The importance of crop genetic diversity

In North Carolina, the seventh most-productive blueberry state in the U.S., blueberries ripen between June and August. But North Carolina shoppers can buy blueberries throughout the year. That's because most people only eat a few kinds of food, so farmers around the world are growing the same crops to meet the demand of consumers thousands of miles away. As Rob Dunn points out in his new book, that practice poses some significant risks.

In his book, Never Out of Season, Dunn – a professor of applied ecology at NC State – notes that 90 percent of the calories that humans consume come from only 15 species of plants. Dunn also points out that, in order to increase their yield and meet consumer demand, farmers usually grow only specific varieties of those plants.

This focus on a remarkably small number of plant species means that there is very little genetic diversity among the crops that are most important for feeding people around the world. If an unexpected crop pest – such as an insect, fungus or virus – arrives on the scene, people will starve.

Read more at phys.org