Seasonal Variations in Mineral Nutrients in Leaves of ‘Nova’ and ‘Robinson’ Mandarins Budded on Different Rootstocks

Abstract

The characteristics of rootstock have impacts scion’s nutritional status, resistance to environmental stresses and adaptation to a specific region. Thus the performance of a cultivar is largely dependent on the rootstock-scion interactions. In this study, seasonal variations in mineral nutrients of ‘Nova’ and ‘Robinson’ mandarin cultivars budded on different citrus rootstocks were investigated under Dortyol-Hatay (Turkey) ecological conditions. Nitrogen (N), phosphorus (P) and potassium (K) contents of the leaves exhibited slightly similar trends with each other. In general, these nutrients decreased from January to March-April and increased in the subsequent growing season until mid- and late summer, then decreased again until December. Similar trends were also observed in calcium (Ca) and magnesium (Mg) concentrations of leaves. Leaf Ca and Mg concentrations decreased from January to March, then increased during fruit development until July-August and decreased again during autumn and winter. Also, micro elements such as iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu) increased from January to May–June and then gradually decreases began during the growing season until December. Throughout the entire growing season, mean macro nutrients such as N, K and Ca concentrations ranged from 1.89% (‘Nova’/Carrizo citrange) to 2.02% (‘Robinson’/Carrizo citrange), from 1.10% (‘Robinson’/Carrizo citrange) to 1.39% (‘Nova’/Carrizo citrange) and from 2.62% (‘Nova’ /sour orange) to 3.48% (‘Robinson’/Troyer citrange), respectively. Phosphorus and Mg concentrations showed slightly similar trends and varied between 0.14–0.16% and between 0.31–0.39%, respectively. The ranges of mean micro nutrients such as Fe, Zn, Mn and Cu concentrations were between 65.3 and 75.4 mg kg−1, 33.7 and 39.6 mg kg−1, 64.1 and 70.6 mg kg−1, and 10.5 and 11.4 mg kg−1, respectively. It can be concluded that rootstock-scion relations can cause considerable differences in seasonal nutrition of mandarin cultivars.