I recently got a request from an avocado tree guardian who had just a few trees left from a once flourishing orchard in Carpinteria. There only a few trees left and they were struggling. I was asked to diagnose them from images that were sent. Here they are and my diagnosis. Old trees can pick up all manner of problems over the years brought on by extreme weather - cold, heat, rain, drought - and management decisions over the years by different owners. These trees are 50 years old and, although not in the best of conditions, they will probably plug on for a few more bearing years.
You can get further descriptions of these symptoms and treatments at UC Integrated Pest Management - https://ipm.ucanr.edu/agriculture/avocado/#gsc.tab=0
Image
Image
Image
Image
Image
Image
Image
