Response of four olive (Olea europaea L) cultivars to six B concentrations Growth performance, nutrient status and gas exchange parameters

A greenhouse experiment was conducted to study the effects of boron (B) on growth nutrient status B distribution and gas exchange parameters of olive plants (Olea europaea L) One-year-old own-rooted olive plants of the Greek cultivars Megaritiki Chondrolia Chalkidikis Amfissis and Kalamon were grown in a sand-perlite medium and irrigated with nutrient solutions containing 027 0 5 1 2 5 5 and 10 mg L-1 B (0 27 and 10 mg L-1 were considered as control and excess B treatment respectively) After culturing for 185 days leaves and stems (from basal and apical part of the shoots) and roots were separately sampled Our results showed that the final number of leaves per plant was negatively correlated with B coni entration in the nutrient solution Furthermore in B100 treatment Megaritiki had decreased length and number of lateral stems Chondrolia Chalkidikis and Amfissis showed decreased length of lateral stems and Kalamon decreased length of lateral stems and plant height In general dry weight of stems and leaves was not significantly correlated with B concentration in the nutrient solution B concentration in leaves and stems was linearly correlated with B supply A linear correlation existed between B concentration of the nutrient solution and that of leaves and stems At the end of the experiment B levels in the leaves and stems of B0 27 and B0 5 treatments did not differ significantly In general the increase of B concentration in the nutrient solution negatively affected the nitrogen (N) concentration of leaves and stems while phosphorus (P) and Iron (Fe) concentrations were not affected Furthermore potassium (K) and calcium (Ca) concentration in stems of plants supplied with 10 mg L-1 B was decreased In addition high B supply resulted in Increased magnesium (Mg) and manganese (Mn) concentrations in Chondrolia Chalkidikis and Amfissis and in the decrease of zinc (Zn) concentrations in all plants A significant decline in photosynthetic rate at the end of the experiment was observed in the B5 0 treatment regardless of cultivar (C) 2010 Elsevier B V All rights reserved