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: Wed 8 Apr 2009
Source: El-annabi, Le Quotidien d'Oran report [in French, machine trans., edited]
<http://actualite.el-annabi.com/article.php3?id_article=9088>

Late blight: the threat to the potato continues in Algeria

Fungal diseases of crop plants remain a topical issue in Algeria. Late blight, which in 2006 destroyed 75 per cent of the harvest of table potatoes in the provinces of Mostaganem, Chlef, and Ain Defla, continues to be an issue, even if in the last 2 years its toll on the potatoes was lower.

The early planting of potatoes in Mostaganem is thought to have avoided disaster. "This region has a special microclimate for the cultivation of early potatoes," says the director of the regional station of the National
Institute of Plant Protection (INPV). The weather of recent weeks has been conducive to the spread of the fungus. "The epidemic can spread very quickly in the field," he says.

A threat to potato yield must be taken seriously. INPV warned farmers against this threat while providing them with a treatment schedule and the list of fungicides needed. So why does this disease continue to be an issue in Algeria?

[The reason may be that] throughout the region, farmers remain skeptical. There are few who use preventative treatments on their plots, and this explains the prevalence of the disease. And yet, according to experts,
fungicide treatments are enough to prevent the spread of this disease. The director of the regional INPV believes that if the advice had been strictly followed by farmers, the disease would never have taken hold in Algeria. In
addition, the price for agricultural fungicides is being blamed which has been increasing in recent years.

--
communicated by:
ProMED-mail rapporteur Susan Baekeland

[Potato late blight (PLB) is caused by the fungus-like organism _Phytophthora infestans_. It can cause 100 per cent crop losses in potato and tomato, but considerable variation in aggressiveness between different strains has been observed. The pathogen is spread by plant material, wind, and water. Untreated potato seed tubers pose a high risk for crop infection, and this may be a source of spread in Algeria as well. PLB disease management generally relies on fungicide treatments of seed tubers and crops, but new and more virulent strains are emerging frequently. For more information on PLB see links and previous ProMED-mail posts below.

Maps
Algeria:
<http://www.m-w.com/maps/images/maps/algeria_map.gif>  and
<http://healthmap.org/r/009O>
Algerian provinces:
<http://www.mapsofworld.com/algeria/algeria-political-map.html#>
Pictures
PLB symptoms:
<http://www.potatomuseum.com/images/exblightfieldwithinsert.jpg>,
<http://farm1.static.flickr.com/81/281344513_74bbffe5fe.jpg>  (tuber) and
<http://www-biol.paisley.ac.uk/bioref/Chromista/potato_blight.jpg>  (leaves)
Potato field destroyed by late blight:
<http://www.apsnet.org/education/LessonsPlantPath/LateBlight/images/fig29.jpg>
Microscopy of PLB infected cells:
<http://micro.magnet.fsu.edu/optics/olympusmicd/galleries/brightfield/images/potatoblight.jpg> 

Links
Late blight factsheets:
<http://ohioline.osu.edu/hyg-fact/3000/3102.html>  and
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Potato_LateBlt.htm>
Disease history and background:
<http://www.apsnet.org/online/feature/lateblit/>,
<http://www.olympusmicro.com/micd/galleries/brightfield/potatoblight.html>, 
and
<http://www.agric.wa.gov.au/pls/portal30/docs/FOLDER/IKMP/PW/PH/DIS/VEG/FS0401_REVIEW.PDF> 

Late blight information and resources:
<http://www.potato.org.uk/department/knowledge_transfer/fight_against_blight/advice_blight.html> 

_P. infestans_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=232148>
Global Initiative on Late Blight:
<http://gilb.cip.cgiar.org/>.  - Mod.DHA]

[see also in the archive:
Late blight, potato - UK, Bangladesh 20090406.1332
Late blight, potato - India, Bangladesh: update 20090310.0989
Blight & undiagnosed disease, potato, chilli - Bhutan 20090211.0612
Late blight, potato - India (02): (WB) 20090131.0435
Leaf blight, potato - Bangladesh: (KH) 20090121.0255
Late blight, potato - Nepal (BR) 20090114.0162
Late blight, potato & tomato: USA (FL), Ireland 20090109.0083
Late blight, potato - India: (PB) 20090103.0018
2008
---
Late blight, potato - Papua New Guinea (02): recovery 20081103.3454
Late blight, potato - India, Canada alert 20080815.2534
Late blight, potato - Bhutan: (TM) 20080811.2473
Late blight type A2, tomato - Taiwan: 1st report 20080615.1891
Late blight, potato - UK: (Scotland), alert 20080430.1482
Late blight, tomato, potato - USA: (FL) 20080219.0664
Potato diseases - India: (West Bengal) 20080206.0477
Late blight, potato - Papua New Guinea: recovery 20080121.0256
Fungal diseases, potato - Bangladesh 20080107.0091
2007
---
Late blight, potato - India (02): (Punjab, W Bengal) 20071221.4099
Late blight, potato - UK: new strains 20071207.3939
Late blight, potato - India: (Punjab), alert 20071116.3715
Fungal diseases, vegetable crops - Canada: cucumber, potato 20070730.2442
Late blight, potato & vegetable fungal diseases - Europe 20070708.2174
Late blight, potato - India, UK 20070509.1491
and older items in the archives]