Asian soybean rust was found in several southern states in November 2004. The fungus is expected to overwinter on weed hosts in southern Florida and the southern tip of Texas. Rust outbreaks in Iowa will depend on the northward seasonal dispersal of rust spores from these overwintering areas.
Robertson, Alison and Tylka, Greg, "Asian soybean rust and common soybean leaf diseases" (2005). Integrated Crop Management News. 2367.