The most common type of banana, the Cavendish, is under threat.
Climate change, insects, and diseases threaten the security of banana plants. But the most present threat is a plant pathogen called Fusarium wilt that is ripping through banana plantations worldwide. Scientists are pretty certain of the devastating effects this fungus will have. They’ve actually seen it before.
A Brief History Of The Gros Michel And TR1
There are thousands of banana varieties worldwide, but farmers grow only a few types for exportation. Before the Cavendish was king, the most common banana cultivar was a large, creamy, and sweet type of banana called the Gros Michel. Apparently, the taste of the Gros Michel was delicious – even more delicious than the modern-day banana.2
To keep up with the global demand for the Gros Michel, bananas were planted all over Latin America. Starting in 1903, Tropical Race 1 (TR1) began to spread through these plantations. As more bananas were planted, the pathogen kept up the pace. Within 50 years, TR1 drove the Gros Michael to virtual extinction.3
With Gros Michael under threat of extinction, breeders started developing a banana plant that could replace it. A new type of banana called the Cavendish was born.4
The Rise Of The Cavendish Banana
The Cavendish saved the banana industry. In the 1950s, growers cleared their plantations of Gros Michael and replaced them with Cavendish trees. The Cavendish began to dominate the global market. For the last six decades, it has continued to spread. It’s now planted all over Southeast Asia, Africa, and Latin America.5
Today, almost 50% of worldwide banana production and 99% of exported bananas are Cavendish.
There are hundreds of species of bananas – from silvery-blue blotchy ones to fuzzy pink ones. But when most people think “banana” they are thinking of the Cavendish.6,7
That classic yellow banana you see in your local grocery store? It’s a Cavendish. If you pick up a banana at a market anywhere else in the world, it’s likely Cavendish too.
What’s Happening Now With Race 4?
The widespread popularity of this single type of banana has now become the industry’s Achilles heel. The fungal Panama disease has returned, and this time the Cavendish is not resistant.
The new strain of the disease, known as Tropical Race 4 (TR4), was first discovered in Southeast Asia in the 1990s. Since then, the pathogen has slowly but steadily destroyed crops throughout Asia.
In 2014, scientists discovered that the fungus leaped over to Mozambique and Jordan. This worried researchers. It meant that the pathogen was getting closer to Latin America, where around 80% of the world’s banana exports are grown.8,9
In 2019, it happened. Colombian growers spotted crops infected with TR4, and a national emergency was declared.10
What Might The Effects Be?
The Global Economy
When the Race 1 infection took out the Gros Michel in the ‘50s, it caused $2.3 billion in damage (around $18.2 billion today). So far, Race 4 has already caused $400 million in damage in the Philippines alone.11
Food Security In Developing Countries
Scientists believe that Race 4 is capable of killing 80-85% of banana and plantain species worldwide. This goes far beyond the Cavendish cultivar.
As many as 400 million people in developing countries rely on the varied types of bananas for 15-27% of their daily calories. This is a potentially devastating food security issue.12
The Potential Collapse Of Banana Production
While it may take some time for Race 4 to take out Latin America’s Cavendish population, scientists believe it is inevitable. As of right now, scientists haven’t yet found a viable replacement for the Cavendish. They are looking for something that has a familiar flavor, can withstand lengthy transport times, and has resistance to TR4.13
How Could One Pathogen Take Out A Whole Species?
All Cavendish bananas are genetically identical. That’s right – every banana you see in the store is a clone of the one next to it. This is because Cavendish bananas are sterile. They have no seeds. They must reproduce asexually. To do this, growers use cuttings of one plant to propagate new plants.14
So far, this cloning has helped banana growers. The quality of Cavendish bananas is consistent. They all share the same positive traits. All of the crops on a plantation are ripe and ready to eat at the same time. From an economic standpoint, this type of agriculture is very efficient.
But there’s one big problem with this lack of agricultural diversity. All Cavendish bananas share the same genes.
This leaves them extremely vulnerable to any disease. Once the disease infects one plant, it can easily infect the entire plantation. Which is what is happening now.15
Sometimes, bananas are grown interspersed with coffee or other crops.16 But typically, bananas are grown in a monoculture system. This is a farming method where the same type of crop is grown shoulder-to-shoulder on the same land over and over again.
This allows growers to yield more crops on their land, but it also leaves them vulnerable to pathogens like TR4.17 Intercropping other plants, like coffee or garlic for example, might help keep TR4 at bay.18
It Spreads Easily
Fusarium wilt spreads through the soil. A single clump of contaminated dirt is enough to spread it like wildfire. It can be transported by a grower’s boots, tires, farm equipment, and more.19
Once there, the fungus remains in the soil. Infected plants are unable to pick up water or nutrients from the ground. The only way to get rid of it is to burn the banana plantations to the ground and begin in a new location with a different species.20
Here are a few ways that scientists are attempting to solve this problem:
- Quarantine of infected plantations21
- Genetically modified crops with a similar flavor and characteristics
- Using nematode worms (roundworms) to block TR422
While scientists are faithfully searching for solutions, enjoy your bananas (if you eat them) while you still have them. Just make sure to only eat GREEN bananas — for your health! And yes, even if you grab a green banana at the store… it’s still a Cavendish banana.