I baught this Improved semi-dwarf meyer lemon tree about 1-2 weeks ago from my local nursery. I applied neem oil on the leaves, fertilizer and mulch. I have also watered it when it gets about one-two inches dry.

The leaves are turning more yellow each day. It doesn't show well on the picture but it's pretty pale or yellow.

My zone is 9A in Henderson, Nevada. Facing the North and East side. Could it be sunburn? or what? I need help.