To the surprise of officials in some states, Asian soybean rust is spreading quite slowly across the U.S. Hundreds of soybean fields as far north as Kansas, Delaware and Ohio have been scouted for the devastating airborne plant disease and found to be "clean" of the fungus.
So far, according to the USDA, Georgia's Seminole County remains the only U.S. county where rust was discovered on soybeans -- and it was found on volunteer plants in two locations. Four counties in Florida found rust on common ditch weeds.
The USDA says, "Potentially by mid-June, some new infections may be expected to be observed on non-soybean plants in Florida, Georgia, Alabama and South Carolina."
If found on soybeans, the fungus can quickly defoliate the plants and produce yield losses of 80-to-90 percent.