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Orkine, don't know how long you've been growing avocados so don't take this wrong but avocados drop/replace leaves several times a year. What you have may be nothing more than normal leaf senescence or may be a case of phytophora with all your rains. I've sent off black avocados sticks to the U. of Florida tissue lab analysis services and those folks are excellent. Also, there are quite a few products that nail phytophora as a soil drench and or leaf spray. Magnabon CS2005 is one of them. It's a systemic. Frank Miele is from your neck of the woods and developed it. It's also OMRI certified if you happen to roll that way.
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No offence taken Mark and rest assured, I will always take advice and feedback from experienced folks, even when not delivered as nicely as you do
This tree is one of two I had and used to be a Lula before I grafted it to Oro Negro (scions from Carlos) a few years ago. I have seen it drop leaves but this looks different. It is over the entire tree with complete die back of limbs after the leaves drop. The fruits are wrinkled and seem to be drying out. Here are a few pictures.
This other one below, I fear may be the future of this tree. It was a vigorous productive Monroe (at least so I thought) that was knocked down by two storms, propped back up both times, and it looked like it was coming back. Then started deteriorating just the same way the Oro negro is now. It is dead now and I will take a chain saw to it soon. I will leave a stump in the off chance that I am wrong and it is not dead.
I am trying whatever I can to save the tree, sentimental reasons (first successful graft ever). However, I am looking at the silver lining, if this dies, I will have space for one of the many plants in my seedling areas in need of a spot in the yard.