Downy mildew and Ergot of pearl millet
- 1. DOWNY MILDEW AND ERGOT OF CUMBU COURSE TEACHER: Dr. PARTHASARATHY S Asst. Professor (Plant Pathology) STUDENT: Mr. KALIRAJ G ID. NO. 2016021016 COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore3) Kullapuram (Po),ViaVaigai Dam, Theni-625 562
- 2. • Common name: Pearl millet • Scientific name: Pennisetum glaucum • Family: Poaceae
- 5. DOWNY MILDEW
- 6. SIGNIFICANCE OF THE DISEASE • It is also known as green ear disease • It was first reported by Butler in 1907
- 7. ECONOMIC LOSS • It will cause 30% of yield loss in India • During 1975, it caused 100% of yield loss in Karnataka and Maharashtra
- 8. DISTRIBUTION It is widely distributed in temperate and tropical areas of world It is occurs in India, Iran, Israel, China, Japan, USA and many African countries In India it is occurs in Rajasthan, Gujarat, Maharastra and Uttar Pradesh
- 9. Global distribution of Downy Mildew ©https://www.plantwise.org
- 10. SYMPTOMS Downy mildew stage Green Ear Stage
- 11. DOWNY MILDEW STAGE Infected leaves showing chlorotic streaks on their upper surface Opposite to the streaks fine downy growth on the lower surface In advance stages, the infected leaves become distorted and wrinkled
- 13. GREEN EAR STAGE The whole or part of the inflorescence is transformed into twisted leafy structures This imparts the ear an appearance of green leafy mass so it is called as green ear The transformation of floral parts is due to hypertrophy and hyperplasia of the concerned tissue
- 15. CAUSAL ORGANISM Kingdom: Stramenophila (Chromista) Phylum : Oomycota Class : Oomycetes Order : Scleroporales Family : Scleroporaceae Genus : Sclerospora Species : graminicola Author : (Saccardo) J. Schroter
- 16. PATHOGEN CHARACTER It is an obligate parasite Hyphae: Coenocytic, intercellular Haustoria: small bulbous haustoria inside the host cells to obtain nutrients Asexual stage – Sporangiophore Sexual stage – Oospore
- 18. Sexual stage – Oospore ©Plant Pathology, Singh.R.P
- 19. Disease cycle of Downy Mildew ©https://www.plantvillage.psu.edu
- 20. SURVIVAL It is a soil borne disease Oospores are abundantly present in the diseased leaves during summer season It can survive from eight months to ten years
- 21. SPREAD Primary infection by Oospores present in soil and infect the plant Secondary infection by Zoospores present in infected plant Sporangia are disseminated by wind, water and insects
- 22. FAVOURABLE CONDITIONS RH above 75% favours the disease Temperature about 15-25 ͦ C favours the disease Disease occurs in July, August and September
- 23. MANAGEMENT Cultural method Chemical method Resistant Varieties
- 24. CULTURAL METHOD Crop sanitation Early Sowing Transplanting of Pearl millet Roguing
- 25. CHEMICAL METHOD Seed treatment with Metalaxyl 35% at 6g per kg of seeds Spray Ridomil 0.1% 20 days after plantation
- 26. RESISTANT VARIETIES WC-C75 ICMS 7703 ICMV 221 TNAU cumbu hybrid CO 9
- 27. ERGOT OF CUMBU
- 28. SIGNIFICANCE It was first reported from South India It is epidemic form was first reported in Maharashtra- 1956 It contain toxic alkaloid – Ergotoxin
- 29. ECONOMIC IMPORTANCE Average incidence of the disease is 62% It cause grain loss of about 58% HB-1 and HB-2 are more susceptible
- 30. DISTRIBUTION It is distributed in India, Pakistan and several African countries like Nigeria, Somalia, Uganda, Zambia and Zimbabwe In India it is distributed in Delhi, Uttar Pradesh, Rajasthan, Maharashtra, Karnataka, Tamil Nadu, Andhra Pradesh and Haryana
- 31. Global distribution of Ergot disease ©https://www.agropedia.iitk.ac.in
- 32. SYMPTOMS Small droplets of pinkish or light honey-coloured fluid exuding from the spikelets Later the droplets become darker, coalesce and cover larger areas of the cob Advanced stages, small dark brown sclerotia projecting between two glumes It contain the Ergotoxin
- 34. CAUSAL ORGANISM Kingdom: Fungi Phylum : Ascomycota Order : Hypocreales Family : Clavicipitaceae Genus : Claviceps Species : fusiformis Author : Loveless
- 35. PATHOGEN CHARACTER Vegetative stage Honey dew stage
- 36. VEGETATIVE STAGE – ASEXUAL STAGE Macroconidia: Hyaline, fusiform and unicellular It will germinate by producing germ tubes Microconidia: Globular, hyaline and unicellular
- 37. HONEY DEW STAGE – SEXUAL STAGE Sclerotia is produced It is elongated to round, light to dark brown Sclerotia produce perithecium Perithecium will release ascospores
- 41. Disease Cycle of Ergot ©https://www.mdpi.com
- 42. Disease Cycle of Ergot ©Agrios Plant Pathology
- 43. SURVIVAL The conidia are viable for 13 months The conidia are abundantly present on the sclerotial structures
- 44. SPREAD Primary infection by Sclerotia present in the soil Sclerotia will germinate and produce perithecia Perithecia contain 8 ascospores Perithecia will burst and the ascospores infect the plant Secondary infection is insect borne
- 45. FAVOURABLE CONDITIONS High RH (85-95%) during flowering Cloudy weather, low sunshine and daily night showers favours the disease Temperature about 20-25ͦ C favours the disease
- 46. MANAGEMENT Resistant varieties Cultural method Chemical method
- 47. RESISTANT VARIETIES WC-C75 ICMS 7703 ICMV 155
- 48. CULTURAL METHOD Adopt long crop rotation programme Use of clean seeds – Seeds are soaked in 20-30% salt solution Repeated ploughing reduce the viability of sclerotia in soil Removal of collateral host – Cenchrus ciliaris, Cenchrus setigerus and Panicum antidotale
- 49. COLLATERAL HOSTS OF ERGOT
- 53. CHEMICAL METHOD Seed treatment with captan @ 4g per kg of seed Spray combination of Acibenzolar-S-methyl (0.05 kg a.i./ha) and Mancozeb (1.5 kg a.i./ha)
- 54. REFERENCES Singh.R.P, 2018, Plant Pathology, Kalyani publishers, New Delhi- 110 002. pp 449-452 Singh.R.S, Plant Diseases, Oxford & IBH Publishing Company, New Delhi 110 049. pp 264-268
- 55. THANK YOU