Crop Diversity in Danger (If You Carrot All about the Future of Food and Farms, Read This)

, agroecologist | May 27, 2015, 8:47 am EDT
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One of my favorite things about a trip to a farmers market is the possibility for surprise, the huge variety of tasty treats—perhaps a juicier plum, sweeter watermelon, perfectly tart apple, or new shade of cauliflower. Such discoveries are surely signs of an abundant and increasing diversity in fruits and vegetables… right? Do not be fooled!

Behind the scenes: produce in peril

In an era where grocery store shelves would hint that the diversity of our food system is increasing, the sobering truth is that many of our fruit and vegetable varieties are in a state of crisis. While farmers markets do typically carry more varieties than the average grocery store, they represent only a tiny fraction (1.6%) of US agricultural sales. Moreover, regardless of where we all may shop, many of the crops that make their way onto our plates are disappearing.

As I am sure you have heard, the farmers and ranchers of the future will need to grow more healthy food under increasingly variable conditions and climates. Thus, the loss of produce varieties is not just an inconvenience, but also a threat to future food security. More on that later, but let’s begin with a few examples:

  • The number of plant varieties available in the U.S. has plummeted over the past century, alongside perpetual decreases in public funding for plant breeding programs.  Tomato, Sweet Corn, Cucumber, and Beets are just a few of the crops that have suffered significant losses of variety according to surveys of the National Seed Storage Library (now called the National Center for Genetic Resources Preservation). Adapted from the figure produced by Rural Advancement Foundation International, available at http://rafiusa.org/issues/reinvigorating-public-plant-and-animal-breeding/.

    The number of plant varieties available in the U.S. has plummeted over the past century, alongside perpetual decreases in public funding for plant breeding programs. Tomato, Sweet Corn, Cucumber, and Beets are just a few of the crops that have suffered significant losses of variety according to surveys of the National Seed Storage Library (now called the National Center for Genetic Resources Preservation). Adapted from the figure produced by Rural Advancement Foundation International.

    Tomatoes in trauma: If your mouth is already starting to water at the thought of summer heirloom tomatoes, listen up! Of the tomato varieties available in the National Seed Storage Laboratory in 1903, we have lost >80% (see graph at right)! According to the Rural Advancement Foundation International, as of 1983 we had only 79 varieties of tomato left. (In sharp contrast, there are at least 109 varieties of canned tomato products immediately available from my local supermarket). Even worse, there are only a few researchers who are looking out for those tomatoes and breeding new ones for the future. So, although I could bet my buttons that I will have multiple brands of pizza sauce to choose among, I cannot say the same for their star ingredient.

  • A sweet corn conundrum: For anyone who has driven past some of the >90 million acres of corn planted in the U.S. last year (covering about 2.5x the area of Iowa) and dreamt of corn on the cob, this may come as a shocker: despite the general abundance of corn in the U.S., almost none of it is sweet corn—the kind we eat—but instead is industrial raw products or animal feed. And this seasonal treat has suffered tremendously over the past century. A loss of >96% of all sweet corn varieties has brought us to a point where we have just 12 varieties left, and only a few breeders working to keep these tasty treasures in our fields of gold.

    All our eggs are in too few baskets. This basket contains the fruits and vegetables that are facing the most severe shortage of resources when it comes to our nation’s plant breeding programs: watermelon, sweet corn, onion, cucumber, celery, carrot, beet, and sweet potato. Adapted from data provided in the 2014 Summit on Seeds & Breeds for 21st Century Agriculture ( http://rafiusa.org/publications/seeds/ ).

    All our eggs are in too few baskets. This basket contains some of the fruits and vegetables that are facing the most severe shortage of resources when it comes to our nation’s plant breeding programs: watermelon, sweet corn, onion, cucumber, celery, carrot, beet, and sweet potato. Adapted from data provided in the 2014 Summit on Seeds & Breeds for 21st Century Agriculture, available at http://rafiusa.org/publications/seeds/.

  • This is bananas: Losing diversity from crop fields can leave agricultural lands at high risk for widespread disease. Have you ever noticed that the majority of bananas look and taste identical? It turns out that a single banana—the neatly transportable Cavendish—rules today’s marketplace. Believe it or not, your great-grandparents also enjoyed only one option when it came to bananas, but theirs was far tastier : the Gros Michel. So what happened? Year after year, monoculture after monoculture of Gros Michel was planted, and field after field was wiped out by Panama disease. As the prized varietal approached extinction, the banana industry marched towards bankruptcy until a substitute banana turned up just in time to save the day. Today, we settle for the Cavendish, while history stands as a reminder that a lack of diversity on farms is a risky business with a slippery slope. If this story doesn’t drive you nuts, consider reading up on the Irish Potato Famine, the Southern Corn Leaf Blight, or other tales of massive food ravages from around the world.

Not as cool as a cucumber

The loss of plant diversity that we are experiencing today is, to put it lightly, not cool. Each lost variety increases the probability that the plants of the future will not be sufficiently diverse to handle the multitude of challenges in our immediate future. Our monocropped, uniform agricultural lands are at risk of being:

  1. Less resistant to droughts, floods, extreme temperatures, and changing climates,
  2. Prone to damage or massive losses due to diseases and pests,
  3. Dependent on expensive, toxic and unsustainable chemical inputs,
  4. Producers of less abundant and less healthful food, and
  5. Less profitable.

Don’t miss a beet

I don’t know about you, but I am hoping for a better future! One with highly productive crops adapted to diverse and low-input farms, with specialized cover crops that sequester carbon and restore soils, with healthier soils that produce healthful foods, and so on. The good news is that we actually know what we need to do to secure this future…and it’s not much: the public breeding programs that produce diverse and healthy crop varietals – and the agroecological research programs that incorporate those crops – are up to the challenge. Lettuce give them the attention and support that they need to thrive.

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  • First, many of the varieties that have disappeared did so because they were not disease resistant. Or they did not store well, or they did not yield well, or were susceptible to some pest. How do you propose bringing those back and who would grow such varieties? Contrary to what you say, it is those varieties that would be at risk of damage or losses from pests or disease.

    Second, it is not the vegetable fields in general that are the monocropped uniform lands at risk, it is the grain producing lands. We cannot grow tomatoes, beets or sweet corn on all that land, the market would not take it, but we could grow other grains, or oilseeds,

    Third, just because a variety is in a good rotation does not mean it will not suffer from pests and diseases. That is where judicial use of pesticides could actually save a good tasting, perhaps more nutritional variety, but one that is also susceptible to a certain pest or disease.

    Finally, I doubt that losing the varieties you speak of would risk making the lands “less abundant.” In fact, those varieties were probably less productive, or else they would have been kept, or at least used for breeding other varieties.

    You simplify this issue too much. I am all for diverse crop rotations, but you miss the mark here.