Meyer Lemon Yellowing leaves and spots
I need help diagnosing this problem with my Meyer Lemon tree. It was put in the ground last fall and has been doing very well up until two months ago. All the leaves are starting to lose their dark green color and are lightening up. On about 5% of the leaves, the yellowing is progressing as displayed in the pictures below. The tree is about 4 feet tall and has stopped producing fruit. There are no brown spots. The yellowing starts as faint dots around the midrib and then move out to the rest of the leaf.
Please help as I really want to give some love to this tree, but have no idea what to do. My wife has fed it a few times with organic plant food fertilizer. I have no idea how much she used. She's been known to have a loose wrist. ;) My first thought is that the tree is burning from too much nitrogen, but my knowledge is very little, so any assumption on my part is hogwash.