In greenhouse experiments the susceptibility of meadow fescue, perennial ryegrass and Italian ryegrass to Fusarium avenaceum, F. cu/mor um and F. grami num infection was studied. Various responses to Fusarium spp. infection were observed among the tested grass species and their cult i vars. Meadow fescue was the most susceptible to all the Fusarium isolates used. F. avenaceum isolates also strongly reduced perennial ryegrass emergence. In the experiments with Italian ryegrass the number of seedlings having survived the artificial infection of seeds with Fusarium spp. was significantly larger for Atos, Gran, Mitos and Polus cultivars than for Kroto, Lotos and Tur. All of the studied grasses were more susceptible to the strongly pathogenic F. avenaceum isolates than to F. culmorum and F. graminum isolates, having moderate pathogenicity.

Spring triticale 'Migo', and spring barley 'Maresi' grown in pure stand and in their mixtures were used in field experiment. Disease occurrence, number of culms and heads as well as yield were assessed. Powdery mildew and scald of barley and Septaria leaf blotch of triticale occurred in lower degree in mixtures than in pure stands, but only in the years with weather conditions favourable for the diseases development. Fusarium stem rot and eyespot of both plant species as well as net blotch of barley occurred in similar degree in all treatments or even in some mixtures in higher degree than in pure stands.