Red rot of sugarcane and there causes by clostridium falcatum virus.

1 Red rot is a disease of sugarcane.
2 It is caused by the fungus Colletotrichum falcatum.
3 It causes red and white patches on the cane and gives then alcoholic odor when the cane is split open.

1. Red rot of sugarcane Presented by Nisha nag MSc 4 th sem Department of microbiology

2. Content:- Introduction History Casual organism Pathogen character Etiology transmission Disease cycle Symptoms Survival and spread Favorable conditions Disease management Integrated disease management Reference

3. Introduction Red rot is one of the major constraints in the profitable cultivation of sugarcane in many states of India. Except Maharashtra the disease has been recorded in all the state. This disease drastically retards the yield and considerably deteriorates the juice quantity and quality thus hitting both the cane growers and millers Many good varieties have gone out of cultivation due to red root.

4. History:- First reported in 1893 from Java (Indonesia). In India first reported in 1901 in Andhra Pradesh. Disease epidemic occured in 1939-1940 in UP & BIHAR. Disease is soil and seed borne. This accepted name, ‘Red rot’ was given to this cane disease in 1906 by sir E.J Butler.

5. Casual organism:- Kingdom :- fungi Phylum :- Ascomycota Class :- sordariomcetes Order :- phyllachorales Family :- Glomerellaceae Genus :- Colletotrichum Species :- falcatum

6. Pathogen Character:- Anamorph :- colletotrichum fakatum Teleomorph :- Glomerella tacumanensis . Etiology :- Caused by collectotrichum falcatum , a facultative saprophyte. Sexual stage known as Glomerella tucumanensis . Mycellium :- both intracellular and intercellular. Asexual fruiting bodies known as Acervuli . Conidiophores:- linear or club shaped, hyallne,septate . Conidia:- elongated,single celled, thin walled, uninucleate , colourless, sickle shaped (falcate) with granuar protoplasm with a large oil globule. Chlamydospores – thick walled, greenish black - produce a phytotoxic metabolite- anthroquinone compound.

7. Transmission:- Primary transmission through soil and disease sets while the secondary transmission through air, rain splash and soil.

8. Disease cycle:- The fungus is sett born. The fungus also persist in the soil on the disease clumps and stubble as acervulli . The primary infection is mainly from infected setts. Secondary spread in the field maybe through irrigation water and cultivation tools. The rain splash air currents and dew drops also help in the spread of conidia from the disease to healthy plant in the field. The fungus also survives on collateral host like Sorghum vulgare , S. Haleperse and saccharum spontaneum .

9. Symptoms:- Two types of symptoms:- Stalk symptoms leaf symptoms

10. Stalk symptoms:- Stalk symptoms:- . The first symptom seen after the rainy season when the normal plant growth stops and sucrose formation was started. Loose of colour and dropping of third or fourth leaves from the top are the early symptoms the intert weakness withers. In letter States the canes become shriveled the red shrinks and become longitudinally wrinkled. Such canes are lighter invade and easily broken. If the disease canes are split open longitudinally, especially when withering of leaves started the pic took red coloured.

11. Continue- In very advance stage, red colour maybe replaced by dirty brown cavities filled with Greyish mycelium and the juice gives a bad smell due to conversion of sucrose into glucose and alcohol as a result of enzymetic action of pathogen.

12. Leaf symptoms:- Tini reddish lesion of the upper surface of lamina these lesions are 2 to 3 mm in length and about 0.5 mm in width. Menu trade rot on upper surface of midrib of leaf later on become straw coloured in centre with development of darker acervuli .

13. Survival and spread:- They reply heavily on water, particularly rainfall, for dissemination. The fungus is sett borne and also perists in the soil on the diseased clumps and stubbles. Spread Of the fungus occurs in Planting material, and this can be over both short and long distance. Spread also occurs as spore produced on infected plants, water – splashed to those nearby. The fungus can survive for a few months in the soil on plant debris & in sugarcane stems.

14. Favorable conditions:- Successive raton cropping Water logged conditions and injuries caused by insects. Mean temperature range from 29.4 to 31 degree c for disease development. pH 5-6. Drought condition during the initial growth is favorable . High humidity. Water logged condition of the soil.

15. Disease management:- Use always disease free setts. Hot water treatment- 52°c for 8hrs 54°c for 2hrs. Hot air treatment- 54°c for 6 hrs. Removal of infected stools . Crop rotation 2-3 yrs. Use disease res.varaties - cos-767,co-840,co-1148,co-1158, Bo-32, co-975,1148,1158,1336 & 6611, co-5-561,544,B.O-3,10,47.

16. Integrated disease management:-

17. Reference:- Bagyraj and Rangasamy . Slideshare Biology notes https://agritech.tnau.ac.in/crop_protection/sugarcane_diseases/sugarcane_d4.html