Skip to main content

Red rot in sugarcane

Red Rot:

Causal Organism: Colletotrichum falcatum

It is the most dreaded fungal disease of sugarcane. The pathogen is both sett and soil borne. However, primary spread is mainly through infected setts.


Symptoms:

  • The disease starts with yellowing of leaves from top except crown leaves, after rainy season followed by considerable shrinkage of the stalk.
  • Presence of reddish discoloured patches or lesions interspersed with white horizontal patches on the internal tissue i.e. pith.
  • As the disease progresses the internal tissues become darker in colour and dry resulting in longitudinal pith cavities. The fugal mycelium may be seen in these dry cavities.


0
Your rating: None

Red rot of sugarcane

Red rot of sugarcane was first reported from Java (now Indonesia) by Went in 1893. During 1895-1900 the disase assumed epidemic proportion in the Godavari Delata of Andhra Pradesh, India (Barber 1901). Butler(1906) published a detailed account of this disease from PUSA, Bihar and gave it the name 'Red rot'. The disease is caused by the fungus Colletotrichum falcatum Went (imperfect state); perfect /ascigerous state = Glomerella tucumanensis (Speg.) von Arx and Muller). The disease is the number one problem of sugarcane in India and entire cane breeding in India is geared around this disease. Today, no sugarcane variety is released for cultivation without resistance to red rot.

The pathogen is mainly sett-borne (goes in the field along with the planting material) and thus affects the cane plant from the germination. The damage starts with germination failure, settling mortality to the dying of the full-grown cane. In full-grown cane the disease appears as the yellowing of the crown leaves. On splitting open the cane of such affected plants, interrupted red and white patches (white spot) along with sour alcoholic odour are observed. In later statge numerous acervuli develops on the rind. The pathogen mainly spreads during the rainy season and if environement favours it can wipe out entire sugarcane plantation.

The disease is currently managed through host resistance as fungicides do not get adequate entry( conc. is less to effect eradication) into the stalk. Application of biocontrol agents like Trichoderma has shown promise in the containment of the disease through antibiosis and induced systemic resistance. 

Internal symptom of red rot, note the white spotYellowing of crownSpindle infectionColletotrichum falcatum

Internal symptoms                  Yellowing of crown        Spindle infection                     Colletotrichum falcatum