New strain of stem rust on wheat being screened at the Njoro research station in Kenya.

The World’s Wheat Crop is Under Threat from New Disease

An eye-opener for donors and scientists at the launch of the Global Rust Initiative in Nairobi.

Representatives of major donor countries and organizations, together with wheat specialists from around the world, agreed that Ug99, the new strain of wheat stem rust, is a major, strategic threat to global wheat production, in a meeting in Kenya to sound the alarm.

“Nobody's seen an epidemic for 50 years, nobody in this room except myself,” said Norman E. Borlaug, Nobel Peace Laureate and former CIMMYT wheat breeder. “Maybe we got too complacent.”

The group, 75 strong, gathered in Nairobi on 9 September 2005 to hear a report from an expert panel about the status of the rust strain, first reported in Uganda in 1999. Only now is the significance and potential danger of the new strain becoming clear. The disease, also called black rust, has spread to Kenya, Ethiopia, and possibly other countries.

Wafa Khoury of FAO gets up close to wheat with stem rust at Njoro research station

The new strain or strains—it is not yet known if the new rust is from a single mutation—are especially dangerous, because many wheat cultivars in major wheat producing countries show little or no resistance. The spores of the fungus are well-adapted for long distance travel on high-altitude wind currents.

To identify new sources of resistance, the Kenya Agricultural Research Institute (KARI) is screening thousands of wheat lines from all over the world at its station in Njoro, in the Great Rift Valley, a known hotspot for wheat rusts. Those attending the Nairobi meeting had a chance to see for themselves just how bad the disease could be when they visited the site. Wearing special clothing that was later left behind to ensure that no spores took a free ride out of Kenya, the visitors saw row after row of wheat carrying the powdery, rust-colored fungus on spikes, leaves, and stems. “Despite the overall impression that most wheats are susceptible, we’ve found a few lines at Njoro that show resistance,” says CIMMYT rust specialist Ravi Singh.

But resistance in an experimental wheat line is a long way from a resistant, high-yielding cultivar that farmers will actually grow. The delegates recognized that and endorsed the creation of the Global Rust Initiative to monitor the spread of the disease and to work on long-term solutions—including new, locally-adapted, resistant wheat varieties and a global testing and distribution system—not just for Ug99 but for other, potentially dangerous wheat rust pathogens.

Lead members of the consortium developing the initiative are CIMMYT, ICARDA, KARI, and the Ethiopian Agricultural Research Organization (EARO). Several major donors have expressed interest in participating. The meeting in Nairobi was sponsored by the Rockefeller Foundation. A news conference held as part of the event was attended by more than 30 media representatives and resulted in reports being published in dozens of outlets worldwide, including a story in the “Science” section of The New York Times on 9 September 2005.

For further information, contact Ravi Singh (r.singh@cgiar.org).