Chitosan was degraded by gamma irradiation in solid state to obtain the irradiated oligochitosan. With increasing
dose, the molecular weight of irradiated oligochitosan decreased. Lactic acid was used to dissolve the irradiated
oligochitosan instead of acetic acid because the C.gloeosporioides growths were considerably inhibited by acetic
acids. The inhibition activity was dependent upon the irradiated oligochitosan concentrations, and higher
concentration resulted in higher antifungal activity. In our study demonstrated that irradiated oligochitosan has
potential for use in controlling C.gloeosporioides causing chili anthracnose.