A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>

Date: 26 Oct 2008
Source: IrishFarming [edited]
<http://www.irishfarming.ie/2008/10/26/brown-rot-in-water-sample/>

Brown rot in water samples

As part of the Department of Agriculture, Fisheries and Food's ongoing testing survey for potato brown rot disease, the Department has recently detected brown rot in water samples taken at 2 potato merchants' premises. The brown rot annual water survey involves the taking of samples of wastewater at merchants' premises and this has resulted in 2 positive findings recently being reported.

All samples taken from potato stocks on the premises involved have been tested and proved negative. This would indicate that infected material had passed through the premises in the recent past. The premises themselves have been thoroughly cleaned and disinfected as required by the Department and upgrading of their water treatment systems is being put in place.

The management of the disease is governed by EU legislation, which is being strictly followed by the Department in this case. The Department is working closely with the potato industry to ensure that all appropriate action is being taken to control the situation.

Investigations are still ongoing but to date there is nothing to indicate any connection between these findings and last years' [2007] brown rot outbreak or other previous findings.

--
Communicated by:
ProMED-mail
<promed@promedmail.org>

[Brown rot (also called bacterial wilt) of potato is caused by _Ralstonia solanacearum_ race 3 and is widely distributed in warm temperate areas. Symptoms include internal staining and rotting of tubers, wilting and death of plants and may result in substantial yield losses. However, there may also be latent infections. The pathogen can survive in potato tubers during storage posing a high risk for introduction of the pathogen to new areas. Tomato and other solanaceous crops are also susceptible.

The pathogen is spread by mechanical means (including insects), contaminated equipment, infected plant material (including seed potatoes), soil, and water. Some weeds and unharvested potato plants may serve as pathogen reservoirs.

Disease management is difficult relying mostly on exclusion from new areas. Some cultural methods and limited genetic resistance may be used. Brown rot of potato was reported for the 1st time in Ireland in
2007 (for this report and more information on the disease see ProMED-mail post no. 20071022.3438).

_R. solanacearum_ has been classified into various races and biovars affecting more than 200 plant species including major crops. Races 2 and 3 have been placed on the quarantine lists of the European Plant Protection Organisation (EPPO).

Maps
Ireland:
<http://www.fishing-ireland.de/karte.html> and <http://healthmap.org/promed?v=53.2,-8.2,5>
Worldwide distribution of _R. solanacearum_ race 3 (September 2006):
<http://www.eppo.org/QUARANTINE/bacteria/Ralstonia_solanacearum_race3/PSDMS3_map.htm>

Pictures of brown rot symptoms:
<http://www.eppo.org/QUARANTINE/bacteria/Ralstonia_solanacearum/PSDMSO_images.htm>
and
<http://www.redepapa.org/murcha.jpg>

Links
Brown rot disease information:
<http://www.agriculture.gov.ie/crops_and_plants/brown_rot/PotatoBrownRotinfo.doc>,
<http://www.defra.gov.uk/planth/brownrot.htm> , and <http://www.scotland.gov.uk/Topics/Agriculture/plant/17937/newpotatobrownrot/Newpotatobrownrotrs>
_R. solanacearum_ data sheet:
<http://www.eppo.org/QUARANTINE/bacteria/Ralstonia_solanacearum/PSDMSO_ds.pdf>
Diagnosis and description of _R. s._ races:
<http://www.eppo.org/QUARANTINE/bacteria/Ralstonia_solanacearum/pm7-21(1)%20PSDMSO%20web.pdf>
Description and taxonomy of _R. solanacearum_:
<http://expasy.org/sprot/hamap/RALSO.html>  and via <http://www.bacterio.cict.fr/qr/ralstonia.html>
EPPO A2 quarantine list:
<http://www.eppo.org/QUARANTINE/listA2.htm>
Irish Department of Agriculture, Fisheries and Food:
<http://www.agriculture.gov.ie> . - Mod.DHA]