avocado tree dying

Question

Dying of thin branches on avocado tree from which the fruit is hanging. Start turning black from the tip of the branch and keep dying back. Please identify the problem or disease and what can be done to save the young fruit and tree. The tree is quite big and a few years old already.

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Answer 1

Root rot is one possibility, since it would cause dying branches as well as the browning leaf tips seen in the photo. This happens because the disease damages the roots and then the tree can't take in enough water:
http://www.californiaavocadogrowers.com/cultural-management-library/avocado-tree-root-rot-symptoms

Also check for holes in the branches which could be left by insects called borers. These can damage the tree directly and could introduce fungi.
https://www.gardeningknowhow.com/edible/fruits/avocado/avocado-pests-and-diseases.htm
http://cisr.ucr.edu/polyphagous_shot_hole_borer.html

The diseases and pests that are common differ by region, so the best thing to do is to contact your local extension service for diagnosis and treatment options.