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 17 Sep 2010
Source: AllAfrica, Inter Press Service (IPS) News Agency report [edited] <http://allafrica.com/stories/201009200378.html>
Following a yellow wheat rust epidemic across the country, millions of farmers are seriously affected. The epidemic has reached all wheat-growing areas of Ethiopia, covering over 2 million hectares [approx 5 million acres] of land and will lead to an over 50 percent harvest loss unless farms get sprayed with chemicals in a matter of weeks, said the Ethiopian Institute of Agricultural Research [EIAR].
[Some] pathologists fear the loss could be as high as 90 percent.
Ethiopia has just developed 2 new wheat varieties that researchers say [have] durable [resistance] against [several fungal] wheat diseases. Unfortunately the new varieties are not available for public use as yet. The approval and subsequent multiplication processes normally take years.
But the farmers cannot wait that long. So far, government has sprayed a few private and all state-owned farms. Farmers are not sure whether this will save the crop and most cannot afford the chemicals.
EIAR are attempting to release the new varieties of wheat before officially having them approved. Even in this way, the new varieties will reach only a small portion of wheat farmers in the next [growing] season.
[Byline: Omer Redi]
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[Stripe rust (also called yellow rust) of cereals is caused by the fungus _Puccinia striiformis_ var. _striiformis_. It causes yellow leaf stripes and stunting of plants with yield losses of 40 to 100 percent. The disease affects wheat, some barley varieties, triticale (wheat/rye hybrids), and a number of wild grasses. Spores are wind dispersed in several cycles during the cropping season, and the fungus survives on living host plants generating a "green bridge"
between seasons. Disease management includes the use of resistant varieties, fungicide applications, and control of volunteer crops.
Monitoring programmes are important to recognise emerging new strains.
New stripe rust strains with increased virulence have been reported in recent years from Europe, North America, Australia, and India and are also suspected to have emerged in China. The International Centre for Agricultural Research in Dry Areas (ICARDA) has reported earlier in 2010 that a number of countries in the Middle East and North Africa are seriously affected by a new strain in the current growing season, including Iran, Iraq, Morocco, Syria, Afghanistan, Algeria, and Tunisia (ProMED-mail posts 20100531.1803 and 20100609.193). It is unclear from the report above whether this is the same strain that affects Ethiopian wheat.
Since new stripe rust strains will differ in national or regional significance depending on the susceptibility of preferred cereal varieties, regional breeding programmes for resistance to stripe rust or combined resistance to stripe, stem and leaf rusts (as mentioned
above) are in progress. The process of releasing new varieties to farmers has been slow not just in Ethiopia.
Maps
Ethiopia:
<http://www.usask.ca/agriculture/soilsci/ethiopia-map.jpg> and
<http://healthmap.org/r/01bp>
Ethiopian regions:
<http://www.geographicguide.net/africa/images/ethiopia-map.gif>
Pictures
Stripe rust on wheat leaf:
<http://www.grdc.com.au/uploads/images/Stripe%20rust%20Colin%20Wellings%20ACRCP.JPG>
Stripe rust on wheat head:
<http://gallery.cimmyt.org/main.php?g2_itemId=949>
Stripe rust on resistant and susceptible wheat cultivars:
<http://www.ksre.ksu.edu/path-ext/factSheets/wheat/Wheatimages/wheats1.jpg>
Barley with stripe rust:
<http://www.ipmcenters.org/cropprofiles/docs/Graphics/WAbarleyStripeRust.jpg>
Ryegrass with stripe rust:
<http://plant-disease.ippc.orst.edu/plant_images/ryegrass_stripe_rust.jpg>
Links
Information on wheat stripe rust:
<http://pnw-ag.wsu.edu/smallgrains/Stripe%20Rust.html>,
<http://www.ars.usda.gov/Main/docs.htm?docid=9918&pf=1&cg_id=0>,
<http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/158964/stripe-rust-in-wheat.pdf>,
and
<http://www.ksre.k-state.edu/path-ext/factSheets/Wheat/Wheat%20Stripe%20Rust.asp>
Stripe rust management:
<http://www.grdc.com.au/uploads/documents/striperustmgt.pdf> and
<http://www.ipm.ucdavis.edu/PMG/r730100511.html>
_P. striiformis_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=427989>
ICARDA:
<http://www.icarda.org/> - Mod.DHA]
[see also:
Fungal diseases, cereals - Australia: alert 20100825.2989
Stripe rust, soft wheat - Syria (east) 20100609.1930
Stripe rust, wheat - Africa, Asia: new strain 20100531.1803
Stripe rust, wheat - USA: (AR) new strains, alert 20100510.1522
Stripe rust & downy mildew, cereals - USA: (TX) 20100504.1443
Fungal diseases, maize, wheat - USA 20100331.1017
Stripe rust, wheat - India, UK: alert 20100121.0234
2009
----
Stripe rust, wheat - Switzerland 20091228.4366
Stripe rust, wheat - UK (03): alert 20091218.4274
Cereal rusts - Australia: (WA) alert 20090820.2948
Stripe rust, wheat - Australia 20090813.2884
Stripe rust, wheat - Canada: (AB) alert 20090724.2614
Fungal diseases, cereal crops - China, Ireland 20090528.1983
Stripe rust, wheat - UK (02): new strain 20090514.1806
Rust diseases, wheat - UK, Pakistan 20090424.1543
Stripe rust, wheat - UK 20090417.1452
Stripe rust, wheat - India: new strain 20090329.1216
Wheat rusts - Kenya, India, Australia 20090312.1019
Rust diseases, wheat, mustard - India: (JK) 20090305.0897
Stripe rust, wheat - China 20090208.0579
2008
----
Stripe rust, wheat - Australia (02): (VIC) 20080916.2897
Stripe rust, wheat - Australia: (QLD, NSW), alert 20080716.2156
Cereal rusts - Australia: (NSW) 20080624.1945
Wheat stripe rust, oilseed rape sclerotinia - China 20080408.1297
Stripe rust, wheat - Denmark: new strains 20080211.0542
and older items in the archives]
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