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[1] Cavity spot, sclerotinia - carrots
Date: Sun 21 Dec 2008
Source: FreshInfo [edited]
<http://www.freshinfo.com/index.php?ei=h&fiemt=10022008122261835110&s=n&ss=nd&sid=47360>
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Carrot growers battle crop disease

Carrot growers in the UK are struggling with a difficult season, following another summer of low light levels and unseasonably heavy rainfall.

Martin Evans, chairman of the British Carrot Growers' Association, said: "Most of us in England only have about 85 percent yields because of the lack of sunshine in August [2008], and the wet conditions have caused cavity spot too, but in Scotland the situation is worse."

Some Scottish growers report not just cavity spot problems, but sclerotinia. One trade observer estimated that some Scots growers will lose 50 percent of the crop to sclerotinia, which affects the top of the carrot if it is under water for too long.

The fact that an increasing number of agri-chemicals are no longer available to growers in the fight against pests and disease is having an impact.

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[2] Sclerotinia, ringspot, white blister, botrytis - multicrop
Date: Tue 2 Dec 2008
Source: FreshInfo [edited]
<http://www.freshinfo.com/index.php?ei=j&fiemt=10022008120361835110&s=n&ss=nd&sid=47164> 
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Disease threat increase for veg

With the continuing wet, warm and humid conditions, this season will be a particularly high pressure year for a number of diseases in brassicas, according to John McCulloch of specialist agronomist County Crops. There are also concerns about controlling these diseases adequately, but without increasing resistance risk.

Advising growers in the North West, McCulloch said that he has seen more sclerotinia this year [2008] than ever before. "I have seen a lot of it in the usual crops such as lettuce, celery, carrots, and oilseed rape and also in some more unusual crops such as calabrese.

"These high levels can be put down to this year's [2008] terrible weather and high rainfall, which have encouraged sclerotinia as well as other wet weather diseases including ringspot (_Mycosphaerella brassicola_), white blister (_Albugo candida_), and botrytis."

McCulloch advises his growers to adopt an appropriate fungicide programme, but with fungicide resistance and crop safety being top of the agenda.

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[Sclerotinia
------------
The disease is caused by the fungus _Sclerotinia sclerotiorum_. It affects many different hosts causing varying symptoms. On carrot, it causes severe root rot and also affects the leaves. The pathogen is  primarily soil-borne and can survive in soil as sclerotia. It is also spread by infected plant material, mechanical means, and wind-borne spores. Risk of crop infection depends on the previous disease history of an area as well as weather conditions. Disease management includes cultural practices and fungicide applications. For more information see ProMED-mail post no. 20081008.3187.

Cavity spot
-----------
This is a disfiguring disease of carrots and related root crops and is caused by species of soil fungi belonging to the genus _Pythium_. It develops slowly and is favoured by cool soil temperatures. The fungi can be dispersed by water and mechanical means. Control measures include tolerant host varieties, cultural practices, and crop rotation. Chemical control is not always reliable. For more information see ProMED-mail post no. 20071026.3477.

Ringspot
--------
Ringspot disease on _Brassica_ crops is caused by the fungus _Mycosphaerella brassicicola_. Symptom development is favoured by warm, humid conditions. The pathogen is spread by splashing water, mechanical means, and insects and overwinters in plant debris and biennial seed crops. The disease is managed mainly by timely fungicide applications. For more information see ProMED-mail post no. 20080923.2997.

White blister
-------------
This disease is caused by the fungus _Albugo candida_ and affects most species of the brassica family. Disease management includes phytosanitation, cultural practices, and fungicides. For more information see previous ProMED-mail post no. 20080218.0661.

Botrytis
--------
Grey mould rots and blights caused by fungi in the genus _Botrytis_ affect a large number of vegetable, fruit, and other crops. Disease development may occur on different parts of the host and is favoured by cool, moist conditions and low air movement. The pathogen can overwinter in dead plant tissue as sclerotia and is also spread by mechanical means and water. Disease management includes phytosanitation, cultural practices, and fungicide treatments. For more information see links below.

Maps of UK:
<http://www.lib.utexas.edu/maps/europe/united_kingdom.gif> and
<http://healthmap.org/promed?v=54.5,-2,5>

Pictures
Sclerotinia on carrot:
<http://www.gov.mb.ca/agriculture/crops/horticulture/report/07-09-28/07-09-28carrotsclerotinia.jpg>
Sclerotinia on lettuce:
<http://ag.arizona.edu/PLP/plpext/diseases/vegetables/lettuce/lettsclero4.htm>
Cavity spot on carrot:
<http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm7736/$FILE/car_csp48_l.jpg>
Fungal ringspot on cabbage leaves:
<http://www.bitkisagligi.net/Crucifer/cruciferresim/Mycosphaerella%20brassicicola-5.jpg>
White blister on brassicas:
<http://www.hri.ac.uk/site2/research/path/blister.jpg>
Botrytis blight of lettuce:
<http://vegdis.cas.psu.edu/VegDisases/Identification_files/smiden/letbgm1.jpg>

Links
Additional news story:
<http://www.freshinfo.com/index.php?s=n&ss=nd&sid=47170.html> 
(subscription required)
Information on _S. sclerotiorum_:
<http://www.extento.hawaii.edu/kbase/Crop/Type/s_scler.htm> and
<http://www.cals.ncsu.edu/course/pp728/Sclerotinia/S_sclerotiorum.html>
Sclerotinia on carrots:
<http://www.organicagcentre.ca/ResearchDatabase/res_carrots_canopy.asp> and
<http://www.abdn.ac.uk/web/test/organic/research/sclerotinia_advice.php>
Information on cavity spot of root crops:
<http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm7736>  and
<http://www.agric.wa.gov.au/content/PW/PH/DIS/VEG/F02999.PDF>
Fungal pathogens of brassicas, including ringspot:
<http://mtvernon.wsu.edu/path_team/newsaug03.htm>
Information on white blister of brassicas:
<http://www.growcom.com.au/_uploads/22331white_blister_handout.pdf>
Brassica diseases including ringspot and white blister:
<http://www.hri.ac.uk/site2/research/path/pathogen.htm>
Botrytis diseases on different hosts (with pictures):
<http://www.ipm.uiuc.edu/diseases/series900/rpd942/index.html>  and
<http://plantclinic.cornell.edu/FactSheets/botrytis/botrytis_blight.htm>
Taxonomy of all fungal species via:
<http://www.indexfungorum.org/Names/Names.asp>.  - Mod.DHA]

[see also in the archive:
Sclerotinia, multicrop - UK 20081008.3187
Fungal diseases, wheat, oilseed rape - UK 20080930.3083
Ringspot & white blister, brassicas - UK: (England): alert 20080923.2997
Verticillium wilt & sclerotinia, oilseed rape - UK 20080718.2180
2007
----
Cavity spot disease, root crops - UK 20071026.3477
Foliar diseases, brassica crops - UK 20070913.3037]