USDA Soybean Rust Information site Map (Mac users need to use Mozilla, Firefox or Safari as browsers)

Dr. Greg Shaner

October 17, 2007

This morning we found rust on soybean leaves from a late-planted field in Owen County. In a sample of 100 leaflets, one leaflet had several pustules scattered over the surface, and these were all producing spores. A second leaf had two lesions that appeared to be rust pustules that had not yet reached the stage of spor production. The field was at the R6 stage of development and leaves were starting to lose their green color. Plants were reported to be 75% defoliated. This rust poses absolutely no threat to our soybean crop. Finding rust now does not mean our risk of rust is any greater for next year. Once there is a killing frost, any soybean rust in Indiana will be eliminated.

The main importance of this finding is for the people who are modeling the continental spread of rust spores by wind and deposition of spores by rain. This will provide another data point which can be compared with predicted dispersal over the past 3 weeks.