A novel antibiotic-producing Bacillus sp. is provided that exhibits antifungal activity only on certain specific plant pathogens and no antibacterial activity is provided by this invention, as well as a biologically pure culture of a strain having all the identifying characteristics of this strain. Also provided is a method of treating or protecting plants, fruit and roots from fungal infections by applying an effective amount of these strains, supernatants produced by these strains or a metabolite isolated from these strains. The invention further encompasses the synergistic fungicidal effect of using a strain of NRRL Accession Nos. B-30087 together with B-21661 (AQ 713).