PROBLEM TO BE SOLVED: To provide a method for treating plants with an agent to activate the self defensive mechanisms of the plants, thereby avoiding the low temperature troubles, diseases, insect damages, and replant failures of the plants. SOLUTION: This self defensive substance-inducing agent for the plants contains at least one compound selected from the group consisting of theobroxide and its analogues as an active ingredient. The method for inducing the production of a self defensive substance in the plants includes supplying water containing at least one compound selected from the group consisting of theobroxide and its analogues as an active ingredient. COPYRIGHT: (C)2007,JPO&INPIT
