Red rot of sugarcane

Red rot of sugarcane is caused by the fungal pathogen Colletotrichum falcatum (teleomorph: Glomerella tucumanensis). It is considered one of the most destructive diseases in sugarcane production, primarily affecting the stalk and causing significant quality degradation of the juice quality.

The fungus is host-specific, primarily infecting sugarcane (Saccharum officinarum). It enters the plant system through mechanical injuries caused by insects, harvesting equipment, or through nodal entry points such as leaf scars or bud scales, establishing itself within the internal tissues.

Symptoms are identified by the internal reddening of the pith tissues, often accompanied by white cross-wise bands. Infected stalks become hollow as the fungus degrades the tissue; external symptoms include the withering and yellowing of the upper leaves, followed by the eventual death of the entire stalk and a characteristic alcoholic odor.

The development and spread of Colletotrichum falcatum are highly dependent on environmental factors, particularly high humidity and warm temperatures. The pathogen survives in infected crop debris and soil, and can also be transmitted through the use of infected setts (seed canes) for planting, which is the most common way for the disease to spread across fields.

Economic damage is severe, as the pathogen causes a dramatic reduction in sucrose content and weight of the cane. Management involves a comprehensive approach:

• Cultivating resistant or tolerant sugarcane varieties.
• Selecting healthy, disease-free seed canes for planting.
• Implementing crop rotation to break the pathogen's life cycle.
• Applying fungicides to seed setts.
• Managing stalk-boring insects that create entry points for infection.