New Form of Fungus Threatens Wheat Supply
Fifty years ago, a fungus called stem rust was a major threat to the world food supply. But scientists came up with new wheat varieties that kept the disease in check. Now, a new variety of rust has arisen in Africa and is rapidly spreading around the globe.
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A fungus that kills wheat has been spreading across continents. It was first detected in Africa. Last year it moved into Asia. Scientists are urgently trying to fend off the threat, but they say they're getting very little help from the U.S. government. Dan Charles has this story of the wheat-killing fungus and the efforts to stop its spread.
DAN CHARLES: The great enemy of wheat, ever since people started growing it thousands of years ago, is a fungus called stem rust. Hans Braun, director of the wheat program at the International Center for the Improvement of Wheat and Maize in Mexico, says rust epidemics came and went.
Dr. HANS BRAUN (International Center for the Improvement of Wheat): The last stem rust epidemic the United States experienced was in the mid '50s, and they lost about 40 percent of their spring wheat.
CHARLES: But in the 1960's, scientists, plant breeders came to the rescue. They found wheat plants that could fend off stem rust, and they bred the wheat-resistance genes from those plants into wheat varieties that farmers could plant all over the world. Ronnie Coffman, who's in charge of international agricultural projects at Cornell University, says for 40 years, farmers didn't have to worry about this fungus.
Dr. RONNIE COFFMAN (International Agricultural Projects, Cornell University): But that lasted so long that, you know, that people became complacent.
CHARLES: In 1998, though, in a small plot of wheat in Uganda, researchers noticed something disturbing - stem rust attacking plants that were supposed to be resistant to it. The next year, it was confirmed. A new race of stem rust had emerged.
Dr. COFFMAN: And now, everybody realizes that we really have to get back to business, here.
CHARLES: Cornell's Ronnie Coffman says wheat fields everywhere are vulnerable. The wind can blow fungus spores hundreds of miles. Last year, the new form of stem rust leaped from Africa, across the Red Sea to Yemen. This spring, it was detected in Iran, a big step closer to the bread basket of Asia in Pakistan and India.
Dr. COFFMAN: Everybody in the path of this thing who depends on wheat has to be worried.
CHARLES: There is hope. Wheat breeders have tested their vast collections, and they've found some varieties that seem to withstand the new race of stem rust. Pakistan, India and many other countries now are testing those varieties, growing as much as they can, collecting the harvest for farmers to use as seed. Hans Braun from the International Wheat Research Center in Mexico says it will take five years or more before enough seed is available, but no one knows how quickly the fungus will spread and when it will cause an epidemic.
Dr. BRAUN: It's very difficult to predict. It could happen next year, if the conditions are favorable. It could take 10 years. It's very difficult to say, but once the conditions are right, then it will spread like a bush fire.
CHARLES: Experts on wheat say this is the most urgent seed breeding campaign they've seen in a generation. But they say some governments, including the US government, don't seem to recognize the urgency. This year, the United States cut its funding for international agricultural research centers such as the one in Mexico by about half. Budgets also are being slashed at the USDA laboratory that works specifically on stem rust in St. Paul, Minnesota. The stem rust campaign has turned to private funders, and last month, they got $26 million from the Bill and Melinda Gates Foundation. A local farmers union in Mexico threw in another half million.
For NPR News, I'm Dan Charles.
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