In carrying out the research program, the research fellow will have to study epiphytic, foliar and carpospheric microbial populations, and subsequently validate their antagonistic efficacy against tomato phytopathogenic fungi in controlled environement and post-harvest trials. Conventional and molecular microbiological techiques will be applied for the in vitro evaluation of the efficacy of antagonistic bacteria, alone and in mixture, and for study of their mechanisms of action with reference to antifungal activity and plant growth promotion. Efficacy assays will then be carried out in a controlled environment and in post-harvest, in order to verify the results previsiouly obtained in vitro. Data will be processed by multivariate statistical analisys.