Top Banana: How the world’s favourite superfruit is facing a pandemic of its own – again.


Photo courtesy of the Rainforest Alliance

A fungal disease called Tropical Trace 4 (TR4) threatens to wipe out the world's most consumed fruit, and not for the first time.


Around the world, bananas are our favourite fruit in terms of consumption and export. In the United Kingdom we purchase over 5 Billion bananas annually, munching through an average 10kg of our yellow fruit friend - that’s over 100 bananas consumed per person, per year. Over 21 million tons of bananas are exported annually, the bulk of which are exported from Latin America, the Caribbean and parts of Asia and Africa. The Banana business is a complex and lucrative industry. And not surprisingly so.


Bananas rank as a leading food crop in world agricultural production and trade. Relatively cheap to produce, they are grown in 150 countries worldwide. We also have much more in common with this super fruit, as humans we share 50% of our DNA with bananas. The bulk of banana cultivation is produced by smallholder farmers in Latin American, the Caribbean and parts of Asia - with an estimated worth of 31billion USD per year. And that figure does not taken into account the global curveball 2020’s Covid-19 pandemic and rampage will no doubt affect.


Although bananas come in a thousand varieties (including plantain), only one is most loved, consumed and internationally traded; the Cavendish. This sweet-tasting variety was named after the 7th Duke of Devonshire William Cavendish, who grew the plant in his greenhouse in 1960’s at Chatsworth House, London. Vegans and vegetarians look set to make up a quarter of the British population in 2025, and flexitarians just under half of all UK consumer, and with bananas providing a rich source of vitamin B6, vitamin c, manganese, potassium, dietary fibres and protein, we will surely miss the banana if it goes extinct.


What is happening to our favourite fruit?


TR4 also known as the Panama disease, is a soil-borne fungal disease, which creepily resembles aspects of Covid-19, as it remains undetected in banana plants in the first-instance. The fungus infects the plants’ root and vascular system preventing it from absorbing water and nutrients, thereby causing it to wilt and perish. It’s difficult for banana growers to tell which plant is infected with TR4 as the plant often shows no signs of the disease although it is a carrier and fungus spores can remain dormant in the soil for decades.


A diseased banana plant appears healthy for up to a year before it shows the familiar TR4 signs of infection — yellow wilting leaves. At this stage, it is too late to reverse the disease which has already spread via spores within the soil to other nearby banana plants and surfaces it can cling to. Tropical Race 4 (TR4) now threatens to wipe out the planet’s most consumed fruit. There is currently no cure for plants infected with TR4 although they have been some controversial chemical trials in Australia.


How long has this been going on?


Dan Bebber, associate professor of ecology at the University of Exeter, led a £1.2 million UK funded 2016-2019 research project BananEX to investigate challenges to the banana supply system. He currently heads MUSA a 4-year, €4 million international biocontrol banana research project funded by the European Commission Horizon 2020 and recommends the best way for the banana industry to survive TR4, is to change how bananas are farmed.


He says the disease may have lay dormant for centuries within the earth’s soil and has now become climate and pesticide resilient.


“It is unclear historically, when the panamas disease first emerged, it was probably in the soil structure in South East Asia for 10,000 years or more and the fungus that causes this disease, has now evolved genetically”.


The disease has been popping up over the past 40 years and nearly wiped out the banana industry when the previous popular variety – Gros Michael was number one banana. Human activity and travel may be restricted, but our demand for international goods only increases. And due to the Covid-19 pandemic, we might not be flying around the planet by the millions as we previously did, but our fruits and vegetables are.


Professor Bebber says “rapid globalisation” over the past four decades has allowed the virus to be transported far and wide as humans have.


“The cavendish variety has become extremely globally popular, and thereby allowing this disease to travel with the banana, from small deposits of soil, to surfaces. Bananas present the most extreme example of having a single gene commodity, therefore susceptible and vulnerable to disease. Genetic diversity is extremely important in all crops


TR4 is extremely contagious in soil and irrigation water and farm equipment can spread the disease if not properly cleaned after use. The disease is transported by Spores which are easily transported on the soles of shoes, boots and machinery. All of this helps to explain how TR4 has been spreading since its original outbreak in Taiwan.

Photo by Mathew Feeney


Mini Me – All bananas are cloned


Bananas are sterile, therefore aren't grown from seeds, so each banana is a cloned twin of another banana. And we benefit as consumers, from the advantages of genetic cloning. In colder climates, we purchase and consume bananas as they ripen — year-round. This highly perishable, exotic and nutritious fruit is harvested green, travels thousands of miles around the world and lands in our shopping baskets to ‘ripen at home’.


Decades of mass production cloning of only one variety of banana (the Cavendish), has led to over-production, weakening the plants genetic structure leaving it vulnerable to diseases, and this is not the first time this disease has threatened the global banana industry.


History repeats – Humans repeat mistakes


Up until the 1960s, Gros Michel, or "Big Mike," as it was popularly known, was the most popular banana variety eaten in the world. Similar to the cavendish, it was the number one banana growers world-wide choose to create large monocultures from, converting thousands of hectares of forest land in Latin American in the process to grow it. Farm irrigation water, machetes and other tools carry bits of fungus via small patches of soil from infected plants to healthy ones, if the equipment is not properly disinfected after use. Even soil particles on the soles of shoes can transport spores from one spot to another. This explains how infectious TR4 is and why it has been spreading so rapidly since its original outbreak in Taiwan then first reported in Australia.


Previous outbreaks of the TR2 strain of the Panama disease, affected the Gros Michel, almost wiping out the world’s entire banana export. This would be detrimental to food security in low-income regions of Africa and Latin America if repeated with the Cavendish, as bananas (and plantain), are a staple food source there. To-date there is no effective cure or TR4 management methods known, and prevention is currently viewed by scientists and industry experts as the main strategy to avoid further spread.


Alternatives have pointed to the controversial use and development of GM bananas, however last week Pakistan's National Agricultural Research Centre announced it has developed two new varieties of banana, using 300,000 disease-free plants produced through tissue cultures. This presents interesting developments in the continued fight against the spread of TR4.

Photos by Alexander Popoviski, Courtney Cook and The Rainforest Alliance.


Women in sustainable farming and the banana industry


Women represent a crucial resource in farming and comprise nearly half of the agricultural labour force in low and middle-income nations — in totality approximately 400 million small farm holders.


Agriculture is a sector in which both female and male farmers and workers play a vital role to the balance of successful crop production. Yet in many countries, gender equality* is severely lacking in regard to agricultural opportunities combined with unequal access to financial, productive and technological resources for women. Female farmers often have zero options in owning the very land they farm; and lack of access to credit, education, and empowered decision-making remain stubborn cultural barriers.


Equal entrepreneurial and economic opportunity are vital everywhere, to shift lives unto better standards of living, self-sufficiency and wellbeing for all. However, many admirable female farmers are making strides in sustainable farming practices and slowly breaking this cycle in geographical locations which experience direct consequences of rapid climate change.

Rainforest Alliance farm owner Fanny Araujo Durán in Ecuador


Growing bananas — the ethical and sustainable way


The Rainforest Alliance is one of the world’s largest banana producers of sustainable farming and began its banana certification program nearly 30 years ago, pioneering more sustainable production in this challenging sector. It has created the climate-smart agriculture method which provides sustainable agricultural techniques to banana farmers so they can better adept to the effects of the climate crisis, build resilience, and protect their incomes. This approach favours long-term sustainable farming techniques, which climate the need for pesticides and Genetically modified crops created in laboratories.


Leonie Haakshorst is Sector Lead for banana & fruit at The Rainforest Alliance working together with producers, buyers and other stakeholders from all over the world. She says working together to build partnerships in which people and nature thrive in harmony is key to a sustainable agricultural sector in an effort to combat climate change.


“Banana farmers are at the front lines of the climate crisis. Because bananas are the world’s most popular fruit, their production is often linked to high pesticide use, low prices and wages, and violations of workers’ rights”.


One Rainforest Alliance farm owner is Fanny Araujo Durán she is a small banana producer in the city of Machala- El Oro, in Ecuador, a country that is the largest exporter of bananas in the world. A proud owner of her farm La Gacela, they produces sweet-aroma bananas. She says consumers abroad need to know and have greater awareness of where the bananas they eat come from.


“Consumers should know that when they buy bananas from a sustainable farm like mine with the Rainforest Alliance seal, we take care of the environment, water and biodiversity as a normal operating practice and we look after the well-being of our employees and their families".


You eat bananas don’t you? here are 5 ways you can help now


1. Purchase bananas with a certification seal such as Fair Trade or Rainforest Alliance.

2. Have your bananas delivered by an organic supplier such as Riverford (UK) or locate an organic certified supplier such as Fyffe in the United States.

3. Ask your supermarkets for fairly traded and certified bananas.

4. Want to learn more about our favourite fruit? Banana Link is an excellent resource.

5. Share this post to inform others.


As consumers we need to pay greater attention to how, and from whom all our food is grown and imported.


Public awareness and education surrounding ocean plastic, led to the retail reduction and ban of plastic bags and look at the positive global changes our collective action manifested. We can do the same here with foods and fruits we wish to continue to enjoy.

Next time you buy a banana think about how it might have been produced and check that it carries a certification to ensure it has been farmed ethically and environmentally or ask your retailer about their supplier. It is important to note: The TR4 disease affects the banana plant in its growing stage but does not affect the safe consumption of the banana fruit itself from a fully grown plant.


Written by Caroline S. Asante

Environmental Scientist, Sustainability Consultant, Columnist and Founding Editor-in-Chief of Sustainable Diva.


This article is part of our new series Soil, Agriculture and Women in Sustainable Farming launching soon on podcast, SD and broadcast created by the author.


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