Wheat is among the planet's most important food crops, but it has a natural enemy that can turn the crop into a black tangle of broken stems.

Cornell University hopes a new $26.8 million grant can help them combat the emergence of deadly new strains of rust disease and help avert a pandemic that could produce catastrophic wheat crop losses worldwide.

The grant, from the Bill & Melinda Gates Foundation, will be used to develop improved rust-resistant wheat varieties and support critical wheat rust screening facilities in Kenya and Ethiopia, as well as track the spread of new variants and foster global awareness, said project director Ronnie Coffman of Cornell.

"We need to mobilize a worldwide effort. This could have a staggering impact if left unchecked," he said in a telephone interview from Obregon, Mexico, where Cornell and Gates Foundation officials announced the new Durable Rust Resistance in Wheat project Wednesday at the International Maize and Wheat Improvement Center.

Wheat represents approximately 30 percent of the world's production of grain crops. The United Nations' Food and Agriculture Organization estimates that 598 million tons of wheat will be harvested this year from 543 million acres of land - nearly half of that in developing countries.

Cornell scientists estimate that about 90 percent of the world's wheat crop is vulnerable to the new types of stem, or black, rust disease emerging out of East Africa.

Recurring droughts and increased demand already have driven the price for some types of wheat to as much as $20 a bushel, up from about $4.50 a year ago - even without the full effect of the newest fungus strain.

Rust disease has been a historical scourge for farmers. The Romans prayed to a "stem rust god" to protect their crops. In 1953, a rust epidemic reduced spring wheat production in Canada and the U.S. by as much as 40 percent.

Over the last half century, wheat breeders developed a series of resistant wheat strains but their success was so seemingly thorough that scientists and agricultural officials became complacent, Coffman said.

The latest wheat killer first emerged in Uganda in 1999 and was therefore called Ug99. It began spreading through East Africa via airborne spores and is now epidemic in Kenya and Ethiopia, he said.

"A year ago it jumped the Red Sea into Yemen, and within past two months, the Iranian government confirmed it is now in Iran," said Coffman.

Scientists worry that Ug99 will continue its spread and migrate to other areas of Asia, including Pakistan and India, where there are more than 50 million small-scale wheat farmers, who are more vulnerable to disease than bigger producers, said Rajiv Shah, director of agricultural development for the Seattle-based Gates Foundation's Global Development Program.

Large commercial wheat farmers in developed countries can afford to purchase expensive fungicides to protect their crops - although Shah noted that such treatments are only a short-term fix and pose risks to human health and the environment.

Even greater losses could occur if Ug99 continues to spread across Central Asia, where there are at least 296 million acres of wheat fields, said Nobel Laureate Norman Borlaug, who developed some of the original rust-resistant wheat varieties in the 1940s and is regarded as one of the fathers of the so-called "green revolution."

"The rust pathogens recognize no political boundaries and their spores need no passport to travel thousands of miles in the jet streams," said the 94-year-old Borlaug. "Containing these deadly enemies of the wheat crop requires alert and active scientists, strong international research networks, and effective seed supply programs."

Coffman and his colleagues at Cornell will focus on identifying genetic markers and developing rust-resistant wheat types in collaboration with scientists in Ethiopia, Kenya, Mexico and Syria.

Cornell also will work with scientists in China and the Philippines to study rice, a cereal crop that has proven immune to rust diseases. Research laboratories in Australia, Canada and South Africa also will be involved in the project.

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On the Net:

http://www.wheatrust.cornell.edu