Variegated pink lemon problem, need your help

[Dirt Diva]

I just discovered this problem on my variegated pink lemon after days and days of rain

What is this and how should I treat it?

Thanks all !

any advice ?

[Millet]

perhaps citrus snow scale.

http://blogs.ifas.ufl.edu/nassauco/2017/06/12/q-white-powdery-stuff-trunk-citrus-tree/

[brian]

I've never seen anything like that on my citrus trees... sorry

[Dirt Diva]

perhaps citrus snow scale.

http://blogs.ifas.ufl.edu/nassauco/2017/06/12/q-white-powdery-stuff-trunk-citrus-tree/

it does not resemble snow it is reddish brown

[Millet]

Looking at the pictures of your tree that you posted, I thought your tree's problem was the white covering on the branches, not the brown spots. 

[Laaz]

Mold.

[citrange]

I don't know much about citrus in Texas but to me this looks like a tree lichen or algae which probably won't do any harm to your tree. Certainly the grey/white patches are another species of lichen.
It might help to see a photo of the whole tree. There seem to be dead bits and crossing branches which may need pruning, and the tree appears to be growing in long grass which should be cleared from the trunk.