The effect of gums formed in stone-fruit trees on the in vitro growth and development of Verticillium albo-atrum and V. dahliae cultured on Czapek Dox Agar (CzDA), Malt Extract Agar (MEA) and Potato Dextrose Agar (PDA) was investigated. Addition of gums at concentration 5 mg/cm3 to all used media greatly stimulated mycelium growth of V. albo-atrum and V. dahliae and sporulation of the pathogen. Surface of colony of the pathogens after 8 days of culturing on CzDA, MEA and PDA supplemented with gums increased twice on the first two media and three fold on PDA as compare to the control.