If the grass come within 4 feet of the tree trunk I would remove the grass in a way that the trees shallow roots aren't compromised.

I removed a 4 foot diameter of grass, but that probably wasn't enough I'm guessing by your suggestion.

I don't know the size of your tree but it will only help if your circle is to small

Uuuuuuuhhh, where are you located? If my tree had that kind of asymmetric blotching, I'd send a picture to the local citrus station. It could be serious.

Is your fruit also kinda weirdly bitter? Have you noticed little bugs sucking on your tree, kinda brownish looking?

No bugs, and it hasn't produced fruit yet, just flowering.

I'm in north Florida.