LEAF ANALYSIS AS A TOOL FOR EVALUATING NUTRITIONAL STATUS OF HAZELNUT ORCHARDS IN CENTRAL ITALY

Despite the fact that Hazelnut is a one of the major crops in Viterbo Province (Lazio Region, Central Italy), there is little available experimental data concerning reference values for leaf analysis interpretation and referring to the most widespread cultivar in the area (mainly ‘Tonda gentile romana’) and specific pedoclimatic conditions. The objectives of this work were to study the dynamics of the macro and micro-nutritive contents of leaves during the vegetative cycle of hazelnut and to determine provisional standards for foliar analysis interpretation. The results obtained made it possible to describe general trends and variability in leaf concentrations of nutritive elements during the vegetative cycle of hazelnut. On the basis of the data observed, time of sampling and provisional standard values for leaf analysis interpretation for hazelnut cv. Tonda gentile romana cropped in the Cimini mountains area have been proposed for N, P, K, Mg, Ca and B.