PURPOSE: To increase the yield of azuki bean (red bean in Japan) in high efficiency by scattering a plant growth regulation agent having gibberellin biosynthesis inhibiting action to the leaf and stalk of an azuki bean plant in e.g. stage of forming pollen mother cell and embryosac mother cell. CONSTITUTION: The yield of azuki bean can be increased by applying a plant growth regulation agent having gibberellin biosynthesis inhibiting action such as a triazole compound e.g. (E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1- yl)-1-penten-3-ol (salt) or an isonicotinanilide compound e.g. 4'-chloro-2'-(α- hydroxybenzyl)isonicotinanilide (salt) to the leaf or stalk of an azuki bean plant in a flowering stage or a stage from the pollen mother cell and embryosac mother cell forming stage to a flower organ completing stage.
