PROBLEM TO BE SOLVED: To provide an agent for suppressing the pathogens of blast blight of useful crops, enabling easy and convenient application, exhibiting high controlling effect on blast blight and having high safety and provide a method for controlling the pathogens of blast blight. SOLUTION: The agent for suppressing the growth of the pathogens of blast blight of useful crops contains a cellulose derivative as an active component. The method for the control of blast blight comprises the use of the agent for suppressing the growth of the pathogens of blast blight. COPYRIGHT: (C)2003,JPO