Q.How To Treat An Avocado Tree With Dying Leaves
I have a large outdoor avocado tree in my garden but patches of leaves are turning brown or dying. Do I cut off the branches where these leaves are not green or can I treat the problem with a mixture of “Wonder plant food” that contains Nitrogen, Zinc, and Manganese extra?

Certified GKH Gardening Expert
Yes you can trim out affected branches. This article tells how to fertilize and care for an avocado tree:
https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-growing.htm