White growth killing cherry blossom branch

[wystery]

First time here! There's been a whiteish growth creeping down one of the branches of our cherry blossom tree. We decided to cut off the diseased part, and the wood was totally dead. I believe it may spread to the entire tree eventually, which is a shame for how beautiful our cherry blossoms are. Does anyone know what this is and how to treat it?

[David Humphries]

This is a resupinate crust fungi, something like Basidioradulum radula (toothed crust)

 

It is a saprobic fungi, feeding on dead wood and not the primary reason for the tree declining. It is spreading in to dysfunctional wood.
 

There will be another agent of decline occurring, like a soil issue (successive drought, water logging, compaction, contamination) Or an airborne pathogen. This in turn will lead to sections of the tree shutting down and then possibly the whole teee dying. 

[wystery]

8 hours ago, David Humphries said:

This is a resupinate crust fungi, something like Basidioradulum radula (toothed crust)

 

It is a saprobic fungi, feeding on dead wood and not the primary reason for the tree declining. It is spreading in to dysfunctional wood.
 

There will be another agent of decline occurring, like a soil issue (successive drought, water logging, compaction, contamination) Or an airborne pathogen. This in turn will lead to sections of the tree shutting down and then possibly the whole teee dying. 

Thank you for your prompt answer, I really appreciate it! Do you know how I might identify what other factor it is that is affecting the tree? Especially airborne pathogen.

[David Humphries]

Can you show us images of the whole tree in context with its surroundings?

 

Is there any recent  history of soil change around the tree ?

[wystery]

On 02/08/2022 at 14:13, David Humphries said:

Can you show us images of the whole tree in context with its surroundings?

 

Is there any recent  history of soil change around the tree ?

Hope these images give you a better idea, the diseased part was on the lower left-most branch in the first photo.

 

As for soil change, I don't believe so, unless you count applying mulch to the base of the tree in the past few years. 

[David Humphries]

Looks likely to be a soil/root issue on the roadside of the tree, with associated branches becoming dysfunctional. Trees will eventually struggle in an urban grass environment. If the tree is valued consider losing the grass from underneath the canopy and increase the width of the mulch and (if used) reduce the use of fertilisers/weed killers around the trees.