Nattrassia mangiferae

Nattrassia mangiferae (formerly known as Hendersonula toruloidea) is a significant plant pathogen belonging to the Kingdom Fungi, Phylum Ascomycota. This fungus is widely recognized for its ability to cause severe wood-decay diseases, often manifesting as branch necrosis, cankers, and dieback in a variety of woody perennial crops.

The host range of this pathogen is extensive, including economically important plants such as mango, citrus, walnut, grapevines, and various ornamental tree species like poplars. The fungus typically gains entry into the host through wounds, pruning cuts, or sunburn cracks in the bark, where it then colonizes the xylem and phloem tissues, causing systemic issues within the tree.

The biology of Nattrassia mangiferae is characterized by its thermal tolerance and ability to thrive in hot, arid climates. It produces various types of spores that are easily disseminated by wind, rain splashes, and human activity. The pathogen is highly opportunistic, often attacking trees that are already suffering from environmental stress, such as water deficit or extreme temperature fluctuations.

The impact of this disease on agricultural productivity is profound. Once established, the fungus disrupts the plant's vascular system, preventing the upward movement of water and nutrients. This results in the rapid wilting of leaves, chlorosis, and the death of individual branches or the entire tree if the trunk becomes girdled by necrotic lesions.

Control and management strategies focus on prevention and sanitation:

• Strict sanitation measures, including the pruning and immediate removal/burning of infected wood.
• Sterilizing all pruning equipment between trees to prevent cross-contamination.
• Painting exposed pruning wounds with fungicidal pastes or protectants to prevent spore entry.
• Protecting tree trunks from sunscald with white latex paint to minimize entry points for the pathogen.