24May 2018

INCIDENCE AND DISTRIBUTION OF DOWNY MILDEW DISEASE (PERONOSCLEROSPORA SORGHI) OF SORGHUM IN UGANDA.

  • Department of Agricultural Production, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda.
  • Department of Crop Science, College of Agricultural and Natural Sciences, University of Cape Coast, P.M.B Cape Coast, Ghana.
  • National Semi-Arid Resources Research Institute (NaSARRI), Serere, Uganda.
  • Abstract
  • Keywords
  • References
  • Cite This Article as
  • Corresponding Author

Sorghum (Sorghum bicolor) ranks as the third most important staple cereal food crop in Uganda after maize and millet. The crop is hampered by several biotic stresses of which Sorghum Downy Mildew disease is one of the most devastating diseases. The disease is caused by a soil-borne fungus Peronosclerospora sorghi but it is also air-borne through conidia. Incidence and severity of downy mildew were conducted between March-June, 2016 and September-December 2016 growing seasons in 13 sorghum-growing districts across ten agro-ecological zones. Data collected were subjected to analyses of variance, correlation and linear regression. Significant (P < 0.001) differences were recorded for disease incidence and severity across the different agro-ecologies. The mean downy mildew disease incidence varied significantly (P< 0.001) from 49.4 % for Pader to 78.9 % for Namutumba. Disease severity varied significantly (P <0.001) from 2.3 for Pader to 3.5 for Pallisa. Chi-square test for independent association between cropping season and downy mildew disease incidence showed a high significant test statistic values (χ2 = 140.89, d.f = 3, and P < 0.001). A significant (P<0.001) positive correlation was observed between disease incidence and severity (r = 0.498) while a significant negative correlation was observed between disease incidence and rainfall (r = -0.675) due largely to temperature and relative humidity. Multiple linear regression analysis revealed that temperature, relative humidity, rainfall and altitude explained 49 % of the total variation associated to disease incidence. Variations in the incidence and severity of downy mildew disease prompt the need to screen for resistant/tolerant sorghum varieties.


  1. Adipala, E., Bigirwa, G., Esele, J. P. and Cardwell K. F. (1999). Development of sorghum downy mildew on sequential plantings of maize in Uganda. International Journal of Pest Management, 45(2):147-153.
  2. Barbosa, F. C. R., Pfenning, L. H. and Casela C. R. (2006). Peronosclerospora sorghi, the causal agent of sorghum downy mildew. (Peronosclerospora sorghi, o agente etiol?gico do m?ldio do sorgo.) Fitopatologia Brasileira, 31(2):119-132.
  3. Bigirwa, G., Adipala, E., and Esele, J. P., (1998). Occurrence of Peronosclerospora sorghi in Uganda. Plant Diseases. 82:757-760.
  4. Bigirwa, G., Adipala, E., Esele, J. P. and Cardwell, K. F. (2000). Reaction of maize, sorghum and Johnson grass to Peronosclerospora sorghi. International Journal of Pest Management, 46(1):1-6.
  5. Bock C. H., Jeger M. J., Mughogho, L. K., Cardwell, K. F. and Mtisi, E. (1999). Effect of dew point temperature and conidium age on germination, germ tube growth and infection of maize and sorghum by Peronosclerospora sorghi. Mycological Research, 103(7):859-864.
  6. Bock, C. H. and Jeger, M. J. (1999). The effect of sowing date on the incidence of sorghum downy mildew on sorghum in Zimbabwe. Tropical Science, 39(4):194-203.
  7. Bock, C. H., Jeger, M. J., Mughoho, L. K., Cardwell, K. F., Adenle, V., Mtisi, E., Akpa, A. D., Kaula, G., Mukasambina, D. and Blair-Myers C, (1998). Occurrence and distribution of Peronosclerospora sorghi (Weston and Uppal (Shaw)) in selected countries of West and Southern Africa. Crop Protection, 17(5):427-439.
  8. Datta, M. S., Poshadri A., Srinivasa R. P,, Ravinder R. C. and Reddy B.V. S. (2012). Innovative use of sweet sorghum juice in the beverage industry. International Food Research Journal 19(4):1361?1366.
  9. EPPO (2014). PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
  10. FAOSTAT (Food and Agriculture Organization of the United Nations). (2013). Production statistics: crops. FAO statistical databases, http://www.fao.org/faostat/en/#data/QC
  11. Hulluka, M., and Esele, J. P. E. (1992). Sorghum diseases in Eastern Africa. Pages 21-24 In: Sorghum and Millets Diseases: A Second? World Review. W. J. A. de Milliano, R. A.? Frederiksen, and G. D. Bergston, eds. ICRISAT, Patancheru, India.
  12. Jeger M. J, Gilijamsea E, Bock C. H, Frinkinga H. D., (1998). The epidemiology, variability and control of the downy mildews of pearl millet and sorghum, with particular reference to Africa. Plant Pathology, 47:544-569.
  13. Jeger, M. J. (1998). The effect of sowing date on the incidence of sorghum downy mildew in Zimbabwe, Tropical Science. 39: 194-203.
  14. King, S. B. and Mukuru, S. Z. (1994). An overview of sorghum, finger millet and pearl millet in eastern Africa with special attention to diseases. Pages 24-34 in: Breeding for Disease Resistance with Emphasis on Duarability. D. L. Danial, ed. Wageningen Agricultural? University, Wageningen, The Netherlands.
  15. Kutama, A. S., Aliyu, B. S. and Emechebe, A. M, (2010). State of sorghum downy mildew in maize in the Sudan and Sahel savanna agro-ecological zones of Nigeria. Bayero Journal of Pure and Applied Sciences, 3(1):233-237.
  16. Ngugi H. K., King S. B., Abayo G. O. and Reddy Y. V. R. (2002). Prevalence, incidence, and severity of sorghum diseases in western Kenya. Plant Disease 86, 65-70.
  17. Patan?, C., and Saita, A., and Sortino, O. (2012). Comparative Effects of Salt and Water Stress on Seed Germination and Early Embryo Growth in Two Cultivars of Sweet Sorghum. Journal of Agronomy and Crop Science. 199. doi 10.1111/j.1439-037X.2012.00531.x
  18. Promkhambut, A., Younger A., Polthanee A. and Akkasaeng C. (2010). Morphological and physiological responses of sorghum [(Sorghum bicolor L.) Moench] to waterlogging. Asian J. Plant Sci. 9, 183?193.
  19. Rao P. S., Kumar C. G., Prakasham R. S., and Rao A. U., Reddy B. V. S. (2015) Sweet Sorghum: Breeding and Bioproducts. In: Cruz V.M.V., Dierig D.A. (eds) Industrial Crops. Handbook of Plant Breeding, vol 9. Springer, New York, NY.
  20. Reddy, B. V. S., Ashok K. A. and? Sanjana R. P. (2010). Recent advances in sorghum improvement research at ICRISAT. Kasetsart Journal (Natural Science) 44:499?506.
  21. Sharma R., Rao V. P., Upadhyaya H.D , Reddy V. G. and Thakur R. P. (2010) Resistance to grain mold and downy mildew in a mini-core collection of sorghum germplasm. Plant Disease 94, 439-444.
  22. Steel, R.G. D., Torrie J. H. and Dickey, D. A. (1997). Principles and procedures of statistics; a biometrical approach, 3rd edn. McGraw-Hill, Boston.
  23. Thakur R. P. and Mathur K. (2002). Downy mildews of India. Crop Protection 21, 333-345.
  24. Thakur, R. P. and Pande, S. (1995). Genetic management of major fungal pathogens of sorghum. Pages 315-326 in Detection of plant pathogens and their management (Verma, J.P., Varma, A., and Kumar, D. eds.). New Delhi, 110 041, India: Angkor Publishers (P) Ltd.
  25. Thomas, M. D. (1992). Sorghum diseases in Western Africa. Pages 25-29 in: Sorghum and Millets Diseases: A Second World Review. W. J. A. de Milliano, R. A. Frederiksen, and G. D. Bergston, eds. ICRISAT, Patancheru, India.
  26. Tongco, M. D. (2007). Purposive Sampling as a Tool for Informant Selection. A Journal of Plant, People and Applied Research Ethnobotany Research and Applications, 1-12.
  27. (2010). Uganda Census of agriculture 2008/ 2009.Volume IV: Crop Area and Production Report. 54pp.
  28. Wang, M. L., Ryley, M. and Meinke, H, (2000). Prediction of sorghum downy mildew risk in Australia using daily weather data. Australasian Plant Pathology, 29(2):108-119.
  29. Ward, J. M. J., Laing, M. D., and Rijkenberg, F. J. (1997). Determining incidence and severity if downy mildew disease in Maize and Sorghum. Plant Disease 81:41-48.
  30. Ward, J. M. J., Stromberg E. L., Nowell, D. C. and Nutter, Jr. F. (1999). Grey leaf spot: A disease of global importance in maize production. Plant Disease 83: 884 - 895.
  31. Wortmann, C. S. and Eledu, C. A. (1999). Uganda?s agro-ecological zones: A guide for policy makers. Uganda; CIAT Kampala.

[Kumi Frank, Agbahoungba Symphorien, Badji Arfang, Odong Thomas, Edema Richard, Ochwo-Ssemakula Mildred, Nakubulwa Dianah, Tusiime Geoffrey, Biruma Moses and Rubaihayo Patrick. (2018); INCIDENCE AND DISTRIBUTION OF DOWNY MILDEW DISEASE (PERONOSCLEROSPORA SORGHI) OF SORGHUM IN UGANDA. Int. J. of Adv. Res. 6 (May). 954-965] (ISSN 2320-5407). www.journalijar.com


Frank Kumi
Department of Crop Science University of Cape Coast Cape Coast, Ghana

DOI:


Article DOI: 10.21474/IJAR01/7117      
DOI URL: https://dx.doi.org/10.21474/IJAR01/7117