Screening,Identification and Action Mechanism of Bacteria as Biocontrol Agent against Cucumber Powdery Mildew

One hundred and twenty-five bacteria were tested for their ability to control cucumber powdery mildew in greenhouse.Results showed that 12 bacterium strains could significantly decrease the disease index of this disease.In field plot,the 10 bacteria strains of these 12 bacteria showed significant efficacy to control this disease.Among them,the bacterium strain XJT-7,NZT-14-84 and BDT-25 expressed better efficacy to control cucumber powdery mildew with 79.02%,67.51% and 57.38% respectively in the field plot.The research on mechanism of these 3 bacteria to control this disease indicated their extra cellular metabolites could control the disease.The strain XJT-7 was identified as Bacillus firmus.