It was good to see you last week. I enjoyed meeting with you and your members.
I also enjoyed the tour of your course. I have to say, it is in great conditions outside of the weak areas on a few of your greens. In regard to those areas, I believe there are four physical issues that are, in some combination, causing the problem. These are:
Overseeding - applying seed to the greens every year introduces a competitor to your TifEagle thru the winter months when the TifEagle is not actively growing. This weakens the grass which then has to recover each spring. As you mentioned, the weak areas we observed finally grow-in by the end of summer and then you overseed them again. I think it would go along way to solving the problem if you were able to get away from overseeding, at least for a couple of years.
Irrigation - Poor coverage by some of the irrigation heads around the greens has contributed to the weak areas we looked at. You can see improvement where the heads have been adjusted and the coverage is better. I would continue making these adjustments wherever possible. At some point, you need to consider new irrigation loops around the greens with inboard/outboard heads which would allow you to control greens irrigation independently.
Shade - there are about 7 to 10 pine trees that are contributing to the problem. We talked about most of them. These trees should be identified ( possibly using the Sunseeker App that we discussed) and removed.
Drainage - You have a few spots where collar dams have developed and are blocking surface flow of water draining off of the greens and trapping subsurface water in the profile. These can be removed and perhaps some subsurface drain pipe installed to alleviate the problem.
I believe you can go along way towards eliminating these weak areas if you are able to address the above. It is easy to see that you have a good agronomic program by looking at the great condition of the rest of the green surfaces outside of the small problem areas.
Let me know if I can be of further assistance.
Pike Creek Turf Inc.