Abstract: In the laboratory studies, fluorescent Pseudomonas sp. strain P_420-4, Bacillus sp. strain B_526-7 and a mixture of the two showed high antagonistic effect against Physollospora piricola, Glomerella cingulata and alternaria mail. _P420-4 and B_526-7 labeled by rifimpicin could colonize and multiply on the phylloplane and fruit surfurv. In field tests when three applications of the mixture of P_420-4 and B_526-7 were made at an interval of 15 days in the early apple growing season, the percentage of rot fruit and diseased leaves reduced by 70.2-77.3% and 39.6-69.3%, respectively, while the weights of 100 leaves and 100 fruit increased by 29.9-44.8% and 16.2-22.4%, respectively in the later season. In an laboratory experiment of inoculating fruit with the anthracnose pathogen followed by treatment with the mixture formulation, it was found that prolonged interval time between the inoculation and the treatment reduced the effect of the mixture in suppressing infection and development of the pathogen.