The Wildly Infectious Banana Plague

Ecuador is the world's largest exporter of bananas - supplying 70 different countries and responsible for a third of global exports. In September 2025, they reported their first official case of Fusarium oxysporum, special form Cubense, Tropical Race 4. The modern banana plague. The Ecuadorean authorities rapidly quarantined the area, and so far it seems to have been contained to small regions. But the fungus has been spreading elsewhere. It has been wrecking havoc in Southeast Asia since it first emerged there in the late 1960s. And in 2019, it entered Latin America for the first time. First in Colombia and then Peru and then Venezuela. Fusarium is one of the most destructive plant diseases ever discovered. In today’s video, we discuss the Banana. Ever convenient. Ever delicious. Now in a slow-burn crisis. ## Ponder the Banana is maybe humanity's oldest cultivated fruit. The plant belongs to the genus Musa, which has 32 or more species and 100 subspecies. Musa plants largely grow in South and Southeast Asia. Its range stretches from Nepal in the north to the jungles of New Guinea and Indonesia in the south. Fruits identified later as bananas have popped in and out of the written histories of various civilizations. The earliest records of cultivation date to 600 BC in the Buddhist canon from India. And there are these stories about the previous births of the Buddha called the Jataka. One such story from 350 BC clearly mentions a banana. And a cultivated one at that, indicating that they were domesticated a long time ago. In 67AD, the Roman writer Pliny refers to the banana in his book Natural History - saying that it originally grew in India and that the armies of Alexander the Great encountered and enjoyed it. The Chinese probably enjoyed bananas too for hundreds of years. However we do not get written records about the fruit until 200 AD, when a Chinese official named Yang Fu (楊孚) mentioned it in a book about the region of what is now Guangdong. ## Domestication The domestication of the banana is complicated - having took place over thousands of years across many different areas. Wild bananas are edible but way different than the modern fruit. They are packed with these hard, not-very-tasty seeds. Some have more seeds than actual edible banana flesh. Others are downright Trypophobia-inducing. Over the years, people selected bananas for certain traits like size and fruit taste - crossing together various Musa species to create hybrids. Today's commercial bananas have genomes from one of two banana species. The first is the A genome, or Musa acuminata. A-type Bananas tend to be sweeter, softer, and a bit more aromatic. These are your "dessert bananas" that you can eat raw. The second is the B genome, or Musa balbisiana. Bananas that have the B genome tend to be firmer and starchier. These are your cooking bananas. Some hybrids suffered genetic mutations. Normal wild bananas are Diploid like us, with two copies of each chromosome. But a few hybrids went triploid, meaning three of each chromosome. Since the chromosomes cannot evenly pair up, seeds cannot properly develop. The only vestiges of the seeds are the strange dark lines you can see inside the fruit. I always wondered what those were. And by the way, did you know that the banana is, botanically, a berry? Having no seeds leaves these banana plants sterile so replicating them means to clone them. The banana plant is not a tree, but a perennial herb. Quite a tall herb, by the way. Getting up to 4. 8 meters tall. The herb has an underground pseudostem that grows shoots that we call "suckers" or "ratoons". Each sucker will eventually sprout one bunch of bananas. Each bunch has several rows or "hands" of 5-20 bananas clustered together at various angles. A single banana unit is referred to in the industry as a "finger". So farmers will cut off those suckers as they emerge and replant them in new soils. You’d want to cut off those extra suckers anyway because having several of them make for bad tasting bananas. The new plant grows roots and after 9-14 months starts producing fruit.

This cloning enables farmers to guarantee fruit quality at scale. ## Gros Michel Anyway, there are over a thousand banana cultivars around the world. In certain countries like India - where bananas are eaten not just as a sweet fruit but an all-around food - you can experience this massive diversity for yourself. But when most people think about bananas, they think about dessert bananas - the sweet ones. And famously, the bananas exported to North America and Europe were a single dominant sweet cultivar. The Gros Michel. It means "Big Mike". Where that name came from is not too clear. The cultivar itself most likely dates to a sample first collected in South China by the French explorer Nicholas Baudin in the late 1780s. He then planted it on the Caribbean island of Martinique - thus giving it its alternative name: The Martinique Banana. Then so the story goes that in the 1830s the banana was noticed by a Haitian-born French planter named Jean Pouyat. He then started growing it at his coffee plantation in Jamaica. And from there it spread to Central America and beyond. The banana first made its way to the United States in the 1860s from the plantations of Panama and Hawaii. So while Americans were familiar with it for some time, it remained somewhat of a tropical novelty until 1870. That year, a ship's captain from Massachusetts named Lorenzo Dow Baker brought some bananas from Port Morant in Jamaica to the United States - apparently in an attempt to earn some side income from the voyage. But the banana became an immediate hit - leading Baker to get more. Why? Why not? Bananas are awesome. They’re cheap. They taste great, are nutritious and filling, and don't need cooking. They come in its own germ-free packaging. And they are very cheap. US banana imports exploded from 12 million bunches in 1892 to 45 million bunches in 1911. Two-thirds of all the world’s exported bananas went to the US. Boston became one of the world's great banana ports - which sounds funny to me because I suspect you cannot grow a banana there at all. By 1913, US per-capita consumption of bananas cleared 20 pounds - favored across all income and race classes. The only fruit that Americans ate more of then was the apple. Today, the two compete vigorously for the top spot. ## The Fruit Companies During the 1870s and 1880s, many small companies were founded to ship bananas to the US - almost sixty. The business risks were immense. Many companies depended on a single successful shipment to survive. This age of wild competition ended with a series of mergers over the years to form the vertically integrated giant United Fruit Company in 1899. Two others that emerged were Standard Fruit and Cuyamel Fruit. These banana giants are infamous for exercising outsized influence on Central American countries. “Banana Republic”. The phrase means more than just a clothing brand. They wiped out native landscapes to set up banana plantations. They built hundreds of kilometers of railroad and set up banks, radio stations, and schools. They also leveraged country resources to crush labor disputes with bloody effect. They also occasionally overthrew a government or two. Despite that, the United Fruit Company's real strength was not in its huge tracts of land nor its political influence, but rather in its massive transportation system. This includes its railroads, ports, and fleet of ships - United Fruit had 70+ by 1930. ## Shipping and Handling The Gros Michel banana itself fit this corporate strategy. It was and still is a fine tasting banana. People describe it as being quite sweet and creamy. And if you are curious about how they taste, you can still go buy them in specialty shops today. But the Gros Michel did not become THE cultivar of the export industry because it tasted the best. It rose up in the market because it was the easiest available cultivar to ship far and wide with minimal damage. First, the Gros Michel was a very productive cultivar for its time - bearing bunches of eight or nine hands in the right conditions. Its yields were many times higher than wheat or potatoes. And since we basically clone it, we can expect consistent output every time.

Second, the cultivar is hardy. As you might know, bananas are best when they are ripe and bruise-free. So we pick them when they are still green and ship them over. Which in the 1880s meant a wind-powered schooner with minimal cushioning and no climate control. The Gros Michel banana has relatively thick skin. Moreover, its hands and fingers also grow at favorable angles. Both help protect the fruit from bruising whilst it travels on the boat - saving money on packaging. The banana also benefits from a relatively long ripening period - making it more likely to survive the 14 days that it takes to reach the customer before the fruit goes bad. As I mentioned, the fruit companies' real strengths were their shipping and distribution. The Gros Michel played into that by letting the fruit companies ship and sell more high quality fruit to the United States at low prices and still make a profit. ## The Fungus Then came the fungus. The first written records of the fungus appear in Australia. In late September 1871, the Queenslander newspaper's Farm and Garden Memoranda makes mention of a banana disease that has taken ahold in the area. The passage reads: > We are sorry to say that the banana disease, to which we referred a few weeks ago, shows no disposition to abate. The plants are rotting in many places at a very serious rate, and unless something is done to counteract the evil, there is much reason for the fear that the banana will pass away from amongst us. The banana plant becomes infected through spores entering through the tips of its smaller roots - which are not as protected from infection as its larger roots or pseudostems - or through cuts in the roots. The fungus then starts to grow inside the plant - feeding on it whilst keeping it alive. So farmers do not see anything weird on the outside. At least, initially. But inside, the fungus is moving slowly up the plant, making spores that get carried upwards. This progression starts slow - it can take up to four weeks to move 75 centimeters - but speeds up after it hits the plant's water pipes, its xylem vessels. If nothing stops the progression, the fungus reaches the underground pseudostem and spreads rapidly there. At this point, the plant starts suffering from water shortage from the fungus clogging up its water vessels - creating some of the first external symptoms: Yellowing and wilting leaves. The plant's immune system will respond, producing gums and gels inside its xylem. A resistant plant will do this early and aggressively - permanently blocking the fungus's spread and ending the infection. But if the immune response is too slow, then the fungus takes over. The infected plant starts to rot into a soft wet mess from both its top and roots. The heart of the pseudostem turns black and finally, the plant collapses. This whole process is slow and highly dependent on a variety of external factors like the climate, applied fertilizers, soil acidity, and so on. Which of course makes containing this whole thing so much trickier. ## Finding the Killer Initially, farmers thought that the disease was caused by soils with bad drainage, the plants getting worn out, or climate change. Yet even after they changed those things, the banana plants kept dying. In 1876, the East Moreton Farmer’s Association invited Joseph Bancroft - one of the few university-educated individuals in the area - to visit one of the banana plantations and examine. After an investigation, Bancroft writes a brief 400-word report saying that he believed the disease was fungal. To prevent spread, he recommended that infected underground stems should not be replanted. In the early 1900s, the fungus first appeared in Central America - laying waste to banana fields. In 1908, some samples from Cuba were sent to the famed American plant pathologist Erwin Frink Smith. Smith identified a species of a common plant fungus called Fusarium, which commonly infects a bunch of crops like tobacco, potato, or tomatoes. This particular variant munches on banana plants. So it received the name Fusarium Cubense or Fusarium oxysporum, special form Cubense - shortened to FOC. I must admit that this thing having so many names is confusing. Earlier names include Banana wilt - first used when it emerged in Jamaica in 1911 or 1915.

And of course, "Panama Disease" - because the fungus first became epidemic there in the 1910s or possibly even as early as the 1890s. I myself shall use the “FOC” - which is the scientific name. We are not sure where the fungus truly comes from. Some studies say Colombia. Others speculate it shares the same range as wild bananas. All likelihood, it was probably already around before the banana itself. The fungus can spread in a variety of ways. When the plant dies, its spores are released in the soil where they can be picked up by the roots of nearby banana plants. Or they can hitch a ride on people, animals, insects, machinery, and water. Probably the most effective method of spread happens when farmers transport suckers from an infected farm to plant new plots. Suckers can be infected without showing any signs of infection, and might not do so for two whole years. ## Fall of the Gros Michel The banana industry had before seen very serious plant diseases. One such outbreak occurred in the 1930s: Sigatoka disease. Caused by a wind-borne fungus, it produces a condition called "leaf spot" - where the leaves get brown and yellow streaks. Between 1930 and 1938, it wiped out half of banana production in the Honduras. Fortunately, United Fruit technicians frantically innovated an expensive fungicide regime based on copper sulfate. This incident ironically had the side effect of forcing out smaller growers and further entrenched the company's dominance. But there is no known cure or treatment for FOC. Its spores can remain in the soils for years - maybe even decades - and it spreads so easily. There were attempts to "flush out" the spores by flooding the fields with water. But flood fallowing is not only expensive, but also temporary. FOC returns within a few years. Slowly, FOC spread from Panama to Costa Rica, Nicaragua, Guatemala, and Honduras. Once infected, farms can hold out for two or more years, but they often end up suffering such significant declines in productivity that they simply abandon growing the fruit. It should be noted that many banana growing enterprises collapsed during this time for just regular bad business reasons. Many "contaminated" plots should never have been growing bananas in the first place. St. Lucia's entire industry fell apart due to bad financing. The big fruit companies in Central America started suffering massive, ongoing losses in land that can only be replenished by developing new land. You can imagine that such a solution is not very sustainable. ## Running Out of Alternatives Various disease-resistant cultivars were mooted. In 1928, United Fruit offered up the Lacatan, which looks like the Gros Michel. But US consumers found the banana's meat indigestible and unappealing. You had to let it ripen until it was all black. And by then US customers won’t buy it unless sold at a huge discount. Nevertheless, the Lacatan is well-liked in the Philippines as a dessert banana. By World War II, the fungus had spread all across Central America. And by the early 1950s, United Fruit and Standard Fruit were abandoning some 10-15% of their total acreage each year because of the fungus. Rises in production were only fulfilled with slashing up new acreage. Declining Central America exports were filled by Gros Michel bananas grown in South American countries like Ecuador and Colombia. United Fruit and its competitors had no presence there and recognized that they might lose their whole hold on the market. In a desperate effort, the United Fruit Company mustered huge resources to flood-fallow and replant thousands of acres - an impressive feat. But its smaller competitor, Standard Fruit, did not have such resources and so decided to try something else. ## The Rise of the Cavendish cultivar was collected from south China some 250 years ago, which is why it is also called the Chinese banana or the Pei Chiao in Taiwan. For many years, the cultivar was grown along with the Gros Michel mostly in Australia, French West Indies, and the Canary Islands. It was already a widely available commercial cultivar so it wasn't like it just came out of nowhere. But the Cavendish did not appeal to United Fruit and its ilk for a long time. For one thing, the companies had invested so much capital and effort to harvest and transport the Gros Michel. They were loathe to change.

They also felt that the Cavendish banana's skin was too delicate and susceptible to bruises, which turns consumers off. The fruit is also physically smaller than the Gros Michel. It has a smaller stem which makes it harder to harvest and does not last as long after ripening. It is also susceptible to the aforementioned sigatoka fungus and is less tolerant of cold than the Gros Michel. But Standard Fruit had little choice. The Cavendish resisted FOC. In 1957, they planted 15,000 acres of a variant called the Giant Cavendish and built a packaging factory to put the fruit into boxes before shipping. United Fruit saw this and decided to follow suit, adopting another Cavendish variant called the Valery. And from there, the Cavendish rapidly took over the Central American banana industry. By 1965, the switchover was complete. After then, industry people discovered the Cavendish’s other benefits. It is shorter than Big Mike - about 2-3 meters to 4-5 meters - which lets us plant them more densely. It also responds better to modern fertilizers. For this reason, the Cavendish is twice as productive as the Gros Michel as measured by fruits per hectare. Its shorter height also makes it hardier and less likely to topple over from high winds. But wait, there is more! That shortness also makes it easier for workers to safely bag and harvest the fruits. So let us hail our short kings! ## Taiwan and TR4 Until 1967, there were only three known races of FOC. Tropical Races 1 and 2 - which I shall shorten to TR - attack the domesticated banana cultivars. TR3 attacks a wild banana species. TR1 is the one that ended the commercial reign of the Gros Michel. TR4, the one that plagues us today, was first discovered in Taiwan. Yes. Before TSMC silicon or Acer PCs, Taiwan exported bananas. Dating back to the Japanese colonial period, Taiwan's banana industry is one of Asia's oldest - stretching across the counties of Nantou, Taichung and Pingtung. And it was once massive. In 1967, they shipped 26 million boxes. That year, over 20% of Taiwan's export income came from bananas. Then in 1967 in the Jiadong township (佳冬鄉) of Pingtung County, Taiwan, banana farmers discovered a new race of FOC: TR4. And it attacked the Cavendish. It probably didn't originate in Taiwan, but no one will ever know. For the first two years, the fungus seemed to have been contained to one orchard. But infections exploded in the third year, 1970, with the number of infected plants skyrocketing from just 27 to 5,536. People just were not well educated on containment, and it might not have mattered even then. First, irrigation water or rainstorms swept spores to uninfected plots. And second, farmers aggressively cut down infected plants, which got spores onto the knife blades. The farmers then carried those spores around with them. The government and industry frantically rushed to contain the spread - digging up infected banana plants and treating the soils with lime. The government also paid farmers to convert infected banana plots to rice paddies. Ultimately, these measures failed. By 1973, TR4 had established itself in Taiwan. It is basically impossible to eradicate there now. ## TBRI In 1970, the government and banana industries founded the Taiwan Banana Research Institute, now located in Pingtung. Their main goal was then and still is today to produce a banana cultivar that is resistant to TR4 while also retaining the traits that make it so popular for farmers and consumers alike. You might be wondering. How do you breed a banana without seeds? They relied on the fact that even clones will show natural genetic mutations as they grow: Somaclonal Variations. So they generated and infected huge numbers of Cavendish seedlings with FOC and screened them for resistance. Since the mutation rate is low, they accelerated the process with certain chemicals, but it was mostly through sheer numbers. Ten variants were found, with one eventually selected for marketing. The Tai Chiao Number 1 is not 100% resistant to TR4, but it is ten times more resistant than its priors. A descendant of this banana is still grown here in Taiwan today. Though almost all of the island’s banana production is meant for local consumption. What little exports are

only to Japan, where at prices three times higher than of other countries they struggle to compete. ## The Spread of TR4 has since spread around the world, laying waste to banana-growing regions wherever it goes. In the mid-1990s, it spread to Malaysia and Indonesia, causing serious outbreaks there. Peninsular Malaysia has lost thousands of Cavendish hectares to the disease. Farmers in Indonesia burned rice hulls on mats in an attempt to kill the fungus with heat. This failed. Indonesia remains a top banana producing country, but almost all of their production is for local consumption. Others tried soil solarization, a method where you cover the soil with plastic under the sun to heat up the soil. This was found to have delayed symptoms by about six months but did not succeed in stopping the fungus. In 1996, TR4 hit southern China where it annihilated anywhere between 40,000 and 60,000 hectares of Cavendish production in the Guangdong, Hainan, and Guangxi provinces within a few years. Data remains spotty however. China is the second largest banana producing country after India - but again it's all for local consumption. In 2005, the fungus entered the Philippines, Asia's leading banana growing country and the second largest exporter overall. The country's main growing area Mindanao is estimated to have as much as 43% of its land acreage contaminated. Fortunately, the use of new resistant Cavendish variants has maintained production. The fungus first ventured abroad in the early 2010s - spreading to the Middle East countries like Oman, Jordan and Israel. At the same time, it continues to spread downwards in Asia towards Vietnam, Laos and Cambodia. And of course, I covered the fungus' recent entrance into Latin America in the late 2010s. So far, the spread looks to be slow, constrained to local areas. And considering the complicated factors that affect the spread, it would be foolish to make predictions. ## What Now? The Latin countries' current strategy is biosecurity. Basically they are hoping that they can keep the fungus out and from spreading for as long as possible. If that were to ever fail, then they would need to switch over to a resistant cultivar. The TBRI has continued their work producing new banana variants after the first Tai Chiao back in the 1980s. In January 2026, they announced a ninth version of the Tai Chiao that is 70% resistant to the fungus and is meant for export. There also has been work done in Australia. In 2017, researchers at the Queensland University of Technology in Australia announced the creation of a transgenic Cavendish banana plant with resistance to FOC. Education is also necessary. The experience in the Philippines seems to show that even with resistant plants, farms need to adjust their growing practices. They can’t just presume immunity. You still need some form of biosecurity and management to keep pathogen levels from building up. ## Conclusion I want to thank the folks at the Taiwan Banana Research Institute for hosting me on a visit, providing me with information about their research, and helping me collect video and image material. I also want to thank friend of the show Franklin for suggesting this idea. Bloomberg estimates the global banana industry to be worth about $20 billion. The fruit itself remains a cheap and nutritious food - a core ingredient in people's diets. I think people will miss it. FOC TR4 is still around. It continues to threaten banana export industries worldwide. I am not sure if they will be able to keep it at bay forever. I am reminded of the words of one grower in the Philippines who said: > "If you are 1000 km away from this disease you are too close". But I do not want to back all these wild headlines saying that the banana is going extinct. That’s an exaggeration. We can still eat the Gros Michel today, guys. I feel like the spread will be slow. Remember that it took nearly five decades for TR1 to push the fruit companies to take on the Cavendish. So there is time. And there are a number of suitable varieties to replace the banana you see in the western supermarkets. The fact that we here in Taiwan can eat bananas in the first place is proof enough that the Cavendish is not going extinct anytime soon. But more work is needed indeed.