Infected fruit gradually dries and remains attached to the branch rather than dropping. Infected fruit often exudes droplets of sticky bacterial ooze especially when the weather is warm and humid. If infected later expanding red, brown or black lesions appear.
Fruit blightįruit appears small, dark and shriveled if infected when young. Shoot blight infections can expand beyond the current season’s growth into the older supporting wood, causing dark sunken cankers to form. Infected trees appear to be scorched by fire, hence the name ‘fire blight’. When the bacteria invade and kill the cambium tissue of the branch, all flowers, leaves and fruit above the girdled area die. Under favourable conditions shoot blight infections will multiply and continue to expand down the stems. Small droplets of sticky bacterial ooze can often be seen on the surface of fire blight shoots when the weather is warm and humid. The leaves and the stem on young shoot tips turn brown or black and bend over into a characteristic shape similar to the top of a shepherd’s crook or candy cane (Figure 1). Shoot blight is the most obvious symptom of fire blight and can appear one to several weeks after petal fall. Bacteria move from the flowers into the shoots. Generally the entire flower cluster becomes blighted and killed. In the early stages of infection blossoms appear water-soaked and gray-green but quickly turn brown or black. The first symptoms of fire blight can be seen in the flowers as blossom blight (Figure 2).
The most typical symptom is the shepherd’s crook (Figure 1). Descriptionįire blight is a bacterial disease caused by Erwinia amylovora.įire blight can appear as different symptoms, depending on which plant parts are affected and seasonal timing.
CRABAPPLE TREE DISEASES FIRE BLIGHT FULL
Email with a clear photo and your contact detailsĪ full list of notifiable plant pests and diseases can be found in Schedule 2 of the NSW Biosecurity Act 2015.Call the Exotic Plant Pest Hotline 1800 084 881.You can report notifiable plant pests and diseases by one of the following methods: Notifiable statusįire blight ( Erwinia amylovora) is a notifiable plant disease in NSW.Īll notifiable plant pests and diseases must be reported within 1 working day. This plant disease is a serious threat to Australia’s apple and pear industries. Fire blight ( Erwinia amylovora) is an exotic plant pest not present in Australia.
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