The pear tree looks as if it has been scorched, the leaves and fruit often look wilted and black. On large branches dark cankers that ooze an orange-brown liquid can be found. It affects only members of the rose family. The most susceptible members of the family are pears, apples and quinces. The bacteria enter through the blossoms and are spread by pollinating insects, aphids and psyllids around the plants by rainfall or watering. Fireblight likes temperatures above 60 degrees and high humidity. It can spread rapidly in warm and humid weather. During Winter months it lives in infected bark.
Clean up any fruit, leaves or branches that have fallen under trees especially in Autumn.
The first symptom of fireblight is that the flowers of the plant or tree start turning brown and then shrivel. The browning begins at the tips of the shoots and spread toward the roots. The limbs often appear cane-shaped because of the curling at the ends.
Watch susceptible plants carefully in areas that are prone to fireblight. Avoid overfertilizing, which can cause a flush of new growth that is quite tasty to pest insects that carry bacteria. Cut infected branches at least 6 inches below the infection on smaller branches at least 12 inches below. Disinfect all pruning tools with bleach or rubbing alcohol.
Watering is necessary when transplanting, but be careful not to over water.