The Tulloch vineyard and winery is carbon neutral across the growing and wine-making process.

The Tulloch vineyard and winery is carbon neutral across the growing and wine-making process.Credit:Janie Barrett

In Queensland and the Northern Territory,where the majority of mangoes are grown,warming winters have meant that trees aren’t getting the minimum cold snap they need to develop fruit.

“Mangoes are a tropical fruit,so they grow leaves throughout the summer months and then in winter,they don’t like the cold,so the stress triggers flowering and the tree produces fruit,” Gavin Scurr,managing director of Pinata Farms,said.

“So what we need is seven to 10 consecutive days where it’s below 15 degrees. This year and last year we’ve been getting two or three days of that and then it warms back up to 18 or 19 degrees,so the tree gets a bit of a fright but it doesn’t stress it enough.”

Mango harvests have been down by about 30 per cent from their peak in the last two years and growers are expecting that to fall even further this year as the trend continues.

“We’re expecting this year to perhaps be down even more by about 40 per cent,we’ve only been growing mangoes for 19 years but flowering is the weakest we’ve seen in the industry,” Mr Scurr said.

“The climate continually changes but it would appear the trend of warmer winters in the north is continuing and going into a pattern that hasn’t turned around yet. We’re quite concerned.”

In the Hunter Valley,grape growers Alisdair and Keith Tulloch are struggling with warming winters,along with less rainfall and longer heatwaves.

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“Climate change has always been pretty obvious to me,growing up in the Hunter Valley wine community it was always widely appreciated that harvest dates kept moving further and further forward,” Alisdair said.

Warmer winters have also meant that the window to pick grapes when they have their optimal sugar content is shorter,which is creating labour and space issues for farms that are now having to process entire harvests within days.

The harvest window for grape growers is shortening and winters become warmer.

The harvest window for grape growers is shortening and winters become warmer.Credit:Janie Barrett

“Coupled with higher incidences of heatwaves and really,really low rainfall,the difference that makes to the growing season is considerable,” he said.

Rebecca Darbyshire,a senior research scientist at CSIRO,said a gradual shift in seasons would “compound the issue of warming”.

“An increase in summer heat is something that will become more and more of a problem,we can put up nets but that will only take us so far,” Dr Darbyshire said.

The average annual temperature has increased by up to 3 degrees between 2000 and 2020 in parts of the country,weather station records show.

Over that period,the profitability of farms has fallen by more than 100 per cent in parts of Australia,compared to the mid to late 1900s,a recent study by the Department of Agriculture,Water and the Environment into the impacts of climate change on Australian farms found.

With about 93 per cent of food consumed by Australians grown onshore,the impacts of climate change on agriculture will be felt by both growers and consumers.

Cherry farmer Chris Hall said he is also contending with changing rainfall patterns and warmer summers in Young.

“We’re seeing more hail and thunderstorms,and we’re having fruit split because of that,” he said. “Then on the other hand,we’re seeing swings from rain to 40-degree days,which is cooking the fruit on the trees.”

During drier months,water supply has also become an issue.

“Prior to 2000,we relied on dam water for irrigation but after that,it just wasn’t enough. Dams used to fill up about four out of five times before 2000,now we’re seeing them fill up once every five years,” he said.

Instead,farmers are relying on bore water dredged up from underground reservoirs,which is bringing its own new challenges,including higher salt and chloride levels,which can create nutrient deficiencies in plants and degrade the quality of soil over time.

Mr Hall said he is also worried about using up groundwater reserves.

“Bores could have taken millions of years to build up groundwater and if we lose that,we’re not going to get it back,” he said.

How farmers are adapting

Mr Hall has turned to regenerative farming over the past three years and he is already saving hundreds of litres of water and seeing his crops become less susceptible to drought,heatwaves,storms and diseases.

The approach includes increasing the amount of organic matter and microbes in soil,eliminating pesticides and other chemicals and promoting greater biodiversity.

Cherry farmers are turning to techniques such as regenerative farming to meet climate challenges.

Cherry farmers are turning to techniques such as regenerative farming to meet climate challenges.Credit:Kristielle Gibbons

“We found that we could store much more water,170 litres per hectare of extra water for every one per cent of extra organic matter in the soil,” Mr Hall said.

“That means we can capture much more water from big storms whereas before,we’d capture a few inches and the rest would all run off.”

Mr Tulloch said improving soil health has led to similar results for grape vines.

“Increasing organic carbon in soil has improved water-holding capacity,led to better nutrient breakdown and better access to those nutrients for grape vines,” he said.

In a bid to offset its own environmental footprint,Mr Tulloch’s company is also carbon neutral across its growing and wine-making processes.

He and Tasmanian salad and herb grower Anthony Houston,69,are among a number of farmers who are setting aside parts of their land for restoration and planting trees for carbon capture and biodiversity.

“We’ve set aside 1300 hectares for land restoration and carbon capture because it’s the right thing to do,” Mr Houston said.

“Farmers own and control so much land that if the federal government could put in the right policies and a national plan to encourage more farmers to do that,we would all get behind it.”

What the future looks like for farmers and consumers

As climate change threatens to make existing fruit varieties less viable,farmers and scientists are developing new varieties that are better suited to the emerging conditions,but that process is decades long.

“[For mangoes] that work started back in the 1990s but we still don’t have commercial varieties that are better than what we’ve got,” Mr Scurr said.

“Creating a new variety 20 or 30 years in advance takes a lot of time and patience.

“And producing new varieties doesn’t do anything for trees that are already in production. It takes 10 years for a mango tree to fruit so it’s a big thing for farmers to cut those down.”

Mr Scurr said that if harvests kept falling,the price of popular fruits and vegetables would go up.

“Consumers should expect to pay more not just for fruit but for food as the climate changes. It costs us the same per hectare for a small crop as a large crop,” he said.

Growers and researchers have been working for decades to develop new mango varieties that are better suited for the changing climate.

Growers and researchers have been working for decades to develop new mango varieties that are better suited for the changing climate.

Fiona Davis,chief executive at Farmers for Climate Action,a group advocating for change within the farming sector and from the federal government,said climate change could also affect the overall viability of some fruit.

“It’s going to be much harder to grow some of our favourite fruits,such as cherries,” she said.

“We’ve got a closing window of opportunity and we need to take action now so we don’t find ourselves in that position decades from now.”

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