First report of Clavibacter michiganensis subsp. sepedonicus in Bulgaria
The NPPO of Bulgaria recently informed the EPPO Secretariat of the first finding of potato ring rot (Clavibacter michiganensis subsp. sepedonicus – EPPO A2 list’) on its territory. During the official annual survey of potato crops (‘Phytosanitary control of potatoes – 2005), the presence of C. michiganensis subsp. sepedonicus was detected in samples collected in producers’ warehouses. This corresponded to 1 outbreak in seed potato production plots and 3 in ware potatoes. The presence of the bacterium was confirmed by two IF tests (using different antisera), biological tests on aubergine and PCR assays. Phytosanitary measures have immediately been taken to prevent any further spread and eradicate the disease. Infected plots (20.9 ha) have been placed under quarantine. All agricultural machinery, equipment, warehouses or any object which had been in contact with infected tubers were disinfected with formalin and sodium hypochloride solutions. Potato production on infested land is prohibited for 3 years. Infected crops (230 tons) were destroyed by deep burial or burning. Investigations are continuing to trace-back all potato lots which may be related to the infested ones.
The situation of Clavibacter michiganensis subsp. sepedonicus in Bulgaria can be described as follows: Present, first found in 2005, few outbreaks in both seed and ware potatoes (4 outbreaks on 20.9 ha), under eradication.
NPPO of Bulgaria, 2006-09.