Frank,

Do you have some pictures of the white powdery substance on the rose brushes so I can help diagnose the problem?

Frank,

After looking at your picture of the rose bushes. It looks like you may have Rose Mosaic virus.

Unfortunately, there is no known treatment to kill the virus other than removing all infected tissue from the plant. Basically, remove the infected rose bush and replacing with certified disease-free rose bushes from a good nursery that guarantees disease-free plants. Or you can just tolerate the damage to the plant and enjoy it until it no longer produces blooms.

resources:

PP338/PP338: Rose Mosaic Virus: A Disease Caused by a Virus Complex and Symptoms on Roses and Management Practices (ufl.edu)

Rose Mosaic | Oklahoma State University (okstate.edu)

Rose Mosaic | Yard and Garden (iastate.edu)