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Can This Fruit Be Saved?
The banana as we know it is on a crash course toward extinction. For scientists, the battle to resuscitate the world’s favorite fruit has begun—a race against time that just may be too late to win
By Dan Koeppel | August 2005
“A Banana,” says Juan Fernando Aguilar, “is not just a banana.” The bearded botanist and I are traipsing through one of the world’s most unusual banana plantations, moving down row after row of towering plants and ducking into the shade of broad leaves in an attempt to avoid the Central American midday heat. In an area about the size of a U.S. shopping mall, Aguilar, 46, is growing more than 300 banana varieties. Most commercial growing facilities handle just a single banana type—the one we Americans slice into our morning cereal.
The diversity of fruit in Aguilar’s field is astonishing. Some of the bananas are thick and over a foot long; others are slender and pinky-size. Some are meant to be eaten raw and sweet and some function more like potatoes, meant for boiling and baking or frying into snack chips. But Aguilar’s admonition is aimed squarely at our northern lunch boxes and breakfast tables.
For nearly everyone in the U.S., Canada and Europe, a banana is a banana: yellow and sweet, uniformly sized, firmly textured, always seedless. Our banana, called the Cavendish, is one variety Aguilar doesn’t grow here. “And for you,” says the chief banana breeder for the Honduran Foundation for Agricultural Investigation (FHIA), “the Cavendish is the banana.”
The Cavendish—as the slogan of Chiquita, the globe’s largest banana producer, declares—is “quite possibly the world’s perfect food.” Bananas are nutritious and convenient; they’re cheap and consistently available. Americans eat more bananas than any other kind of fresh fruit, averaging about 26.2 pounds of them per year, per person (apples are a distant second, at 16.7 pounds). It also turns out that the 100 billion Cavendish bananas consumed annually worldwide are perfect from a genetic standpoint, every single one a duplicate of every other. It doesn’t matter if it comes from Honduras or Thailand, Jamaica or the Canary Islands—each Cavendish is an identical twin to one first found in Southeast Asia, brought to a Caribbean botanic garden in the early part of the 20th century, and put into commercial production about 50 years ago.
That sameness is the banana’s paradox. After 15,000 years of human cultivation, the banana is too perfect, lacking the genetic diversity that is key to species health. What can ail one banana can ail all. A fungus or bacterial disease that infects one plantation could march around the globe and destroy millions of bunches, leaving supermarket shelves empty.
A wild scenario? Not when you consider that there’s already been one banana apocalypse. Until the early 1960s, American cereal bowls and ice cream dishes were filled with the Gros Michel, a banana that was larger and, by all accounts, tastier than the fruit we now eat. Like the Cavendish, the Gros Michel, or “Big Mike,” accounted for nearly all the sales of sweet bananas in the Americas and Europe. But starting in the early part of the last century, a fungus called Panama disease began infecting the Big Mike harvest. The malady, which attacks the leaves, is in the same category as Dutch Elm disease. It appeared first in Suriname, then plowed through the Car- ibbean, finally reaching Honduras in the 1920s. (The country was then the world’s largest banana producer; today it ranks third, behind Ecuador and Costa Rica.)
Growers adopted a frenzied strategy of shifting crops to unused land, maintaining the supply of bananas to the public but at great financial and environmental expense—the tactic destroyed millions of acres of rainforest. By 1960, the major importers were nearly bankrupt, and the future of the fruit was in jeopardy. (Some of the shortages during that time entered the fabric of popular culture; the 1923 musical hit “Yes! We Have No Bananas” is said to have been written after songwriters Frank Silver and Irving Cohn were denied in an attempt to purchase their favorite fruit by a syntactically colorful, out-of-stock neighborhood grocer.) U.S. banana executives were hesitant to recognize the crisis facing the Gros Michel, according to John Soluri, a history professor at Carnegie Mellon University and author of Banana Cultures, an upcoming book on the fruit. “Many of them waited until the last minute.”
Once a little-known species, the Cavendish was eventually accepted as Big Mike’s replacement after billions of dollars in infrastructure changes were made to accommodate different growing and ripening needs. Its advantage was its resistance to Panama disease. But in 1992, a new strain of the fungus—one that can affect the Cavendish—was discovered in Asia. Since then, Panama disease Race 4 has wiped out plantations in Indonesia, Malaysia, Australia and Taiwan, and it is now spreading through much of Southeast Asia. It has yet to hit Africa or Latin America, but most experts agree that it is coming. “Given today’s modes of travel, there’s almost no doubt that it will hit the major Cavendish crops,” says Randy Ploetz, the University of Florida plant pathologist who identified the first Sumatran samples of the fungus.
A global effort is now under way to save the fruit—an effort defined by two opposing visions of how best to address the looming crisis. On one side are traditional banana growers, like Aguilar, who raise experimental breeds in the fields, trying to create a replacement plant that looks and tastes so similar to the Cavendish that consumers won’t notice the difference. On the other side are bioengineers like Rony Swennen, who, armed with a largely decoded banana genome, are manipulating the plant’s chromosomes, sometimes crossing them with DNA from other species, with the goal of inventing a tougher Cavendish that will resist Panama disease and other ailments.
Banana experts disagree on when the Latin American and African crops will be hit by the Panama fungus. Ploetz won’t venture a guess, but he notes that the Malaysian plantations went from full-scale commercial operations to “total wipeout” in less than five years. Currently, there is no way to effectively combat Panama disease and no Cavendish replacement in sight. And so traditional scientists and geneticists are in a race—against one another, for certain, but mostly against time.
http://www.popsci.com/popsci/science/article/0,20967,1076199,00.html
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