Chitosan has beenwidely used to reduce the growth of Rhizoctonia fragariae
(Elmer and LaMondia, 1994), Sclerotium sclerotiorum (Cheahet al., 1997) and P. botryosa (Sunpapao and Pornsuriya,2013). Furthermore, chitosan changes the pathogen morphologies of Fusarium oxysporum f.sp. radis-lycopersici, R. stolonifer and S. sclerotiorum, to abnormal shapes and sizes