Australia
June 9, 2005
A endemic Australian grass, found as far north as Townsville and
as far south as Tasmania, could provide the answer to the half
century quest by scientists to find – or breed – frost tolerant
wheat.
An improvement of two degrees in wheat’s frost tolerance after
head emergence – from around minus four degrees Celsius to minus
six – could mean up to 50 per cent more grain being harvested in
some regions of northern New South Wales and Queensland.
In other Australian grain areas, where damaging frosts at or
after ear emergence occur once in eight or 10 years, that two
degree increase in frost tolerance would slash the frequency of
damage to once in more than 50 years.
More than five years ago,
Queensland Department of Primary Industries and Fisheries
(QDPI&F) plant physiologist Troy Frederiks and his highly
regarded, now-retired mentor David Woodruff identified frost
tolerance after head emergence of more than minus 12 degrees in
the novel grass species under study.
The grass – its identity not revealed for commercial reasons –
is from the same family as wheat and barley and scientists hope
they can identify the mechanisms it uses to escape frost damage
and use this knowledge to improve winter cereals.
Mr Frederiks, whose frost research with QDPI&F is supported by
the
Grains Research and Development Corporation (GRDC), says
that, despite decades of intensive screening, scientists have
been unable to identify useful levels of frost tolerance after
head emergence in winter cereals.
“Yet minimisation of frost damage is of paramount importance to
growers and a major objective of the GRDC,” Mr Frederiks said.
“The direct yield loss from frosting of winter cereals in
Queensland and northern New South Wales runs into millions of
dollars annually.
“Strategies farmers have adopted to minimise the risk of frost –
planting later and so losing early planting opportunities and
using longer season varieties – also reduce yields.”
Mr Frederiks said yield increases of 0.8 tonnes to the hectare
were common when earlier flowering varieties had been planted in
Central Queensland and escaped frost.
Significant yield improvements were possible right across the
northern region by earlier crop flowering, if frost tolerance
after head emergence could be increased by just a couple of
degrees Celsius.
It could mean around 50 per cent more wheat production in parts
of Queensland, almost one million tonnes, worth more than $170
million, a year, in a normal season in the north.
Mr Frederiks said his research was concentrating on identifying
the mechanisms used by the novel grass to achieve its frost
tolerance.
One interesting and complicating reality was the lack of
variation in the degree of frost tolerance in the grass, even
though accessions had been drawn from areas as climatically
diverse as North Queensland and the Australian Alps. |
