Western Australia
June 3, 2009
Source:
GRDC's The Crop Doctor
Fusarium is associated with
fungi that greatly trouble grain growers.
A range of Fusarium species can be associated with crown
rot, fungal stained grain and head blight symptoms.
Fusarium pseudograminearum, the major cause of crown rot, ranks
in the top five most damaging wheat diseases in Australia. F.
graminearum is commonly associated with Fusarium Head
Blight, although other Fusarium species are also associated with
head blight and contaminated grain.
Fusarium Head Blight (not found in Western Australia (WA) in the
2008 harvest) and Fusarium grain contamination can be serious
with wet weather at flowering and harvest.
Crown rot is widespread in Australia, annually costing about $50
million in lost yield. Surveys of WA paddocks with a high
frequency of wheat by the Department of Agriculture and Food WA
(DAFWA) in 2005-2007 and CSIRO in November 2008, found crown rot
at damaging levels in all districts, but particularly the
southern region.
A GRDC supported study by Dr Sukumar Chakraborty and his CSIRO
team found Fusarium species and strains within a species
differed in virulence and their impact on wheat yield and
quality.
For crown rot, Dr Chakraborty says fallowing or rotating
non-cereals, helps with moderate epidemics and reduces Fusarium
infestation the next season.
GRDC is also supporting development of Fusarium resistant wheat.
The CSIRO team has identified two potential sources of crown rot
resistance that are currently being evaluated.
In 2008, harvest along WA’s southern coast was affected by pink
and orange stained wheat and barley, with DAFWA confirming an
association with various Fusarium species. In addition to
Fusarium, other identified causes of the pink stained grain were
pink yeast and physiological pink staining.
According to Dr Rohan Rainbow, GRDC Manager, Crop Protection,
humid and mild weather conditions at crop maturity favours
Fusarium infection of grain. Wet weather and harvest delays can
allow Fusarium to proliferate.
Extremely wet conditions in November/December 2008 were the most
likely cause of the Fusarium grain mould seen at harvest in WA’s
southern region.
Albany and Esperance received more than 125mm in November and
December, which favoured the proliferation of fungi on mature
grain.
Geoff Thomas, GRDC supported DAFWA Plant Pathologist, says
stubble from winter cereals and grass weeds can host Fusarium
inoculum. Sowing cereals following non-host crops and rotating
affected paddocks out of cereals could reduce the risk of fungal
agents contaminating grain. |
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The Crop Doctor is
GRDC Managing Director,
Peter Reading |
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