Update on the situation of Ralstonia pseudosolanacearum in surface water in the Netherlands
In the Netherlands, Ralstonia pseudosolanacearum (EPPO A2 List) was first found in surface water in 2020 in the province of Utrecht, and in the province of Overijssel (EPPO RS 2021/179, RS 2023/165). In order to prevent any further spread of the bacteria with water, it is prohibited to use surface water to irrigate seed potatoes across the whole country. In areas where EU regulated Ralstonia species have been found in surface water, it is prohibited to use surface water to irrigate any type of potato crops.
Since July 2023, R. pseudosolanacearum was first recorded in the province of Friesland and new findings were also recorded in two other areas (provinces of Utrecht and Overijssel) in the vicinity of findings reported before. The findings in Friesland are at a great distance from the earlier findings and do not appear to be connected.
As part of the 2023 water survey in total 13 water samples (out of 1937) tested positive for R. pseudosolanacearum, as well as one sample of the weed Solanum dulcamara (out of 51). The irrigation prohibition area for potato cultivation has been adjusted accordingly.
The pest status of Ralstonia pseudosolanacearum in the Netherlands is officially declared
Sources
NPPO of the Netherlands (2023-11). https://english.nvwa.nl/topics/pest-reporting/documents/plant/plant-health/pest-reporting/documents/pest-report-update-finding-of-ralstonia-pseudosolanacearum-in-surface-water-in-the-netherlands-provinces-friesland-utrecht-and-overijssel-november-2023