Symptoms, etiology and control measures of red rot of sugarcane

Symptoms, etiology and control measures of red rot of sugarcane


Red rot of sugarcane is a serious and destructive disease of sugarcane. It was first discovered from Java by went in 1893.


It can be seen in the tropical and subtropical region of the world


Red rot of sugarcane



Serious epiphytotics have occurred in Uttar Pradesh and Bihar during 1939 -1940 and 1946 - 1947 respectively.


Symptoms:-

1. In early stage it is difficult to recognise the disease in the field. 

The symptoms of the disease become apparent after the rainy season.


2. The symptoms of the disease occur on all aerial parts being more prominent in stem and midrib areas of leaves.


Red rot of sugarcane



3. The early symptoms show drooping of leaves and loss of colour.


4. Later the cane becomes completely rotted within looses its natural bright colour, becomes full and shrinks at node.


5. The leaves now begin to either completely and droop. 


6. The split stem show longitudinally reddened internodal tissue, generally at base.


The characteristic symptoms of the disease is formation of cross bars in reddened areas 


7. Juice often gives bad colour due to conversion of sucrose into glucose and alcohol.


8. On the leaves, infection appears in the midrib as dark, reddish area that elongates rapidly forming blood red lession whose margins become darker.


Red rot of sugarcane


In old lession, the centre becomes straw coloured.

9. The lession get covered with powdery mass at the time of reproduction of pathogen.


Etiology ( causal organism ) :-

The caused  agent of the red rod sugarcane disease is the Colletotrichum falcatum (went) of the class deuteromycetes / fungi imperfecti.



Recently perfect or sexual stage of the fungus has also been found by Arx and Muller who discovered as Glomerella tucumanesis of the class Ascomycetes -


1. The fungus my senior growth both inter and intracellulary in the parenchymatous cells of the host tissue.


2. The hyphae are colourless, slendre, freely branched and septate.

Red rot of sugarcane


3. The hyphae produce terminal or intercalary thick walled greenish black chlamydospores in the peter sales which remain dormant in the soil for a long period.


4. Ascospores are aseptate, hyaline, straight or slightly fusoid, ellipsoid or avoid.


5. The perfect stage comprises of perithecia which are glubose superficial with bottom embedded the host tissue.

6. Asci are numerous, clavate are paraphysate bearing 8 ascospores.


Disease cycle -

The source of primary inoculum are the old fragmented stalks and leaves and other rubbish in which the fungus is known to be growing saprophytically and unknowingly planted diseased stalk during cultivation.


 That are produced in the acervuli developed along the midrib of the disease leaves during primary infection from the secondary inoculum.


They are disseminated by wind, rain splashes, irrigation water and also by insects.


The conidia germinate readily by germ tube which on coming in contact with any hard surface i.e soil particles or plant parts, from appreossorium from which infection hypha is produced.


The pathogen mein gain entrance throw the notes at the leaf sears through any kind of wound, through roof primordia and seed cuttings.


Red rot of sugarcane



The diseased canes are frequently found to be injured by insects, especially borers and no doubt these wounds facilitate he entrance of the fungus, which is turn does much more damage the insects.


Red rot is got a root disease, through roots are often infected by the fungus.


High humidity due to water loggings, weak growth of host plant for one of proper cultural operations continuous cultivation of the same variety of sugarcane in a particular locality and cultivation of susceptible game variety in the neighbouring areas are some of the aspects that help disease incidence and often to epiphytotics.


Control measures

Following are some of the suggested control measures:-

1. Careful selection of red rot seeds salts recommendation for planting.


2. Seed should always be taken from disease free nurseries.


3. Reddening showing seed salt should be discarded.

4.  Roguening and burning of the affected clumps.


5. Ratoon of sugarcane should not be kept in red rot affected fields.


6. Treatment of seeds with fungicide like Arasan (0.25%).


7. Epidemic can be minimised with other practice of long crop rotation (2 to 3 years).


8. Resistance to red rot sugarcane varieties should be recommended.


9. Hot water treatment of seeds ( at 50 degree Celsius for 2 hours).


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