My Crab Apples are struggling

[Tomb73]

I planted these crab apples three years ago and they have been doing fine. I had minimal
Leaf drop last summer due to Apple scab so this spring I sprayed them with dormant oil. I followed the label etc. and fell as though my timing was good. Last week they were full of flowers and leafing out nicely however this week they are in serious decline. Leaves are dried out, shriveled up and dropping in dramatic fashion. Any thoughts?

 

[Chuck]

On the second picture, is that limb black? The dead foliage looks like fire blight and if that limb is black it probably is fire blight. Dormant oil does nothing about fungal infections or bacterial diseases. It only takes care of overwintered insects and their eggs.

 

[Chuck]

On the second picture, is that limb black? The dead foliage looks like fire blight and if that limb is black it probably is fire blight. Dormant oil does nothing about fungal infections or bacterial diseases. It only takes care of overwintered insects and their eggs.

Some dormant oils do contain some anti-fungal and anti-viral components but controlling insects is its main use. Here in Texas we don't grow many apples but we do grow a lot of pears. When a pear tree contracts fireblight about the only thing one can do is to inject the tree with oxytetracycline or streptomycin and this only works about 1/2 of the time. As I understand it pears and apples are treated the same.