ABSTRACT The purpose of this study is to identify the fungus that causes the shallot moler disease in Rumbai Bukit, Rumbai subdistrict, Pekanbaru, as well as to test and obtain chitosan concentrations that are more capable to inhibiting the growth of the F. oxysporum cause of moler disease in shallots. Both experiment and observation were used in this study. Observational investigation, namely…