Diplodia gall cancer

The causal agent of this condition is the fungus Diplodia tumefaciens. It is a pathogenic organism that induces the formation of galls, which are abnormal growths or tumors on the branches and main stems of woody plants. The disease typically follows a chronic pattern, causing significant structural damage to the host.

The primary hosts affected by this pathogen include various species of the Populus genus. The fungus typically enters the host tissue through wounds, pruning cuts, or frost cracks in the bark. Once inside, it colonizes the tissue and stimulates abnormal cell proliferation, leading to the characteristic gall formation.

The most recognizable symptom is the development of knobby, tumor-like growths on the stems and branches. These galls often continue to expand over time, potentially girdling the affected branch, which disrupts the transport of water and nutrients. Consequently, the branch above the infection site often withers and dies.

Development and spread of the fungus are favored by moist conditions and moderate temperatures, which facilitate spore production and dispersal. Wind, splashing rain, and pruning equipment act as primary vectors for spreading the spores to healthy parts of the tree or to neighboring specimens in the stand.

Managing Diplodia gall cancer requires a combination of cultural and sanitary practices. The most effective approach is the early removal and destruction of infected branches to reduce the inoculum load. Furthermore, it is essential to ensure that pruning tools are properly disinfected between cuts to prevent mechanical transmission of the pathogen to healthy tissues.