Walnut tree - bleeding Canker

[Ploughctg]

Hi,

We have a walnut tree close to our house which has a bleeding canker that has been enlarging in the 5yrs we have lived here.

 

In terms of the general tree health, it has fruited twice in the last 5 years (most walnuts good, some necrotic but maybe from drying process). In the past we have removed petrified branches up to a metre long, and in recent winds lots of small fallen branches. Some has a yellow lichen. Due to the shape of the tree, there is quite a deep separation in pics as seen too.

 

Just wondering if anyone knows what this is/what treatment we can do? Have read that excavating and cauterizing the canker could be an option? Or taking weight of the limbs/pollarding?

 

Thanks

 

 

 

whole treeBleeding CankerTree seperation 1Tree Seperation 2