New research shows that short periods of extreme heat and drought during flowering could become one of the biggest threats to global wheat production in the coming decades.
As the climate changes, farmers around the world are facing more frequent and intense weather extremes. While drought has long been seen as the main danger to wheat crops, this new study suggests that heatwaves at a key moment in the plant's life cycle may soon pose an even greater risk.
Flowering: a critical moment:
Dr Mikhail Semenov, Mathematical Modeller and Emeritus Fellow at Rothamsted Research said: "Flowering is one of the most sensitive stages in wheat development. It's when the plant sets grain, which ultimately determines yield. Even a few days of very high temperatures or severe water stress at this stage can reduce grain numbers and significantly cut final harvests."
The study used advanced climate projections and the Sirius wheat model to estimate how short, intense heatwaves and droughts during flowering could affect global wheat yields in the future.
What the research found
The results show a clear shift in risk:
Drought during flowering currently causes more yield loss than heat. However, its overall global impact is expected to decline slightly in the future.
Heat stress during flowering, on the other hand, it is projected to become much more damaging. By 2050, global yield losses linked to extreme heat at flowering could rise by about one-third. By 2090, those losses could increase by more than three-quarters.
While drought remains important, extreme heat at flowering is set to become a growing challenge for wheat growers worldwide.
Professor Malcolm Hawkesford, Leader of the "Delivering Sustainable Wheat" Institute Strategic Programme at Rothamsted Research said: "This kind of modelling studies provide critical information on, and pointers to, the traits we should be breeding for now, ready for predicted future climate conditions."
What this means for farmers
For farmers, this highlights the importance of:
Choosing varieties with improved tolerance to heat as well as drought
Considering sowing dates and management strategies that reduce the risk of flowering during peak heat periods
Staying informed about local climate trends and seasonal forecasts
Plant breeders will also need to place greater emphasis on developing wheat varieties that can cope with short bursts of high temperature during flowering.
Looking ahead
With global demand for wheat continuing to grow, protecting yields under changing weather patterns is essential for food security. This research shows that preparing for heat stress - not just drought - will be key to keeping wheat production stable in the decades ahead.
By understanding when crops are most vulnerable, farmers and researchers can work together to build more resilient farming systems for the future.
