Emerging Pest Alert

Ug99 race of wheat stem rust continues to spread

Scientific Name: Puccinia graminis f.sp. tritici race Ug99

Describer: North American race designation: TTKS

Common Name: Wheat stem rust, stem rust of cereals, wheat rust, stem rust, black stem rust

Title: Ug99 race of wheat stem rust continues to spread


Significance: Puccinia graminis f.sp. tritici race Ug99 is a new virulent physiological race of wheat stem rust (WSR), which was discovered in Uganda in 1999 (NAPPO-PAS, 13 September 2005). This new race was later found in Kenya in 2001, and then in Ethiopia in 2003. 

Researchers with the Global Rust Initiative (GRI) and the USDA's Agricultural Research Service confirmed that Ug99 has now spread from eastern Africa across the Arabian Peninsula, and is now infecting wheat in Yemen and Sudan. Given that spores of the fungus can travel great distances on the wind, there is concern that the new race could spread to the vast wheat-growing areas of North Africa, the Middle East, Pakistan, India, Southeast Asia and beyond, where it has the potential to cause major crop losses. Wheat grown in other continents is also at great risk from Ug99, as studies have shown that many of the wheat cultivars grown are very susceptible to this new race. 

Fortunately, scientists working through the Global Rust Initiative have identified experimental wheat materials with resistance to Ug99, however the development of new rust-resistant cultivars and deployment at the farm level will require a massive international effort and years of research.


Dangerous Wheat Disease Jumps Red Sea - Devastating fungal pathogen spreads from eastern Africa to Yemen, following path scientists predicted. 16 Jan., 2007. HULIQ.com. http://www.huliq.com/6510/dangerous-wheat-disease-jumps-red-sea  

Global Rust Initiative.  www.globalrust.org/ 

NAPPO-PAS. Phytosanitary Alert System. 13 September 2005. Virulent strain of wheat stem rust spreading in East Africa. http://www.pestalert.org/viewArchNewsStory.cfm?nid=354