Update on the situation of Clavibacter michiganensis subsp. sepedonicus in Sweden
In EPPO RS 2002/036, the NPPO of Sweden had reported a few cases of Clavibacter michiganensis subsp. sepedonicus (EPPO A2 quarantine pest). As investigations continued, a further update is now provided.
1. In addition to the 2 previously notified cases, 2 other findings of ringrot were made in 2 lots of ware potatoes cv. Folva, produced at 2 different places of production. In all 4 cases (4 places of production), the origin of seed potatoes was a Swedish certified lot class A sold in spring 2000. This lot had been produced in Sweden in 1999 but originated the year before from a Danish certified seed potato lot (class E). Before certification of the 1999 harvest, the lot had been tested and found free from ringrot.
2. In addition to the 3 previously notified cases, ringrot was found in 3 other lots cv. Folva, produced (in total) on 6 different places of production. In all 6 cases, seed potatoes originated from the same Danish producer of seed potatoes. These had been bought as certified seed potatoes class E or A from Denmark in spring 2001.
3. Two cases of ringrot were found in 2 lots of cv. Satina. These lots were produced in 2 different places of production. The origin of seed potatoes came from 1 lot of certified seed potatoes bought from Germany in spring 2001.
In all cases, phytosanitary measures were taken according to EU Directive 93/85/EEC.
The situation of C. michiganensis subsp. sepedonicus in Sweden can be described as follows: Present, found on the 2001 potato harvest in 12 lots, at 12 production sites, under official control.
NPPO of Sweden, 2002-04.