Effect of Rates and Sources of N Fertilizer Application on Dynamics of Rice Brown Leaf Spot Disease (Bipolaris oryzae) Incidences in the Dry Zone of Sri Lanka

  • Chamarika Priyadashani Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
  • Darshika Madhavi Wickramasinghe Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
  • Chaminda Priyanka Egodawatta Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
  • Dilshan Beneragama Department of Plant Sciences, Faculty of Agricultural and Food Sciences, University of Manitoba, Canada
  • Prathiba Aruni Weerasinghe Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
  • Udeni Devasinghe Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura, Sri Lanka
Keywords: conventional, nitrogen fertilizer, organic, rice brown leaf spot


Nitrogen inputs; sources or application amounts are key determinants of yield determination and determination of resistance or sensitivity to pathogen activities. This study aimed at assessing the impact of source and rate of application of N fertilizers on Rice Brown Leaf Spot (RBLS) disease incidences and dynamics in lowland irrigated rice crops. Leaf N using relative leaf chlorophyll content, leaf N concentration and crop yield were assessed during the wet 2018/19, 2019/20 and 2020/21 seasons and dry 2019 and 2020 seasons in the field research facility of Rajarata University of Sri Lanka. The conventional systems (The Department of Agriculture recommended inorganic fertilizer application at 100% N), integrated system (50% N with conventional through inorganic fertilizer and 25% N with organic manure mixture), and organic system (50% of N conventional through organic manure) were tested using a new improved rice variety Bg300, using a randomized complete block design with six replicates. Wet and dry seasons were contrastingly different in disease prevalence, where critical levels of incidences were visible earlier in the wet season compared to the dry season. Initial stages of the study, organic systems resulted in higher disease incidences, thus reaching infections of the full crop before conventional and integrated. Several seasons of continuous organic manure incorporation enhanced the resistance of organic systems to RBLS disease compared to the rest. The leaf N concentrations were higher in conventional, thus the RBLS incidences were relatively low, due to negative correlations between disease incidences. Rice yields also resulted in a significant negative correlation with disease incidences and were diminished in integrated and organic systems later. The yield suppression due to diseases such as RBLS in organic transition can be overcome by using an integrated approach and building a balanced substitutable nutrient management strategy.


Bremner, J.M., and Mulvaney, C.S. (1982). Total nitrogen. In: “Methods of Soil Analysis”. American Society of Agronomy, Soil Science Society of America, Madison, Wisconsin. pp 595- 624.
Chattopadhyay, S.B., and Gupta, D. (1965). Factors affecting conidial production of Helminthosporium oryzae. Indian Phytopathology 18, 160-167.
Dordas, C. (2008). Role of nutrients in controlling plant diseases in sustainable agriculture. A review. Agronomy for Sustainable Development 28, 33-46. DOI: 10.1051/agro:2007051
Ghorbani, R., Wilcockson, S., Koocheki, A., and Leifert, C. (2009). Soil management for sustainable crop disease control: a review. Organic Farming, Pest Control and Remediation of Soil Pollutants, 177-201. DOI: 10.1007/978-1-4020-9654-9 10
Groth, J.V., Ozmon, E.A., and Busch, R.H. (1999). Repeatability and relationship of incidence and severity measures of scab of wheat caused by Fusarium graminearum in inoculated nurseries. Plant Disease 83, 1033–8. DOI:10.1094/PDIS.1999.83.11.1033
Hossain, M.M., Sultana, F., and Asadur Rahman, A.H.M. (2014). A comparative screening of hybrid, modern varieties and local rice cultivar for brown leaf spot disease susceptibility and yield performance. Archives of Phytopathology and Plant Protection 47, 795-802. DOI: 10.1080/03235408.2013.822753
Huber, D.M., and Thompson, I.A. (2007). N and plant disease. In “Mineral Nutrition and Plant Disease” (L.E. Datnoff, W.H. Elmer and D.M. Huber, eds.) pp. 31–44. St Paul, MA, APS Press.
Imran, M., Sahi, S.T., Atiq, M., and Rasul, A. (2020). Brown leaf spot: an exacerbated embryonic disease of rice, a review. Journal of Innovative Sciences 6, 108-125. DOI: 10.17582/journal.jis/2020/
Jha, A.C. (2001). “Development and management brown spot of rice caused by Drechslera oryzae (Breda de Haan) Subramanian and Jain”. [Thesis]. RAU Bihar, Pusa Samastipur.
Kohls, C.L., Percich, J.A., and Huot, C.M. (1987). Wild rice yield losses associated with growth-stage-specific fungal brown spot epidemics. Plant Disease 71, 419-422.
Siavoshi, M., and Laware, S.L. (2011). Effect of organic fertilizer on growth and yield components in rice (Oryza sativa L.). Journal of Agricultural Sciences 3, 217-224. DOI:10.5539/jas.v3n3p217
Mew, T.W., Gonzales. (2002). “A Handbook of Rice Seed-borne Fungi”. International Rice Research Institute, Los Banos, Philippines.
Myint, S.S., Nyut, H.K., Ko, H.K., and Thein, M.M. (2007). Study on the effect of different urea fertilizer rates and plant populations on the severity of bacterial blight of rice. Journal of Agriculture and Development in the Tropics and Subtropics 2, 161-167.
Nanda, H.P., and Gangopadhyay, S. (1984). Role of silicated cells in rice leaf on brown spot disease incidence by Bipolaris oryzae. International Journal of Tropical Diseases 2, 89-98.
Ohata, K., Kubo, C., and Kitani, K. (1972). Relationship between susceptibility of rice plants to Helminthosporium blight and physiological changes in plants. Shikoku National Agricultural Experiment Station 25, 1-19.
Ou, S.H. (1985). “Rice Diseases” 2nd ed. Kew, Surrey, UK, Commonwealth Mycological Institute.
Padmanabhan, S.Y. (1973). The great bengal famine. Annual Review of Phytopathology 11, 11-24.
Palti, J. (1981). “Cultural Practices and Infectious Crop Diseases”. Springer, Berlin.
Roberts, T.L. (2008). Improving nutrient use efficiency. Turkish Journal of Agriculture and Forestry 32, 177-182.
Rush, C.M., Piccinni, G., and Harveson, R.M. (1997). Agronomic measures In “Environmentally Safe Approaches to Crop Disease Control” (N.A. Rechcigel, J.E. Rechcigel, eds.). CRC Publications, Boca Raton.
Sun, Y., Wang, M., Mur, L.A.J., Shen, Q., and Guo, S. (2020). Unravelling the roles of nitrogen nutrition in plant disease defenses. International Journal of Molecular Sciences 21, 572. DOI: 10.3390/ijms21020572
Sunder, S., Singh, R., Agarwal, R. (2014). Brown spot of rice: an overview. Indian Phytopathology 67, 201-215.
Sunder, S., Singh, R., Dodan, D.S., and Mehla, D.S. (2005). Effect of different nitrogen levels on brown spot (Drechslera oryzae) of rice and its management through host resistance and fungicides. Plant Disease Research-Ludhiana 20, 111.
Tajani, M., Douira, A., Haloui, N.E., and Benkirane, R. (1993). Impact of fertilization on disease development and yield components. Cahiers Options Mediterranennes 3, 95-99.
Webster, R.K., and Gunnell, P.S. (1992). “Compendium of Rice Diseases”. American Phytopathological Society, St. Paul, Minnesota. pp. 62.
Wickramasinghe, W.M.D.M., Priyadarshani, T.D.C., Herath, U.S., Egodawatta, W.C.P., Beneragama, D.I.D.S., and Sirisena, U.G.A.I. (2021). Effect of nitrogen fertilizer, weed control, and seed rate on incidence and severity of narrow brown leaf spot in rice cultivation under the dry zone of Sri Lanka. Ruhuna Journal of Science 12, 155-166. DOI: