need advice; nectarine tree did not do well this summer
I planted a nectarine tree in my Phoenix yard this January. It was about seven feet tall when planted and did very well during the winter and spring. When July came and things got real hot, the tree got very brown (much worse than the peach tree next to it). When it cooled down a little, we got some new growth on the tree, but now all the leaves are brown and falling off.
Does the tree think its autumn already? Should I prune the tree back? What do I need to do to ensure a healthy tree?