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1. The response of bean plants to additions of 8, 16, and 32 m.e./l. NaHCO3 to a base nutrient solution was compared with that of plants grown on base nutrient solution adjusted to pH 8.0 with NaOH. 2. Higher concentrations of sodium bicarbonate were associated with greater intensities of chlorosis and marked inhibition in growth. 3. The treatments primarily effected a lowered iron "activity" and calcium content of the leaves and an enhanced potassium content. 4. The accumulation of citric acid in leaves showing intensified chlorosis was found to be a direct concomitant of potassium content. 5. It is suggested that the primary effect of the bicarbonate ion was through its effect on protoplasmic consistency of the absorbing cells of the roots so that these bean plants showed an accentuated accumulation of monovalent cations and a depressed accumulation of divalent cations. 6. The relation of bicarbonate-induced chlorosis to lime-induced chlorosis in the field is discussed.

1. The response of beet plants to additions of 0, 8, 16, and 32 meq/l NaHCO3 to a base nutrient solution was compared with the response of bean plants grown on substrates of the same composition in a previous experiment. 2. The growth of beets was less influenced by the level of the bicarbonate ion in the substrate than was the growth of beans. 3. The bicarbonate treatments effected large accumulations of sodium and oxalate in beet leaves. 4. Comparison of cation accumulation in bean and beet leaves showed that treatment and chlorosis were not correlated with any particular cation or with the K/Ca ratio in both species but rather with monovalent cations or the Na + K/Ca + Mg ratio. 5. The increased accumulation of organic acids in bicarbonate-induced chlorosis appears to depend on the maintenance of ionic balance.