Bravo and maneb are registered for rust. Tilt has a section 18 for dry beans in both North Dakota and Minnesota. I would also recommend sampling rust if a field of a resistant variety has considerable rust. Collect rust samples, place them loosely in a paper envelope and allow them to air dry before mailing. Although there have been no reports of sunflower rust yet, recent hot weather would favor rapid buildup of rust.
Infection can occur is as little as four hours of dew at high temperatures.
In addition, more spores are produced per pustule at high temperatures. Folicur is available in North Dakota under a section 18. Severity can be estimated by using the illustrations in NDSU Extension circular PP-998, Sunflower Rust . Folicur, available under a section 18, can be used up to 50 days before harvest, which is about ray petal wilt. Once the crop is past ray petal wilt, a fungicide will no longer be economic.