The Chemical Status of Bean Plants Afflicted with Bicarbonate-Induced Chlorosis

Abstract

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.