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Phomopsis Canker



P_phomopsiscnkr

Phomopsis Canker

Usually appear in

Spring to Autumn.


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Caused By:-     Several species of Phacidiopycnis (Phomopsis) Fungi

Description

Phomopsis Canker is caused by several species of the Phacidiopycnis (Phomopsis) fungus. It attacks a range of plants including Pines, Conifers, American and European Cranberries, Blueberry. Some species of Phomopsis are notifiable diseases in certain countries. Pines are most often damaged by this fungus which damages one or two year old twigs or branches especially after frost damage or mechanical wounds, which allows the entry of the fungus. The stems are girdled by the fungus and the new growth wilts and die. The fungus is commonly found on dead conifer branches and foliage, but can also infect living tissues after wound damage after first colonising dead branches, frost-killed shoots, or frost-induced bark cracks. Infection by spores may occur either at shoot tips or lower in the stem. Growth within living tissue is limited, and infection in shoot tips do not normally grow down past the second or third internodes. Lower stem infection may lead to canker formation or, if girdling occurs, to wilting and death of the whole shoot.
Minute black fungal fruiting spores (pycnidia) may form on the dead stems, leaves and berries. Phomopsis fungi overwinters in the dead stems. Spores are produced from Spring until Autumn. Spores are dispersed by rainwater and splashing. Warm, wet conditions are most conducive for spore germination. Picture by University of Georgia Plant Pathology Archive, University of Georgia, Bugwood.org.
See these other Cankers Apple and Pear, Bacterial, Bleeding, Canker, Cytospora, European, Horse Chestnut Bleeding, Mulberry, Parsnip, Pear and Apple, Poplar Bacterial, Rose Stem and Dieback, Willow Black.


Control

Spraying is not very effective, but a winter tar or oil wash may limit the damage. Pruning out and burning dead or dying branches during the growing season is probably the best way to limit the damage. Avoid mechanical damage where possible and prune to allow good air circulation.



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