A novel antibiotic-producing Streptomyces sp. is provided that exhibits antifungal activity only on certain specific plant pathogens. Also provided is a method of treating or protecting plants from fungal infections comprising applying an effective amount of an antibiotic-producing Streptomyces sp. having all the identifying characteristics of NRRL Accession number B-30145. The invention also relates to fungicidal compositions comprising this novel Streptomyces strain and the antibiotics and metabolites produced by this strain either alone, or in combination with other chemical and biological pesticides.