Jim, I've been lurking around the Rose and Antique Rose Forum and there are some good discussions about fungicides. I grow about 75 roses, some bs prone and some pretty disease resistant and here's what works for me. I use a systemic (Banner Maxx) which has the same chemical as Fertilome's Systemic Fungicide and Bonide's Infuse. These systemic fungicides have to be sprayed only every 10-14 days and aren't affected by the rain once the spray dries on the leaves. I also use a contact fungicide intermittently during the year (Mancozeb).
After a bad start to the year due to my not spraying early (several of the roses completely lost all their leaves) I started using the systemic and they recovered and have been virtually free of bs since. Hope this helps. By the way, where in MS do you live?

Here is a link that might be useful: Rose Forum

Vicksburg, well realy Oakridge it's just north of town JIM