A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
In this posting:
[1] Ring rot - UK (Wales) ex Poland
[2] Blackleg - Philippines (Benguet) ex Canada
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[1] Ring rot - UK (Wales) ex Poland
Date: Wed 5 Dec 2012
Source: Farmers Weekly [edited]
<http://www.fwi.co.uk/Articles/05/12/2012/136583/Suspect-ring-rot-outbreak-probed-in-Wales.htm>
Suspect ring rot outbreak probed in Wales
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A suspected case of the notifiable potato disease ring rot is being investigated by officials in Wales. The suspected tubers are part of a ware consignment imported from Poland.
Ring rot is a serious non-indigenous [to the UK] bacterial disease requiring quarantine of potatoes. The disease is known to occur in parts of the EU.
Sharon Hall, Potato Council, confirmed that the Food and Environment Research Agency (FERA) were awaiting the results of tests, which may take several weeks. The potatoes were found at a processor in Wales and had already been processed. "Inspectors have checked the waste disposal route and even if the tests proved positive, there is no cause for concern," she said. She added that [this] is a timely reminder that all importers should adhere precisely to import requirements.
The last outbreak detected in Wales was in 2003 [ProMED-mail post 20031116.2843]. The disease was eradicated and further spread through the UK was prevented.
[Byline: Gus Hartley Russell]
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[2] Blackleg - Philippines (Benguet) ex Canada
Date: Tue 11 Dec 2012
Source: Philippine Daily Inquirer [edited] <http://newsinfo.inquirer.net/321969/da-probes-potato-disease-spread>
DA probes potato disease spread
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Government plant experts are tracking down Benguet farmers who may have unwittingly bought imported potato seeds [tubers] that could be infected with a disease. The Department of Agriculture (DA) raised the alert after receiving reports that Canadian seeds distributed by a local cooperative might have carried the potato blackleg.
The Bureau of Plant Industry (BPI) and the National Crop Research and Development Center, said initial surveys confirmed several cases of rotten potato plants. The BPI, however, has yet to conclude that these cases came from imported potatoes. The BPI's task is to identify the farmers who bought the imported seeds.
Farmers still rely on imported seeds because the government can [not] supply [sufficient] potato seeds. In Benguet, 7000 farmers annually produce an average of 97 834 metric tons of potatoes.
[Byline: Vincent Cabreza]
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[Bacterial ring rot
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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.
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 by 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.
Illegal farm saved seed potatoes are known to pose a serious risk for the spread of ring rot. Disease management is expensive and may include cultural practices and plant hygiene measures before and after harvest, but the use of certified clean seed potatoes is vital.
Blackleg
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Blackleg of potato can be caused by _Pectobacterium carotovorum_ subsp. _atrosepticum_, as well as the recently emerged, more virulent new species _Dickeya solani_ (ProMED-mail post 20091207.4162).
Symptoms of blackleg include rotting of stems leading to wilting of plants, as well as tuber rot.
The bacteria are spread with contaminated plant or other material (including seed tubers), by mechanical means, and water. Disease management may include seed tuber handling and cultural techniques, use of clean planting material, and phytosanitation to prevent introduction of the pathogen from external sources. Low levels of seed tuber infection pose a major risk of pathogen spread and certification schemes are a vital part of disease management for these pathogens.
_Dickeya_ species as well as _Pectobacterium carotovorum_ subspecies also cause bacterial soft rot of potato. They can also affect other crops, causing, for example, a foot rot disease in rice as well as stem and root rot of sweet potato.
Maps
UK:
<http://www.lib.utexas.edu/maps/europe/united_kingdom.gif> and <http://healthmap.org/r/1KlH>
Philippines:
<http://www.worldatlas.com/webimage/countrys/asia/lgcolor/phcolor.htm>
and
<http://healthmap.org/r/4ukP>
Philippine provinces:
<http://www.silent-gardens.com/img/map-philippines_admin_93.jpg>
Pictures
Potato ring rot symptoms:
<http://www.eppo.org/QUARANTINE/bacteria/Clavibacter_m_sepedonicus/CORBSE_images.htm>
Blackleg of potato:
<http://www.blackthornarable.co.uk/photography/potatoes/disease/T048-0012.jpg>,
<http://www.blackthornarable.co.uk/photography/potatoes/disease/06-28-01-S2%20%2009%20POTATOES%20BLACKLEG_jpg.jpg>,
<http://www.blackthornarable.co.uk/photography/potatoes/disease/t157-06%20potato%20tuber%20blackleg_jpg.jpg>,
and
<http://people.umass.edu/psoil120/images/blackleg.jpg>
Links
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>
Information on potato blackleg (and soft rot):
<http://www.ipm.ucdavis.edu/PMG/r607100111.html> and via <http://www.omafra.gov.on.ca/english/crops/hort/news/hortmatt/2003/20hrt03a7.htm>
(with pictures)
Taxonomy of all bacterial species via:
<http://www.uniprot.org/taxonomy/2>. - Mod.DHA]
[see also:
Bacterial ring rot, potato - USA: (ID) 20121004.1322810 Bacterial ring rot, potato - Netherlands, Germany: update
20120503.1121126
2011
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Bacterial ring rot, potato - Netherlands (South) 20111229.3697 Dickeya blackleg, potato - UK: (N Ireland) ex Netherlands
20110711.2090
2010
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Dickeya, potato & sweetpotato - UK, China 20101112.4106 Bacterial ring rot, potato - Canada: (PE) 20101107.4043 Early blight & Dickeya, potato - UK (02) 20100705.2229 Dickeya, leaf blights, potato - UK, Ireland 20100528.1775 Early blight & Dickeya, potato - UK: update 20100208.0421
2009
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Potato diseases - UK, USA 20090821.2960
Dickeya solani blackleg, potato: new pathogen 20091207.4162 Potato diseases - UK, USA 20090821.2960
2007
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Bacterial ring rot, potato - Algeria ex Canada 20071105.3601
2004
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Clavibacter and Ralstonia, potato - United Kingdom 20040831.2425 Bacterial ring rot, potato - UK (England)(04) 20040814.2252 Bacterial ring rot, potato - UK (Wales) 20040227.0608 Clavibacter, potato - Finland 20040706.1803 Bacterial ring rot, potato - Slovakia 20040628.1723
2003
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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 and additional items in the archives]
Topics
Species
