Help with Meyer lemon tree

[Kty06101]

Anyone have any insight as to why my Meyer lemon tree isn't doing well and what I can do to help it? Cara cara is doing ok and Tahitian limes are doing extremely well. All three are next to each other.

 

[Chuck]

If I were to guess I would say that it needs to be fed. That grass is robbing the plant of nutrients and from what little I can see in the picture, I see a lot of yellow. Better and close up pictures would be of great help