Update on the situation of Ralstonia solanacearum on roses in Switzerland
In Switzerland, Ralstonia solanacearum race 1 (EPPO A2 List) was found for the first time in December 2016 in 2 sites of cut flower production of roses (Rosa spp.) (EPPO RS 2017/085). Since this first notification, the bacterium was detected in 3 additional rose production sites. These findings were made in the cantons of Bern, Solothurn and Zürich and resulted from tracing forward investigations triggered by the fact that the Dutch NPPO had provided the Swiss NPPO with a list of potentially infected lots of Rosa plants. These plants had been delivered by Dutch propagation companies between June 2015 and August 2016. During these investigations, R. solanacearum was also detected in a small number of plants of Olea europaea and Strelitzia which were irrigated with drain water from infected roses, indicating that the pathogen was being spread via irrigation water within the companies. The actual number of infected plants is unknown, but it is estimated that approximately 50 000 rose plants could be potentially infected. Eradication measures including the destruction of all infected lots, disinfection and hygiene measures are continuing.
The pest status of Ralstonia solanacearum in Switzerland is officially declared as: Transient, actionable, under eradication.
NPPO of Switzerland (2017-07).