Black stem rust (Ug99) Puccinia graminis f.sp. tritici (Ug99) is a serious disease of wheat and barley. While wheat in the United States is resistant to most strains of black stem rust, it is not ...

This fungal disease, primarily caused by the fungi in the genus Puccinia, thrives in conditions ... released by ruptured pustules. In advanced stages, rust fungus weakens the turf, resulting ...