From the Previous Pics It looks like Its In a Low Lying area and Im hoping it's Not root rot.
(this happens when the soil's drainage isnt too good and the roots are constantly sitting in a puddle in the bottom of the hole).

Its kind of hard to Make a diagnosis with out actually being there.
But check the soil directly around the Pant.
make a small hole with a stick or somthing just to see If the soil Is too Damp down below.
I Make small mounds and Plant ontop Just Incase Because I lost a Good Patch a few years ago due to root Rot.

dont Panic Just yet I'm Only guessing here.
see what HARDON has to say He's defenetly a grow encilopedia.(i mean that with all respect)..

ps.New Music on the way today....
NoosaHeads Reviewed by NoosaHeads on . Harddon or Noosa....I need your help!!! Ok, you guys are pretty damn informed about my plant and situation, and very experienced. so I wanted to ask yall...On my tree, at the very bottom where the very first sets of leaves formed...the leaves are turning yellow and dying off. I thought maybe it was because I have such a big fuckin bush that the light wasnt reaching those leaves anymore and I picked them off as they died. Well I just went out and looked at my girl and its like a damn epidemic....more of the leaves are yellowing and Rating: 5