LAUSR

ABSTRACT To investigate the effect of oxalic and citric acids on the uptake and relationship of phosphorus and zinc in corn (Zea mays L.), some greenhouse experiments were performed by individual and combined application of monopotassium phosphate [KH232PO4] and zinc sulfate [65ZnSO4.7H2O] fertilizers in microcosm. For this purpose after planting corn seeds, solutions of phosphorus (32P) and zinc (65Zn) (14 and 2 M) and organic acids treatments (1 and 10 mM) were injected in microcosms at suitable times. Then, plants were harvested, digested, extracted, and activity of 32P and 65Zn was measured in samples. Results revealed that the highest uptake of 32P in shoots was 18.8% and observed at 10 mM concentration of oxalic acid. But no effect on 65Zn uptake was seen and the highest uptake was observed in control (1.27%). The highest uptake of 32P and 65Zn in plant shoots and roots was observed at 10 mM concentration of oxalic and citric acids, respectively.