Studies on Fungicidal Activity of Metabolic Products of Actinomycetes

The bioassay results of the fermentation product of No.24 strain actinomycete isolated from the soil of Qinling mountain areas are reported. The results show that the fermentation product had a strong inhibition on various fungi by means of mycelium growth rate, the EC_(50) value against Macrophom kawatsukai and Bipolaris sorokiniana was 146.87 mg·L~(-1) and 164.09 mg·L~(-1). By means of spore germination test, the EC_(50) value against Exserohilum turcicum and Fusarium oxysporium was 129.33 mg·L~(-1) and 184.99 mg·L~(-1). The results of pot tests show that the fermentation product exhibited 76.1% of protective efficacy and 70.7% of therapeutic efficacy against Pseudoperonospora cubensis, 66.9% of protective efficacy and 61.1% of therapeutic efficacy against Botrytis cintrea at the concentration of 6 000 mg·L~(-1). The field trails results indicate that the fermentation product of No.24 had a certain control effect against Pseudoperonospora cubensis and Botrytis cintrea.