Effect of Root Cation Exchange Capacity (CEC) and Root Weight on Leaf Cation Content of Three Citrus Rootstock Seedlings

Effects of root cation exchange capacity (CEC) and root weight on the leaf cation content of three citrus rootstock seedlings were studied. Significant differences in the root CEC and root weight of the seedlings were observed. Of the three seedlings, Swinglea had the least root dry weight, but exhibited the greatest root CEC. Leaf cation content of the rootstock seedlings correlated more with root CEC than with the root dry weight. Also, the ratio of the leaf Ca content failed to fit the conditions of Donnan-equilibrium as shown by the relation, (CEC₁/CEC₂ = (Ca₁/Ca₁)² = (K₂/K₁) However, the reciprocal ratios of leaf K content fit the conditions. Possible explanation for this behaviour are suggested.