August 6, 2004
From: Farmers Weekly Interactive, 04 August 2004 [edited] <http://www.fwi.co.uk/home.asp?hier=1&sec=1>

Fight to contain potato disease

Growers across the UK are being urged to check their potato seed in the fight to contain an outbreak of the contagious bacterial ring rot disease.

Defra officials made the plea after it emerged that a Herefordshire farmer whose potatoes were infected with the disease purchased 2 batches of Dutch seed.

The disease was detected in 2 potato tubers of the Sante variety as they passed through a packing machine in Cambridgeshire last Friday (30 Jul 2004).

John Mercer, the Hereford farmer whose potatoes contained the disease,
said: "My concerns are that this doesn't get taken out of context and scare consumers or have a negative effect on the industry."

While it is known that the seed was produced in the Netherlands, Defra officials could not be sure of its origin.

The situation echoes the case of Welsh farmer John Morgan, whose Provento seed crop suffered the first ever UK outbreak of ring rot in November 2003.

Both Morgan and Mercer sourced seed through the Dutch company Agrico.

Agrico seed director Jan van Hoogen said: "We are concerned and shocked that there is another case -- the UK represents a large part of our business. We are working with the Dutch department of agriculture and have initiated trials on potatoes from both growers to establish whether the disease originated in the Netherlands."

van Hoogen also confirmed that Morgan had bought a different batch of seed to the seed purchased by Mercer.

Morgan said he was devastated when he heard there had been another outbreak, adding that he really thought that it would be eradicated for the sake of the industry.

[Byline: Andrew Watts]

--
ProMED-mail
<promed@promedmail.org>

[It is essential that the Dutch authorities trace back the origins of the 2 Sante potatoes in order to determine the source of _C. michiganensis_ subsp. _sepedonicus_ (Cms) in this cultivar. Cms is a pathogen for which there is a world-wide zero tolerance in seed potatoes. An extremely sensitive, absolutely specific DNA-based detection system was developed for detecting Cms. Primer sets have been synthesized that enable multiplex polymerase chain reaction (PCR) amplification of 3 single-copy regions of the bacterial genome in plant cell extracts of infected plant tissue.
Multiplex PCR ELISA, TaqMan, and molecular beacon chemistries based on this system have proven highly specific and sensitive for Cms detection.

References:
<http://www.apsnet.org/phyto/abstract/1997/pau97ab.htm> (Abstract) <http://www.apsnet.org/phyto/PDFS/1997/0527-01R.PDF> (PDF) - Mod.DH]
 

August 2, 2004
From: The Scotsman [edited] <http://news.scotsman.com/latest.cfm?id=3286318>

[ProMED-mail thanks to Mary Marshall <tropical.forestry@btinternet.com> for submitting a similar piece on this outbreak. - Mod.MPP]

Fight to contain potato disease

Potatoes grown in Herefordshire, and packed at a firm in Cambridgeshire, were discovered to be infected with bacterial ring rot, when suspect symptoms were identified. The firm involved acted promptly, and responsibly, and notified the Plant Health and Seeds Inspectorate, on Fri 30 Jul 2004, which arranged an immediate visit.

Subsequent testing at the Central Science Laboratory, on Sat 31 Jul 2004, by 2 separate methods (immunofluorescence (IF) and polymerase chain reaction (PCR)), gave positive results. An eggplant (_Solanum melongena_) test, as required under EC legislation, will be carried out, but, there is no doubt about the results of testing already completed.

There has been good cooperation between the grower and the packing company, and holding action has been taken to prevent the use, or movement, of material or equipment, which may present a risk.

A tracing and testing program has been initiated, which will include an investigation into the origin of the potatoes supplied to the grower in Herefordshire.

[This is the 2nd outbreak of ring rot caused by _Clavibacter michiganensis_ subsp. _sepedonicus_ in the UK since November 2003. Disease management depends upon eradication of the pathogen. A strict phytosanitary regimen
requires maintenance of ring-rot-free conditions in buildings and storage bins, decontamination of equipment and clothing used in cutting and planting of potatoes, and the use of seed free of the bacterium.

Full details about ring rot can be found on Defra's web-site at <http://www.defra.gov.uk/planth/ring.htm>  including Defra's contingency plan for dealing with outbreaks: <http://www.defra.gov.uk/planth/ring.pdf>

The UK's first ring rot outbreak was in 2003.
Details are available at http://www.defra.gov.uk/planth/ring/repfinal.htm> - Mod.DH]

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