I have a 5 year old apple tree which has always blossomed but never produced apples until this year. Mind you the fruit was poorly. I recently noticed what appears to be canker on the trunk of the tree just where it branches outwards. I have checked previous questions and you suggest potash and also to cut the canker out. I was just wondering would it be necessary to cut it out of this tree considering it’s position on the tree.
Canker cannot be cut out on the trunk but if it girdles the trunk and the top dies, the tree will make new shoot below the canker.
Use some potash, no farmyard manure or compost, and control weeds to the spread of the branches.