PROBLEM TO BE SOLVED: To provide an agent for inhibiting the flower stalk formation and/or flower bud differentiation of a plant, and to provide a method for inhibiting the flower stalk formation and/or flower bud differentiation of the plant with the agent for inhibiting the flower stalk formation and/or flower bud differentiation. SOLUTION: This agent for inhibiting the flower stalk formation and/or flower bud differentiation of the plant contains theobroxide or its analogue. The agent for inhibiting the flower stalk formation and/or flower bud differentiation is applied under conditions for inhibiting the flower stalk formation and/or flower bud differentiation of the plant to inhibit the flower stalk formation and/or flower bud differentiation of the plant. Since the flower stalk formation and/or flower bud differentiation of a long day plant such as Spinacia oleracea L. are performed under a long day condition, the agent for inhibiting the flower stalk formation and/or flower bud differentiation of the plant is applied under the long day condition. The agent for inhibiting the flower stalk formation and/or flower bud differentiation of the plant can be applied to the plant in an application form such as a foliar application form. COPYRIGHT: (C)2006,JPO&NCIPI
