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: 3 November 2008
Source: The Daily Graphic, Portage la Prairie News [edited] <http://www.portagedailygraphic.com/ArticleDisplay.aspx?e=1277537>
Sunflower yields down
Sunflower producers in the Central Plains region of Manitoba are
spitting mad over this year's [2008] harvest. Compared to the
past 2 years, test weights for sunflower seeds are down across
the province, which may mean farmers will have a hard time
marketing them.
Producers across Manitoba planted 185 000 acres (74 867 ha) of
sunflowers this year [2008], and average yields are 1500 pounds
(680 kg) per acre.
Although producers in the Central Plains are doing slightly
better, with averages between 1700 and 1900 pounds (771-862 kg)
per acre, the numbers are still not as good as normal.
Jim Leslie, who planted 600 acres (243 ha) of sunflower on his
farm near Poplar Point usually sees yields of 2500 pounds (1134
kg) per acre, and this year [2008] he's bringing in between 1000
and 1800 pounds (454-816 kg) per acre. Even more concerning for
Leslie is the fact that as much as 5 per cent of his crop has
been hit with sclerotinia, a disease causing white mold to grow
on crops. "We've got lots of disease. We don't know what's going
to happen," he said.
Processors won't accept the diseased crop unless all the
sunflowers are cleaned, which is a very expensive process.
"We're not sure what we're going to do," said Leslie. "We've
never had a problem with it, ever."
--
communicated by:
ProMED-mail
<promed@promedmail.org>
[The problem referred to above is most likely the fungus
_Sclerotinia sclerotiorum_, although the related species _S.
minor_ has been reported to cause similar symptoms on sunflower.
_S. sclerotiorum_, also called white mold, is one of the most
nonspecific and successful of plant pathogens with around 400
known hosts and is present worldwide. It is primarily soilborne
and has a complex disease cycle. It can survive in soil as
sclerotia (soilborne fungal bodies) and is also spread by
infected plant material, mechanical means, and wind-borne
spores. Risk of crop infection depends on the previous disease
history of an area as well as weather conditions.
Disease management includes cultural practices and fungicide
applications.
The pathogen causes 3 of the most important diseases of
sunflower: wilt, middle stalk rot, and head rot. Sclerotinia
wilt is caused by sclerotia infecting the roots; it is the most
serious of the diseases and can destroy whole sunflower fields.
Head rot and middle stalk rot are caused by airborne spores and
are above ground diseases; they are usually associated with wet
weather periods. The presence of sclerotia in seed can reduce
the grade and market value of the crop. For more details on
these diseases please see links listed below.
Maps
Canada:
<http://www.lib.utexas.edu/maps/americas/canada_pol_1986.gif>
and <http://healthmap.org/promed?
g=6065171&v=55.4,-101.9,4>
Manitoba:
<http://atlas.nrcan.gc.ca/site/english/maps/reference/provincesterritories/manitoba/referencemap_image_view>
Pictures
Sclerotinia wilt on sunflower:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840-1.jpg>
and <http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840-3.jpg>
Head rot:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840-2.jpg>
Middle stalk rot:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840-6.jpg>
Sunflower seed contaminated with sclerotia:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840-10.jpg>
Links
Sclerotinia diseases on sunflower:
<http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/pp840w.htm#The%20Pathogen>,
<http://www.gov.mb.ca/agriculture/crops/diseases/fac31s00.html>
and <http://www.inra.fr/hyp3/pathogene/6sclsc5.htm>
Sunflower diseases, including sclerotinia:
<http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm7735>
Information on _S. sclerotiorum_:
<http://www.extento.hawaii.edu/kbase/Crop/Type/s_scler.htm>,
<http://anrcatalog.ucdavis.edu/pdf/8042.pdf>
and <http://www.cals.ncsu.edu/course/pp728/Sclerotinia/S_sclerotiorum.html>
_S. sclerotiorum_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=212553>
_S. minor_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=271273>.
- Mod.DHA]
[see also
in the
archive:
Sclerotinia, multicrop - UK 20081008.3187 Fungal diseases,
wheat, oilseed rape - UK 20080930.3083 Verticillium wilt &
sclerotinia, oilseed rape - UK 20080718.2180 Wheat stripe rust,
oilseed rape sclerotinia - China 20080408.1297 Fungal diseases,
potato - Bangladesh 20080107.0091
2004
---
Sclerotinia blight, peanut - USA (TX) 20041001.2702
2003
---
Sclerotinia minor, chickpea - Australia (Qld) 20030625.1565
2002
---
Sclerotinia spp., sunflower wilt - Spain 20020706.4677
2001
---
Sclerotinia shoot blight, grapevine - Chile 20011103.2724
1999
---
Crop diseases - Canada (Manitoba) 19990816.1417]
