STUDY OF ESCA DISEASE OF GRAPEVINE IN BOJNOURD

During growing seasons 2005-2007 samples of grapevine with esca symptoms were collected from different vineyards in Bojnourd (North Khorassan province). Isolation were made from affected wood tissues from branches and trunks on PDA, MEA and OA media. In this study, 64 fungi isolates were recovered and identified as Phaeoacremonium parasiticum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium sp. and Phoma sp. Pathogenesity tests were carried out for Pm. Parasiticum, P. chlamydospora and F. mediterranea under field and greenhouse conditions. within 6 months after inoculation of cuttings, symptoms developed as sever defoliatin and wilting under greenhouse conditions. F. mediterranea caused white wood decay while Pm. parasiticum and P. chlamydospora produced wood discoloration in inoculated grapevines. in the field The pathogens were re-isolated and identified from inoculated grapevines after symptoms observed.