Building A Better Banana

It is the world's No. 1 fruit, with millions of people dependent on it to stay alive. Now diseases threaten many varieties, prompting a search for new hybrids of the "smile of nature"

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Sleet slices through the sky nearly sideways, propelled by Arctic blasts from the North Sea. I am in northern Belgium, wandering the grounds of a Baroque castle at the Catholic University of Leuven, about 15 miles northeast of Brussels. I am on a pilgrimage of sorts, seeking enlightenment about Musa sapientum, better known as the common supermarket banana. Building 13, a plain two-story brick structure within the castle walls, houses the world’s largest collection of banana varieties.

The basement room is the size of a semitrailer. It is cool and humid, with a slight musty odor. Two rows of metal shelving hold hundreds of wire racks filled with yellowcapped test tubes. Each tube contains a small, rooted plantlet about the size of your little finger. All told, the room contains nearly 1,200 varieties of bananas. They look like overgrown bean sprouts. “After you’ve worked with tissue cultures for a while, you begin to recognize different types,” says Ines Van den Houwe, the Belgian agricultural engineer in charge of the collection. She points out specimens. “This one is probably a type of dessert banana. Here’s a hybrid plantain. And this looks like a balbisiana cooking banana,” she says, referring to its wild forebear, Musa balbisiana. “Roughly 900 of these are traditional cultivated varieties. Another 100 are improved varieties or hybrids from various breeding programs. And about 180 are wild relatives. We have material from 44 countries, from the plantations of Central America to the deepest rain forests in Malaysia.”

And why are they all here, in deepest Belgium?


She flashes a smile. “Belgium doesn’t grow bananas, so we don’t have banana pests and diseases. It’s easy to quarantine the plants—there’s no risk of introducing dangerous diseases to a native population of bananas, because there isn’t any.”

This living library of Musa diversity stands in contrast to my neighborhood grocery store back in the United States. On a recent visit to the produce section, I counted 11 varieties of apple, four kinds of pear, six different potatoes, nine types of onion and seven kinds of lettuce. Then I came to the banana bin. To paraphrase Henry Ford’s comment about Model Ts, I could have any kind of banana I wanted, as long as it was a yellow Cavendish.

The $4 billion-a-year worldwide banana export trade is almost entirely based on vast plantations filled with genetically identical Cavendish clones. It is the supermarket banana’s lack of genetic diversity that has put it at risk, perhaps even (as some scientists say) at risk of extinction. A similar situation with another crop, the potato, set the stage for the great Irish famine of the 1840s, after the high-yielding potato varieties favored by Irish farmers fell prey to an airborne fungus that turned whole fields of tubers black and rotten overnight. Today, similar pests are stalking the banana. Topping the list is a fungal disease called black sigatoka. Originally found in Indonesia’s SigatokaValley, it attacks the leaves of banana plants, shutting down the plants’ ability to photosynthesize. The wind-borne fungus has spread throughout Asia, Africa and Latin America. Many kinds of bananas are susceptible to black sigatoka, but none more so than the Cavendish. Large-scale growers can keep it from devastating their harvests only by spraying fungicides from airplanes. This escalating chemical warfare is economically unsustainable, to say nothing of its toll on the natural environment or the health of field workers. “Is sigatoka the end of the banana as we know it? No. Rumors of its demise are exaggerated,” says Dave McGlaughlin, an environmental director with Chiquita Brands International. “But it’s a serious issue. Sigatoka control is 20 percent of our costs, and it’s not getting better.” Banana growers in some tropical countries face threats even worse than sigatoka, such as bunchy-top virus, fusarium wilt and cigar-end rot. As a result, efforts to develop new, disease-resistant types, including alternatives to king Cavendish, are growing increasingly urgent.

More is at stake than a healthy snack. While the banana is America’s No. 1 fruit (on average, each person in the United States gobbles more than 26 pounds of them a year, compared with 16 pounds of apples), bananas play a small role in the American diet. But for hundreds of millions of people in developing countries, bananas are a dietary staple—the least expensive source of nutritious calories. The banana ranks fourth after rice, wheat and corn among the world’s most economically important food crops. Of the nearly 80 million tons of bananas produced annually around the globe, less than 15 percent are exported to the United States, Europe and Japan. The rest are consumed locally. India and Brazil, the top two banana-producing countries, export almost none. Yet sub-Saharan Africa leaves both countries far behind in per capita consumption. Atypical person in Uganda, Rwanda or Burundi consumes more than 550 pounds of bananas a year. They eat (and drink in beer and juice) a type known as east African highland bananas. In Uganda, the word for this banana is matooké. It is cooked and mashed in a traditional dish that is also called matooké. In its broadest definition, matooké means “food.” If you held a feast in Uganda and did not serve bananas, the guests would say you had served no food.

But in the past 30 years, banana yields in east and west-central Africa have declined by half. Black sigatoka and other diseases weaken the growing plants, which become more susceptible to attack by weevils and worms. Infested plots that supported a continuous crop for 50 years must be abandoned, and the specter of hunger looms ever larger. “Only five scientists in the world are currently leading programs to breed improved bananas,” says Emile Frison, director general of the International Plant Genetic Resources Institute, a Rome-based organization that promotes genetic diversity of food crops. “Such a meager research effort is out of proportion to the scale and importance of the problem. This must be reversed if the world’s most popular fruit is not to decline further.”

One of those five scientists is Kodjo Tomekpé. “Here in Africa, the banana is not about dessert or a snack,” Tomekpé says. “It is about survival. Our challenge is to multiply and distribute improved varieties for people who rely on them as a central part of their daily diet.”


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