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Date: Wed 28 May 2014
Source: ABC (Australian Broadcasting Corporation) Rural [edited] <http://www.abc.net.au/news/2014-05-28/chickpea-spores-ascochyta-blight/5483316>
Chickpea disease spreading in southern Australia
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The outbreak of a chickpea disease is threatening new crops throughout Victoria and South Australia. Industry organisation Pulses Australia is receiving a growing number of reports of ascochyta blight in Victoria's Wimmera and Mallee and South Australia's Yorke Peninsula.
Ascochyta blight causes plants to wither and die. An outbreak in 1998 wiped out the Wimmera and more than 100 000 hectares [about 247 000 acres] of chickpea crops.
Pulses Australia's Mary Raynes says it's crucial growers inspect their crops for the disease. "We identified self-sown chickpea plants to have ascochyta blight spores on them," she said. "These have popped up since the good autumn rain." She expects chickpea plantings across the country to be down this year [2014].
[Byline: Brett Worthington]
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ProMED-mail
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[Ascochyta blight (AB) of chickpea is caused by the fungus _Mycosphaerella rabiei_ (previously _Ascochyta rabiei_) and is considered the most important disease of chickpeas worldwide. The pathogen attacks all aerial portions of the plant and is specific to chickpeas. Disease development is favoured by cool, wet conditions.
Symptoms may include spots and lesions on leaves, stems, and pods which may lead to partial wilting, or the whole shoot may break off and the plant will die. Infected seeds are shriveled, spotted, and discoloured.
The pathogen can survive on infected plant material for at least 2 years under dry conditions, but viability is lost rapidly in high humidity. It is seed borne at a high rate of 50-80 percent. Seed transmission is the primary mode of spread both locally and worldwide.
Disease management includes cultural methods, seed treatment, prophylactic fungicide applications and use of varieties with improved resistance. A wet season, as reported above, favours pathogen development and spread, as well as hindering application and effectiveness of fungicides.
Ascochyta blight (AB) of lentil caused by the fungus _Didymella lentis_ (previously _Ascochyta lentis_) also affects crops in Australia. Although the 2 pathogens are now being classified into different genera, the same common name derived from their previous classification into the same genus is still used for both of the diseases.
Maps
Australia (with states):
<http://www.ga.gov.au/image_cache/GA4073.jpg> and <http://healthmap.org/promed/p/186>
South Australia:
<http://www.atn.com.au/sa/south/graphics/sth-map.jpg>
Victoria:
<http://www.atn.com.au/vic/east/graphics/vic-map.jpg>
Location of Wimmera and Mallee regions:
<http://www.seedbank.com.au/images/rollover-maps/Vic-Rollover-Map.png>
Pictures
AB symptoms on chickpea:
<http://www4.agr.gc.ca/resources/prod/img/pmc/img/1247678986193_img1.gif>,
<http://qcl.farmonline.com.au/multimedia/images/full/346826.jpg>
(leaf),
<http://www.forestryimages.org/images/768x512/5377413.jpg> (stem lesion), and <http://www.apsnet.org/publications/imageresources/PublishingImages/PDCover2003/jun_3.jpg>
(pod)
Chickpea field affected by AB:
<http://www.forestryimages.org/images/768x512/5475102.jpg>
Links
Information on chickpea AB:
<http://www.agric.wa.gov.au/PC_91419.html?s=1001>,
<http://www.ag.ndsu.edu/pubs/plantsci/smgrains/pp1362.pdf> (with
pictures) and
<http://www.publish.csiro.au/paper/AR04143.htm>
_A. rabiei_ disease cycle:
<http://www.agriculture.gov.sk.ca/adx/aspx/adxGetMedia.aspx?DocID=1016,1009,340,185,81,1,Documents&MediaID=732&Filename=disease_cycle_final.jpg>
_M. rabiei_ taxonomy and synonyms:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=466036>
and
<http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=466036>
Pulses Australia:
<http://www.pulseaus.com.au/>
- Mod.DHA]
[See Also:
2010
----
Ascochyta blight, lentil - Australia: (SA) 20100927.3496 Ascochyta & undiagnosed disease, chickpea - Australia 20100903.3145 Ascochyta blight, chickpea - Australia: (NS) 20100802.2589
2008
----
Ascochyta blight, chickpea - Australia (02): (QLD) 20081008.3186 Ascochyta blight, chickpea - Australia: (QLD) 20080828.2698
2007
----
Fungal blights, wheat, corn & chickpea - USA (NB, MT) 20070621.2000
2003
----
Ascochyta blight, chickpea - Chile 20030604.1368
2002
----
Ascochyta blight, chickpea - USA (Nebraska) 20020710.4714
1999
----
Chick pea disease (ascochyta blight) - Australia 19990731.1298] .
Topics
Species
