Once considered such a strange exotic treat that they were eaten on a plate with knife and fork, bananas are now a ubiquitous fruit — the most popular in the U.S. But the breakfast fruit and pick-me up snack is under threat. A fungus is wiping out banana plantations.

The fungus, something called a Fusarium wilt, has hit Asia and Africa and has now reached Australia’s banana-growing regions, Phoebe Sedgman reports for BloombergBusiness (H/T Mark Frauenfelder at Boing Boing). The banana industry is worried, mostly because they have no other alternatives. This is a problem of the industry's own making. And they had a similar issue before.

The banana most commonly encountered outside of the regions where bananas are native is the Cavendish, a large, yellow, hardy — and some say — bland banana. It replaced the Gros Michel, which fell from its top-banana spot on the global market due after plantations were decimated by the same fungal pathogen in the 1950s. Sedgman writes:

“The monoculture, the reliance on a single banana breed that makes all this possible -- that makes the low margins work -- also makes that fruit very susceptible to disruption,” said Dan Koeppel, who has traveled to 30 countries to sample varieties and wrote Banana: The Fate of the Fruit That Changed the World. “The biggest problem is disease.” A lack of plant diversity isn’t unique to bananas. After a history in which more than 7,000 species were cultivated for human consumption, today just four crops — rice, wheat, corn and potatoes — are responsible for more than 60 percent of human energy intake, the UN’s Food & Agriculture Organization estimates.

The Fusarium infecting banana crops today is a newer strain than the one that bested the Gros Michel. It’s called Panama disease Tropical Race 4, and it first yellows the banana plant’s leaves, then browns them as they dry out. It spreads easily on dirt clinging to shoes, truck tires and shipping containers.

While the fungus hasn’t reached the Americas or western Africa, it may only be a matter of time. "[It] is probably five or 10 years away," Dan Koeppel told Steve Mirsky at Scientific American. "And as of now there is no cure, and when it comes it will go fast and it will go very devastatingly, will probably wipe out the entire banana crop, unless something is done about it, unless some kind of cure is found or unless we diversify our banana crop before that."

Researchers are working on saving the Cavendish, but they may run out of time. Instead that popular banana may someday be replaced by a resistant variety. Then writers will pen nostalgic odes to the fallen Cavendish, just as they do to the Gros Michel today.