Ralstonia (Pseudomonas) solanacearum race 3 (biovar 2) in surface water and natural weed hosts: First report on stinging nettle (Urtica dioica).
The population dynamics of Ralstonia solanacearum in surface water of two selected water-areas in the Netherlands, were monitored over a two-year period. In some cases during summer, high bacterial numbers (up to 106 cfu/litre) were observed. In a host plant survey a few plants of U. dioica were found to be a natural host of the bacterium when plants were growing with their roots in contaminated water. The significance of U. dioica in the epidemiology of the brown rot bacterium is not yet known and subject to further investigation. Pathogenicity of R. solanacearum to U. dioica and bittersweet (Solanum dulcamara) was demonstrated in a greenhouse experiment.