Ug99, a virulent strain of stem rust first identified in Uganda in 1999

Ug99 is a virulent and fast-mutating strain of stem rust, named after the location and year of its first identification: Uganda, 1999 [1-3]. The stem rust fungus, Puccinia graminis,  is spreading across the globe. It is a feared disease of wheat, known for centuries and causing significant losses of crop yield. The Ug99 strain spread from Uganda through other parts of Africa, including Kenya, Ethiopia and Sudan, crossed the Red Sea into Yemen and jumped the Persian Gulf into Iran.

How can the Ug99 threat be contained or eliminated? This depends on the success in developing a Ug99-specific fungicide (keeping up with the pace of mutations) or—probably a better solution—to find and grow resistant wheat varieties.

References
[1] Charles Siebert: Food Ark. National Geographic July 2011, 220 (1), 108-131. [ngm.nationalgeographic.com/2011/07/food-ark/siebert-text].
[2] Ravi P. Singh et al.: Current status, likely migration and strategies to migrate the threat to wheat production from race Ug99 (TTKS) of stem rust pathogen. CAB Reviews: Perspective in Agriculture, Veterinary Science, Nutrition and Natural Resources 2006, 1 (054). [www.ars.usda.gov/SP2UserFiles/ad_hoc/36400500Publications/YJ/PAV054.pdf].
[3] Tiffany Stecker: Stem Rust Ug99 - Agricultural Bully, June 20, 2011 [www.scientificamerican.com/blog/post.cfm?id=stem-rust-ug99---the-agricultural-b-2011-06-20].