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: 19 January 2009
Source: The New Nation, United news of Bangladesh (UNB) report
[edited] <http://nation.ittefaq.com/issues/2009/01/19/news0069.htm>
Potato cultivation being hampered due
to leaf blight disease
Potato cultivators of the district of Jessore [Khulna division]
have become frustrated due to widespread outbreak of leaf blight
disease in potato fields. Department of Agricultural Extension
[DAE] sources said some 1000 hectares [2470 acres] of potato
fields have been affected with the disease.
Dense fog at night and hot weather in the day caused the
outbreak of the disease in the potato fields, a DAE official
said. They have suggested farmers use anti-fungal medicines in
the potato fields.
Farmers said they have brought less land under potato
cultivation this season [2009] due to high price of pesticide,
seeds, and fertilizer. Besides, they said they have lost
interest in potato cultivation as they incurred loss last year
[2008].
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[There are 2 major leaf blights of potato, and both are due to
fungus-like organisms. Early blight (_Alternaria solani_) causes
symptoms of spotting and early senescence of leaflets, as well
as lesions on tubers. Infected plants remain symptomless until
they approach maturity, and yield is reduced. Late blight
(_Phytophthora
infestans_) affects both leaves and tubers and may cause yield
losses of up to 75 percent. This pathogen also affects tomato,
and solanaceous weeds can serve as pathogen reservoirs.
Early blight occurs over a wider range of climatic conditions
than late blight. The fungi are spread with infected plant
material (including tubers), by mechanical means, wind, and
rain. Management strategies for both diseases include fungicide
treatments of seed tubers and crops, as well as use of cultivars
with reduced susceptibility. For more information see
ProMED-mail post no. 20080107.0091 for early blight, and
previous posts and links listed
below for late blight.
It is not specified above which leaf blight has been diagnosed.
Both diseases were reported from Bangladesh last year (2008,
ProMED-mail post no. 20080107.0091) and are likely to have
contributed to the 2008 crop losses mentioned in the story.
While several outbreaks of late blight have been reported
recently in the region, it is possible that either pathogen or a
combination of both is the cause of this outbreak in Bangladesh.
Maps
Bangladesh:
<http://www.lib.utexas.edu/maps/middle_east_and_asia/bangladesh_pol96.jpg>
and
<http://healthmap.org/promed/en?g=1337207&v=23.8,90.3,6>
Bangladesh divisions:
<http://www.mapsofworld.com/bangladesh/bangladesh-political-map.html>
Pictures
Early blight lesions on potato leaf:
<http://www.ag.ndsu.edu/pubs/plantsci/hortcrop/pp1084-4.gif>
Potato late blight, tuber symptoms:
<http://www.sciencedaily.com/images/2007/01/070102132649.jpg>
Potato late blight, leaf symptoms:
<http://www-biol.paisley.ac.uk/bioref/Chromista/potato_blight.jpg>
Links
Description of potato late and early leaf blights:
<http://www.ag.ndsu.edu/pubs/plantsci/hortcrop/pp1084w.htm>
and
<http://www.mnseedpotato.org/extension/leafblight/leafblight.htm>
Late blight information, history, and background:
<http://www.apsnet.org/online/feature/lateblit/>
_A. solani_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=444460>
_P. infestans_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=232148>
List of diseases and pathogens of potato:
<http://www.apsnet.org/online/common/names/potato.asp>
Bangladesh DAE:
<http://www.dae.gov.bd/>.
- Mod.DHA]
[see also
in the
archive:
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
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
Late blight, potato - India, UK 20070509.1491
2006
----
Late blight, potato - India (Kashmir) 20060424.1200
Late blight, potato - USA (AK), Bangladesh 20060324.0911
2003
----
Late blight, potato - Papua New Guinea 20030306.0554]