If you have Bermuda problems this is the time that you need to start to attack the situation.

Bermuda is a warm weather grass that thrives in night time tempatures that are 77 degrees and above.  The key to attacking the problem is that you will need to spray the grass when it is healthy and growing.  The chemical that is used is a systemic chemical that needs the plant to be healthy and growing so that it will suck the poison down to its roots.  The following pictures are before and after shots of a Bermuda spray. 

This was taken on April 10th 2012 only 13 days later.  The following steps would be to water and entice any living Bermuda to grow and then spray again in 14days if needed.