Dothiorella gummosis and rot

Pathogen and disease type: Dothiorella gummosis and rot is a serious plant disease caused by the fungus Neofusicoccum ribis. It is a fungal pathogen that specifically targets the woody parts of the plant, causing systemic vascular obstruction and tissue necrosis, which disrupts the physiological processes of trees.

Host plants and damage: The pathogen affects a wide variety of woody plants, with significant impact on citrus orchards. It results in reduced tree vigor, premature fruit drop, and branch dieback. In severe cases, the infection spreads throughout the main trunk, which can eventually lead to the complete death of the tree, causing significant economic losses for growers.

Symptoms and signs: The most characteristic symptom is the formation of cankers on the bark, accompanied by the exudation of gum (gummosis). As the disease progresses, the bark becomes brittle and cracks, revealing dark, necrotic lesions in the underlying wood. Infected branches often show wilting, chlorosis, and sudden dieback, which is frequently confused with water stress.

Development and spread: The fungus thrives in warm, humid environments. Spores are primarily dispersed by splashing rain and wind, entering the host through natural openings or physical wounds caused by pruning, insects, or frost damage. High density planting and poor orchard hygiene can accelerate the spread of the pathogen throughout the farm.

• Implement rigorous sanitation by pruning and destroying infected branches.
• Disinfect pruning tools with alcohol or bleach after each use.
• Apply copper-based fungicides to protect pruning wounds.
• Improve overall tree health through proper fertilization and irrigation.
• Monitor for insect pests that create entry points for fungal spores.