Your lawn may need iron or it may be suffering from a disease called Take-All root rot. I suggest you take a sample (4" X 4" with roots) of the lawn to your County Extension Office along with a photo if possible for them to identify and then prescribe an appropriate remedy. Their contact information is:
Volusia County Agricultural Center
3100 E. New York Ave.
DeLand, FL 32724
West Volusia (386) 822-5778
Daytona Beach (386) 257-6012
New Smyrna Beach (386) 423-3368
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips