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The world’s banana supply is at risk. Here’s what you need to know

September 11, 2019

You’ve probably had it in some way, shape, or form today. Peeled, pureed, in a smoothie, or in a loaf. The CEO of a startup I just interviewed is walking away from me, eating one right now. The banana is inescapable in nearly all of our lives. But what’s terrifying is that we could soon be living in a world without the world’s most popular fruit.

A fungus called Fusarium is threatening to wipe out the world’s banana supply. It has touched down in major banana exporter Colombia, which led authorities to declare a state of emergency on August 8. That spurred thousands of farmers to rush to quarantine their plantations and destroy crops to curb the rapid spread of the fungus. But what’s keeping the industry on tenterhooks is that Fusarium could be creeping into neighboring Ecuador, the world’s largest exporter of bananas, effectively endangering a third of the supply of the world’s favorite yellow fruit.

Snapshot: The importance of the humble banana


  • Global banana industry generated $8 billion in 2016
  • People consume more than 100 billion bananas globally each year
  • Makes up 25% of the daily calorie intake of certain communities

Source: United Nations’ Food and Agriculture Organization, Bananalink

Apart from maiming the $8 billion global banana industry, the further spread of the fungus could prove catastrophic for thousands of farmers in banana farming-heavy South America. They may also be forced to grow other crops, as its spores remain infectious for up to 20 years, and can stay dormant in soil.

“The spread of Fusarium Tropical Race 4 into an area leads to the loss of bananas as an economic activity to the detriment of local growers and the local and national economy,” says Charles Staver, banana production research coordinator at Bioversity International, speaking to AFN.” Further spread means further loss of bananas as an economic activity.”

The absence of bananas would send shockwaves through the diets of millions. The banana, its various shapes and forms, makes up some 25% of the daily caloric intake of some communities in the Philippines, Brazil, Rwanda, and Uganda, according to the UN’s Food and Agriculture Organization (FAO)

AFN has also reached out to the world’s largest banana companies Dole and Fyffes, as well as the food safety authorities of the major exporting countries. Stay tuned for updates.

Though some researchers have refrained from calling the outbreak an apocalypse, Staver calls it an ‘extremely serious long-term threat that will spread for decades and decades, with the potential to ‘cause major dislocation to current banana production.’ Over at Rothamsted Research in the UK, Molecular Plant Pathologist Dr Kim Hammond-Kosack says her outlook is “gloomy,” as there are no “fully effective control options currently available.”

UK-based startup Tropic Biosciences says he disagrees with the nihilistic tone the media is taking with the outbreak. He says that if it did end the industry, the fungus was “that final nail in that coffin.” Company CEO Gilad Gershon tells AFN that banana planters have faced “challenging situations” in recent times, such as global warming and the number of diseases out there, like bunchy top virus that’s endemic in Asia, south-east Asia and Oceania, as well as banana bacterial wilt, which is ravaging central African banana-cultivation regions. 

“It will only take a few years until this outbreak of Fusarium spreads throughout Latin America. And what’s bad is that this region is very important, as it’s where over 80% of global banana exports come from,” he says. Gershon’s company is currently using gene editing tech to create a type of banana that could one day, successfully fight off the fungus.

What is Fusarium, or Panama disease?

There have been many body counts in the constant tussle between humans and nature to stamp each other out. And with most epidemics, this fungus is no different. In the 1950s, it was first diagnosed in Panama (after which it was named), causing a worldwide banana shortage. It spread across plantations, moving north through Costa Rica to Guatemala and south into Colombia and Ecuador, driving a banana species called Gros Michel to extinction.

Big banana planters like Dole found a way to fight back, restructuring its entire banana empire to cultivate the Cavendish banana instead, which had proven itself to be more resistant to the fungus. Fast forward to the present day, 99% of exported bananas are Cavendish. It also accounts for nearly half of all bananas cultivated worldwide.

Snapshot: What’s Fusarium Tropical Race 4 (TR4)?


  • A fungus that kills banana plants by choking their vascular systems
  • No known cure, nor have fungicides or biocontrol measures proven effective
  • Spores persist in surrounding soil for decades, making it impossible to contain it without destroying all infected plants

Source: United Nations’ Food and Agriculture Organization

In a cruel twist of fate, Fusarium reared its ugly head yet again, 60 years after the Cavendish won our hearts over – being spelt out in a rap in a hit Gwen Stefani song, and featured in Andy Warhol’s art in its slightly overripe form. The new strain, called Tropical Race 4 (TR4), affects the Cavendish, infecting its vascular system through its roots, causing a slow death by cutting off its water and nutrient supply, according to the FAO’s page on the fungus.

What complicates the detection of TR4 is that infected bananas look completely healthy until they are four months old, when they start to show signs such as discoloration and wilting (giving rise to its other moniker, Fusarium wilt). Adding to that, the fruit does not exhibit any symptoms, compounding the difficulty in pinpointing which batches of trees TR4 is infecting.

Timeline: The spread of Fusarium TR4


  • 1989: First identified in soil samples from Taiwan, Malaysia and Indonesia, before spreading to China
  • 2013: Detected in the Middle East and Africa
  • 3 March 2015: Detected in Queensland, Australia 
  • 8 August 2019: Colombia declares a national emergency

Source: United Nations’ Food and Agriculture Organization

Here’s an interesting fact for you. The new strain, TR4, has been around for three decades, first appearing in soil in Taiwan in 1989, before spreading to Malaysia, Indonesia and China. Farmers in East and Southeast Asia had largely contained it by constantly razing and regrowing crops. In 2013, it showed up in soil samples in the Middle East. In 2015, TR4 was first discovered in a farm in Queensland, Australia, which was shut down immediately on March 31. Two years later, it was again detected in the same region, prompting Biosecurity Queensland to impose quarantine conditions. But the measures have proven exhaustive, leading authorities to conclude that it ‘isn’t feasible to eradicate the fungus.’

Stopgap measures like destroying or burning banana trees have proven ineffective in curbing the spread of the fungus. Staver tells us that the fungus’ spores are “long-lived and survive in the soil for decades” and that they are “extremely difficult to detect.” Deactivating the spores has also proven to be cumbersome, as their spread tends to outpace the extent of preventative measures used. 

“Biosecurity measures must be directed at the spread of contaminated soil and infected plant material. Soil adheres on shoes, vehicle tires, animal feet or snouts and almost any equipment or material coming in contact with infected areas,” says Staver, elaborating on the prevalence of the spores. 

“Soil can also be moved in water drained from contaminated fields in overland flow, irrigation drainage, and floods. Banana plants infected with TR4 are also a means for disease spread in pieces and strands of banana corm or stem, planting material and even as compost from diseased plants.” To date, no known fungicides or biocontrol measures have proven effective against TR4. 

So how can tech help keep the tradition of a daily, affordable Cavendish banana alive for billions across the globe?

How can tech stop Fusarium TR4?

There already are bananas that resist the deadly fungus. Researchers from the Queensland University of Technology have isolated the gene from that banana plant and implanted it in our everyday Cavendish. But this makes the new plant a genetically modified organism (GMO), even though the two ‘parent plants’ are of the same genus. Due to its status, this TR4-resistant plant cannot be commercialized, due to existing laws barring GMO imports from Australia in Europe, for fear that its introduction could potentially harm existing ecosystems. On top of that, we don’t know if adding a gene would change the taste or yield of the bananas the new plant produces, affecting its viability for sale and cultivation. (It may not be what we’re used to in a banana split.)

However, Tropic Biosciences tells AFN that it is confident its non-transgenic bananas wouldn’t be considered as GMO in most relevant geographies. Its GEiGS (Gene Editing induced Gene Silencing) tech redirects the silencing functions of RNAi genes in the banana to ‘turn off’ genes in the Fusarium directly, building on existing CRISPR (short for clustered regularly interspaced short palindromic repeats) technology.

“With GEiGS, in three months, we know what fungal genes exactly to target, versus what takes five to seven years in other research. We don’t target banana protein-coding genes, so that means we won’t  generate deleterious effects on bananas, such as deleting protein-coding genes that could affect its yields, or taste,” explains Dr. Eyal Maori, Chief Scientific Officer of Tropic Biosciences. “We’re confident it will work – that we are going to conquer TR4 with our tech.”

Maori tells us that they expect to have a TR4-resistant Cavendish in “less than five years,” and that Tropic Biosciences aims to start field trials of banana plants by next year.

Tropic booked a $10 million Series A for its CRISPR tech in June 2018. Check out our previous coverage of it here.

As the folks at Tropic Biosciences tackle genes in the Cavendish, Hammond-Kosack’s research uses gene editing to take on the antagonist. Her team at Rothamsted Research aims to ‘silence’’ the genes in spore cells that give it instructions to infect banana plants. She tells AFN that although her tech focuses on infections in cereals, it would also work towards the benefit of banana plants. Her research portfolio primarily aims to improve global food security.

Host induced gene silencing (HIGS) is a promising new approach to disarm the fungus at the very start of the plant infection process. It can operate in every invaded cell to silence the Fusarium genes required to cause the infection,” she says. As for a more cost-effective, proven way of eradicating the fungus’ spores, she suggests ‘completely burying Fusarium-infected’ material to stop the sexual phase of the pathogen.  

Staver, however, suggests practices to improve soil health may be useful. This includes organic matter, ground cover and application of beneficial microorganisms, though he tells AFN the latter is still in the research stage.

“Certain plants have suppressed TR4 in the soil, suggesting a line of research to develop substances that suppress spore germination,” he adds. 

Could history repeat itself?

We’re talking about entire supply shift chains – a banana species getting eradicated across all continents. The problem is that this time around, planters have yet to find a suitable breed immediately available to replace the Cavendish. 

Over in Fusarium TR4 ground zero, the Taiwan Banana Research Institute has developed cultivars that show partial resistance, using mass selection to pick out plants that didn’t get infected by the fungus. But Staver disputes the viability of this solution.

“These same cultivars have not performed as well in other sites. Moreover, they are also a longer cycle and may not have the finger shape needed for the normal packing of hand into boxes,” he says, questioning the longer-term efficacy of the plants, also doubting that their resistance would hold up. 

Gershon, too, is doubtful of the efficacy of introducing new species of bananas to the industry, as he says the Cavendish is the banana nearly most of the world has grown accustomed to. He also calls it the “perfect banana” for the industry.

“The Cavendish has many different positive attributes. It travels well, people like the taste, it’s sweet. And even if it’s not resistant to TR4, it’s resistant to other diseases. We might be able to use other bananas, but they may not travel well, not be sweet, and be weak to other diseases,” he argues.


AFN has reached out to the Taiwan Banana Research Institute for comments on its strains of Cavendish that have shown resistance to TR4. Stay tuned for updates.

Know a solution that could solve this banana crisis? Drop me an email at [email protected].


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