Could that area be dryer than the surrounding area? Looks very dry. Don't know much about Std. Augustine grass and whether it goes dormant.

St Aug does not go dormant in the growing season. I would need more information.

What is your watering schedule normally? How often and for how long do you water?

How high/low do you mow and how often?

When were the last two times you fertilized and what did you use?

Have you use any insecticides, fungicides, or herbicides in the past 6 months? If so what products?

Ok great. I knew it shouldn't go dormant. For some reason i remembered hearing it can go dormant but only if you over/under watered or under/over fertilized, etc. I cant remember.

As far as your questions..

I have no real watering schedule, I used to water 1 time a week for an hour with a generic sprinkler. Now that it is Hurricane season, we get so much water i am battling bogginess on the bottom of our property. This area in question drains well though, never had an issue with standing water. It is sandy soil and this area in particular is in more sun than the rest of the yard. Although that doesn't mean it is all day sun.

I mow every two weeks, although I did let it get pretty high ( 6" ) the second last time i mowed. My mower died and I just got a new one last week. The mower has no movement on the height so i would guess around 2" ?

I have not fertilized this year, it usually grows very well and quite fast at that. I've never had an issue with yellowing, except occasional small spots from the dogs peeing in the yard.

The only product i have used was Cutter Backyard spray. I have used it before this year and last year with no effects.

Hope that helps some.. anything else just ask.

The only thing i can begin to guess at would be that i left the yard too high for about 3-4weeks and the dogs peed in that area mainly and it sat there rather than drained out. Although with all our rains lately i would have guessed it would have drained anyway ?