Gibberellic acid when sprayed to the tops of Vicia faba seedlings even in lower concentration, causes significant changes in the physiology of the plant. Simultaneous spray of gibberellic acid and Knop solution brings about an increase in the rate of P32-uptake. Gibberellic acid shows some inhibitory effects on the absorption and/or translocation of radioactive phosphorus from the roots to the leaves. Delayed treatments with Knop solution shows similar results to those of the direct treatments except at the highest concentration.