Soybean Rust Update September 15, 2015

— Written By and last updated by

from Jim Dunphy, Extension Crop Science Specialist (Soybeans)

Asiatic Rust has recently been confirmed on soybeans in DeKalb, Elmore, and Escambia counties, AL; Burke and Tift counties, GA; East Baton Rouge and Washington counties, LA; and George, Granada, Itawamba, Lafayette, Lowndes, Monroe, and Union counties, MS. The DeKalb County, AL confirmation is about 115 miles from Murphy, and 290 miles from Charlotte. The Burke County, GA confirmation is about 165 miles from Charlotte, 400 miles from Elizabeth City, 225 miles from Fayetteville, 185 miles from Murphy, 270 miles from Raleigh, 330 miles from Washington, 250 miles from Wilmington, and 235 miles from Winston-Salem, NC.

I do not consider these confirmations to signal any imminent threat to NC soybeans. I still consider Steve Koenning’s (recently retired Extension Plant Pathologist) and my recommendation to not spray soybeans that have not yet bloomed, nor blooming soybeans that are more than 100 miles from confirmed presence of rust on soybeans, to be a valid recommendation for most soybeans in NC. I do not recommend spraying for rust after stage R6 (full-sized beans in the top four nodes). Check the label on the fungicide you prefer to use to see how late in the season that chemical may be sprayed.

The current status of rust in the continental US can be found anytime at http://sbr.ipmpipe.org.