A ProMED-mail post
ProMED-mail is a program of the
Date: 19 Nov 2010
Source: Daily Star [edited]
Lebanon's wheat production is at risk from virulent strains of fungi that threaten to devastate production. An unusually mild winter 2009-2010 already resulted in a "serious" outbreak in the country of the mutated and especially potent adaptation of "rust fungi" [stripe rust], but experts are fearful that knock-on effects of global warming will only further intensify the country's susceptibility in the coming years.
The disease has the capacity to destroy some 50 percent of wheat stock and is presently being blamed for the loss some one million hectares in Syria [ProMED-mail posts 20101021.3815 and 20100609.1930]. If serious steps are not taken to monitor the spread of rust fungi and take measures to diversify wheat crops, the situation could spread across the region, said the Food and Agricultural Organization (FAO) Food Outlook report.
[Byline: Simona Sikimic]
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ProMED-mail
[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.
New stripe rust strains with increased virulence are emerging, and regional monitoring programmes are important to recognise them. A new strain identified by ICARDA (International Centre for Agriculture in Dry Areas) is currently causing serious outbreaks in the Middle East, North Africa and Central Asia (see previous ProMED-mail posts listed below). Although it is not clearly stated above, from the Lebanese report it can be inferred that this pathogen is also affecting wheat production in that country. However, additional rust fungi and/or different strains may be present as well.
Breeding programmes for resistance to stripe rust are in progress at ICARDA and elsewhere, but the process of releasing new varieties to farmers is slow.
Maps
Lebanon:
Syria and Lebanon:
Pictures
Stripe rust on wheat leaf:
Stripe rust on wheat head:
Stripe rust on resistant and susceptible wheat cultivars:
Barley with stripe rust:
Ryegrass with stripe rust:
Links
Information on wheat stripe rust:
and
Stripe rust management:
_P. striiformis_ taxonomy:
ICARDA:
- Mod.DHA]
[see also:
Stripe rust, wheat - Turkey, Syria 20101021.3815 Stripe rust, wheat - Ethiopia 20100922.3420 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
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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
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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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