Xylaria grammica EL 000614 strain has a nematicidal activity against root knot nematode. A method for controlling root knot nematode includes treating a crop, a crop seed, or a field for cultivation with a nematicidal microorganism formulation. The method has very little possibility of having a problem related to environmental contamination, and exhibits a high mortality and activity of inhibiting egg hatching for sweet potato root knot nematode (M. incognita). It is expected that the strain can be very advantageously used as an innovative biological control agent which enables prevention of problems associated with environmental contamination.
