Stalking the Wild Banana Stalking the Wild Banana

One man’s “never-ending quest” for the least-known varieties of the world’s most-eaten fruit.

Gabriel Sachter-Smith is a banana aficionado who has identified some 500 varieties of banana on expeditions around the tropical world. “It’s like collecting Pokémon,” Mr. Sachter-Smith said at his farm, Hawaii Banana Source, on the North Shore of Oahu. He was walking through rows of young plants, some of the 150 varieties he grows, in a T-shirt splotched with mud and banana sap. His one-eyed dog, Mendel, trotted along at his boots. “My default mode of being alive is ‘What is that banana?’” he said.

Mr. Sachter-Smith, 35, caught the banana bug when he was 14, on a trip with his mother to Washington, D.C., where he saw banana plants in her friend’s yard. The friend said they weren’t trees, that she could dig them up for winter, stick them inside and replant them when it warmed. When he returned home to Colorado, he started growing them as house plants. “I was trying to figure out what is a banana plant,” he said. “It’s just been a never-ending quest since then.”

Mr. Sachter-Smith left banana-inhospitable Colorado to study tropical plant and soil science at the University of Hawaii at Manoa, ultimately earning a master’s degree. His global quest has introduced him to bananas that are egg-shaped and orange, a foot long and pale yellow, sausage-stubby and green. They are eaten fried, roasted, boiled and as is, but also grown for pig feed, decoration and weaving fabric. In Papua New Guinea, where Mr. Sachter-Smith has gone on two expeditions hunting for bananas, their names carry many meanings: “young men” (mero mero), “can feed a whole family” (navotavu), “something that was fought over” (bukatawawe), “breast” (nono).

You probably know just one banana: long, yellow, kind of flavorless. You eat it plain, put peanut butter on it, or toss it, overripe, in the freezer to make banana bread someday. (You won’t.) Its name, Cavendish, comes from a 19th-century English duke who was sent a package of the bananas and whose gardener grew them in a greenhouse. The Cavendish now accounts for almost half of all bananas produced globally and nearly all exports. It holds a Guinness World Record as the most eaten fruit.

But for years, scientists have warned that fungal diseases like black sigatoka and Tropical Race 4 could wipe out this monocrop, just as a fungus annihilated its predecessor, the Gros Michel, in the 1950s and 1960s. Genetic engineering and breeding are the most likely solutions, so scientists have built a stash of backup bananas from around the world, with genes that might someday see action on the global market.