The role of organic acids on the uptake and relationship of phosphorus and zinc in corn (<italic>Zea mays</italic> L.) by application of 32P and 65Zn radioisotopes.

To investigate the effect of oxalic and citric acids on the uptake and relationship of phosphorus and zinc in corn (<italic>Zea mays</italic> 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 <inline-graphic></inline-graphic>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. [ABSTRACT FROM AUTHOR]