A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>

Date: Fri 18 Apr 2008
Source: Reuters UK [edited]
<http://today.reuters.co.uk/news/articlenews.aspx?type=scienceNews&storyID=2008-04-18T160809Z_01_L18934279_RTRIDST_0_SCIENCE-KENYA-UN-DC.XML&pageNumber=1&imageid=&cap=&sz=&WTModLoc=NewsArt-C1-ArticlePage1>

A fungus [rice blast] has destroyed 5600 hectares (13 840 acres) of rice in Central Province, which produces the bulk of Kenya's rice, OCHA [UN Office for the Coordination of Humanitarian Affairs] said.
This is equivalent to 10 to 20 percent of annual output and means Kenya will have to increase imports even though global rice prices have soared by 75 percent in the past 2 months, it said.

"This risks worsening Kenya's food insecurity and makes import of additional quantities even more expensive," Byrs [OCHA Public Information Officer, Geneva] said. "It is a fresh blow for this country, where the situation remains tense."

[Byline: Stephanie Nebehay, Tim Pearce]

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[A serious outbreak of rice blast is being reported from the area referred to above (see previous ProMED-mail post no. 20080402.1211).
This disease is caused by the fungus _Magnaporthe grisea_. It is one of the most destructive diseases of rice worldwide with reported losses of more than 50 percent in infected fields. Symptoms include lesions on all parts of the shoot, stem rot, and panicle blight. When nodes are infected, all plant parts above the infection die and yield losses are severe. When infection occurs at the seedling or tillering stages, plants are often completely killed. More than 50 species of grasses and sedges can be affected by different strains of the fungus, but most strains isolated from rice can only infect a limited number of cultivars.

Symptom severity and spread of the blast fungus are influenced by climatic conditions. The disease is spread by infected plant debris, mechanical means, water, and wind. Disease management may include fungicides and cultural practices, but relies mainly on resistant varieties. The fungus is highly variable, however, and new strains are emerging, breaking down host resistance.

The current epidemic in Kenya has been attributed largely to heavy rains, poor cultural practices, and infected rice seed. It has been reported that control by fungicide applications was attempted, but that so far it was apparently not effective.

Maps
Kenya:
<http://www.ogiek.org/photo-gallery/kenya-map-big.jpg>  and <http://healthmap.org/promed?v=0.5,37.9,6>
Kenya provinces:
<http://www.lib.utexas.edu/maps/africa/kenya_pol88.jpg>

Pictures of rice blast symptoms:
<http://www.imtech.res.in/raghava/rbpred/lesion.jpg>,
<http://www.msstate.edu/dept/drec/rice/rice_blast/blast2.JPG>,  and <http://www.msstate.edu/dept/drec/rice/rice_blast/blast3.JPG>

Links
Rice blast fact sheet (with pictures):
<http://www.knowledgebank.irri.org/ricedoctor/default.htm#Fact_Sheets/Diseases/Rice_Blast.htm>

Information on rice blast:
<http://www.imtech.res.in/raghava/rbpred/home.html>,
<http://ascus.plbr.cornell.edu/blastdb/about.html>,  and <http://www.msstate.edu/dept/drec/rice/rice_blast/rice_blast.htm>
_M. grisea_ taxonomy:
<http://www.indexfungorum.org/Names/SynSpecies.asp?RecordID=317113>
OCHA:
<http://ochaonline.un.org/>.  - Mod.DHA

[see also in the archive:
Blast disease, rice - Kenya (CP) 20080402.1211 Virus & blast diseases, rice - Viet Nam (Mekong Delta) 20080204.0454
2005
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Rice blast fungus, genome sequence - China 20050424.1147
2001
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Magnaporthe grisea, rice blast - Vietnam 20010214.0298 2000
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Rice blast: new method of control (02) 20000928.1678 Rice blast: new method of control 20000825.1419
1998
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Rice blast - USA (California) 19980224.0361]