Question
I live in central florida on the west coast and I have St. Augustine grass.  I think I had Brown patch and put a fungicide on it and then after about a month I put cornmeal on it.  It looks look the brown patch stopped but my grass is yellowing. I used Scotts turf builder in late spring.  Do you have any answers.

Answer
The yellowing is a normal symptom of brown patch.  The spot will have to recover and grow new grass.  Do not fertilize or water.  Since this disease is a fungus, either one will aggravate the situation.
Of the ten common diseases for St. Augustine grass, eight are fungus, one is nematodes, and one is a virus.  Preventative fungicide applications are recommended.  Increase drainage in the soil.  Keep the pH less then 6.5.  Do not overwater.
Give the grass some time to recover.  Fertilize only the recommended amount.  I would spread the fert. appl. over several months and avoid the spring shot because it is when some fungi are active in temps between 70 and 85.