Soybean rust was only detected in 20 counties in the U.S. in 2011. Rust was reported in 16 counties in Florida, three counties in Georgia, and in one county in Louisiana. The majority of positive reports were made on kudzu during mobile scouting this Fall though the disease was also detected in two soybean sentinel plots in Georgia and Florida. By the end of November soybean rust was detected along the Florida panhandle and into the southern portion of Georgia but was not found in either Alabama or Mississippi this year.
The lack of soybean rust development in 2011 can be traced back to unfavorable weather conditions that started with the deep freezes early last winter in the southeast. These freeze events killed-back much of the kudzu that the pathogen typically overwinters on along the Gulf Coast and down into Florida. A relatively dry spring was followed by a severe drought from Texas across to Georgia that, coupled with extremely high summer temperatures, continued to inhibit development of the disease in the South. These conditions along with the lack of significant tropical storm activity in the Gulf region in June and July hindered development and spread of the disease reducing the risk to soybean farmers in the U.S.
The biweekly national conference calls on soybean rust were concluded in September this year due to limited soybean rust activity. Observations and commentaries from individual states are still being displayed on the ipmPIPE Soybean Rust public web site.