Abstract
In order to determine the best iron (Fe) sources under alkaline conditions, an factorial experiment was conducted based on a completely randomized design with two factors of Fe fertilizer at four forms [iron sulfate (FeSO4), Fe- ethylenediaminetetraacetic acid (EDTA), Fe- diethylenetriaminepentaacetic acid (DTPA) and Fe- ethylenediamine-N,N’-bis (EDDHA), and sodium bicarbonate (NaHCO3)] at three levels (0, 10 and 15 mM) with three replications. Results showed that the highest loss of vegetative growth (stem length, leaf number, leaf area, stem diameter, and leaf, stem and root dry weight) and ecophysiological parameters (Fv/Fm, SPAD and RWC) was observed in plants treated with FeSO4. Alkalinity stress increased proline concentration especially in FeSO4 treatment. Bicarbonate treatments decreased Fe concentration in plant tissues. Fe-EDTA and Fe-DTPA fertilizer sources acted similar or even better than EDDHA at 10 mM NaHCO3 concentration, but the best Fe fertilizer source was Fe-EDDHA at 15 mM NaHCO3 concentration.