Canker or something else..

Apple tree grafted in its 3rd years,  seems like it is waking up in this fine spring.

In two places on the trunck there are dried cracked areas, one going fully around the trunck the other almost there.

Not sure if it is canker?
Is it a death sentence for the tree?
Anyone can tell me if i am as well to go ahead and replace it ?

Thank you

something damaged the trunk and removed the bark.  It could be as simple as a sloppy limb removal or, in our case, a tractor being drive by the wrong person.  Livestock and wildlife can also make this kind of damage.

Think scar tissue on a human when you slice an inch of skin off on a mandolin.  

Most of the time the tree can manage just fine if it has at least a quarter of the trunk bark in place.  The bark will grow around the wound over the next 10 years or so.  

You can always check with a horticulturalist in your local area against diseases local to your area.  But from the pictures alone, I wouldn't condemn the tree with just the one symptom.  Trees are resilient.