Effect of cultivar on leaf-mineral composition of olive tree

The effect of cultivar on leaf-mineral composition of fifteen olive cultivars was studied, during three years, in an experimental olive orchard grown on a calcaric regosol, in the Portuguese region of Ribatejo. Leaves were collected during the winter (February/March) from the middle section of last season terminal shoots. A significant effect of interaction between each year environmental conditions and cultivar on leaf-N, P, Ca, Mg and Zn concentration was found (p less than or equal to 0.05). The mean effect of the cultivar on the foliar concentrations of N, P, K, Ca, Mg, S, Mn, Zn and B was significant (p less than or equal to 0.05). Experimental results indicated the need of more studies, including both factorial fertilisation trials and olive-grove surveys, in order to establish leaf-standard range values for each cultivar or groups of related cultivars with major regional interest.