Avocado plant and the problems with their leaves
Why do the leaves of an avocado plant turn brown or look like there is rust on them?
Certified GKH Gardening Expert
Is this in container? This looks like a severe magnesium deficiency... Dolomitic lime will correct this. This article will help: https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-tree-growing.htm