Abstract: Three kinds of extracts from ginkgo (Ginkgo biloba L.) testas were examined for the inhibiting effects against plant pathogen Cylindrocladium colhounii using mycelium growth inhibition method. MIC and MBC of three kinds of extracts were also determined. The results showed that, in the same experiment days, ethanolic extracts exhibited the best inhibiting effect and its minimum efficacy is 37.4%, followed by petroleum ether extracts with a minimum efficacy of 23.7%, and the minimum efficacy of fresh extracts is 18.4%. When extracts concentration comes to an appropriate value, three kinds of extracts could achieve an efficacy of 100%. MIC and MBC of three kinds of extracts were 86.25/86.25 172.5/276 and 293.25/345 mg·mL^-1, respectively. The results indicated that the inhibiting components of ginkgo testas dissolved in ethanol more easily than in other two solvents, which provides scientific reference for the application of extracts from ginkgo testas as biological fungicide in agriculture.

Key words: ginkgo testas, extracts, inhibiting experiment, MIC/MBC