Fire blight on weeping louisa crabapple
I recently purchased two plants earlier this spring, and both seem to have come down with Fire Blight. The second plant is a Lady Banks Rose.
First it was the new growth around the blossoms, shriveling, then curling, eventually turning a horrible black... but never dropping. It was the uppermost arching branches of the tree...I was hesitant to cut them until I was sure, since I never had a crab apple nor blight. Once I realized the severity of the bacteria... I cut off three branches at the trunk, rinsing my shears with isopropyl alcohol between use. I burned the infected limbs and sprayed the remainder of the tree with an organic 'helpful' bacteria that will supposedly help minimize the blight.
Now, another three large branches have blight... and if I cut those the tree will be down to two or three small branches...needless to say butchered.
My questions.... is this tree doomed? We are continuing to have a moist, humid, hot spring... I wonder if I am going to kill the tree with all the pruning and it has only been in the ground a few months.
Second... how contagious is this bacterial infection? I only have the one crab apple...and the one rose... no other fruiting trees.
Any advice is appreciated.
Thanks in advance.