Growing reliance on foreign crops threatens diversity

Countries increasingly rely on introduced plants for food and need to cooperate to protect crop diversity, a study has found.

The study, published today in Proceedings of the Royal Society B, found that awareness of the geographic origin of major food crops is shrinking, threatening conservation and breeding efforts.

Governments should spend more money and effort on joint research and conservation to protect both original crop species and their wild relatives, says lead author Colin Khoury, a researcher at the International Center for Tropical Agriculture in Colombia.

“We all need each other because there is no country that uses only native crop plants,” Khoury explains. “China, as the world’s biggest producer of peanut, should, for example, be interested in conservation in Brazil, where peanut crops [originally] come from.”

Nearly 70 per cent of the world’s crops are grown outside their country of origin, say the international team of biologists behind the study. So-called foreign crop use is particularly high on island nations, which can rely almost exclusively on introduced crops.

The countries with the highest use of local crops were Bangladesh, Cambodia and Niger, where only around a fifth of the calories people eat come from crops that originated elsewhere.

Khoury says that growing a diverse mix of local and foreign crops ensures a food supply throughout the year and improves people’s nutrition.

But the paper found that some foreign crops are becoming dominant in certain regions, pushing local varieties from the market. At the same time, the foreign crop’s wild relatives are not protected in their country of origin, it says.

Having access to crop wild relatives is important to breed varieties that are resistant to pests and cope with changing environments under global warming, the paper says.

“As more of the world relies on wheat, soybean or palm oil, it becomes ever more important that their production is stable and sustainable,” Khoury says. Such crops should be considered global public goods, and their wild relatives should not be sold for profit, he adds.

The International treaty on plant genetic resources for food and agriculture, adopted by the UN in 2001, aims to go some way towards ensuring this, but Khoury says the treaty lacks the resources to be successful.

“We have the technical and political ability to do the job, but finances are lacking and some political will is also lacking,” he says.