Sick Leyland?

[eeseasdas]

Not sure but think its Se-iridium canker? Planted 4 years ago. They were about 2 feet tall now about 20 feet. What do you think at least 5 of them have inside the tree browning of branches, I do not see it on the outside and I guess this picture is a canker?

Help please.

 

[treeseer]

yup that's it. i've experimented with phosphite and cambistat. seeems to do some good but no silver bullet.