Fusicoccum amygdali

Systematic position and nature of the pathogen: Fusicoccum amygdali (synonym Phomopsis amygdali) is a fungal plant pathogen belonging to the kingdom Fungi and the phylum Ascomycota. It is recognized as a significant agent responsible for the disease known as fusicoccum canker, which severely affects trees in the Prunus genus.

Diseases and host plants: The primary host of this pathogen is the almond tree, although it also causes significant damage to peach and apricot orchards. The disease manifests as necrotic lesions on branches, twigs, and trunk, which eventually girdle the plant tissues, leading to wilt and death of the branches or the entire tree.

Biology and life cycle: The fungus overwinters as mycelium and pycnidia within infected wood. During spring, especially under humid conditions, the pathogen releases spores (conidia) which are disseminated by wind and rain splashes. Infection occurs through natural openings such as buds, or through mechanical wounds including pruning cuts and insect damage.

Conditions for development and harmfulness: The development of the fungus is favored by high humidity and moderate temperatures ranging from 15°C to 25°C. Prolonged wet periods facilitate the infection process. The economic damage caused by this pathogen is substantial, as it leads to reduced tree vigor, poor yields, and often the necessity to remove and replace entire orchard blocks.

Protection and control measures: Effective management of fusicoccum canker requires a combination of sanitation and chemical interventions:

• Strict removal and destruction of infected limbs and dead wood.
• Sanitation of pruning tools to prevent cross-contamination.
• Application of protective fungicides, including copper-based products, during dormant and active growth stages.
• Proper orchard management practices to ensure optimal air circulation within the tree canopy.