ABSTRACT
Historically, wheat stem rust (Puccinia graminis f.sp. tritici) was the most feared pathogen affecting wheat cultivation. For over 30 years, effective genetic resistance has kept the disease under control. The identiŽcation of new virulent races, typiŽed by the Ug99 lineage, in East Africa during the late 1990s has made wheat stem rust once again a cause for global concern. The nature of the threat posed by new virulent races of wheat stem rust is outlined in this chapter. Using the Ug99 lineage of stem rust races as an example, the ways in which GIS/geospatial technologies are being applied to support the global efforts to combat this reemerging threat are described. GIS is playing a vital role because most of the critical factors involved with occurrence, movements, and establishment of the disease are inherently spatial in nature. International collaborative efforts are now underway to develop a global cereal rust monitoring and surveillance system, which is underpinned by GIS. Progress and challenges surrounding these international efforts are also described.
