Fire blight just hit our small orchard, have read the only option is to cut the blight out, how quick does it need to be done, have 40 or so 8-10 year old trees.
thanks

Sooner the better. I prune heavy when I see fire blight. Take a small paint cup, the one with the strap for your hand, and put it on your belt. Fill it 1/3-1/2 way full of Alcohol (I use the 91% from walmart). And dip your pruners between each cut to help prevent reinfecting the tree. Do not let the cutting hit the ground. I use a 5-gallon bucket with a trash bag in it for the cuttings. I want them removed completely from the property.

THIS

Cut back to healthy wood a good 6-12 inches below any sign of blight. It travels from sight of infection, usually through the blooms, down the vascular system. You want to get ahead of it.

You also want to do this on a dry day followed by a few days of dry as blight can enter through open wounds and humidity favors the blight.

Wet damp springs during bloom are the worst for blight and storms and hail can also trigger an outbreak due to open wounds.

Prevention is antibiotic sprays, streptomycin, or a new one that uses benign bacteria to colonize the blooms that out competes and occupies the space blight would need to get a foothold.