Effects of Different Concentrations of Boron on Concentration and Distribution of this Element and some other Nutrients in Hydroponic Condition in two Olive Cultivars

Boron toxicity usually occurs in arid and saline soils. Among all the pollutant''s resource، irrigation water is the most important factor in boron elevating in the soil. Modification of boron-rich soils is difficult and in this case، resistant varieties can play an important role in increasing the cultivation in areas with high boron level. To assess the effects of different concentrations of boron on nutrient concentration and its distribution in olive plants، a factorial experiment was carried out in completely randomized design with six levels of boron (0،2، 10، 20، 30، 40 and 50 mg L-1) and two varieties (Konservolia and Amygdalolia) with four replicates. Results showed that with increasing the levels of boron، the level of nitrogen، phosphorus، potassium and calcium decrease significantly. With increasing of boron concentration to 50 mg L-1، nitrogen levels decreased to 47% in Amygdalolia compared to control. Boron concentrations in all plant parts increased with increasing boron level in the nutrient solution. Described diagnostic symptoms of boron toxicity were appeared 45 days after beginning of the experiment in the concentrations of (30، 40 and 50 mg L-1) and in Konservolia appeared 75 days after beginning of the experiment in the concetrations of 40 and 50 mg L-1.