Future-proofing the mango

Mangoes are worth about $172 million to Australia each year, with about 54% of them grown in the Northern Territory.

But as temperatures rise, what does the future look like for one of Australia’s favourite fruits?

Researchers Dr James Makinson, Associate Professor Robert Spooner-Hart and Professor James Cook from Western Sydney University’s Hawkesbury Institute for the Environment have partnered with the home of the mango – India – to help prepare mango farmers for what could be ahead.

Their study, funded by an Australia-India Council grant, is investigating mango varieties and their pollinators, along with climate modelling, to come up with some recommendations for planting in response to climate change.

“Mangoes are a really important industry in the Northern Territory, but there has been limited research into pollinators,” Makinson says.

“We are looking at what is visiting the flowers and how effective they are as pollinators. We identify what pollen is turning up on the bodies of bees and other important pollinators such as hoverflies.”

Researchers are using what Makinson describes as “old-school technology” – a hemocytometer – to check for molecular markers in the pollen carried by the pollinators. Genotyping of mango seeds is also revealing whether the fruit is the result of self or cross-pollination.

Identification of the key pollinators, both in the Northern Territory and India, will help look at how those species are responding to climate change and help build ways to future-proof the industry.

As part of the project, a series of workshops are being held in Western Sydney University, and in Tamil Nadu Agricultural University in India. Funding for a PhD scholarship for mango research in Tamil Nadu has also been included.

Makinson says there has been a lack of research into effective pollinators in India, which produces nearly 25 million tonnes of mangoes a year in comparison to Australia’s 51,500 tonnes.

“This is the beginning of a joint look at pollination,” he says. “In India, we first need to know what the important pollinators are so we can begin modelling.

“Climate modelling in India is also almost non-existent. In recent years, India has been struck by enormous heatwaves. Modelling shows yields could decline in the future.”

Alongside the identification of pollinators in each country and the importance of cross-pollination in mango yields, the scientists plan to update research originally undertaken for  the Northern Territory Government and the Earth Systems and Climate Change Hub in 2020. The study on the impact of climate change on flowering induction in mangoes in the Northern Territory found cool temperatures were an “essential climatic factor” in flowering for mango trees. The study found changes in temperature would affect flowering and fruit production in northern Australia.

Makinson says the project will revisit those models based on the more drastic climate data available today.

“Farmers need to know what they are facing and what is going to be changing in the coming decades,” he says.

The information could lead to effective strategies for ameliorating the effects of climate change, such as switching to more resilient varieties, shifting growing regions, using man-made solutions such as shade structures, or following France’s lead in burning small fires at night to protect grapes from frost.

“The message is we have to start thinking about how we are going to adapt for the future climate,” Makinson says. “It could have an extreme impact on the mango industry.

“I am hoping this is the beginning of an important collaboration with India and, going forward, our universities can partner in more collaborative research.”