Published today in Nature Climate Change, the research has found that Australian wheat crop yields could be substantially increased by early sowing of winter wheats -- despite recent declines in autumn rainfall caused by climate change.
The time at which grain crops flower is critical to yield and lead La Trobe researcher Dr James Hunt said that a sharp decline in autumn rainfall in south eastern Australia since the 1990s has led to a significant reduction in wheat crop yields, in part because the crops are being established and flowering too late.
Combination - Season - Opening - Rains - Springs
"A combination of less reliable season opening rains and hot and dry springs has led to a stagnation in national wheat crop yields," Dr Hunt said.
"The approach Australian growers have used for more than a century -- of sowing spring wheats sometime in late May or June following autumn rains is no longer reliable. Growers have been able to increase yields by pushing sowing into a narrow window in early May -- but this is getting harder to achieve."
Years - Research - Team - Alternatives - Sowing
For the past seven years, the research team has been investigating alternatives to the sowing of spring wheats in May and has discovered that sowing winter wheats from March increases the window of opportunity for sowing because it potentially uses stored soil water from summer rains, which haven't declined and have increased in some areas.
"We needed to find a genotype of wheat in which development is slowed so that sowing could be moved earlier but flowering still occur during the optimal window," Dr Hunt said.
Flowering - Days - Photoperiod - Need - Winter
"This needed to be slowed either by slower flowering caused by short days (photoperiod) or through the need to experience cold winter weather (vernalisation)."
The research team used almost genetically identical (near-isogenic) lines of wheat developed by Dr Ben Trevaskis at CSIRO that varied in vernalisation and photoperiod sensitivity...
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