The influence of low Cr III concentrations (0, 0.25, 0.5, and 1.0 μM as CrCl3.6H2O) on growth, chlorophyll and carotenoid content, the concentration of selected mineral nutrients (Fe, Mn, P), and Cr content was determined in both Fe-control (10 μM Fe as Fe-EDTA) and Fe-deficient (no Fe supply) bush bean (Phaseolus vulgaris L.) plants grown hydroponically. Chromium significantly enhanced growth of both Fe-control and Fe-deficient plants. In Fe-deficient plants, Cr significantly reduced chlorosis in young leaves, increasing the concentration of chlorophyll and carotenoids. This beneficial effect of low Cr concentrations was neither correlated to changes of Mn, P, or Fe tissue concentrations nor to Cr-induced alterations of the Fe/Mn and P/Fe ratios. As total Fe was analyzed, the effect of Cr on the subcellular Fe distribution or on the Fe2+/Fe3+ ratio can not be excluded. Copyright © 1991 by Marcel Dekker, Inc.