#Crabapple tree diseases fire blight how to

If cankers are present on large branches and trunks, remove them in winter. Avoid excessive pruning which can also cause lush growth, but do remove suckers at the base of the tree and watersprouts which arise from the trunk or branches.ģ. If plant vigor is lacking, fertilize lightly in the fall. Ensure good drainage and avoid heavy fertilizing in spring that leads to an abundance of succulent growth.

#Crabapple tree diseases fire blight how to

Here is a good video by Nathan Brandt of MU Extension on fireblight and how to prune it out.

Also, clean up and dispose of any dead twigs and mummified fruit on the ground. Avoid pruning in spring when bacterial ooze is prevalent. Disinfect tools between cuts by dipping in a 10% chlorine bleach solution. In late summer or winter, prune out all diseased wood at least 10 to 15 inches below the infection and destroy. When terminal buds set and tissue hardens, the disease stops progressing.ġ. Hail damage is often followed by a rapid spread of the disease. The ooze dries and is carried to new sites by insects, wind, rain, or pruning equipment where it causes new infections. In spring, the cankers produce a white or amber ooze which contains the bacteria. Young trees can be killed in one season, but it generally takes several years of continuous dieback for death to occur.įireblight bacteria overwinter in cankers larger than one inch in diameter and in mummified fruits. These can girdle the stem causing even more dieback. As the twigs die back, dead sunken areas on the stem called cankers develop.

A characteristic shepherd's crook often develops as tender growth rapidly wilts and dies. As the disease progresses, leaves and twigs take on a black shriveled appearance as if scorched by fire. Common entry points are through wounds, blossoms, and natural openings such as stomatas and nectaries. Symptoms begin as dark green, water-soaked spots on tissue where it is penetrated by bacteria. If not controlled, it can cause flower and fruit blight, twig and branch dieback, or even kill the plant. Temperature, humidity, insect vectors, and wounding can all affect the severity of infection. It is a serious disease that affects new leaves, fruit, flowers, and stems of over 75 species of trees and shrubs in the rose family including: apple, crabapple, hawthorn, pear, pyracantha, cotoneaster, spirea, flowering quince, and mountain-ash. Fireblight canker and twig dieback on crabapple ( Malus)įireblight is caused by the bacterium, Erwinia amylovora.