Findings of Clavibacter michiganensis subsp. sepedonicus in Sweden
The NPPO of Sweden recently informed the EPPO Secretariat that Clavibacter michiganensis subsp. sepedonicus (EPPO A2 quarantine pest) has been found in 2 lots of ware potatoes (cv. Folva) produced at 2 different places of production. In both cases, the origin of the seed potatoes used was a lot of Swedish certified seed potatoes (class A) bought in spring 2000. This lot had been produced in 1999 in Sweden but originated from a seed potato lot from Denmark (class E) produced in 1998. Before certification of the 1999 harvest, the lot had been tested and found free from ring rot. Another finding of ringrot was made in 2 lots of seed potatoes (cv. Folva) not yet certified and in one lot of ware potatoes of the same cultivar. All lots originated from the same Danish producer of seed potatoes, and had been bought in spring 2001 as certified seed potatoes (class E). During the investigations made to trace back the above mentioned cases, 3 other lots of ware potatoes (cv. Folva), at 3 different places of production, were also found infected by ringrot. The origin of the seed potatoes is still to be found in these cases. Investigations are continuing.
NPPO of Sweden, 2002-02.