Red rot of sugarcane

The fungus Colletotrichum falcatum, also known in its sexual stage as Glomerella tucumanensis, is a notorious ascomycete pathogen responsible for red rot disease in sugarcane. It is considered one of the most destructive diseases in the sugarcane industry, directly impacting yields and sugar content.

The disease manifests primarily inside the stalks. Internally, the pith tissue displays reddening with white cross-striations. As the infection advances, the pith disintegrates, and the stalks emit an alcoholic odor due to the fermentation of sugars caused by the fungal activity within the vascular tissues.

The life cycle of the pathogen is facilitated by conidia, which are produced in acervuli on infected tissues. These spores are disseminated by wind, rain splashes, and irrigation water. The pathogen enters the plant mainly through root zones, growth cracks, or wounds caused by insect borers, which are the primary vectors.

Environmental conditions play a crucial role in the development of the disease. High humidity, heavy rainfall, and temperatures between 25°C and 30°C are highly conducive to the spread of the pathogen. Poorly drained fields and waterlogging increase the susceptibility of the crop to infection.

Integrated management is essential for controlling red rot. Key strategies include planting resistant varieties, which is the most effective approach. Additionally, field sanitation, the use of disease-free seed canes, the implementation of crop rotation cycles, and rigorous control of stem-boring insects are necessary to minimize economic losses.