FireBlight on Apples and Pears

Fireblight is a serious bacterial disease that afflicts apple and pear trees. Fireblight may appear in two distinct forms. From April to early May flowers and fruit clusters may blacken (die). From May to mid-June a more serious symptom (photo) is sudden dieback, almost overnight, of branch tips . Leaves appear as if someone had poured gasoline over the tree and torched it. Infected branch tips may also look curled, as a so-called "shepherd's crook".

To prevent the spread of fireblight, prune off all diseased wood, cutting back 6 - 8 inches into adjacent healthy shoots. Pruning is done either when first seen or when the tree is dormant. Disinfect the pruning shears after each cut, dipping the blades into either rubbing alcohol or 20% bleach to water solution. Remove all diseased prunings from the property. Do not compost.

When planning an apple or pear home orchard, avoid planting very susceptible varieties such as 'Lodi', ‘Gala’, ‘Jonathan’, ‘Rome’, and ‘ Yellow Transparent'. Among pear varieties, ‘Bartlett’, D’Anjou’, ‘Bosc’ and ‘Clapps Favorite’ are most susceptible, and ‘Moonglow’, ‘Maxine’, ‘Magness’, and ‘Seckel’ are moderately resistant to fireblight. Most Asian pear varieties are very susceptible.