results showed that yield was higher on Adara, Gisela 5 and MaxMa 14, intermediate on Cigančica and Krymsk 6, and lower on Colt, Gisela 6, and Myrobalan rootstocks. The average fruit weight (FW) was highest on Gisela 6 and lowest on Myrobalan seedlings, and FW was higher in the second year of the trial. Significant effect of rootstock was found on the leaf mineral analysis properties evaluated. Thus, Adara showed the best capacity to uptake and translocate to the scion leaves for most macro- and microelements, whereas the poorest nutritional status was, in general, obtained for Myrobalan, probably due to the incidence of graft incompatibility disturbances with the ‘Šumadinka’ cultivar. MaxMa 14 showed the best balanced nutritional values (ΣDOP) whereas the wider imbalance among elements was induced by Myrobalan seedlings. ‘Krymsk 6’ had, in general, lower values for most leaf mineral elements but higher ΣDOP macro and ΣDOP micro-indexes, showing more unbalanced nutritional index than the rest of rootstocks, with the exception of Myrobolan, and both of them followed by Colt. This work demonstrates that the rootstock strongly influences some important sour cherry attributes such as yield, fruit size, leaf macro- and microelements. The significant positive correlations between yield and mineral elements as Mn and Ca could indicate the interest of rootstocks having higher absorption and uptake for these elements in the present growing conditions. Considering their overall performance and tolerance to heavy and acidic soils, and according to the PCA results, Adara, MaxMa 14, and Gisela 6 appear as new promising rootstocks and can be recommended for sour cherries growing under similar soil conditions. We believe that sufficient information on the influence of different rootstocks on yield, fruit size, and leaf mineral composition of sour cherry would enable less ambiguous comparisons within and among them and ensure the best choice for growing a specific cultivar in similar environmental conditions.