My Tif 419 is showing similar signs. Put down some DiseaseEx last week. Fingers crossed

 

Not an expert in the least regarding fungus but it just looks a bit "hungry" to me. Lightly verticut and 10-10-10 is what I would do.

 

Hmmm... not sure @Redtwin. This area has been fertilized and verticut with the rest of my lawn. Put down .75lb/N at the beginning of June & July.

 

Hmmm... not sure @Redtwin. This area has been fertilized and verticut with the rest of my lawn. Put down .75lb/N at the beginning of June & July.

Funny you should say that... I just had a similar spot pop up in my 419. My plan is to push through it. I'm hoping I don't make it worse.

 

Couldn't tell you what kind, but looks like fungus to me. I would drop down some DiseaseEX (azoxystrobin) and give it a week or two. If no improvement, I'd try something like BioAdvanced (propiconazole).

 

Looks like its getting a lot of traffic since its near walkway?

 

It does not appear to me like fungus, based on the lack of any real pattern, and the appearance of the blades of grass. It looks like it's probably something more basic, such as drought stress or perhaps stress brought on by lack of some nutrient. .