This power point is related to disease of cumbu-pearlmillet-bajra Downy mildew and ergot

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

12. Chlorosis
©https://www.tifton.uga.edu

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

14. Green ear
©https://www.agropedia.iitk.ac.in

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

17. Sporangiophore
©Plant Pathology, Singh.R.P

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

33. Droplets on Ear
©https://www.apsnet.org

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

38. Sclerotia
©https://biologydiscussion.com

39. Perithecium
©https://www.instruct.uwo.ca

40. Ascospore
©https://www.biologydiscussion.com

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

50. Cenchrus ciliaris
©https://www.en.wikipedia.org

51. Cenchrus setigerus
©https://www.forestryimages.org

52. Panicum antidotale
©https://www.rmsi.in

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