You Don't Know Jack(fruit)

Prolific and nutritious, this funny-looking fruit could help feed the world.

November 09, 2015

Peter Nijenhuis/FlickrPhoto: Peter Nijenhuis/FlickrJackfruit growing in Indonesia

A single 15-foot jackfruit tree stands tucked behind some flowers in an exhibit within the Chicago Botanic Garden’s tropical greenhouse, its broad, waxy leaves covering the exhibit sign. Dangling from its gangly branches are light green male flowers the size of a swollen finger. They appear to be waiting for the plant’s lady flowers to bloom. When and if that happens, the tree will bear a large, funny-looking fruit.

“It’s a nice tree,” says botanist Nyree Zerega. “I really love it.”

Zerega has reason to. It’s because of her that the tree is there and not, say, growing in its native India or Bangladesh. With graduate students from Northwestern University’s plant biology and conservation program, she’s looking into the origins and evolution of the jackfruit tree, which could help other researchers better understand how the tree pollinates and how to select for desirable traits. That knowledge, in turn, could make jackfruit a more valuable crop.

As the human population soars, scientists, agronomists, and farmers are racing to figure out how to grow enough food to feed 8 billion mouths—especially as global warming puts agricultural lands at risk. Part of the solution may be to take a second look at nutritious yet underutilized crops. The poster child for that group, says Zerega, is jackfruit. 

Humans today rely on roughly 40 crops (think corn, wheat, and soybeans) to nourish our growing numbers. Over the centuries, we’ve selected for varieties that sell well or thrive in certain climates but have reduced the genetic diversity of our crops along the way. Should a virus or drought strike, our monocultures could wither and leave us hungry. In its most recent report, the Intergovernmental Panel on Climate Change states that farmers across the world are already seeing smaller yields thanks to heat waves, extreme rainfall, and droughts brought on by global warming. Supplementing our short list of crops with more reliable fruits, vegetables, and grains, Zerega says, could help keep our bellies full in an uncertain climate future.

And that’s where jackfruit comes in. Because it’s a tree, it doesn’t need to be replanted every year. It’s also pretty hardy, resisting pests and diseases, and produces lots of huge fruit. A single tree can yield hundreds of jackfruit—some weighing up to 100 pounds. A 6- to 8-pound specimen is considered tiny, says Zerega.

Photo: ajeshodayanchal/Wikimedia CommonsA jackfruit tree and fruits

Each oblong fruit comprises hundreds of seeds surrounded by a layer of edible flesh that ranges from slightly crisp to soft and custardlike. That flesh is used to make everything from juice to ice cream to chips and may be eaten on its own. The seeds can be ground for flour, and their fleshy envelopes (technically floral tissue) are full of potassium, phosphorus, calcium, iron, and vitamins A and C.

Aside from producing food, a jackfruit tree is handy in other ways, too. Its wood makes great timber, and a reddish dye derived from its heartwood was traditionally used to color the robes of Buddhist monks. Oh, and let’s not forget about feeding livestock: Goats love to eat the tree’s leaf litter.

There are a few issues, however. First, jackfruit has an image problem—at least in India, where the tree is abundant. Appearing naturally in yards and fallow lands across the Western Ghats, an Indian mountain range, jackfruit is known as the “poor man’s fruit,” and landowners focus on cultivating other crops rather than growing something that already flourishes. Another barrier to the tree’s popularity is that its fruit can be sticky, and its sweet, Juicy Fruit–like smell can be overwhelming to some. And since jackfruit trees are cross-pollinated, growers end up with fruits that vary wildly in size and flavor.

If you’ve ever seen jackfruit in the grocery store, it probably came from Vietnam or Thailand, where farmers graft trees to create orchards full of clones, which helps ensure consistency. India could potentially do the same thing.

In Bangalore last year at an international conference on jackfruit (yes, such meetings exist), scientists discussed how to better market the potential staple. The conference took place at the University of Agricultural Sciences, where horticulturist Shyamala Reddy has studied jackfruit for more than 12 years.

“With increases in drought and floods, farmers are looking for new avenues,” she says. Reddy’s collected a variety of jackfruit genotypes, cataloging some that flower in the off-season and others that develop more fruit. She grows the most bountiful varieties and then sells them to farmers, in the hope that she can help expand the industry.

If all goes well that funny-looking fruit just may be the food of the future. So go on…try some

Photo: Mullookkaaran/Wikimedia CommonsJackfruit flesh

onEarth provides reporting and analysis about environmental science, policy, and culture. All opinions expressed are those of the authors and do not necessarily reflect the policies or positions of NRDC. Learn more or follow us on Facebook and Twitter.

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