Doesn't look like disease to me. Just struggling.

How much light does it get?

When was it last repotted?

When and how often do you fertilize?
And what do you use?

The black & white stuff in the final image looks like woolly whitefly (the white stuff) with sooty mold on the honeydew (the black stuff).

This post was edited by jean001a on Sun, Aug 11, 13 at 22:54

Its always had plenty of light, been outdoors in Los Angeles.

Never repotted, which I suspect it needs to. My mom used to fertilize it every now and then, but it was still not well. I fertilized again a couple weeks ago. She used some type of fertilizer sticks, I use Lilly Miller Citrus + Avacado food (it says natural ingredients).

A lot of the leaves fall off, as well as the tiny lemons that try to grow. It is definitely struggling.

Thanks!