Crop Diversity Revisited

Does a decline in crop diversity threaten future food production? A report in the August 2011 National Geographic suggests so. The article, “Food Ark,” reports that the “extinction” of food varieties could be a real problem.

Food varieties extinction is happening all over the world—and it’s happening fast. In the United States an estimated 90 percent of our historic fruit and vegetable varieties have vanished. Of the 7,000 apple varieties that were grown in the 1800s, fewer than a hundred remain. . . . .

Why is this a problem? Because if disease or future climate change decimates one of the handful of plants and animals we’ve come to depend on to feed our growing planet, we might desperately need one of those varieties we’ve let go extinct.

But it’s actually not at all clear that available food varieties are dwindling at such a dramatic rate. As I’ve noted before here and here, the research of Paul Heald and Susannah Chapman suggests that available crop varieties are actually increasing. In the case of apples, for example, Heald and Chapman show that the number of varieties available to apple farmers today is nearly four times greater than in 1900.

Particularly misleading is this graphic, which purports to show “our dwindling food variety.” Based upon a 1983 study by the Rural Advancement Foundation International, it compares commercial seed house offerings from 1903 and varieties maintained in the National Seed Storage Laboratory eighty years later, finding a shocking 93 percent decline in available varieties. But this is not an apples-to-apples comparison. Had the study instead compared commercial seed offerings in 1903 with those available from contemporary seed catalogs it would have found no appreciable decline. In fact, that is the point of this Heald and Chapman study, which found contemporary seed catalogs offer just as many crop varieties as the RAFI study found in 1903.  Some varieties available in 1900 are no longer around, to be sure, and available varieties of some crops have declined while others have climbed, but the overall variety has not “dwindled” as National Geographic suggests.

What about the future? As the National Geographic author explains, it took centuries of careful selective breeding for farmers and breeders to develop crops and livestock breeds suited to various climates and regions. True enough. But the article gives little consideration to how modern biotechnology techniques have accelerated and honed this process. Developing new breeds and strains occurs with greater speed and precision than ever before. Modern biotechnology is no panacea, but combined with the actual trends in the availability of various crop varieties, it provides much reason for optimism, rather than gloom.