James greives apple tree issues

Have a james grives apple tree planted 4 years ago last year I had blossoms wilt and early fruit drop this year in spring had wilt on some flowers leaves and small branches so had to do some pruning so tree is bare on one side and pruned on one side to remove any risk of deased wood I have on big bare branch left on that side, I am worried now there will be no new growth on that side now as see no new buds , pruned it 1 month ago , what should I do was this tree and bring it back to health?

 

@Bear , have you looked at images for apple canker? James Grieve are a lovely apple - crisp, juicy, sweet, and lots of flavour. But they are very susceptible to apple canker…