My poor avocado tree has fallen ill. We have had a very mild summer with lots of fog and moisture in the air with cool 50-65 degree weather. Then suddenly there was a two day heat wave, one day being 100F. Sometime after the heat, I noticed the top of my avocado tree defoliating and the remaining leaves yellowing. Then I noticed that most of the leaves had brown rusty looking spots. Pictures below of the tree and leaves:
The tree flowered early this spring but most of the flowers turned brown with no fruit. The few fruit that started to develop dropped off.
I think the brown spots are fungus so I sprayed the whole tree with neem oil. Don't know what more I shuold do though. Should I cut off the branches on the top that are now nearly leafless?
Any help is very appreciated!!