Infection ability of mycelium and spores of<Emphasis Type="Underline">Microdochium</Emphasis><Emphasis Type="Underline">nivale</Emphasis> (Fr) samuels hallett to<Emphasis Type="Underline">Lolium</Emphasis><Emphasis Type="Underline">Perenne</Emphasis> L.

Mycelium and spores ofMicrodochium nivale /Syn.Fusarium nivale/ were compared according to their ability to infect plants ofLolium perenne. The experiments were carried out according to the “cold chamber” method (Cormack, Lebeau 1956 modified by Pronczuk 1987). Between these two types of inoculum significant differences were found. The spore inoculum did not give any symptoms while the mycelial inoculum incited a severe disease in plants ofLolium perenne during one month of incubation.Under laboratory conditions it was found that the spore cultures ofMicrodochium nivale grew very slowly at 0 – 1°C, whereas their growth at 18 – 20°C was very fast. Growth of the mycelial cultures was not as profoundly affected by temperatures studied as the spore ones.It was concluded that to incite a disease the spore inoculum require longer incubation time than mycelial ones. The mycelial inoculum is more useful for screening of plants for resistsance.