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September 24, 2007
Source: National Post / Financial Post, CanWest News Service report [edited]
http://www.canada.com/nationalpost/financialpost/story.html?id=ed70cd9c-1144-4042-80b1-d54db0903236&k=83822

Edmonton-area farms are the epicenter of a new and devastating plant-disease outbreak that is threatening the country's CAD 11 billion-canola industry, authorities say. Provincial and county governments are taking swift action to contain the rapidly spreading and incurable soil-borne disease called clubroot.

"It is terrible, terrible, terrible," said Greg Porozni, chairman of the Alberta Canola Producers Commission. "It is the biggest single threat we have in the canola industry right now, bar none. There's no question." Porozni's producer-funded commission is working with Alberta Agriculture and the University of Alberta to pay for research aimed at stopping the threat to this province's CAD 3.2 billion-canola industry.

Meanwhile, a move by the province this spring to declare clubroot a pest under its Agricultural Pests Act gives counties and municipalities the right to take drastic measures to slow the disease's spread. Counties can now test farmland for the disease and order farmers not to plant their lucrative canola crops on infected fields for at least 5 years.

Clubroot is spread through resting spores in the soil that can survive for up to 20 years. Infestations are usually carried to new locations when farm equipment, or sometimes oilfield equipment, moves contaminated soil.

Clubroot has traditionally affected cole crops such as broccoli, Brussels sprouts, cabbage, cauliflower, and kale, mostly in market gardens in British Columbia, Ontario, and Quebec. Those strains of clubroot had no effect on canola crops, said clubroot expert Stephen Strelkov, assistant professor of plant pathology at the University of Alberta.

But suddenly, clubroot appeared on canola in the St. Albert area in 2003. It was the 1st report of clubroot on canola in Canada, according to Alberta Agriculture. The discovery sparked immediate concern and lots of research, said Strelkov. "We have a very nasty strain of clubroot here, I guess," he said. "Since that initial discovery in 2003 of about a dozen (12) fields, now there are several hundred fields that are known to be infested with this disease."

There is no way producers can buy insurance against clubroot, which is deemed to be a crop-management issue, Porozni said. A report last year [2006] from the Canola Council of Canada pegged canola's economic impact in Alberta at CAD 3.2 billion. Alberta is the 2nd-largest canola producer, behind Saskatchewan's CAD 3.8 billion industry. Canola is worth about CAD 11 billion to the Canadian economy.

[Byline: Andrea Sands]

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[2]
Date: Mon 24 Sep 2007
Source: The Canadian Press [edited]
<http://canadianpress.google.com/article/ALeqM5jouRpJnWvb77qSQ0b-bhkKbp8MuQ>


A devastating disease called clubroot is threatening Alberta's CAD 3-billion-a-year canola crop and forcing government officials to ban dozens of farmers from growing the oilseed. "It could be a very huge threat unless we can get a handle on how to prevent the expansion of areas being infected," says Rod Scarlett, executive director of Wild Rose Agricultural Producers, Alberta's largest farm group. "If it impacts a tremendous amount of land, that will limit the opportunities for growing canola in Alberta and Western Canada."

Agriculture Minister George Groeneveld says clubroot could have a terrible impact in Alberta. "We're working with the canola people and saying, 'Hey, this is a big problem and let's not drag our feet.
Let's pull out all the stops."'

Clubroot may have gone undetected in the province's canola crops for several years, Groeneveld says. "I think we've been misdiagnosing it, probably for quite a while, giving it a chance to get a foothold here," he said Monday [24 Sep 2007] in an interview. "It's going to be darn tough on the canola industry." Groeneveld said the disease "has the potential to move south very quickly."

[A man], who farms about 650 hectares (about 1606 acres) near Leduc just south of Edmonton, said he discovered rotting roots on his canola last year [2006]. He is among 50 farmers in the region who have been ordered to stop growing canola. [The man] is hoping that researchers can come up with a solution. "Science hasn't developed anything yet that can eradicate this, so I'm hoping perhaps there will be more funding made available," he said. "I'm quite confident that it will happen."

[The farmer] said many of his neighbours have also found clubroot in their canola crops, but were reluctant to talk about it at first. "I think that in our county, the survey that they did shows almost half the lands have it," he said. "People are finally admitting ... it.
They're past the denial stage." He plans to grow wheat in the field where the canola crop was infected and said he's hoping that higher grain prices will temper his losses. But he's also planning to go back to canola once the 5-year ban has expired.

A key factor in curbing clubroot's spread is educating farmers to clean their equipment before they move to another field, said Groeneveld. There may also be a need to encourage producers to disinfect their equipment after each use, a move Groeneveld concedes would not be popular among farmers "who are always in a hurry. I'm sure there's not a farmer out there who wants to hear me say that, but we may have to take this to the extremes if it gets that bad."

Alberta's agriculture researchers are working on a solution to help eradicate the root disease and the minister is hoping they come up with one quickly. Groeneveld isn't considering any compensation for farmers who are being forced to stop growing canola. They may face some financial losses, but will still be able to grow other crops, he said. "Yes, it's a concern, but they can look after themselves to some degree, so at this stage of the game I'm counting on the farmers to do that."

Scarlett said there's no question that steps must be taken quickly to prevent clubroot's spread. "Perhaps we haven't been as well prepared as what we need to be and perhaps we haven't spent as much money on research to ensure that we can get a handle on this very quickly."
Farmers who are forced to stop growing canola may be able to offset any financial losses because of recent increases in grain prices, he suggested

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[Clubroot is caused by the fungus _Plasmodiophora brassicae_ and is a destructive soil-borne disease which affects nearly all cultivated, as well as many wild and weed members of the cabbage family. It is found worldwide and is most damaging in temperate regions and tropical highlands. The fungus enters root hairs and wounded roots, and multiplies rapidly, causing abnormal enlargement of the underground stem, taproot, or secondary roots. These roots often decay before the crop has matured, releasing many resting spores, which can survive for a decade in the absence of a susceptible host plant. Affected plants are stunted and may have discoloured purple leaves. Due to the distortion of the root, plants may wilt in dry weather and then recover at night.

Disease management is difficult due to the longevity of the spores and the inaccessibility of underground plant parts to fungicides.
Raising soil pH by addition of lime has been shown to be effective but is hardly practicable on large fields. Use of clean planting material is essential.

The pathogen is composed of numerous pathotypes which have hampered efforts to breed cultivars with durable resistance. At least 2 prevalent clubroot pathotypes have been reported in Alberta. This appears to be a new outbreak of a very virulent strain of the pathogen.

Maps
Canada:
<http://www.lib.utexas.edu/maps/americas/canada_pol_1986.gif>
Alberta:
<http://atlas.nrcan.gc.ca/site/english/maps/reference/provincesterritories/alberta/referencemap_image_view>
Pictures
Clubroot symptoms on canola plant: link 1 / link 2
Clubroot on brassica plant:
<http://www.hri.ac.uk/site2/research/path/virus/clubroot.jpg>  and <http://counties.cce.cornell.edu/Wyoming/agriculture/resources/ipd/clubroot_crucifers/clubroot_crucifers.jpg>
Cabbage field with clubroot symptoms:
<http://vegetablemdonline.ppath.cornell.edu/Images/Crucifers/Clubroot/Clbrt_Crucfs1.jpg>

Links
Additional news stories:
<http://www.canada.com/calgaryherald/news/story.html?id=e53a3591-c42f-433a-9ebc-727bc6329bca&k=74777>,
<http://www.theglobeandmail.com/servlet/story/RTGAM.20070924.wcanola0924/BNStory/National/?page=rss&id=RTGAM.20070924.wcanola0924>,
and
<http://www.630ched.com/news/news_xml.cfm? cat=1&rss=1&rem=75442&red=80110923aPBIny&gi=1&gm=news_local.cfm>
Factsheets on clubroot of canola, with pictures:
<http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex8593?opendocument>
and
<http://webpub2.strathcona.ab.ca/Strathcona/Rural+Life/Country+Talk/March+2006/Clubroot+disease+of+canola.htm>
Information on clubroot on crucifer crops:
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Crucifers_Clubroot.htm>,
<http://www.avrdc.org/LC/cabbage/clubroot.html>, and <http://www.omaf.gov.on.ca/english/crops/facts/85-043.htm>
_Plasmodiophora brassicae_ taxonomy:
<http://www.indexfungorum.org/Names/SynSpecies.asp?RecordID=214750>. - Mod.DHA]



[see also in the archive:
2005
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Clubroot, canola - Canada (AB) (02) 20051113.3319 Clubroot, canola - Canada (Alberta) 20050512.1301]

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