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<http://www.promedmail.org>
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Date: 22 September 2008
Source: DTN Markets Newsletter [edited]
<http://www.dtnsoybeanrustcenter.com/index.cfm?show=10&mid=85&pid=45>

South Carolina has confirmed its first instances of Asian soybean rust in 3 counties: Dorchester, Hampton and Orangeburg. Rust has also been confirmed in DeKalb County, Alabama; Stewart and Sumter counties in Georgia; the parishes of East Carroll, West Carroll, Tensas, Tangipahoa, St. John and East Baton Rouge in Louisiana; and Carroll, Grenada and Webster counties in Mississippi. Rust was also confirmed in San Luis Potosi, Tamui, Mexico over the weekend.

Consult the PIPE [Pest Information Platform for Extension and Education, US Department of Agriculture] website <http://www.sbrusa.net> for further updates and information.

[Byline: by Steve Negus]

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ProMED-mail <promed@promedmail.org>

[Asian soybean rust (ASR) is caused by the fungus _Phakopsora pachyrhizi_. It can cause premature defoliation with yield losses of up to 70 percent reported on farms in Asia. It is widespread in Asia and Africa, but data are lacking on its establishment in Europe.
Besides soybean, a number of other species of _Fabaceae_, for example kudzu (_Pueraria lobata_), can also be affected and can serve as pathogen reservoirs. Spores are spread by wind over long distances.
Fungicides may be used in disease management, and partially resistant soybean lines are available. However, new fungal strains with increased virulence and fungicide resistances are emerging. A less-virulent related species (_P. meibomiae_) is found in South America and the Caribbean causing similar symptoms.

ASR was introduced into the USA in 2004 and was reported for the 1st time in Mexico in 2005. It over-winters in southern regions, and spores are being carried northwards every season. The disease spreads locally from the initial focus of infection, and several epidemic cycles may occur in one growing season. By the end of 2007, ASR had been reported as far north as Canada.

Maps
US states:
<http://www.census.gov/geo/www/us_regdiv.pdf>
Mexican states:
<http://faculty.smu.edu/rKemper/anth_3311/Mexico-states-capitals-map-P4100066.jpg>
North and Central America:
<http://www.gulfmex.org/graphics/usmexicomapsm.jpg>
Current distribution of soybean rust in the US via:
<http://www.sbrusa.net/>
Worldwide distribution of soybean rust (December 2005):
<http://www.eppo.org/QUARANTINE/Alert_List/fungi/maps/PHAKPA_map.htm>

Pictures
ASR symptoms on soybean:
<http://www.ent.iastate.edu/images/plantpath/soybean/asianrust/asian_soyrust_lesions.jpg> 
(leaf lesions),
<http://www.state.nj.us/agriculture/plant/soybeanrust.jpg>,
<http://soybeanrust.unl.edu/soybean/siteImages/plantdate.gif>  (whole plant) and
<http://ces.ca.uky.edu/extension_regions/Picture1.%20Defoliation.jpg> 
(defoliated field)
Electron microscopy of ASR spores:
<http://www.wbhm.org/pics/features/soybean-spores.jpg>

Links
Information on soybean rust:
<http://www.aphis.usda.gov/plant_health/plant_pest_info/soybean_rust/background.shtml> 
and
<http://www.eppo.org/QUARANTINE/Alert_List/fungi/PHAKPA.htm>
Diagnostic fact sheet:
<http://nt.ars-grin.gov/taxadescriptions/factsheets/index.cfm?thisapp=Phakopsorapachyrhizi>
Disease history and background (with pictures):
<http://www.apsnet.org/online/feature/rust/>
Rust background, tracking, and current information:
<http://www.usda.gov/soybeanrust/>,
<http://www.stopsoybeanrust.com/> and
<http://www.sbrusa.net/>
_P. pachyrhizi_ taxonomy:
<http://www.indexfungorum.org/Names/SynSpecies.asp?RecordID=121037>
- Mod.DHA]