Phoma negriana is a little-known pathogen of grapevine canes but increasingly often it is listed in the countries of southern Europe and Asia. The work concerns a study of the opportunities for growth and development of the fungus at different temperatures, pathogenicity tests and the influence of biotechnical preparations on the growth and development of the fungus in vitro. Studies have shown that mycelial growth of P. negriana is possible at the temperature range from 5 to 32ºC with the thermal optimum from 20 to 24ºC. The optimal temperatures for the abundant sporulation was 20, 24 and 28ºC. The positive results of pathogenicity tests as well as re-isolation of the fungus from inoculated shoots confirmed the possibility of grapevine canes infection by P. negriana. A significant factor in facilitating infection were injuries of shoots, what indicates that the fungus is a facultative pathogen of grapevine. Biosept Active limited the growth and development of P. negriana significantly more strongly than Beta-Chikol. When it was applied at the concentration of 0.3%, it caused destruction and loss of fungal hyphae vitality.

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