Deciduous trunk diseases ID

[Sagebrush]

Trying to ID a trunk issue on a couple of trees in my landscape. Photo is of a Chinese pistache. The other is a seed grown apricot. The trunk begins by splitting of bark which progesses to decay of inner hardened wood. I caught the apricot as the bark began to split. I cut around the area, applied cut paste, sprayed with Daconil and put a collar around it to avoid wetting the area. I am concerned this might spread to my bonsai.

 

[rockm]

Does this tree face south or southwest? It looks like it gets afternoon direct sun and the damage runs the length of the trunk. Both of those are signs of "southwest disease" which is basically a freeze/thaw in winter on younger trees. Sun heats up the tissue and sap, only to have it freeze in place when a cold night arrives. Can be solved by covering the bark with a PVC tube until thicker bark develops.

 

[Wires_Guy_wires]

Freshly planted trees around here get a burlap wrap for about two or three years to prevent the bark from getting sunburned.
Painting them white is a practice that sometimes works but sometimes doesn't.

 

[Sagebrush]

Thank you for the posts. The one in the picture is a volunteer up against a rock wall. Bark damage faces south. Come to think of it the apricot damage is on sw side also. We do get some quick daily temp fluctuations. Teens in early morn but 50 by afternoon. I take it neither of you leans toward disease as the initial insult for this condition?

 

[rockm]

Thank you for the posts. The one in the picture is a volunteer up against a rock wall. Bark damage faces south. Come to think of it the apricot damage is on sw side also. We do get some quick daily temp fluctuations. Teens in early morn but 50 by afternoon. I take it neither of you leans toward disease as the initial insult for this condition?

Nope. the damage on the stump near the tree has almost the exact same injury. It's a physical thing--the heavy callusing is a result of that. That localized heavy scarring typically doesn't happen with bacterial or fungal infections.