THE CHEAT SHEET. We’re running out of bananas. Yes, seriously

Is someone eating them all up?

A fungus, actually, with a rather benign name. But the Tropical Race 4 will soon wipe out the world’s favourite fruit. And that’s not the worst bit of the news.

Then, what is?

It will be doing this for the second time.

Oh, wow!

A study published late last month in the open access public library PLOS (Pathogens) traces the history of this particular fungus and its mutations that are threatening bananas out of existence.

So what is this history?

It all began in the late 1800s, when a fungus known as Panama Disease slowly started killing local banana plantations. The fungus slowly and surely moved across continents all the way to the other end of the map in South America, the largest (then and now) grower and exporter of bananas. According to the study, the Panama Disease drove the Gros Michel — at that point, the world’s most consumed variety of banana — into extinction.

And the same is happening now?

The most popular variety of banana in the world today is the Cavendish, which accounts for 99 per cent of the fruit’s export market. And a “more potent mutation” of the Panama Disease — the Tropical Race 4 — is gradually killing the banana crop in Asia, Africa, West Asia and Australia. It’s only a matter of time, the researchers say, till the disease spreads through the world’s banana basket in South America.

How does the fungus affect the banana plant?

Tropical Race 4 is a soil-borne fungus that only harms bananas. According to a report in The New Yorker, the fungus can survive in the dirt for decades and it spreads through the transportation of infected mud or diseased plants.

Chemicals are ineffective against an infection that debilitates acres of crop. In a diseased plant, the leaves turn yellow and start drooping to the base. When the plants are cut open, the inside smells like garbage, a “putrefying mixture of brown, black, and blood-red”.

The roots become unable to support the plant. The Tropical Race 4 first appeared in Taiwan in the late eighties, destroying 70 per cent of the country’s Cavendish plantations while in Indonesia, more than 12,000 acres of crop grown for export were abandoned. Havoc followed the disease’s spread through Malaysia, China and the Philippines.

That’s sad

Yes, especially because the banana, if you go by consumption patterns, is the world’s favourite fruit. It also ranks among the top ten food commodities for Southeast Asia, Africa, and Latin America. It’s loaded with vitamins, potassium, magnesium, and fibre; and is eaten in almost every country including India.

But why are bananas so vulnerable?

The study says this is because of the way the fruit is cultivated. Edible bananas reproduce asexually through rhizomes (underground stem), but since the early 1970s, mass production began of genetically identical plants.

While such monocultures control quality of the crop and make the product cheaper, it also makes them more vulnerable to pests and plant diseases.

Should I stock up on bananas then?

Not yet. The death of the Cavendish seems unstoppable right now, but it’s still a few decades away. During this time, scientists can try to develop a new variety that is Tropical Race 4-resistant, but that’s not really solving the problem of killing crop varieties.

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