Heatwaves are becoming so extreme, they're 'breaking the biology' of plants

Heatwaves during spring can have a detrimental impact on flowering wheat, causing significant losses. (ABC Midwest: Joanna Prendergast)

Heatwaves are becoming more extreme and frequent, making it harder to grow food crops.

Extreme temperatures are happening not just in summer, but also during critical spring flowering periods for crops such as wheat.

Research is underway to discover and develop more heat-resistant crops, but scientists say more is urgently needed.

When record-breaking heatwaves hit parts of Australia over summer, it was not just people and wildlife that suffered.

The extreme heat also wiped out entire crops and highlighted a growing struggle for farmers with what is likely to become an even bigger challenge.

Researchers warn increasingly extreme heatwaves throughout the year are putting food security at risk, with more studies urgently needed to help growers adapt.

Anthony De leso manages Thorndon Park Produce, a family business north of Adelaide growing a wide variety of leafy vegetables and herbs.

During summer, his farm was hit by three extreme heatwaves that decimated delicate crops.

Anthony De leso grows spring onions, continental parsley, coriander and dill all year round north of Adelaide. (Supplied: Anthony De leso)

"The last heatwave we had was probably the worst in memory, because we had about three days of 45 degrees, and the days before and after were in the mid to high-30s, so there was no relief for us, the staff, and no relief for the crops," Mr De leso said.

"That was kind of like the last nail in the coffin for a lot of our crops.

"In the second heatwave, our coriander just decided 'That's it, I'm done'.

"It was easier for us just to rotary hoe in our existing crop and start afresh."

Mr De leso said lost income from ruined crops, combined with rising input costs, was taking a significant toll on his budget.

"In the past, I would have said, 'This is just what's going to happen and we have to take these hits every now and then,'" he said.

Coriander is one crop that is highly fragile and prone to heat stress. (Supplied: Anthony De leso )

"Since 2022 onwards, our input costs, everything's gone through the roof, so now to take these hits is a lot harder to do, to take a loss and just go on.

"There definitely has been discussions on what else we do differently: whether we focus on other crops, or put in some protected cropping in certain areas … because now when we have weather events, we definitely feel the losses harder than we used to."

Australian National University professor of plant science Owen Atkin