Suppressiveness of Vermicompost against Fusarium Wilt of Tomato

Vermicompost added to various container media significantly inhibited the infection of tomato plants by Fusarium oxysporum f. sp. lycopersici. The protective effect increased in proportion to the rate of application of vermicompost. Every type of container media amended with this substrate, used in the experiments, were suppressive to the pathogen. Vermicompost lost its activity after heating. Sterilized extracts of vermicompost added to potato dextrose agar stimulated the growth of F. oxysporum mycelium. The results indicate that chemical factors in this substrate had no direct inhibiting effect on the fungus. The total number of micro-organisms and populations of antagonistic bacteria and fungi were significantly higher in vermicompost than in the control peat substrate. A biotic nature is suggested for the suppressiveness of the vermicompost.