Survival and possibilities for extinction of Pseudomonas solanacearum (Smith) Smith in cool climates

The importance of biovar 2 of Pseudomonas solanacearum (syn. Burkholderia solanacearum; syn. Ralstonia solanacearum) in cool temperate climates has been recently emphasised by outbreaks of potato brown rot disease in some European countries. Dissemination of the pathogen in latently infected potato tubers and in contaminated irrigation water, and overwintering in aquatic roots of the weed host Solanum dulcamara have been implicated. Evidence from the literature suggests that in cool climates the organism is unlikely to persist long term in soil in the absence of a susceptible host. Effective control strategies rely on the enforcement of quarantine legislation at both national and European Community levels. This requires knowledge of the biology of the pathogen in cool environments, methods for accurate monitoring of its survival and distribution at and around disease outbreak sites and application of effective measures for pathogen exclusion, containment and eventual eradication. This paper reviews current knowledge on the above.