A biological material is disclosed for exerting antagonism against vegetable pathogens, which contains Bacillus mojavensis R3B mutant strain deposited under # NCAIM (P) B 001389 according to the Budapest Treaty. The biological material according to the invention is an effective antagonist against the pathogens of vegetables, preferably tomato, pepper, lettuce and/or cabbage, in particular against the pathogens selected from the group of Xanthomonas vesicatoria, Pseudomonas syringae and Clavibacter michiganensis vegetable pathogen bacteria and Pythium debaryanum, Phytophthora infestans, Alternaria alternata and Fusarium oxysporum vegetable pathogen fungi. Furthermore, the invention relates to a composition comprising the biological material according to the invention and optionally a copper-containing pesticide and a process for controlling vegetable pathogens, furthermore use of the biological material or composition according to the invention for the protection of vegetables, preferably tomato, pepper, lettuce and/or cabbage.