The good news: soybean rust is progressing slowly in the southeastern U.S., and spores from that region should no longer be a threat this year to areas west of the Appalachians.
The bad news: soybean rust was found in several northern Texas counties last week, and has now also been reported in southwestern Arkasas - and it could reach as far north as Iowa or central Illinois this year.
Iowa State University professor of plant pathology X.B. Yang and St. Louis University climatologist Zaitao Pan report that while dry conditions have stemmed the progress of soybean rust at the eastern pathway along the Mississippi River, the occurrence of the fungus in northern Texas increases the likelihood that spores could be blown "as far north as central Illinois" in August.
Favorable weather has also increased the chances that the disease could move up the western pathway as far as Iowa, especially southeastern Iowa.
The scientists say that their computer models show "the risk of having an SBR outbreak in Iowa severe enough to reduce soybean yield is low to moderate for the rest of the growing season."