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International Society for Infectious Diseases <http://www.isid.org>
November 2, 2007
Source: Canadian Broadcasting Corporation News [edited] <http://www.cbc.ca/canada/prince-edward-island/story/2007/11/02/algeria-potatoes.html>
A boatload of potatoes shipped from PEI [Prince Edward Island]
to Algeria is being unloaded, at least partially, following
reports of ring rot-infected potatoes on board. The issue 1st
came to public attention in the PEI legislature Thursday [1 Nov
2007]. Agriculture critic Jim Bagnall pressured the government
for information on the shipment. Few details were forthcoming at
that time.
The Canadian Food Inspection Agency [CFIA] has confirmed to CBC
News that there are ring rot-infected potatoes on the ship, but
the potatoes in question are from Quebec. Algeria requires that
imported potatoes be free of ring rot.
Produce from PEI was also on board, but standard testing found
it to be free of ring rot, and since it was stored separately on
the ship, it is being unloaded. The fate of the Quebec potatoes
is not yet known. CFIA said the potatoes were shipped before lab
results were returned, and so went out at the exporter's risk.
--
communicated by:
ProMED-mail
<promed@promedmail.org>
[Ring rot of potato is caused by the bacterium _Clavibacter
michiganensis_ subsp. _sepedonicus_. It is favoured by cool
climates and is found in parts of North America and also
established in northern and eastern Europe. It is listed as a
quarantine pathogen for the EC by the European Plant Protection
Organisation (EPPO).
Symptomless natural infection has been reported in sugar beet,
and the bacterium has also been found in sugar beet seed. Many
solanaceous species, including tomato and eggplant, are
susceptible by mechanical inoculation. Symptoms on potato are
wilting and yellowing of leaves, rot of the vascular ring of
tubers with emerging bacterial ooze, and extensive tuber rot
followed by internal hollowing, cracking, and mummification in
severe cases. Wilting symptoms may occur late in the season and
are often masked by the natural senescence of the crop. Tubers
with ring rot are often subjected to secondary invasion by other
bacteria and fungi, which can result in total rot of tubers in
the field or in storage.
The ring rot pathogen is spread by infected seed tubers or other
plant material, plant-to-plant contact, soil, and mechanical
means (for example during harvest or grading). The bacteria can
survive for several years on dry surfaces and for over a month
in water. They can overwinter in association with unharvested
potatoes or debris from the previous crop.
Symptom expression occurs at different rates in different host
varieties and is affected by temperature and other environmental
conditions. Yield losses of up to 50 percent have been reported.
However, some varieties hardly ever express symptoms. Ring rot
can pass through one or more field generations without causing
symptoms and latently infected tubers are an important means of
spreading the disease. Laboratory tests are needed to detect
latent infections.
Disease management is expensive and includes the use of clean
seed potatoes, cultural practices, and plant hygiene measures
before and after harvest.
Maps
Canada:
<http://www.lib.utexas.edu/maps/americas/canada_pol_1986.gif>
and
<http://healthmap.org/promed?v=55.4,-101.9,4>
Algeria:
<http://www.m-w.com/maps/images/maps/algeria_map.gif>
and
<http://healthmap.org/promed?v=28.2,2.6,5>
Distribution of ring rot (September 2006):
<http://www.eppo.org/QUARANTINE/bacteria/Clavibacter_m_sepedonicus/CORBSE_map.htm>
Pictures
Leaf and tuber symptoms:
<http://www.eppo.org/QUARANTINE/bacteria/Clavibacter_m_sepedonicus/CORBSE_images.htm>
Ring rot affected tubers:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp877-3b.gif>
and <http://www.ag.ndsu.edu/pubs/plantsci/hortcrop/pp756-7.gif>
Links
Additional news story:
<http://www.elkhabar.com/FrEn/lire.php?ida=85780&idc=52>
Ring rot fact sheets with pictures:
<http://www.defra.gov.uk/planth/pestnote/ringrot.pdf>
and <http://ohioline.osu.edu/hyg-fact/3000/3103.html>
EPPO pathogen information:
<http://www.eppo.org/QUARANTINE/bacteria/Clavibacter_m_sepedonicus/CORBSE_ds.pdf>
and
<http://archives.eppo.org/EPPOStandards/PM9_NATREG/pm9-02(1).pdf>
Ring rot information and regulations in Canada:
<http://www.agf.gov.bc.ca/cropprot/brr.htm>
Molecular detection of _C. m._ subsp. _sepedonicus_:
<http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO.1997.87.8.853>
_Clavibacter_ species taxonomy via:
<http://www.bacterio.cict.fr/c/clavibacter.html>
EPPO alert list:
<http://www.eppo.org/QUARANTINE/listA2.htm>
CFIA:
<http://www.inspection.gc.ca/english/toce.shtml>.
- Mod.DHA]
[see also in the
archive:
2004
---
Clavibacter and Ralstonia, potato - United Kingdom 20040831.2425
Bacterial ring rot, potato - UK (England)(04) 20040814.2252
Bacterial ring rot, potato - UK (England)(03) 20040807.2170
Bacterial ring rot, potato - UK (England) (02): correction
20040806.2148 Bacterial ring rot, potato - UK (England)
20040802.2106 Bacterial ring rot, potato - UK (Wales)
20040227.0608 Clavibacter, potato - Finland 20040706.1803
Bacterial ring rot, potato - Slovakia 20040628.1723
2003
---
Clavibacter, potato - UK (England) (02) 20031120.2875 Bacterial
ring rot, potato - UK (Wales): 1st report 20031116.2843
Clavibacter sp., Ralstonia sp., potato - Germany 20030814.2020
2002
---
Bacterial wilt, potato - Canada (PEI) 20021215.6074 Clavibacter
and Ralstonia spp., potato - Germany 20021016.5561 Bacterial
pathogens, potato - Slovakia 20020724.4852 Bacterial wilt, ring
rot, potato - Estonia 20020723.4841
2001
---
Clavibacter & Ralstonia species, potato - Estonia 20011124.2882
2000
---
Clavibacter & Ralstonia in water: chemical control
20000521.0804] |
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