The addition of potassium chloride and potassium sulphate at a rate of 200 g/m2 to the culture medium had no effect on the growth of Sclerotinia trifoliorum, Acrostalagmus roseus I and II, Coniothyrium minitans, Gliocladium sp., Mucor hiemalis, M. spinosus, Sporotrichum carnis and Trichothecium roseum. Treatment of the culture medium with PCNB suppressed to some extent the development of A. roseus I and II, Gliocladium sp., C. minitans I and II, Mucor hiemalis and M. spinosus. The fungal species S. trifoliorum, Rhizopus nigricans and Sporotrichum carnis did not grow at all on PCNB-treated medium. S. trifoliorum, A. roseus I, Gliocladium sp., T. viride and T. roseum were able to grow in the pH range of 4—9. When the pH of the medium was 2, only T. viride grew. Oxygen deficiency suppressed the growth of S. trifoliorum, and the growth and the conidia formation of A. roseus I and II, M. hiemalis and T. viride.