Abstract: Using Colletotrichum gloeobosporioides, Fusarium oxysporum, Botrytis cinerea, Pythium aphanidematum as the model targets, six fungi standard strains and six actino standard strains were tested by semi-solid medium method （PDB medium with the appropriate amount of agar） and disk diffusion method （PDA medium）. The activities of fermentation broth, supernatant and mycelium of fungi and actino were compared by semi-solid medium method and agar disk diffusion method. The results showed that the activity of the sample was directly related to the screening method and incubation time. The activity resolution of fermentation broth and mycelium in semi-solid medium method was blurring, and the activity response to the supernatant of standard strains of fungi and actino was clear; in the agar disk diffusion method, with the increase of culture time, the activity of fermentation broth and mycelium increased, while the activity of the supernatant of standard strains of fungi and actinomycetes fungicides decreased. The semi-solid medium method was suitable for the screening of supernatants without living cells, and the agar disk diffusion method was suitable for the screening of fermentation broth and mycelium with living cells. Selecting the appropriate screening method and culture time according to the type of sample could reduce the false negative results.

Key words: mode target, bio-fungicide, semi-solid medium method, disk diffusion method