Prof. L.R. Jayasekara

Prof. L.R. JayasekaraProfessor Emeritus

Dr. rer. nat.(Ph D); Dip. Biol.(M Sc) (Osnabrueck, Germany), B Sc (Kelaniya), F I Biol (Sri Lanka)

University Location : Room No. B1 320
email: ranjith@kln.ac.lk
Telephone: +94-11-2903222 / + 94-11-2914480
Fax: + 94-11-2914480
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Research Interests

Comparative studies on chemical composition and biogeochemistry of tropical plants/plant matrices.
Rice weed management using botanicals.
Formulation of organic liquid fertilizers from widely available weeds for urban agriculture.
Formulation of organic liquid fertilizers from widely available weeds, agricultural and animal wastes for urban agriculture.

Selected Publications

Jayarathna, N.; Athapattu, R.; Senanayake, S.P.; Jayasekera, R.; Rajapakse, S. and Paranagama, P. (2019). Bioactivity and volatile chemical constituents in selected Piper species in Sri Lanka. BMC Complementary and Alternative Medicine (Accepted for publication).
Hewavitharana, N., Kannangara, S.D.P., Jayasekera, L.R. and Senanayake, S.P. (2018). Formulation of an organic potting medium incorporated with Trichoderma spp. to enhance growth and disease suppression of Abelmoschus esculentus, Sixth International Conference on Plants and Environmental Pollution (ICPEP-6) at CSIR-NBRI, Lucknow, India, 2018, p. 82.
Hewavitharana, N., Kannangara, S.D.P., Jayasekera, L.R. and Dissanayake, D.M.P.S. (2018). Formulation of an organic potting medium enriched with Trichoderma spp. and their effect on growth and disease suppression of Solanum melongena L, International Journal of Agricultural and Environment Research, 4(4): 254 – 258.
Hewavitharana, N., Kannangara, S.D.P., Jayasekera, L.R. and Weerasinghe, P. (2018). Determination of nutrients and fiber contents of seven invasive plants and their decomposition rates, Tropical Plant Research, 5 (3): 286-291.
Senanayake, D., Jayasekera L. R. and Lucke, A. (2018). Taxonomical and chemical characterization of Panicum maximum L. from different agro ecological zones of Sri Lanka. Vegetos 31:1, 1-4, DOI: 10.4172/2229 4473.1000383
Fonseka, W.A.S.I, Adikari, S., Jayasekera, L.R., Ranasinghe, P. and Premakumara, G.A.S. (2017). Seed germination inhibitory effect of Caryota urens L. seed pericarp on rice and associated weeds. Tropical Plant Research, 4(1): 01–06; DOI: 10.22271/tpr.2017.v4.i1.001
Jayasundara, J.M.N.P., Jayasekara, R. and Ratnayake, R.M.C.S. (2016). Liquid organic fertilizers for growth enhancement of Abelmoschus esculentus (L.) Moench and Alternanthera sessilis (L.) Dc.. Tropical Plant Research, 3(2): 336-340.
Wijesudara, N., Jayasekera, L.R. and Rathnayake, R.M.C.S. (2015). Efficacy of liquid organic fertilizers on growth of Anthurium andraeanum L. Abstract published in the Proceedings of the 35th Annual Sessions of the Institute of Biology, 2015, p. 31.
Ratnayake, R.M.C.S. and Jayasekera, L.R. (2011). Effect of burying depth and surface fire on germination of selected dry zone forest plant seeds in Sri Lanka. In: Proceedings of the 31st Annual Sessions of the Institute of Biology, Sri Lanka – 2011, p. 27.
Rajasinghe, M.; Abeywickrama, K. and Jayasekera, R. (2009). Aflatoxigenic Aspergillus flavus and aflatoxin formation in selected spices during storage. Tropical Agricultural Research and Extension, 12(1):1-6.
Karunasinghe, T.G.; Fernando, W. C. and Jayasekera, L. R. (2009). Effect of poultry manure and inorganic fertilizer on the arbuscular mycorrhiza in coconut. Journal of National Science Foundation 37, (4): 285-287.
Dissanayake, D.M.K.W.; Premakumara, G.A.S.; Rajapakse, D. and Jayasekera, L.R. (2008). Proximate composition of seeds of the woody tree Schleichera oleosa in Sri Lanka. In: Proceedings of the 28th Annual Sessions of the Institute of Biology, Sri Lanka, 18 pp.
Cherry, C.C., S. Herremans, V. van Lierde, F. Vanhaecke, M.C. Freitas and R. Jayasekera. 2008. Ultra-micro trace element contents in spices from Sri Lanka. Journal of Radioanalytical and Nuclear Chemistry 276 (1): 143-147.
Fernando, S., J. Dalugama, R. Jayasekera, G. Dassanayake, V. Patu, A. Minato and S. Ozawa. 2007. Development of a Job Control System to Optimize Web Traffics. In: Proceedings of the 8th International Conference on Information Technology-Based Higher Education and Training. 10th -13th July 2007, Kumamoto, Japan, 103.
Dassanayake, G., V. Patu, S. Fernando, R. Jayasekera, A. Minato, H. Noguchi and S. Ozawa. 2007. Improvement of text-based e-learning contents by using a new multimedia-type web authoring tool - A case study from a Sri Lankan university. In: Proceedings of the 8th International Conference on Information Technology-Based Higher Education and Training, 10th -13th July 2007, Kumamoto, Japan, 130.
Jayasekera, R. and M.C. Freitas. 2005. Concentration levels of major and trace elements in rice from Sri Lanka as determined by the k0-standardiization method. Biological Trace Element Research 103(1): 83-96
Jayasekera, R., M.C. Freitas and M. F. Araújo. 2004. Bulk and trace element analysis of spices: the applicability of k0-standardiza-tion and energy dispersive X-ray fluorescence. Journal of Trace Elements in Medicine and Biology 17 (4): 221-228.
Perera, N.I.S., S.P. Senanayake and L.R. Jayasekera. 2001. Leaf flavonoids as chemotaxonomic characters in genus Sida L. (Bevila). Tropical Agricultural Research 13: 260- 266.
Rossbach, M., R. Jayasekera and G. Kniewald. 2000. Marine specimen banking – Archive and pollution control for the 21st century. International Journal of Environment and Pollution13 (1-6): 326-339.
Rossbach, M., R. Jayasekera, G. Kniewald and Huu Thang Nguyen. 1999. Large scale air monitoring: lichen vs. air particulate matter analysis. The Science of the Total Environment 232: 59-66.
Rossbach, M. and R. Jayasekera. 1996. Air pollution monitoring at the Environmental Specimen Bank of Germany: spruce and pine shoots as bioindicators. Fresenius Journal of Analytical Chemistry 354: 511-514.
Jayasekera, R. and M. Rossbach. 1996. Use of seaweeds for monitoring trace elements in coastal waters. Environmental Geochemistry and Health 18: 63-68.
Jayasekera, R. 1994. Pattern of distribution of selected trace elements in the marine brown alga, Sargassum filipendula Ag. from Sri Lanka. Environmental Geochemistry and Health 16 (2): 70-75.
Jayasekera, R. 1994. Sampling of tropical terrestrial plants with particular reference to the determination of trace elements. In: Environmental Sampling for Trace Analysis (Ed. B. Markert),VCH Publisher, Weinheim, New York, pp. 443-447.
Jayasekera, R. 1993. Concentrations of selected heavy metals in different compartments of a mountain rain forest ecosystem in Sri Lanka. In: Plants as Biomonitors: Indicators for Heavy Metals in the Terrestrial Environment (Ed. B. Markert), VCH Publisher, Inc., Weinheim, New York, pp. 613-622.
Jayasekera, R. and H. Lieth. 1993. Soil aeration as an ecological factor governing mangrove zonation. In: Towards the Rational Use of High Salinity Tolerant Plants, Vol. 1: Deliberatitons About High Salinity Tolerant Plants and Ecosystems (Eds. H. Lieth and A. Al Massoum), Kluwer Academic Publishers, Dordrecht, pp. 231-236.
Jayasekera, R. 1993. Interelement relationships in leaves of tropical montane trees. Vegetatio, 109(2):145-151.
Jayasekera, R. 1992.Elemental concentrations in a tropical montane rain forest in Sri Lanka. Vegetatio, 98: 73-81.
Jayasekera, R. and G.H. Schleser. 1991. Seasonal changes in organic carbon content of leaves of deciduous trees. Journal of Plant Physiology,138: 507-510.
Markert, B. and R. Jayasekera. 1987. Elemental composition of different plant species., Journal of Plant Nutrition, Vol. 10 (7): 783-794.
Schleser, G.H. and R. Jayasekera. 1985. δ13C - variations of leaves in forests as an indication of reassimilated CO2 from the soil.Oecologia (Berlin),65: 536-542.

Full List of Publications

Ongoing Research

Administrative Experience

Teaching