Absorption and translocation of manganese and iron by barley seedlings at different ratios and pH values

Short term experiments were carried out to study the absorption and translocation of manganese and iron by barley seedlings at different ratios and pH values. Data obtained revealed that, the uptake and percentage of translocation of Mn and Fe were affected by their ratios in the media. Increasing Mn concentration and keeping Fe constant correspondingly increased the uptake and translocation of manganese but lowered that of iron giving the evidence that there is a competitive inhibition of iron by manganese and that both elements compete for the same carrier site. The uptake of both mutrients, largely increased with the pH increase from pH4 to pH5 due to the competitive effect of H+ on Mn and Fe. Moreover, it seems that competition between Mn and H+ and that between Fe and H+, each operates at different pH value, since the maximum uptake of Mn was reached at pH5 where as that of Fe was attained at pH6. Also this competitive interference was more pronounced on the percentage of translocation than on the uptake of both mutrients