INFLUENCE OF EDTA COMPLEXATION ON PLANT UPTAKE OF MANGANESE(II)

The effect of complexation has been variously described in the literat ure as causing both increased and decreased Mn uptakes by plants. This paper describes short-term experiments using the radiotracer Mn-54 to monitor Mn uptake by barley plants (cv. Georgie), The results show th at when the amount of complexed Mn reached similar to 45% the concentr ation in roots substantially increased - in line with our previous fin dings from a multi-element uptake study. However, for greater than 90% Mn complexation the concentration in roots had decreased slightly com pared to that of 45% and 0% complexation. This variation in uptake wit h complexation explains the apparent discrepancies in the literature a nd points to mutual metal antagonism occurring under conditions of met al (Fe or Zn) deficiency,