Review on brown rot ( Ralstonia solanacearum race 3, biovar 2, phylotype IIB) epidemiology and control in the Netherlands since 1995: a success story of integrated pest management.

摘要

The disease brown rot of potato, caused by the bacterium Ralstonia ( Pseudomonas) solanacearum ( Rsol), Race 3, biovar 2 (R3b2), was found for the first time in 1992 in a potato field in The Netherlands and caused an outbreak in the warm summer of 1995 that appeared to be connected to use of contaminated irrigation water as in other outbreaks in western Europe at that time. The Dutch Plant Protection Service (PPS) immediately took action and started to test all traded seed for (latent) infections, applied strict control measures upon positive detections, and started an intensive survey of surface water contamination. In later years the control measures and testing procedures for Rsol in different substrates, laid down in an EU Directive, were followed. The PPS also conducted intensive applied research (in cooperation with the University of Wageningen, Plant Research International, and foreign research Institutions), also in the framework of an EU-SMT project on the EU brown rot testing method to unravel the complex epidemiology of the pathogen and to improve its detection and identification. These actions have led over a ca. 15-year period to a drastic reduction, actually a functional eradication (only one single finding in 2009/2010 and 2010/2011), of the disease from the production system. A main factor in the combat was a nation-wide irrigation ban for seed potatoes since 2005. The PPS coordinated two EU-funded projects, where the UK, The Netherlands, Belgium and France assisted Egypt in implementing a brown rot safe potato production system. In this project substantial epidemiological research was conducted. This article wants to be a reflection on the work done and the results obtained by the PPS and has a glance into the future, where it will be indicated that the persisting presence of Rsol in surface water necessitates an enduring alert and actively maintained control and survey system. The main lessons learned are: stay away, if possible, from surface water; use disease-free (tested) and certified seed; apply strict hygiene; handle/grade and store seed and ware/industry potatoes separately; compensate growers or enable them to insure against the disease; invest pro-actively in emergency plans and in up to date diagnostic expertise, education and advice; maintain an active and statistically meaningful survey and control system; perform a regular survey in ware and industry potatoes, greenhouse host crops and surface water.