What's wrong with my nishikawa avocado?

[ofdsurfer]

Hello all.  My nishikawa avocado has been in the ground for just over a year now from a 7gal.  It's had some stem dieback issues for the past couple months.  It is flowering and setting fruit and the new growth appears normal.  Is this a nutrient deficiency or a disease? 

[FlyingFoxFruits]

yikes...could be laurel wilt, from ambrosia beetle?

[ofdsurfer]

That was my first thought but it's been doing that since December.  It hadn't really spread much.  I thought that was something that killed the tree fast.  The pics that UF has shows the whole canopy burned.  The burned looking twigs fall off the main trunk but the other twigs and branches don't look any different. 

[CTMIAMI]

I would say disease...............

Looks like root rot.
How is the soil in the hole?
How often are you watering
Where did you buy the tree?
Di you put a lot of organic material in the hole?

I would put some AgriFos or similar Mono- and di-potassium salts of Phosphorous Acid A good drench 3 oz in a couple of gallons of water. Do not water for a while If it does not rain only water once a week.
Then pray

[ofdsurfer]

It's in a high ph beach sand it has a layer of mulch but no organic material was added to the planting hole.  I have been watering once a week if it doesn't rain.  We did have a storm drop three inches of rain back in December when the symptoms started. It's been a very wet winter for me.  It was purchased from Excalibur.  Should I pull back the mulch?

[ofdsurfer]

Carlos,

Do you think I should try and move the tree somewhere else or plant it on a raised hill?  I have three other avocados around the yard and they don't have any of the same issues.  Will I need to take the fruit off the tree if I use a systemic fungicide?  Do you think that this tree will always need these treatments?

[FLnative]

It's in a high ph beach sand it has a layer of mulch but no organic material was added to the planting hole.  I have been watering once a week if it doesn't rain.  We did have a storm drop three inches of rain back in December when the symptoms started. It's been a very wet winter for me.  It was purchased from Excalibur.  Should I pull back the mulch?

I lost a similar sized nishikawa  last June, it died back after some torrential rain.

[Saltcayman]

I lost one to root rot as well

[Mike T]

If it is phytopthera either get rid of it fast before it becomes a source of further infection or treat it aggressively. That may take drainage/containment works to minimise pooling of water around the roots or spore laden runoff to leave the tree.Very heavy mulching but away from the trunk and phosphoric acid treatment both foliar and trunk injection. Being a tonic rather than a fungicide the tree can sometimes go through the disease.
Chop a dying stem and look for the signature of this affliction.

[ofdsurfer]

Mike,

What is the signature of this affliction that I'm looking for?

Thanks

[Mike T]

Oozing 'sores on the trunk that scrape really red and eat into the tree.Scrape these clean and treat with copper based fungicide as a paste or bituminous spreay after cleaning the wound. The wilting branches should be cut and the red ring inside gives a clue.

[ofdsurfer]

Thanks everybody for the help.  I forgot to mention the tree is 400 ft from the ocean.  We have had some strong onshore winds blowing salt spray on everything.  Can salt spray cause symptoms like this?  My choquette gets leaf burn but not stem dieback, is nishikawa more sensitive to salt spray?
There are no red colored sores or red rings in the stem cross sections.
Thanks