SUMMARY

aceae and Urticaceae) were collected in orchards of hazel-nut (Corylus avellana L.) in Samsun and Ordu provinces of Turkey and tested by DAS-ELISA and biological assay methods. Samples belonging to Scandix sp., Artemisia vulgaris L., Campanula sp., Galeopsis sp., Salvia verbenaca L., Prunella sp., Clematis vitalba L. and Rubus canescens L. were found to be infected by Apple mosaic virus (Ap-MV). This is the first report of ApMV infection of these plants under natural conditions. The epidemiology of ApMV in hazelnut orchards is discussed. Key words: ApMV, hazelnut, weed host. Turkey has the largest production of hazelnut (Cory-lus avellana L) in the world, followed by Italy, the USA and Spain (Anonymous, 2004). Hazelnut is grown ex-tensively in the Black Sea Region with nearly 33 % of the production in Samsun and Ordu provinces (Anony-mous, 2003), which are located along the central coast of the Black Sea. ‘Palaz’, ‘Tombul ’ and ‘Sivri ’ are the main cultivars and are grown as bush-like trees called ‘ocak ’ in the region. Apple mosaic virus (ApMV; genus, Ilarvirus, family Bromoviridae) is one of the most important pathogens of hazelnut and may have a synergistic effect when co-infecting with Prunus necrotic ring spot virus (PNRSV; genus, Ilarvirus; family, Bromoviridae) (Anonymous, 2004). ApMV infection in hazelnut has been reported in many countries, including Italy (Scaramuzzi and Ciferri