Chrysoporthe

Chrysoporthe is a genus of ascomycetous fungi responsible for causing severe canker diseases in various woody plants. These fungi are particularly notorious for causing significant economic losses in eucalyptus plantations worldwide, leading to widespread mortality in affected forest areas.

The primary hosts of this pathogen are trees from the Myrtaceae family, most notably eucalyptus species. The fungus acts as a wound pathogen, typically entering the host's vascular system through cracks in the bark, storm damage, or feeding sites created by insects, eventually compromising the tree's structural and physiological integrity.

Visible symptoms of a Chrysoporthe infection include sunken, necrotic lesions on the stem or branches, which often exhibit gum exudation. As the disease progresses, the canopy shows signs of wilting, chlorosis, and dieback. In late stages, small, black, flask-shaped fruiting bodies emerge through the bark, releasing spores into the environment.

Environmental conditions play a critical role in the development of the disease. High humidity and moderate to warm temperatures are conducive to spore production and dissemination. Rain splashes and wind are the primary vectors for the movement of conidia, allowing the fungus to spread rapidly across dense plantations or nurseries.

Management strategies for controlling Chrysoporthe focus on minimizing infection risks and enhancing tree vigor. Essential practices include planting resistant clones or species, maintaining optimal site conditions to reduce tree stress, and conducting rigorous sanitation programs to remove symptomatic trees that serve as local sources of inoculum for healthy neighboring plants.