Provided is a novel and highly effective plant growth regulator for cultivated plants which is to be used in cultivating crops such as banana, characterized by comprising, as the active ingredient, a heterocyclic compound represented by general formula (I). In general formula (I): A represents a nitrogen atom or C-hal (wherein hal represents a halogen atom) B represents a nitrogen atom R1 represents a halogen atom, a C1-6 alkyl group or a C3-6 cycloalkyl group and R2 represents a hydroxyl group, a C1-6 alkoxy group, a benzyloxy group, a benzyloxy group having one or more substituents on the ring thereof, said substituents being the same or different and selected from among a halogen atom, a cyano group, a C1-6 alkyl group, a C1-6 haloalkyl group, a C1-6 alkoxy group and a C1-6 haloalkoxy group, a phenylamino group, or a phenylamino group having one or more substituents on the ring thereof, said substituents being the same or different and selected from among a halogen atom, a cyano group, a C1-6 alkyl group, a C1-6 haloalkyl group, a C1-6 alkoxy group and a C1-6 haloalkoxy group.La presente invención se refiere a un regulador de crecimiento 3-cloro-4-metilanilida del ácido 4-metil-1,2,3-tiadiazol-5-carboxí lico par el incremento del número de hojas diámetro de pseudotallo, altura de la planta hija y rendimiento en frutos de plantas específicamente de plátanos.
