Actavia 0 Renčo, Marek 2005 2005-6-30 80-85 During 2003 and 2004 the occurrence and distribution of Heterodera avenae (Woll.) in the cereal growing areas of the Slovak Republic was studied. 188 soil samples from 27 districts throughout the country were analysed; Heterodera avenae was present in 56.4% of the samples, at an incidence of 2-81 cysts in 100 g soil. At 87 localities the incidence of the parasite was low, at 15 it was medium, and high at 4 localities. 2 41