Australia’s wheat growers are facing increasing challenges from frost as climate variability reshapes production decisions, according to new research released by CSIRO.
The study, supported by the Grains Research and Development Corporation (GRDC), found that changing climate conditions are extending and intensifying the period during which wheat crops are vulnerable to frost damage, despite the use of current best-practice management strategies.
Frost can result in wheat production losses of up to $360 million annually, with the research indicating that late spring frosts, along with earlier heat events, continue to constrain yields.
Wheat is Australia’s major winter crop, typically sown in autumn and harvested during spring and summer. The study examined whether existing management approaches remain effective under increasingly variable climatic conditions.
CSIRO lead author Dr Fernanda Dreccer said growers already employ a range of strategies designed to reduce production risks.
“Growers have access to a range of strategies including cultivar selection and sowing time so crops flower within the optimal flowering period,” Dr Dreccer said.
“That is the window where yield is maximised by balancing frost, heat and water stress, with adequate nitrogen fertilisation.
“But our study asked the question: what are the limits of these best management strategies under increasing climate variability?”
To investigate, researchers conducted long-term simulations across 83 locations throughout the Australian wheatbelt, using climate records dating back to 1970 and a broad selection of wheat cultivars.
The findings showed that frost remained a significant constraint on wheat yields, even when crops flowered within the optimal period under best-management scenarios.
Dr Dreccer said growers increasingly face trade-offs when responding to different climate risks.
“As seasonal conditions vary, attempts to avoid heat and drought can increase exposure of frost during sensitive stages, with impacts compounded by late spring frost and the biggest impacts occurring when frost and heat stresses co-occur,” she said.
The study concluded that while managing crop phenology — the timing of recurring biological events in plant life cycles — remains important, it may not be sufficient on its own to overcome production constraints.
“The results show that reducing crop sensitivity to frost can deliver meaningful gains, particularly in adverse seasons,” Dr Dreccer said.
CSIRO said Dr Dreccer and her team have spent the past two years investigating ways to improve frost tolerance in wheat by evaluating genetically diverse wheat lines across environments in New South Wales, South Australia and Western Australia.
“As part of this work, we are also improving understanding of the environmental conditions associated with frost events, particularly the role of humidity and dew formation, which are key drivers of frost type and damage,” she said.
“This highlights an important gap in current approaches, which often rely on air temperature alone and do not fully capture canopy-level conditions that influence whether damage occurs.
“While progress in managing frost has been slow, this improved understanding is helping to better assess risk and guide both agronomic strategies and the development of crops with reduced sensitivity during critical growth stages.”
The research paper, titled Shifting prospects for wheat production: Long-term simulation-based insights under best management in Australia, provides new insights into the challenges climate variability poses for wheat production and the limitations of existing management practices in mitigating frost-related losses.
