Source: Jim Dunphy Extension Soybean Specialist & Steve Koenning Extension Plant Pathologist NCSU, 9/3/13

Asiatic Soybean Rust was confirmed over the weekend in four more South Carolina counties -- Anderson, Edgefield, Lexington, and Newberry. This puts rust close enough to our Murphy and Charlotte areas to warrant a fungicide recommendation for soybeans that have started blooming, and do not yet have full sized seeds in the top four nodes of the plant.. The closest confirmed rust on soybeans to our North Carolina soybeans is now approximately 80 miles from Charlotte, 310 miles from Elizabeth City, 140 miles from Fayetteville, 90 miles from Murphy, 195 miles from Raleigh, 250 miles from Washington, 160 miles from Wilmington, and 150 miles from Winston-Salem, NC. (The mileages in red are changes from our previous update.)

Rust has now been confirmed this year on soybeans in 57 counties/parishes in seven states (LA, FL, AL, MS, GA, SC & AR).

Rust has progressed at a faster rate this year than in years past. With a late soybean crop, the odds of needing to apply a fungicide is increased. Now is the time to spray a fungicide in the Murphy and Charlotte areas, and to check spray equipment and be sure to have the proper nozzles for applying fungicides in the other parts of the state.

We do not recommend spraying soybeans that have not started blooming with a fungicide to control Asiatic soybean rust. Such pre-bloom applications have seldom improved yields. Once soybeans start blooming, we would recommend spraying if rust has been confirmed within 100 miles of the field.

Some sources for more detailed information on Asiatic soybean rust are listed below:

The USDA soybean rust web site http://www.sbrusa.net/