What is the ratio of cornmeal to water for the roses and can I also use this on my confederate roses as well. It would also be used for the black spots on them as well?

I assume you're referring to cornmeal juice. The link is below.

http://www.dirtdoctor.com/view_question.php?id=153

You would also benefit greatly by adding horticultural cornmeal to the soil.

http://www.dirtdoctor.com/view_question.php?id=326

Use a cup of cornmeal for every foot the plant is tall, but no more than 3 cups. Mix it into the soil at th base of the plant, cover with mulch and water it in. Your roses will be much happier in a very short period of time.

You can also soak a couple of cups of cornmeal in water for an hour or so and then water the plant with it. In my experience, if the blackspot is really bad, putting cornmeal inthe soil works better and more quickly.

Hope that helps!
Kathe

http://www.dirtdoctor.com/view_question.php?id=228 would be worth a look as well.