PROBLEM TO BE SOLVED: To provide a method for easily increasing and promoting accumulation of zinc to plant, especially leaf, stem part and grain part (edible part).SOLUTION: Chemical substance having a thiol group is given to leaves of a plant to thereby change the status of rooting zone and physiological condition of a root, whereby the quantity of zinc absorbed by the plant and the transfer quantity of the absorbed zinc to the ground part of the plant is increased. As such a method, glutathione solution formed by composition of MES-NaOH(pH=6.1) having pH buffer capacity for keeping the pH of the solution equivalent to the pH of apothrust of plant, TritonX-100 which is a surfactant for penetrating the ingredients of the solution into the leaves and glutathione (reduced) is applied or sprayed to the surfaces of the leaves in a proper quantity proper number of times using means such as a brush, whereby glutathione is applied to be limited to the leaves.
