North Carolina State University and Cooperative Extension
Steve Koenning Extension, Soybean Pathology Specialist,
and Jim Dunphy Soybean Specialist, Crop Science
ASIATIC SOYBEAN RUST FOUND ON SOYBEAN IN DECATUR AND COLQUITT COUNTIES IN GEORGIA
Alert: Soybean Rust July 6, 2012:
“Conditions have been quite favorable for spread of soybean rust in Georgia; we now have confirmed soybean rust on kudzu in Decatur, Miller, Baker, Brooks, and Lowndes Counties; soybeans in Decatur and Colquitt Counties. Most soybean acreage along Georgia Coastal Plain will be sprayed with fungicides at bloom-early pod set for rust and anthracnose and insecticides added for kudzu bug.”
Weather has not been conducive to build up of rust with the high temperatures in North Carolina, thus it may be premature for North Carolina soybean producers to spray soybean for rust. Be prepared, however, and remember that applications for Southern Rust of Corn may compete with fungicide/insecticide applications on soybean in terms of the numbers of aerial applicators and amount of fungicide available.
More information is available here
Domark 230me is not listed in the Ag Chem Manual for corn at this time but is labelled at a rate of 4-6 oz. per acre.
When deciding to spray a fungicide, consider these factors in decision making!
- When will the corn reach maturity – early maturing corn may escape infection and you might want to concentrate on the later maturing hybrids.
- Strobilurins provide excellent control of rust in general but their residual activity is short compared to the triazoles. Additionally, Strobilurins have limited systemic movement in plants compared to triazoles such as Tilt, Folicur, Domark, Caramba, and Proline, and are thus less forgiving of less than perfect application.
- Application costs may actually be greater than fungicide costs in many instances, so consider using the higher fungicide rate which will provide more residual protection and increase the likelihood that you can get by with one application.
Vigilance is the key word for 2012! Most sentinel plots have been planted and we will have about 14 this year. Storms following a track similar to Beryl’s could bring rust to North Carolina later in the year.
Resources for Soybean Rust in 2012:
Some sources for more detailed information on Asiatic soybean rust and Southern corn rust are listed below: