Id please as to why this apple tree failed

[Gareth Smith]

It could have been an over weight Tree surgeon trying to limb walk.

 

[Fungus]

1. The infection in malus that is also infected by Nectria galligena look like that, but it is quite common to take the appearance of the picture at the start of this thread.

2. It is also common to be infected by Schizophyllum commune or one of the Coriolus family. these would induce the white rot

 

Gollum,

1. Nectria galligena causes bark and cambium necrosis and is a superficial soft rotter.

2. Schizophyllum commune and Trametes (= Coriolus) species are secundary saprotrophic pioneer white rotters, that superficially decompose dead wood outside in.

The type of intensive white rot of the central wood in the photo's probably is caused by Pholiota aurivella or Polyporus varius.