The Borluag Global Rust Initiative Presents...
Wheat stem rust has two hosts, wheat and barberry. Barberry, the "alternate" host, is needed for the fungus to complete it sexual cycle and geneticly diversify. Without barberry, the fungus only reproduces vegetatively. Therefore, the presence of the alternate host is good for the fungus, but bad for wheat. Barberry eradication programs succeeded in eliminating most barberry plants from wheat growing regions, but continued monitoring is important. This video describes the contribution of barberry to the spread of stem rust, and shows how to identify barberry plants and examine them for the presence of the rust.
More videos and presentations from BGRI here: http://www.globalrust.org/traction/project/bgriworkshop
Via Mary Williams