Soybean Rust Map

Soybean rust is caused by the fungus Phakopsora pachyrhizi and often occurs in the southern soybean production areas in Alabama, Georgia, Florida, Louisiana and Mississippi. Symptoms can be confused with several other foliar diseases of soybean including downy mildew, Septoria brown spot and target spot.

Note that the map may display “gaps” where active monitoring and scouting for soybean rust may not be occurring. If soybean rust has been identified in a county or parish, this should encourage you to scout your fields for this disease. Confirmed soybean rust does not necessarily mean a fungicide application is needed immediately in that area, but only that conditions have been favorable for soybean rust infection. Further disease development will depend on prevailing weather condition in that area. In situations where the risk of rust is relatively low, delaying your first fungicide application until the R3-R4 growth stage may be more effective in managing other foliar diseases as well as protecting against rust infection later into the season. Spraying after the R5 growth stage is not recommended due to a lack of yield response.  For more information about management of soybean rust, contact your local or regional Ag Extension agent or the Extension plant pathologists responsible for soybeans in your state. Information on fungicides available for soybean rust management can be found in “Fungicide Efficacy for Control of Soybean Foliar Diseases” (CPN-1019) which is revised annually.