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Published Date: 2011-12-29 06:57:22
Subject: PRO/PL> Bacterial ring rot, potato - Netherlands (South)
Archive Number: 20111229.3697

BACTERIAL RING ROT, POTATO - NETHERLANDS (SOUTH)
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International Society for Infectious Diseases
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Date: Wed 21 Dec 2011
Source: FreshPlaza [edited]
http://www.freshplaza.com/news_detail.asp?id=90852

Confirmation that potato ring rot has been found in South Holland has
prompted NFUS [National Farmers Union of Scotland] to remind all UK
growers to source safe and healthy seed [tubers]. Since September
[2011], the Dutch Foods and Products Authority have found ring rot in
ware potatoes at 3 premises in one region during a sample study of
potato diseases. The 1st finding was at a grading facility, the other
2 on farms. The suspicion is that illegally traded farm-saved seed
[tubers] were involved. Additional checks are being undertaken in the
Netherlands because ring rot was found in that region during 2009 and
2010.

NFUS's Peter Loggie said: "Although checks on other Dutch farms have
so far proven negative, and all the potentially contaminated potatoes
have been removed, this incident again emphasises the importance of
sourcing seed potatoes responsibly. It is in everyone's interests to
preserve a good record for healthy, disease-free potatoes. We would
urge all growers to show care and diligence when buying seed [tubers]
and would recommend that they consider buying from those who
participate in the Potato Council's Safe Haven Certification Scheme."

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[Ring rot of potato is caused by the bacterium _Clavibacter
michiganensis_ subsp. _sepedonicus_. Yield losses of up to 50 percent
have been reported. Many solanaceous species, including tomato and
aubergine, are also susceptible, and the pathogen has also been found
associated with symptomless infections of sugar beet and sugar beet
seed. The pathogen has been included on the A2 quarantine list of the
European Plant Protection Organisation (EPPO).

Symptoms on potato may include 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. Wilting symptoms may occur late in the season and are
often masked by the natural senescence of the crop. Symptom expression
depends on host cultivar and is favoured by cool climates. Tubers with
ring rot are often subjected to secondary invasion by other bacteria
and fungi which can result in total loss of tubers in the field or in
storage.

The pathogen is spread with 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 unharvested potatoes or crop debris. Ring rot can pass
through one or more crop 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 may include cultural practices and
plant hygiene measures before and after harvest, but the use of clean
seed potatoes is vital.

Maps
Netherlands:
http://worldatlas.com/webimage/countrys/europe/lgcolor/nlcolor.htm
Europe, overview:
http://www.edinphoto.org.uk/0_MAPS/0_map_europe_political_2001_enlarged.jpg

Pictures
Potato ring rot, 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 stories:
http://www.scotsman.com/the-scotsman/business/potato_warning_issued_for_growers_1_2016420
and
http://www.farmbusiness.cc/news.asp?section=242&newsid=11160
Information on potato ring rot:
http://ohioline.osu.edu/hyg-fact/3000/3103.html,
http://www.agf.gov.bc.ca/cropprot/brr.htm,
http://www.eppo.org/QUARANTINE/bacteria/Clavibacter_m_sepedonicus/CORBSE_ds.pdf
and via
http://www.potato.org.uk/node/638,
http://www.scotland.gov.uk/Topics/farmingrural/Agriculture/plant/18273/PotatoHealthControls/PotatoQuarantineDiseases/ring/potatoringrotleaflet
and
http://www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/potatoRingRot.cfm
Molecular detection of _C. m._ subsp. _sepedonicus_:
http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO.1997.87.8.853
_C. michiganensis_ subsp. _sepedonicus_ taxonomy:
http://www.uniprot.org/taxonomy/31964
EPPO A2 quarantine list:
http://www.eppo.org/QUARANTINE/listA2.htm
NFU Scotland:
http://www.nfus.org.uk/
UK Potato Council Safe Haven scheme:
http://www.potato.org.uk/growing/plant-health/safe-haven
- Mod.DHA

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http://healthmap.org/r/1r1l]

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