Question
Can fire blight infect a lemon tree? My pear tree was hit pretty heavily by fire blight last year, and I proceeded to manage it with the standard recommended techniques. The pear tree is doing well, but a lemon tree next to it also exhibited fire blight symtoms, including the blackened shepard's crooks forming at the ends of branches. Newly blackened twigs are appearing again this Spring on the lemon tree, and I am concerned that it may be a continued source of infection for the pear tree. A pear of loquat trees also have the fire blight, and I will probably remove them. If the lemon tree turns out to also be a host, I may remove it as well, as it is showing signs of extreme age.

Answer
I am not aware of fire blight on citrus.  It usually affects apples, pears, and crab apples.  I will not say the lemon is not affected by the bacterium, but I would look for some other problem, such as insects.  There is a disease called citrus canker, which is in Florida, and is caused by a bacterium, but is quarantined to that area at this time.  It could also be that the new growth is being burned by the sun.  I am sorry I can not provide more info on your problem.