Provided are a plant growth regulator that is effective in increasing the amount harvested of plants belonging to the family Musaceae, particularly the banana improving the number of functional leaves promoting growth and the like, as well as a method for using the same. Provided are a plant growth regulator that comprises isoprothiolane (diisoropyl 1,3-dithiolan-2-ylidene malonate) as an active component and is effective in increasing the amount harvested of plants belonging to the family Musaceae, particularly the banana, a method for using the regulator by spreading or application treatment, soil irrigation or infusion treatment, and the like, as well as a method for regulating plant growth.La presente invención se refiere al uso del regulador de crecimiento isoprotiolano para aumentar el rendimiento de fruto en una planta de banana cultivada en suelo.
