The aim of the work was to determine the usefulness of dried leaves of savoy cabbage, red cabbage, horse radish and fringed cabbage in protection of cucumber against damping-off caused by fungi <i>Rhizoctonia solani</i> and <i>Fusarium culmorum</i>. In the laboratory experiments, pathogens were grown on PDA containing dried leaves (3g·100 cm<sup>-3</sup>) and in atmosphere containing volatile substances evolved from plant material. The addition of radish horse leaves into PDA caused total inhibition of <i>R. solani</i> development. Remaining plants were also characterized by high fungistatic activity (% of growth inhibition about 85%). <i>F. culmorum</i> was less sensitive. The horse radish leaves showed the strongest activity (65 %), weakest in combination with fringed cabbage leaves (38,9%). The similar regularity in the case of fumigation activity was observed. The effectiveness of dried leaves in protection of cucumber against damping-off was confirmed in greenhouse experiment. The amendment of soil inoculated with <i>R. solani</i> in dose 2 g per 500 cm<sup>3</sup> of soil significantly increased the number of cucumber sprouts compared to the control. In the experiment with <i>F. culmorum</i> only in combination with horse radish and red cabbage leaves significant action was observed.
Research on possibilities of utilization of chosen Brassicaceae plants in protection of cucumber against damping-off caused by Rhizoctonia solani Kühn and Fusarium culmorum (W.G.Smith)Sacc.
