Two consignments of ware potatoes, imported from Poland to the UK by the same Polish exporter, have tested positive for ring rot, the UK Plant Health Service (PHS) confirmed.
The detections were made during routine inspections and the UK Plant Health Service is now reportedly working with The National Plant Protection Organisation (NPPO) of Poland to ascertain the source of the infected consignments.
Consignments of seed potatoes imported to England and Wales are inspected by the Plant Health and Seeds Inspectorate and samples are taken to be tested for the disease at the Fera Science Ltd Laboratory. Equivalent arrangements apply in Scotland and Northern Ireland.
According to the PHS, tracing of the affected consignments has been completed, with inspections undertaken at several locations linked to its movement, with remaining stocks destroyed.
None of the locations involved were potato growers or linked to agriculture, the PHS said.
As a result of the detections, the PHS announced that 100% of all consignments of imported ware potatoes will be inspected and tested until further notice, up from the previous rate of 50%.
Consignments from the affected Polish exporter have been suspended pending the results of further latent testing, irrespective of whether there are suspected symptoms.
As ring rot (clavibacter sependonicus) is a notifiable disease and listed as a UK quarantine pest, any consignment of ware potatoes found to be infected with the disease will be destroyed under a statutory plant health notice.
Additionally, any findings at a processor would result in a statutory plant health notice being issued, which would require a full clean down and disinfection of the premises before operations could resume.
Ring rot of potatoes is caused by a bacterial pathogen that can potentially cause serious losses to potato growers and potato seed producers.
Symptom expression occurs at different rates in different cultivars and is affected by temperature and other environmental conditions. Some cultivars may only rarely express symptoms, while other infections can be symptomless, the PHS said.
Symptoms are somewhat similar to those of brown rot, but the initial discoloration of the vascular ring is usually glassy and water-soaked, rather than brown, and the ooze from the ring is cheese or cream like.
Further disease development leads to tuber breakdown with internal hollowing, the PHS stated.
The disease favours cooler climates and as it is already established in northern and eastern Europe, it could readily establish under UK conditions, the PHS said.
“If the disease were to become established in the UK, the effects on our seed-potato industry would be substantial, especially the knock-on effect for exports,” it said.
“Once established, the costs of control would also be high because the disease is difficult to eradicate; the bacterium can survive in a dry state for many years contaminating boxes, machinery, and stores,” the PHS declared.
