Asian soybean rust has never been identified in an Iowa field since the disease was reported in the continental United States in November 2004. However, the disease now has been conclusively identified on soybean plant tissue, which was submitted to the Iowa Soybean Rust Team last week.
This soybean residue is reported to have been recovered from a bin of soybeans produced in Iowa in 2006.
Efforts are underway to identify other remnant plant residue that may show symptoms and signs of the disease in order to discern details of this event. The fungus and the spores that cause the disease cannot survive without green leaf tissue and will die during Iowa winters. The recently discovered rust fungus does not pose a risk of infection for the 2007 growing season in Iowa.