Ralstonia solanacearum detected in Rosa in Poland
The NPPO of Poland recently informed the EPPO Secretariat of the first report of Ralstonia solanacearum (EPPO A2 List) on Rosa plants on its territory. The bacterium was detected in a glasshouse producing rose cut flowers and located in the village of Goczałkowice Zdrój (district of Pszczyna, Śląlskie voivodeship), Southern Poland. In September 2016, a grower producing cut flowers informed the NPPO that some rose plants (Rosa hybrid tea cv. ‘Red Berry’ – belonging to a lot of 6000 plants in total) presented poor growth. Three samples from plants (2 entire plants and 105 stem pieces of 1 cm long) and glasshouse irrigation water (2 x 40 cm3) were collected by phytosanitary inspectors and tested. In October 2016, results of the laboratory tests confirmed the presence of R. solanacearum in plant samples but not in water samples. It is noted that no typical symptoms of R. solanacearum were visible on the tested plant samples. However, when stems of these infected plants were cut, bacterial ooze appeared.
The source of this introduction could not be traced. However, it is noted that the cuttings used to produce these infected rose plants had been bought from Germany via two distinct Polish suppliers (but not all necessary documents could be retrieved to trace-back the exact origin of these cuttings). The Polish NPPO also explained that in 2015 the grower concerned had bought rose cuttings from a Dutch supplier whose place of production was found to be infected by R. solanacearum. Investigations were conducted in the Polish production site in 2015, samples were taken but all tested negative. In June 2016, the Dutch NPPO informed the Polish NPPO that R. solanacearum had been detected in samples of ‘Lucky Red’ roses from the Polish production site. However, following this notification all plants from this rose variety, as well as two others grown in the same glasshouse had been destroyed by the grower and therefore could no longer be studied. In July 2016, an official inspection was carried out and 40 samples were collected from all rose varieties (including cv. ‘Red Berry’) and from irrigation water, but all test results were negative.
Phytosanitary measures have been taken to eradicate the disease and include: destruction of the infected plant lot (cv. ‘Red Berry’) and the associated growing medium, disinfection of the glasshouse and its equipment, regular surveys which will be carried out in the glasshouse concerned (visual inspections, testing of plant and water samples every 2 months), and surveys will also be conducted in all other rose places of production in Poland (visual inspections and sampling in case of suspicious symptoms).
The pest status of Ralstonia solanacearum in Poland is officially declared as: Present, under eradication.
NPPO of Poland (2016-12).