The invention relates to a new fungicide product for the biological control of phytopathogenic fungi, which contains a new isolate of Bacillus velezensis strain AH2, deposited in the Spanish Type Culture Collection (CECT) as CECT-7221, which has a high antagonist activity against this type of pathogen, as well as the property of stimulating plant growth by different mechanisms. The invention also relates to a liquid formulation which has good stability at ambient temperature and is effective in the treatment of diseases caused by phytopathogenic fungi and for the stimulation of plant growth.