Our favourite fruit is under attack. It’s not some anti-banana group running high-impact smear campaigns. Nor is it an imminent natural disaster, ready to devastate Australia’s crops. Rather, a virulent disease of disastrous proportions is attacking Cavendish banana plantations around the world.
Aussies consume more than five million bananas every day – that’s about one and a half bananas per person, per week ...it’s easy to see why the banana industry has been on high alert.
The banana industry is grappling the most deadly strain yet of what’s known as Panama disease – so-called Tropical Race 4 (TR4). This vicious disease first appeared in the 1990s in Taiwan and spread rapidly, making its way into other large banana growing countries in South East Asia including China, Indonesia, Malaysia and the Philippines, as well as Australia.
The disease kills plants from within, can lie dorment for decades, spreads with great ease and there’s no cure. Bad news for growers, and for banana-loving Aussies too – we eat more than five million bananas every day.
So what’s Panama disease?
Panama disease is caused by a soil-borne fungus called Fusarium oxysporum f. sp. Cubense that infects the plant through its root system and then settles in the plant.
It can wait, like a deadly trap, for many, many years. “One of the worst effects of Panama disease is the production of so-called chlamydospores, or resting spores, which survive in the soil for decades,” Panamadisease.org explains. “As soon as a susceptible banana plant is grown nearby, these spores germinate, infect the plant, and kill it.”
Herein lies the problem. Most bananas worldwide are produced as a result of asexual reproduction – meaning they aren’t grown from seeds. New plants are propagated from shoots at the stem of established banana plants.
As the disease can survive in the soil for 30 years or more, banana production can’t continue in the contaminated area unless a resistant variety is grown. Because the fungus is spread with great ease – through soil, water, and on contaminated equipment, shoes, or possibly anything, really, that touches affected soil – Panama disease poses a huge threat to the global banana industry.
History repeats itself
But this isn’t the first time panama disease has wreaked havoc on the global banana industry. In the 1950s an earlier strain of the disease called ‘Race 1’ wiped out entire banana plantations worldwide, taking a huge toll on the Gros Michel, then the world’s most popular variety.
Banana growers then turned to the Cavendish, a variety seemingly immune to the fungus. “The Cavendish was considered a junk banana before it was finally adopted,” says Dan Koeppel, author of Banana: The Fate of the Fruit That Changed the World.
It wasn’t as hardy as the Gros Michel either. Its sensitivity in transport caused the entire supply chain to be altered to ensure the Cavendish was a commercially marketable product (no one wants bruised fruit). Most importantly, however, the Cavendish was resistant to Panama disease Race 1 and therefore capable of growing in panama-infected soil.
That was until the 1990s, when the new strain of the fusarium fungus, TR4, began to spread. It struck Australian soil in 1997 with its first detection near Darwin and brutally damaged the Northern Territory’s small banana industry. While TR4 continued to spread like wildfire in South East Asia over the coming decades, it was not detected again in Australia until March last year.
Which gets us to where we are today: banana growers worldwide are facing their biggest threat yet, with experts fearing it is merely a matter of time until the strain leaps into Central/Latin America.
A fair share of our huge annual banana consumption surely ends up in banana bread... like our upside-down caramel banana bread (find the recipe link below). Source: Alan Benson
There's good news for Australia, sort-of
For Australia’s single largest horticultural industry – worth $600 million at the farm gate annually – there’s a lot on the line. More than 90 per cent of Australia’s bananas are produced in North Queensland. The remainder is grown in the state’s south-east, northern New South Wales, Western Australia and the Northern Territory.
Aussies consume more than five million bananas every day – that’s about one and a half bananas per person, per week. The Australian Banana Growers Council (ABGC) boasts that bananas are the number one selling supermarket product, not only outselling every other fruit and vegetable but all other product lines (now that’s a lot of banana smoothies!).
The Cavendish is by far the most popularly grown variety, but you may be able to find Lady Fingers, Ducasses, sugar bananas, Goldfingers, Red Dakkas and cooking bananas at your grocery store or market, too.
With such a significant place in the Australian food sector, it’s easy to see why the banana industry has been on high alert since the detection of TR4 on a farm in the Tully Valley in North Queensland last March. That farm was immediately quarantined and Biosecurity Queensland, the department charged with managing the response, destroyed banana plants in the immediate area. There have since been three further detections of TR4 on that particular farm, but there haven’t been any on any other properties across all of Australia.
The chairman of the ABGC, Doug Phillips, says the industry and Biosecurity Queensland are taking the TR4 outbreak in North Queensland very seriously.
Doug Phillips of the Australian Banana Growers Council. Source: Australian Banana Growers Council
“It’s a real joint effort because controlling TR4 is all about minimising the movement of soil and making sure anyone who comes onto a banana farm respects farmers’ biosecurity efforts,” said Phillips, who grows bananas at South Johnstone in North Queensland.
There is no cure for TR4; all farmers can do is try to contain it. Key strategies include controlling the movement of infested planting material, soil or contaminated equipment, and making sure planting material is free of disease. The search is also on, internationally, for disease-resistant varieties.
“The measure of how effective our efforts have been will be in how well we continue to contain TR4 – so far the results are very encouraging,” says Phillips.
Dr Gert Kema, a senior researcher at Netherlands University of Wageningen, is an expert in bananas and Panama disease. He says that while the international industry’s response to TR4 has been “very poor”, Australia is the exception. “They have developed overarching [research and development] programs and activities,” says Kema, speaking to SBS from the Netherlands.
Dr Kema is part of a research team that released a study published in November last year in the scientific journal PLOS Pathogens. It’s here he confirms TR4 is a single clone of the original race of Panama which devastated the Gros Michel in the 1950s.
So what does this mean for everyone who loves bananas?
Scientists agree the Cavendish won’t be around forever, but an extinction date is difficult to predict.
“Just take into consideration what Panama disease did to Gros Michel and we all should be aware that we need replacements for Cavendish. In any case, dependence on a single suite of clones is anyhow very risky, if not irresponsible, and definitely not sustainable,” Gert Kema says.
The good news is that prices and availability aren’t likely to change anytime soon as a result of TR4. ... TR4 has been present in Australia for almost 30 years and we’re yet to see an impact on domestic supply due to the disease.
The good news is that prices and availability aren’t likely to change anytime soon as a result of TR4. In Australia all fresh bananas must be domestically grown, due to the disease threat imports pose to local production. Only some processed banana products are imported. TR4 has been present in Australia for almost 30 years and we’re yet to see an impact on domestic supply due to the disease. Rather, the skyrocketing prices you’ve come across at supermarkets have typically been in the wake of a natural disaster such as cyclone Yasi in 2011.
The long-term answer, Dr Kema says, to securing a future with bananas is to bring diversity to the market by breeding new varieties. A number of Panama-related research projects are currently taking place in Australia to trial new resistant varieties in contaminated soil.
That said, we couldn’t expect to see new banana varieties to appear on supermarket shelves for another 15 years. In the meantime, we’ll appreciate the Cavendish just a little more when we eat one.
