Marasmius root rot

Marasmius root rot is a fungal disease caused by the basidiomycete Marasmius sacchari. This pathogen is a significant concern for sugarcane producers, as it directly impacts the root system and the base of the stalks, leading to reduced vigor and economic losses in yield.

The primary host for this disease is sugarcane (Saccharum officinarum). While it can affect mature plants, the most severe damage is often observed in ratoon crops, where the fungus exploits existing wounds or stress points to colonize the plant tissue and disrupt vascular functions.

Symptoms of the infection include chlorosis, wilting, and premature death of the leaves. A hallmark diagnostic feature is the presence of white, fan-like mycelial mats that develop between the leaf sheaths at the base of the stalk, effectively binding them together and often resulting in restricted growth.

The fungus thrives in environmental conditions characterized by high humidity and soil moisture. Marasmius sacchari persists in decaying plant debris and soil, making it a difficult pathogen to eradicate once it becomes established in a field, especially in environments where moisture is abundant.

Control of this disease requires an integrated strategy to minimize the inoculum and protect the crop. Key preventative measures include the selection of resistant cultivars, rigorous sanitation by removing crop residues, and ensuring adequate field drainage to prevent the development of moist microclimates suitable for fungal growth.