Sick dendrubiom

[ronen]

Hi all
It seems that my dendrubiom is sick
It has small brown point on it's leaves
The leaves become grey and fall.
Does anyone now what it is?
How I will heal my plant?

[Ray]

The large tan-colored spot looks like sunburn.

The small brown specks appear to be some damage around the stomata, which might suggest a chemical issue. Tell us about your feeding regimen and water supply.