EN
The occurrence of ergot [Claviceps purpurea (Fr.) Tul.] was studied in eight Lithuania-grown winter rye varieties at Šiauliai University’s Botanical Garden during the years 2002–2004. The source of infection consisted of ergot sclerotia incorporated in superficial layer of the soil between experimental plots of rye. Germination of ergot sclerotia and formation of ascocarps were assessed every three days from the first emergence of ascocarps over the soil surface. Percentage of flowering ears of rye was recorded every three days from the beginning of flowering of the first ears to the end of flowering. Percentage of ergot-infected ears and number of sclerotia per 1 m2 were estimated at rye hard maturity stage (BBCH 87). Averaged data from three experimental years suggest that local winter rye tetraploid variety Rûkai, characterised by late and lengthy flowering, exhibited the highest ergot susceptibility. Diploid varieties Duoniai and Joniai, flowering at a similar period as Rûkai, but having less expressed peak of flowering, were significantly less ergot – infected in 2002 and 2004, but in 2003 the occurrence of ergot on all the three varieties was similar. In our tests we did not reveal any increased ergot-susceptibility of the hybrid variety Esprit, although many authors indicate that hybrid varieties are the most susceptible to this pathogen. From the tested rye varieties, Walet, Motto and Hacada were found to be the least infected varieties, whose flowering was short and only a small number of ears flowered simultaneously. A strong negative correlation between crop density and ergot infection was established.