WHIP SMUT OF SUGARCANE

SYMPTOMS, PATHOGEN, MANAGEMENT

1. STUDENT COURSE TEACHER THAATCHAYINI. A Dr. S. PARTHASARATHY ID. No. 2016021046 Assistant Professor (Plant Pathology). COLLEGE OF AGRICULTURAL TECHNOLOGY Affiliated to Tamil Nadu Agricultural University, Coimbatore Kullapuram , Via Vaigai dam, Theni-625 562 WHIP SMUT OF SUGARCANE

2. COMMON NAME : Whip smut of Sugarcane Causal organism : Ustilago scitaminea OTHER NAME: Culmicolous smut LOCAL NAME: Karipootai disease (Tamil)

3. HISTORY Ustilago , the largest genus of the family Ustilaginaceae is represented by more than 400 cosmopolitan species. Butler and Bisby (1958) reported more than 108 species from India. The name Ustilago have been derived from Latin word ustus meaning burnt.

4. The Members of the genus produce black, sooty powdery mass of spores on the host plant parts imparting them a burnt appearance. This black dusty mass of spores resembles soot or smut, therefore, commonly called as smut fungus.

5. WHIP SMUT OF SUGARCANE http://www.vsisugar.com

6. WHIP SMUT SIGNIFICANCE Whip smut caused by U stilago scitaminea . It is one of the major diseases on sugarcane . The disease organism affect the crop when it is one month old upto the harvesting time. A smut affected sugarcane contains less than 10 percent juice than healthy sugarcane.

7. Ratoon crop is affected more by smut disease. A Yield loss due to this disease varies between 25 percent in main crop to 75 percent in ratoon crop. This disease also reduces the quality of cane.

8. DISTRIBUTION WORLD : India Italy Java Philliphines INDIA: Tamilnadu Andhra Pradesh Maharashtra Kerala

9. SYMPTOMS OF WHIP SMUT OF SUGARCANE Production of whip like structure (25-150cm) from the growing point of the cane. Whip covered by translucent silvery membrane enclosing mass of black powdery spores. In maturation of the whip, the membrane ruptures and releases mass of black smut spores.

10. The smutted whips are commonly produced in many numbers in the crop during may to June and October to November. Initial thin canes with elongated internodes later become reduced in length. Profuse sprouting of lateral buds with narrow, erect leaves especially in ratoon crop. The whip arises from the top of the cane or from lateral buds.

11. agritech.tnau.ac.in Whip like structure Small and narrow leaves

12. agritech.tnau.ac.in http://www.vsisugar.com Black powdery spores Smut infected field

13. SMUT PRODUCED FROM THE TOP OF THE CANE agropedia.iitk.ac.in

14. SYSTEMATIC POSITION Kingdom : Fungi Phylum : Basidiomycota Subphylum : Ustilaginomycotina Class : Ustilaginomyceyes Order : Ustilaginales Family : Ustilaginaceae Genus : Ustilago Species : scitaminea ( Syd .) M. Piepenbr ., M. Stoll & Oberw . 2002

15. PATHOGEN -CHARACTERS The fungal mycelium spores are echinulate , light brown and spherical, measuring 6.5 – 8.5 micron in diameter. They germinate readily in water, producing 2-3 celled promycelia . Sporadia arise terminally or laterally and are hyaline, single celled and elliptical to linear.

16. Ustilago scitaminea agritech.tnau ac.in

17. REPRODUCTION It is of two types Asexual reproduction Sexual reproduction Asexual reproduction: It takes place by fragmentation, budding of basidiospores and formation of conidia. However, it is of rare occurrence.

18. Sexual reproduction: Ustilago is autoecious i.e., it completes its life cycle on a single host. Sex organs are completely absent. It produces two kinds of spores during its life cycle. Teliospores or teleutospores and basidiospores .

19. EPIDEMOLOGY Mode of spread: Primary spread Infected setts . Secondary spread Air –borne, rain and irrigation.

20. Mode of survival : The fungus mainly survives in infected canes as mycelium and these canes provide the primary inoculum . The pathogen may also survive in bud of seed cane or standing cane buds or in ratoon plants. Survives in soil for 10 years in infected crop residues.

21. FAVOURABLE CONDITIONS High temperature 30-35 ◦C with moderate rains with very high humidity. Monocropping . Ratooning . Dry weather. However pathogen requires wet condition for development of teliospores .

22. Collateral host : Saccharum spontaneum Sorghum vulgare Cyperus dilatatus

23. MANAGEMENT Cultural method : Growing of resistant and moderately resistant varieties. Co 86249. CoG 93076. CoC 22. Cosi 6. CoG 5.

24. Cultural method : Discourage ratooning of the diseased crops having more than 10 percent infection. Cajanus cajan can be grown as companion crop between rows of sugarcane, and the secondary spread of the disease is substantially reduced. Avoid ratooning and monocropping . Follow 3 year crop rotation. Crop rotation with green manures.

25. Physical method : Treating the seeds with Aerated Steam Therapy at 50 ◦C for 1 hour or in hot water at 50◦C for 30 minutes or at 52◦C for 18 minutes. Roguing of smut whips with gunny bags/polythene bag and dipped in boiling water for 1 hour, and diseased culms must be uprooted and burnt.

26. Chemical method : Sett treatment with fungicides Triadimefon @ 1gm in 1 litre of water or Carbendazim @1gm in 1 litre of water for 10 minutes. Spray on infected stools with a small amount of a 10% solution of roundup, using a small hand held sprayer. In severe cases spray the entire block with glyphosate 360G/L at 5-7 lit /ha.

27. REFERENCES Sushil Kumar singh , Dinesh singh and Adesh Kumar. 2017. Plant Diseases and their Management. Kalyani Publishers, New Delhi. www.biologydiscussion.com http://www.vsisugar.com agritech.tnau.ac.in