What’s the Deal with Interstellar’s Idea That Corn and Okra Are the Only Crops Left in the Future? Let’s Ask a Scientist.

Interstellar, the new movie from Christopher Nolan, comes out today, and as a lover of sci-fi epics, I’ve been looking forward to it for some time. But as a food writer the basic premise made me do a double take. In the near future the world’s soil, through blight or exhaustion, has stopped supporting all food crops except for corn and okra.

Is there any basis to this premise? A far-fetched yet theoretically possible superbug? And, if there was some massive worldwide die-off of crops, would corn and okra really be the last crops standing? If not, what will we be eating as our spaceships lift off for the the Kuiper Belt? I decided to ask a scientist and find out.

I spoke to Dr. Matthew Kleinhenz, a professor in the Department of Horticulture and Crop Science at The Ohio State University, and asked him to speculate with me for just a moment. He very nicely obliged my dystopic fascination and was, as you might expect, reassuring — to a point.

The big question: Are we ever going to be in danger — in the most extreme and speculative sense — of ever having just corn and okra to eat?

“I got the biggest kick out of this premise,” Kleinhenz said. “But if I were sitting around talking with the filmmakers I’d be a wet blanket.” Blight, disease, and all the other factors that make crops die off, he explained, don’t usually cut such a wide swath. Also, when one plant form dies off or struggles, that often opens a door for another to thrive.

“The way the biological world is constructed just doesn’t support this scenario,” he said. “There are strains of diseases that wreak havoc on individual crops and even on groups of related regions, but these have to not just be adapted to the crop but to the climate and conditions.”

There’s a fundamental tenet of plant pathology called the disease triangle. It says that for any disease to spread widely it needs three things: a susceptible host, a pathogen, and the right environmental conditions. Take any one away, and the disease won’t spread.

“It’s very unlikely that a single superbug would spread across our diverse planet, or even do as well in Alaska as Peru.”

Sure, maybe this kind of scenario isn’t likely, but is there anything — likely or not — that could radically reshape agriculture as we know it? “Well, what you can say,” he said, “is that things are changing.” Why? Two words: climate change.

Extreme weather and the effects of climate change aren’t science fiction. “This is a global phenomenon with local realities,” Kleinhenz said. He works extensively with farmers and agriculture in the Midwest, and in the extreme weather of the last couple years he’s seen unprecedented effects that have a long tail of consequences. “In 2012, for instance, there was no apple crop in Michigan, which meant that the laborers who usually harvest apples didn’t come. But this also meant that the vegetable crops they usually harvest didn’t get picked either. There are all these layers of climate effect on agriculture: social and economic layers, food, diet, health. Individual weather events can really strain the system.”

“In 2012 I was called in by several farmers in their 80s, who had never encountered weather (or challenges) like this in their entire working lives. No one who is working today had previously seen what 2012 brought.”

Kleinhenz hastened to reassure here as well. “I’m not genuinely concerned about something being removed from people’s tables. What I would say is that the supply chain that provides it, the price paid for it, its availability, the way in which it is brought — those may change.”

His work with climate change and agriculture does make him concerned for the agriculture community and their way of life in the United States. “Effects of weather have always been with us and most astute know how to deal with them and over the course of a career. But the system is built to tolerate certain levels of fluctuation and when those tolerances are regularly being exceeded it sends ripples through the whole system.”

But farmers tend to find a way forward. “On a day to day basis,” he said, “I’ve always been impressed by the resilience and adaptability of that same community.”

There are very present challenges to agriculture given the reality of climate change, but we’re not in danger of being reduced to cornbread and okra (or sending farmers off through wormholes looking for new planets). That’s pure science fiction, with emphasis on the fiction.

But still, why corn and okra? I asked. “Corn and okra are not related so it’s odd that they picked those two,” Kleinhenz laughed. “Maybe they needed one familiar and one more unusual crop! But corn and okra are actually grown together all over the world, and part of the reason they’re grown together is they’re not related, so they don’t support the same diseases.”

What would be the last crop left standing, given massive climate change or a worldwide blight? The key to this very speculative question, according to Kleinhenz, is the idea of adaptation. When it comes to food crops, humans have a lot of say.

“It would be something less selected, less heavily managed, with an inherent potential to produce seed and still feed humans. People have to want to eat it, and people need their energy first, and the first line of defense is high carb crops — grains, roots, tubers. And it is narrowly-adapted, one-trick pony crops that are less essential (to health) and that require extensive care that are most at risk.”

So what’s the final answer? What will we be eating on our spaceships? “Good old millet, or teff, or some form of wheat. Or some small leafy vegetable that helps people to remain healthy and can be grown anywhere by anybody.”

Thanks so much for playing along, Matt! We’ll get to work on those millet recipes.

→ Learn to cook millet: How To Cook Perfect Millet Every Time

• Vegetable Production Systems Laboratory at The Ohio State University

• Visit the website: Interstellar