8 plants per bed , defoliate more or less?

[GreaseGardens]

hows it going guys!
Ive been wondering if I should defoliate a lot since my plants are each about 4ft in a 4x8 bed. lately ive been noticing more pm issues in the middle of the canopy where it is thick with leaves and the plants meet. So I have had this question lingering in my mind, if I should defoliate a lot, early in flower, or progressively throughout the first couple weeks of flower.
I should also mention that the ventilation is 3 5 ton ac, and about 16 oscillating .fans along the walls, however no fans along the rows. ( I think this could be a factor as well)
I will try to upload some pictures up later so you can have a better idea of the layout and situation.
Any help is appreciated
ps there are some other issues I am dealing with that I will introduce once I find a solid solution to this one
Thank you!

 

[Growdoc]

pics pls

pics pls

some pics would help

 

[GreaseGardens]

room got chopped. next room we defoliated/ lollipopped aggressively and added double the fans, some blowing straight at the coco beds to help with the moisture.. once I figure out this phone I will post pictures. sorry for no pix

 

[sheik_yerbouti]

Sounds like you figured it out. PM can be a bitch.

I defoliate once at week 2 and once at week 7. If you're that thick of vegetation more defoliation is just going to help even more. Get more airflow and light penetration.