Leaf disease on a large avocado tree in Hawaii

Question

The leaves have developed rust-colored spots that do not scrape off. We have had a very wet winter. Would it help to rake up leaf debris under the tree and then fertilize it? The huge tree is covered with flowers. The spots seem to match pictures of a fungus found on a number of sites. No other leaf problems–just the spots.

Answer 1

There are a couple of diseases that might be affecting your tree. This paper on them will be helpful for you to identify the problem:
http://manatee.ifas.ufl.edu/lawn_and_garden/master-gardener/gardening-manatee-style/a/avocado-diseases.pdf