Avocado big issue Please help!

[msk0072]

My avocado trees are dyung! One by one.
Variety Lamb Hass. Rootstock : Dusa (clonal)
It stars from the main trank or from yhe branches and and spreads to the rootstock

[raiders36]

1. root rot
2. tree is not getting enough water (under water, they need deep watering).
3. either way, leaves and branches are not getting the water they needed. that is why they turn black/brown.

[msk0072]

Sorry for the double topic
Maybe the adminsitrator can delete this one
See the new topic with the same title and with images!