Mesquite tree sick

[mitm01]

Hello,
I have a 25+ yr mesquite tree that is sick. It has lost about 40% of its leaves starting from the top working down. The tree has two main branches. Starting from where they fork and running about 2 ft long is a split in the bark of the branch that is about 1" wide by 1" deep. For 6" on either side of the split and for its entire length the bark is black. I can see some sap leaking out of the split and the flesh of the tree under the bark is also black. Further up the branch where a knott has fallen off exposing the tree flesh I can see half of it has turned black. In other words it looks to be spreading. The other branch has no split but there is a 1 ft long black area exactly like the ulcer I have already described.

Whats going on and can I cave this tree? Just bought the house and I dont want to lose it.

 

[Monkeywitha_saw]

first thing what part of arizona and the split is from a crevase in the fork and water is getting in and rotting the tree from inside out

 

[mitm01]

Apache Junction

There is no crevase at the fork for water to get into. Its dry, clean and a nicely formed union. The trunk takes a 35 degree bend about half way up so no water could stay standing in the fork. The problem existed prior to the rains we had also. Last summer was long, hot and dry.

The split is on the outside of the branch away from the fork and its only the bark thats affected. Its not directly across from the fork but more up the branch that the split starts. The exposed part underneath the bark is dry except for the thin line of sap oozing. There is no rot visible nor moisture .

Closer examination of the other branch shows a split is also forming. Its only about 1" long right now and thats where the black sap is coming from. Both ulcers look to be about equal distance up the brach from the fork. It looks like a bleeding ulcer is as best I can describe it. Both branches are affected similarly, just the main branch is further along. Trunk is sound.

 

[Monkeywitha_saw]

is there a large canopy on top and does it seem like its starting to grow out and not up? cause the reason im asking is that the canopy might be to heavey and is spliting the trunk from being top heavy also some people use expanding foam to seal the splits to keep water,bug, foriegn objects ect... out

 

[mitm01]

It looks to be growing out. The branch thats affected the worst is actually the canopy for the tree because that branch grew up and then back to form a C shape. The smaller branch took the usual sideways growth. The main branch does look to be very heavy since it also has two more forks in it. One of which is a very large branch about 6" in diameter, the other about 3". The canopy does look to be dense with baren stems that had leaves.