Australia’s wheat producers are facing increasing pressure on yields as climate variability reshapes production decisions, with frost playing an increasingly challenging role, according to a new study from CSIRO.
CSIRO said the research found changing climate conditions are extending and intensifying the time window for risk of frost damage across the wheatbelt, complicating decisions on cultivar choice and sowing time.
The study estimated frost can cause up to $360 million annually in wheat production losses. It also found late spring frost and earlier heat continue to challenge producers, based on long-term simulations supported by the Grains Research and Development Corporation.
Wheat is Australia’s major winter crop, with sowing starting in autumn and harvesting usually occurring in spring and summer. CSIRO lead author Dr Fernanda Dreccer said the study examined how well current best-practice management is performing under increasing climate variability.
“Growers have access to a range of strategies including cultivar selection and sowing time so crops flower within the optimal flowering period,” said Dr Dreccer.
“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?”
CSIRO said the research team ran long-term simulations across the Australian wheatbelt at 83 locations, using climate data dating back to 1970 and a wide range of wheat cultivars. The results indicated that even under best-management conditions, frost remained a major constraint on yield, including when flowering occurred within the optimal window.
Dr Dreccer said the findings highlight trade-offs between competing 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 also concluded that while phenology remains a critical tool for management decisions, yields can remain constrained despite advances in agronomy and cultivar selection. “The results show that reducing crop sensitivity to frost can deliver meaningful gains, particularly in adverse seasons,” Dr Dreccer said.
CSIRO said its recent work has focused on evaluating genetically diverse wheat lines across multiple environments, including sites in New South Wales, South Australia and Western Australia, to better understand frost damage and the conditions that drive it. Dr Dreccer said the team is also examining environmental factors such as humidity and dew formation, which CSIRO said can influence frost type and damage and are not fully captured by approaches that rely on air temperature alone.
The research paper is titled Shifting prospects for wheat production: Long-term simulation-based insights under best management in Australia.
