Strange Plumeria leaf blight, not rust (?), cannot diagnose!
This is an issue I had with this cutting before, and was not able to fix (before dormancy set in anyway) with an application of the Bayer Rose and Flower 3-in-1 stuff. A grower I described it to recommended that, as he thought it sounded like rust, but having looked at a lot of photos of rust and descriptions, I really don't think this is rust. I brought it out of dormancy with the growlight setup you can see in the pictures. The leaves all looked perfectly free from this blight until about 2 weeks ago. Around 1 week ago the lower leaves were noticed to be yellowing and then falling off. I wouldn't have thought it was going dormant now, the days are just getting longer and it seems to be producing new leaves at the tip still.
Here is the Plumy with the "growlight" I rigged up:
Here is a shot of the leaf mottling I'm describing:
A close up shot of the mottling:
The underside of the leaves looks good:
Some of the leaves that either fell off or I removed just before they fell off:
I know I should probably transplant to a bigger pot, there are some healthy looking white roots visible through the drain holes at the bottom, but could that be causing the leaf drop or mottling?
I am thinking they are two separate issues, but I have no clue what the mottling is. It doesn't look like anything I have seen searching the web.
I use a weak water soluble fertilizer every time I water, and I let it dry out pretty well between waterings. The light is on for 16 hours a day, and the room is maintained between 65 and 70.
Please help, this Plumy's health means a lot to me!