Good morning from the east coast in halifax.I have a 5 year old fat albert which looks healthy and growing nicely.this year after growth had finished i noticed the top crown of new growth [8-10 in.] started to turn in and down and has now gone brown and appears dead.the rest of the tree appears ok.any suggestions as to why.i can't seem to see any insect problem and moisture through rain and watering is normal.like so many areas of north america it has been very warm and humid.