The Uptake of Inorganic Ions by Plant Leaves

Abstract

A technique for estimating the gross uptake of ions by plant leaves is described. Uptake of strontium-89 and caesium-137 from droplets applied to plant leaves was greatly affected by the humidity of the air, the effect being markedly dependent on the initial concentration of the solution. Uptake was greater in light than in darkness; the effect of temperature was relatively small. The percentage uptake of the nuclides was reduced only to a relatively small extent as the concentration of carrier ion was increased. This was in marked contrast to the situation when leaves were fully immersed in solution. 137Cs was taken up to a greater extent than iodine, phosphate, or sulphate. The role of exchange and of fixed negative charges in uptake is discussed.