Eradication of Ralstonia solanacearum from Ireland
In Ireland, during the annual survey for Ralstonia solanacearum (EPPO A2 List), a water sample from a potato packer was found positive on 2007-09-26. Investigations showed that one potato variety supplied by one grower was at the source of this positive sample. All 120 ha of potato stocks on the growers’ farm were tested with 4 fields testing positive. These plots had all been produced from the same 2006 seed lot. All the 2007 seed progeny from this lot was identified leading to the testing of a further 24 growers. As a result of the investigation, it emerged that contamination appeared to originate from 2 contiguous plots cultivated in 2006 that had both been irrigated that year from a nearby river. Water and weed samples taken at the location concerned and upstream have tested negative. As part of the investigation, 1 positive seed potato lot and 1 positive ware potato lot were detected at 2 farms, both were sister lots to the original finding. These places were designated as contaminated. There were 9 other farms that had received sister lots but had tested negative for R. solanacearum.
Phytosanitary measures were applied in accordance with EU Directive 98/57/EC to eradicate R. solanacearum. Nearly 1000 tonnes of potatoes were designated as contaminated and destroyed (potatoes were lifted and destroyed in the field). 5000 tonnes of potatoes were designated as probably contaminated and were disposed through approved processors for packing to final consumer. These facilities had appropriate water treatment systems and heat-treated all waste potatoes before being used as cattle feed. All seed potatoes marketed and planted in 2008 were tested and found free from R. solanacearum. In addition, all tested samples of surface water were found free of the bacterium. Therefore the NPPO of Ireland considers that eradication has been achieved. Intensive surveys will continue in Ireland.
The pest status of Ralstonia solanacearum in Ireland is officially declared as: Absent, pest eradicated.
Sources
NPPO of Ireland, 2008-09.