I am a University Teacher and an Agricultural Scientist with research interests extending beyond Agriculture. In my teaching and research, I explore the interaction between plants and their environment. In particular, I am interested in unravelling the influence of climate on the functioning (i.e. physiology) of plants, their growth and productivity. Because all higher plants have a fundamentally common physiology, my research has spanned across a range of agricultural crops in agro-ecosystems and natural plant species in forest ecosystems. My interest in climate has taken me in to research on climate change and its impacts on agricultural crops and tropical rainforests. How crops respond to drought, heat and salt stresses has been a continuing theme in my research. My research has been predominantly empirical, strongly based on quantitative observations in the field and data analysis to build relationships, with a limited amount of simulation modelling and molecular biology. My research collaborators have come from almost all crop research institutes and several universities in Sri Lanka. I teach Principles of Crop Production and Crop Physiology to undergraduates. My postgraduate courses are on Plant-Water Relationships, Crop Physiology and Climate Change. As part of my interactions with the wider scientific community at the national level, I take an interest in policy formulation and funding for scientific research and development. I have served in national level research funding agencies, editorial boards, governing boards and research monitoring and evaluation committees of national agencies.

ACADEMIC QUALIFICATIONS:

• BSc Agric. (Peradeniya, Sri Lanka) - 1986
• PhD (Reading, United Kingdom) - 1992

APPOINTMENTS:

• Assistant Lecturer in Crop Science (1987-1988)
• Lecturer in Crop Science (1988-1993)
• Senior Lecturer in Crop Science (1993 - 2002)
• Professor in Crop Science (On Merit) - (2002-2004)
• Professor of Crop Science (Chair) - (2004-2010)
• Senior Professor of Crop Science (Chair) - (2010 - to date)

MEMBERSHIPS:

• National Research Council - Council Member (2005-2018)
• National Science and Technology Commission - Commission Member (2016-2018)
• Consultative Committee for Research of the Tea Research Board - Committee Member (2005-2019) Chairman (2020 - to date)
• Editorial Board (Journal of the National Science Foundation of Sri Lanka) - Member (2006-2014)
• Governing Board of the Sugarcane Research Institute - Board Member (2020-todate)

JOURNAL PAPERS

(† - Publications in indexed journals)

†De Silva, A.L.C., Senarathna, H.A.K.N. Nishadi and De Costa, W.A.J.M. (2021). Genotypic variation of the interactive effects of elevated temperature and CO2 on leaf gas exchange and early growth of sugarcane. Physiologia Plantarum, 1–14. Available from: https://doi.org/10.1111/ppl. 13578.

†De Silva, A.L.C., De Costa, W.A.J.M. and Suriyagoda, L.D.B. (2021).  Effects of elevated temperature and CO₂ on biomass and sucrose accumulation of selected sugarcane germplasm. Tropical Agricultural Research 33 (Accepted and In Press).

†Devika M. De Costa, Janendra M. De Costa, Manasee T. Weerathunga, Kandeeparoopan Prasannath and Virajini N.D. Bulathsinhalage (2021).  Assessment of management practices, awareness on safe use of pesticides and perception on integrated management of pests and diseases of chilli and tomato grown by small-scale farmers in selected districts of Sri Lanka.  Pest Management Science. https://doi.org/10.1002/ps.6542.

†Madhumali, R.M.C., Wahala, W.M.P.S.B., Sanjeewani, H.K.N., Samarasinghe, D.P. and De Costa, W.A.J.M. (2021).  Response of canopy leaf area index and architecture of tropical rainforests in Sri Lanka to climatic variation along an altitudinal gradient.  Tropical Agricultural Research 32 (1): 1-16.

†Sanjeewani, H.K.N., Samarasinghe, D.P., Jayasinghe, H.D., Gardiyawasam, P.H., Wahala, W.M.P.S.B., Wijetunga, W.M.G.A.S.T.B., Ukuwela, K.D.B., Gomes, P., and De Costa, W.A.J.M. (2020). Response of tree community composition, plant diversity and aboveground tree biomass in tropical rainforests of Sri Lanka to variation in altitude. Tropical Agricultural Research 31 (1): 87-101. DOI:http://doi.org/10.4038/tar.v31l.8346.

Pathiranage, S.R.W., Wijeratne, M.A. and De Costa, W.A.J.M. (2020). Field performance of locally available motorized tea harvesters (accepted to be published in Tea Bulletin – Volume 29 of 2020)

†Malika, L.Y., Deshabandu, K.S.H.T., De Costa, W.A.J.M., Ekanayake, S., Herath, S. and Weerakoon, W.M.W. (2019). Physiological traits determining tolerance to intermittent drought in the Capsicum annuum complex.  Scientia Horticulturae 246: 21-33. doi.org/10.1016/j.scienta.2018.10.047

De Costa, W.A.J.M. (2018). Raising crop yields: The missing links from molecular biology to plant breeding.  Ceylon Journal of Science 47(3): 213-220.  DOI: http://doi.org/10.4038/cjs.v47i3.7528

†Abhayapala, Ruvini, De Costa, Janendra, Malviarachchi, Wasantha, Kumara, Aruna, Suriyagoda, Lalith and Fonseka, Ramya (2018). Exploitation of differential temperature-sensitivities of crops for improved resilience of tropical smallholder cropping systems to climate change: A case study with temperature responses of tomato and chilli. Agriculture, Ecosystems & Environment 261: 103-114. doi.10.1016/j.agee.2017.10.027.

†Caldera, H.I.U., De Costa, W.A.J.M., Woodward, F.I., Lake, J.A. and Ranwala, S.M.W. (2017). Effects of elevated carbon dioxide on stomatal characteristics and carbon isotope ratio of Arabidopsis thaliana ecotypes originating from an altitudinal gradient. Physiologia Plantarum 159: 74 - 92. DOI: 10.1111/ppl.12486.

†Somaweera, K.A.T.N., Sirisena, D.N., De Costa, W.A.J.M. and Suriyagoda, L.D.B. (2017). Age-related morphological and physiological responses of irrigated rice to declined soil phosphorus and potassium availability. Paddy and Water Environment 15: 499-511. DOI 10.1007/s10333-016-0567-6.

†Suriyagoda, L.D.B., Sirisena, D.N., Somaweera, K.A.T.N., Dissanayake, A., De Costa, W.A.J.M. and Lambers, H. (2017).  Incorporation of dolomite reduces iron toxicity, enhances growth and yield, and improves phosphorus and potassium nutrition in lowland rice (Oryza sativa L). Plant and Soil 410: 299-312. https://doi.org/10.1007/s11104-016-3012-0.

†Somaweera, K.A.N.T., Suriyagoda, L.D.B., Sirisena, D.N. and De Costa, W.A.J.M. (2017).  Growth, root adaptations, phosphorus and potassium nutrition of rice when grown under the co-limitations of phosphorus, potassium and moisture.  Journal of Plant Nutrition 40: 795-812. https://doi.org/10.1080/01904167.2016.1201497

Pathiranage, S.R.W., Wijeratne, M.A. and De Costa, W.A.J.M. (2017). The key factors responsible for yield reduction with mechanically harvested tea. Tea Bulletin 26(1 & 2) pp 24-28.

†Somaweera, K.A.T.N., Suriyagoda, L.D.B., Sirisena, D.N. and De Costa, W.A.J.M. (2016). Accumulation and partitioning of biomass, nitrogen, phosphorus and potassium among different tissues during the life cycle of rice grown under different water management regimes. Plant Soil 401: 169-183. https://doi.org/10.1007/s11104-015-2541-2.

†Malaviarachchi, M.A.P.W.K., De Costa, W.A.J.M., Kumara, J.B.D.A.P., Suriyagoda, L.D.B. and Fonseka, R.M. (2016). Response of mung bean (Vigna radiata (L.) R. Wilczek) to an increasing natural temperature gradient under different crop management systems.  Journal of Agronomy and Crop Science 202: 51-68. DOI: 10.1111/jac.12131.

Ahmed, T., De Costa, W.A.J.M. and Wijeratne, M.A. (2016). Effect of Different Plucking Systems on Yield and Root Starch Reserve in Two Cultivars of Tea (Camellia sinensis L.). Journal of Environmental Science and Natural Resources 9 (2): 91-95.

Wijeratne, M.A., Gamage, A.G. and De Costa, W.A.J.M. (2016).  Role of shade trees in tea: low country perspective.  Tea Bulletin 25 (1/2): 14-20.

†Ranasinghe, C.S., Kumarathunge, M.D.P., Jayaranjini, S. and De Costa, W.A.J.M. (2015). Photosynthetic irradiance response, canopy photosynthesis and their variation with canopy strata in tall and dwarf x tall coconut cultivars (Cocos nucifera L.).  Scientia Horticulturae 189: 175-183.

Malaviarachchi, M.A.P.W.K., De Costa, W.A.J.M., Fonseka, R.M., Kumara, J.B.D.A.P.  and Suriyagoda, L.D.B. (2015). Can seasonal temperature extremes alter the growth and yield of mung bean (vigna radiata (l.) R. Wilczek)?  An investigation with different agronomic management packages conducive for climate adaptation. Tropical Agriculturist 164 (Accepted and In press).

De Costa, W.A.J.M., Wijeratne, M.A. and Herath, D.R.K.B.K. Herath (2015). Carbon trading and its application to the tea industry of Sri Lanka.  Sri Lanka Journal of Tea Science 80 (1/2): 19-39.

†Suriyagoda, L., De Costa, W. and Lambers, H. (2014).  Growth and phosphorus nutrition of rice when inorganic fertilizer application is partly replaced by straw under varying moisture availability in sandy and clay soils.  Plant and Soil 384 (1-2): 53-68. DOI 10.1007/s11104-014-2049-1.

Wijeratne, T.L., De Costa, W.A.J.M. and Wijeratne, M.A. (2014). Carbon sequestration: an underexploited environmental benefit of tea plantations in Sri Lanka. Tea Bulletin 23 (1 & 2): 1 – 5.

Malaviarachchi, M.A.P.W.K., De Costa, W.A.J.M., Fonseka, R.M., Kumara, J.B.D.A.P., Abhayapala, K.M.R.D. and Suriyagoda, L.D.B. (2014).  Response of maize to a temperature gradient simulating long-term climate change under different soil management systems.  Tropical Agricultural Research 25 (3): 327-344.

Abhayapala, K.M.R.D., De Costa, W.A.J.M., Fonseka, R.M., Prasannath, K., De Costa, D.M., Suriyagoda, L.D.B., Abeythilakeratne, P.D. and Nugaliyadde, M. (2014).  Response of potato to increasing growing season temperature under different soil management and crop protection regimes in the up-country of Sri Lanka.  Tropical Agricultural Research 25 (4): 555-569.

Kumara, J.B.D.A.P., Suriyagoda, L.D.B., De Costa, W.A.J.M. and Malaviarachchi, M.A.P.W.K. (2014).  Modelling canopy development, biomass and yield of maize (Zea mays L.) under optimal management.  Tropical Agricultural Research 25 (2): 214-227.

†Zahra, A.R.F., De Costa, D.M. and De Costa, W.A.J.M. (2013).  Identification of differentially-expressed genes in response to salt-stress in the salt-tolerant Sri Lankan rice variety At354.  Journal of the National Science Foundation of Sri Lanka 41 (2): 93-112.

Navaratne, D.M.S., Perera, G.A.A.R. and De Costa, W.A.J.M. (2013). Effect of time from pruning on the chemical composition of flush and black tea of physiologically and morphologically different cultivars grown in Dimbula Region of Sri Lanka.  Sri Lanka Journal of Tea Science 78 (1/2): 29-41.

Ahmed, T., De Costa, W.A.J.M. and Wijeratne, M.A. (2013). Effects of different plucking systems on shoot growth dynamics and yield in contrasting two cultivars of tea (Camellia sinensis L.).  Tea Journal of Bangladesh 42: 1-9.
  
Zahra, A.R.F., De Costa, D.M. and De Costa, W.A.J.M. (2012). Comparative expression analysis of two selected candidate genes for salt tolerance in rice variety At354 during two phases of salt stress development. Sri Lankan Journal of Agricultural Sciences 49: 75-85.

†De Costa, W.A.J.M. (2012).  Climate change research in Sri Lanka - Are we investing enough?.  Journal of the National Science Foundation of Sri Lanka 40 (4): 281-282.

†De Costa, W.A.J.M., Wijeratne, M.A.D. and De Costa, D.M. (2012).  Identification of Sri Lankan rice varieties having osmotic and ionic stress tolerance during the first phase of salinity stress.  Journal of the National Science Foundation of Sri Lanka 40 (3): 251-280.    

†De Costa, W.A.J.M., Wijeratne, M.A.D., De Costa, D.M. and Zahra, A.R.F. (2012).  Determination of appropriate level of salinity for screening of rice for salt tolerance.  Journal of the National Science Foundation of Sri Lanka 40 (2): 123-136. 

†De Costa, W.A.J.M. and Suranga, H.R. (2012).  Estimation of carbon stocks in the forest plantations of Sri Lanka.  Journal of the National Science Foundation of Sri Lanka 40 (1): 9-41. 

De Silva, A.L.C. and De Costa, W.A.J.M. (2012). Growth and Radiation Use Efficiency of Sugarcane under Irrigated and Rain-fed Conditions in Sri Lanka. Sugar Tech 14 (3): 247-254 DOI: 10.1007/s12355-012-0148-y.

†De Costa, W.A.J.M. (2011).  A review of the possible impacts of climate change on forests in the humid tropics.  Journal of the National Science Foundation of Sri Lanka 39 (4): 281-302.

De Silva, A.L.C., De Costa, W.A.J.M. and Bandara, D.M.U.S.  (2011). Growth of root system and the patterns of soil moisture utilization in sugarcane under rain-fed and irrigated conditions in Sri Lanka. Sugar Tech Vol. 13(3), pp 198-205. DOI: 10.1007/s12355-011-0088-y.

Attaluri, S., Sangakkara, U.R. and De Costa, W.A.J.M. (2011).  Stability analysis for yield in sweetpotato (Ipomoea batatas) genotypes with special reference to orange-fleshed sweetpotato.  Indian Journal of Agricultural Sciences 81 (7): 585-589.

Attaluri, S., Sangakkara, U.R. and De Costa, W.A.J.M. (2011).  Physiological adaptability of sweetpotato (Ipomoea batatas) genotypes as influenced by seasons with emphasis on orange-fleshed sweetpotato.  Indian Journal of Agricultural Sciences 81 (1): 33-37.

Gamage, D.A.S., Wijesekara, S.S.R.M.D.H.R., Sarachchandra, G.W.N.L., Basnayake, B.F.A. and De Costa, W.A.J.M. (2011).  Estimation of nitrate and phosphate leaching from lysimeter simulation of rice straw landfill bioreactor and evaluation of fertilizer quality of resulting compost.  Tropical Agricultural Research 22 (1): 220-228.

†De Costa, W.A.J.M. (2010).  Adaptation of agricultural crop production to climate change: a policy framework for Sri Lanka.  Journal of the National Science Foundation of Sri Lanka 38 (2): 79-89.

†De Costa, W.A.J.M. (2010).  Investing in research [Editorial].  Journal of the National Science Foundation of Sri Lanka 38 (2): 77-78.

De Costa, D.M., Kishimoto, N. and De Costa, W.A.J.M. (2010).  Effects of elevated CO₂ on culturable epiphytic microbial populations on the phyllosphere of rice.  Sri Lankan Journal of Agricultural Sciences 47: 1-23.

Wanduragala, P.S.B., Easwara, J.P. and De Costa, W.A.J.M. (2010).  The electromagnetic potential gradient, Ca²⁺ and starch-statoliths on the uneven growth of plants.  Tropical Agricultural Research 21 (3): 321-326.

Gamage, D.A.S., Sarachchandra, G.W.N.L., Basnayake, B.F.A. and De Costa, W.A.J.M. (2010).  Lysimeter simulation of paddy straw landfill bioreactor for optimum gas production.  Tropical Agricultural Research 21 (2): 177-188.

†De Costa, W.A.J.M., Navaratne, D.M.S. and Anandacoomaraswamy, A. (2009).  Physiological basis of yield variation of tea (Camellia sinensis (L.) O. Kuntze) during different years of the pruning cycle in the Central Highlands of Sri Lanka.  Experimental Agriculture 45: 429-450.

†Madurapperuma, W.S., De Costa, W.A.J.M., Sangakkara, U.R. and Jayasekara, C. (2009).  Estimation of water use of mature coconut (Cocos nucifera L) cultivars (CRIC 60 and CRIC 65)  grown in Kurunegala series (Plintudults) and Kuliyapitiya series (Typic Hapludults) of Low Country Intermediate zone using the Compensation Heat Pulse Method (CHPM). Journal of the National Science Foundation of Sri Lanka 37 (3): 175-186.

De Silva, A.L.C. and De Costa, W.A.J.M. (2009). Varietal variation in stomatal conductance, transpiration and photosynthesis of commercial sugarcane varieties under two contrasting water regimes. Tropical Agricultural Research and Extension. 12(2): 97-102.  http://www.asiajol.info/index.php/record/view/23001

†De Costa, W.A.J.M. (2008).  Climate change in Sri Lanka: myth or reality? – Evidence from long-term meteorological data.  Journal of the National Science Foundation of Sri Lanka 36 (Special Issue): 83-109.

†De Costa, W.A.J.M., Mohotti, A.J. and Wijeratne, M.A. (2007).  Ecophysiology of tea.  Brazilian Journal of Plant Physiology 19: 299-332.

†De Costa, W.A.J.M., Zörb, C., Hartung, W. and Schubert, S. (2007).  Salt resistance is determined by osmotic adjustment and abscisic acid in newly-developed maize (Zea mays L.) hybrids in the first phase of salt stress.  Physiologia Plantarum 131: 311-321.

†Gunasekara, H.K.L.K., Nugawela, E.A., De Costa, W.A.J.M. and Attanayake, D.P.S.T.G. (2007).  Possibility of early commencement of tapping in rubber (Hevea brasiliensis Muell. Arg.) using different genotypes and tapping systems.  Experimental Agriculture 43: 201-221.

†Gunasekara, H.K.L.K., De Costa, W.A.J.M. and Nugawela, E.A. (2007).  Genotypic variation in canopy photosynthesis, leaf gas exchange characteristics and their response to tapping in rubber (Hevea brasiliensis Muell. Arg.).  Experimental Agriculture 43: 223-239.

†De Costa, W.A.J.M., Weerakoon, W.M.W., Chinthaka, K.G.R., Herath, H.M.L.K. and Abeywardena, R.M.I. (2007).  Genotypic variation in the response of rice (Oryza sativa L.) to increased atmospheric carbon dioxide and its physiological basis.  Journal of Agronomy and Crop Science 193 (2): 117-130.

†De Costa, W.A.J.M., Weerakoon, W.M.W., Herath, H.M.L.K., Amaratunga, K.S.P. and Abeywardena, R.M.I. (2006).  Physiology of yield determination of rice under elevated carbon dioxide at high temperatures in a subhumid tropical climate.  Field Crops Research 96:336-347.

†De Costa, W.A.J.M. and Sangakkara, U.R. (2006).  Agronomic regeneration of soil fertility in tropical Asian smallholder uplands for sustainable food production.  Journal of Agricultural Science (Cambridge) 144: 111-133.  (Invited review for the centenary year of publication of the Journal of Agricultural Science, Cambridge).

De Costa, W.A.J.M. and Piyasena, H.D.A.S. (2006).  Influence of temperature on growth, phenology and yield of different rice (Oryza sativa L.) varieties in Sri Lanka.  Sri Lankan Journal of Agricultural Sciences 43: 1-21.

†De Costa, D.M., Rathnayake, R.M.P.S., De Costa, W.A.J.M., Kumari, W.M.D. and Dissanayake, D.M.N. (2006).  Variation of phyllosphere microflora of different rice varieties in Sri Lanka and its relationship to leaf anatomical and physiological characters.  Journal of Agronomy and Crop Science 192: 209-220.

Lakmini, W.G.D., Nainanayake, N.P.A.D. and De Costa, W.A.J.M. (2006).  Biochemical changes of four different coconut (Cocos nucifera L.) forms under moisture stress conditions.  The Journal of Agricultural Sciences, Sabaragamuwa University of Sri Lanka 2 (3): 1-7.

Lakmini, W.G.D., Nainanayake, N.P.A.D. and De Costa, W.A.J.M. (2006).  Physiological responses for moisture stress and development of an index for screening coconut (Cocos nucifera L.) genotypes for drought. Tropical Agricultural Research and Extension 9: 17-26.

†De Costa, W.A.J.M. and Surenthran, P. (2005).  Resource competition in contour hedgerow intercropping systems involving different shrub species with mature and young tea on sloping highlands in Sri Lanka.  Journal of Agricultural Science (Cambridge) 143: 385-393.

†De Costa, W.A.J.M. and Surenthran, P. (2005).  Tree-crop interactions in hedgerow intercropping with different tree species and tea in Sri Lanka:  1. Production and resource competition.  Agroforestry Systems 63: 199-209.

†De Costa, W.A.J.M., Surenthran, P. and Attanayake, K.B. (2005).  Tree-crop interactions in hedgerow intercropping with different tree species and tea in Sri Lanka: 2. Soil and plant nutrients.  Agroforestry Systems 63: 211-218.

†Weerakoon, W.M.W., De Costa, W.A.J.M. and Abeysiriwardena, D.S. de Z. (2005).  Physiological responses of indica rice varieties to increased atmospheric CO₂ and temperature.  Journal of Agricultural Meteorology 60 (5): 601-604.

De Silva, A.L.C. and De Costa, W.A.J.M. (2004).  Varietal variation of growth, physiology and yield of sugarcane under two contrasting water regimes.  Tropical Agricultural Research 16: 1-12.

Weerasinghe, O.R., Perera, A.L.T., De Costa, W.A.J.M., Jinadasa, D.M. and Vishnukanthasingham, R. (2004). Production of Tomato Hybrids for Dry Zone Conditions of Sri Lanka Using Combining Ability Analysis, Heterosis and DNA Testing Procedures. Tropical Agricultural Research 16: 79-90.

†De Costa, W.A.J.M., Weerakoon, W.M.W.,  Herath, H.M.L.K. and Abeywardena, R.M.I. (2003).  Response of growth and yield of rice (Oryza sativa) to elevated atmospheric carbon dioxide in the sub-humid zone of Sri Lanka.  Journal of Agronomy and Crop Science 189: 83-95.

†De Costa, W.A.J.M., Weerakoon, W.M.W., Abeywardena, R.M.I. and Herath, H.M.L.K. (2003).  Response of photosynthesis and water relations of rice (Oryza sativa) to elevated atmospheric carbon dioxide in the sub-humid zone of Sri Lanka.  Journal of Agronomy and Crop Science 189: 71-82.

Weerasinghe, O.R., De Costa, W.A.J.M. and Perera, A.L.T. (2003).  Evaluation of different genotypes of tomato under well-watered and water-stressed conditions on the basis of yield and some selected physiological parameters.  Tropical Agricultural Research 15: 144-156.

†De Costa, W.A.J.M. and Shanmugathasan, K.N. (2002).  Physiology of yield determination of soybean (Glycine max (L.) Merr.) under different irrigation regimes in the sub-humid zone of Sri Lanka.  Field Crops Research 75: 23-35.

†Anandacoomaraswamy, A., De Costa, W.A.J.M., Tennakoon, P.L.K. and Van der Werf, A. (2002).  The physiological basis of increased biomass partitioning to roots upon nitrogen deprivation in young clonal tea (Camellia sinensis (L.) O. Kuntz). Plant and Soil 238: 1-9.

Gunasekara, H.K.L.K., Nugawela, A., De Costa, W.A.J.M. and Attanayake, D.P.S.T.G. (2002).  Exploitation systems for some Hevea brasiliensis Muell. Arg. clones for improved economic performance.  Tropical Agricultural Research 14: 128-137.

De Costa, W.A.J.M. and Nayakarathne, N.M.R.S. (2001).  Effect of two different water regimes on growth and yield of different groundnut (Arachis hypogaea L.) genotypes in Sri Lanka.  Tropical Agricultural Research and Extension 4: 29-35.

De Costa, W.A.J.M. and Nayakaratne, N.M.R.S. (2001).  Effects of water stress on transpiration efficiency and stomatal conductance of groundnut (Arachis hypogaea L.) genotypes.  Sri Lankan Journal of Agricultural Sciences 38: 60-73.

De Costa, W.A.J.M. (2001).  Effects of different irrigation regimes on canopy architecture and radiation interception of mung bean and soybean.  Sri Lankan Journal of Agricultural Sciences 38: 103-128.

†De Costa, W.A.J.M. and Atapattu, A.M.L.K. (2001). Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka. Agroforestry Systems 51: 201-211.

De Costa, W.A.J.M., Hitinayake, H.M.G.S.B. and Dharmawardena, I.U. (2001).  A physiological investigation into the invasive behaviour of eight plant species in the Udawattakelle Forest Reserve. Journal of the National Science Foundation of Sri Lanka 29: 35-50.

De Costa, W.A.J.M. (2000). Prediction of the effects of elevated CO₂ and temperature on irrigated rice yields in the low-country dry zone of Sri Lanka using a process-based simulation model. Journal of the National Science Foundation of Sri Lanka 28: 165-184.

De Costa, W.A.J.M. and Chandrapala, A.G. (2000).  Competition of six hedgerow tree species on mung bean (Vigna radiata (L.) Wilczek) in the mid-country intermediate zone of Sri Lanka. Journal of the National Science Foundation of Sri Lanka 28 (2): 113-125.

De Costa, W.A.J.M. and Chandrapala, A.G. (2000).  Effects of tree root competition on availability of soil and plant nutrients, soil water and light interception in hedgerow intercrops with different tree species in the mid-country intermediate zone of Sri Lanka.  Journal of the National Science Foundation of Sri Lanka  28 (2): 127-142.

Mahendran, S., Bandara, D.C. and De Costa, W.A.J.M. (2000).  Effects of soil moisture stress at selected stages of growth on net photosynthetic rate and stomatal resistance and their impact on the yield of chilli (Capsicum annuum L.). Tropical Agricultural Research 12: 107-118.

†De Costa, W.A.J.M., Anandacoomaraswamy, A. and Tennakoon, P.L.K. (2000). Effect of nitrogen supply on the response of leaf photosynthesis to light in young clonal tea. Indian Journal of Plant Physiology 5 (3): 244-247.

De Costa, W.A.J.M. and Chandrapala, A.G. (2000). Response of mung bean (Vigna radiata (L.) Wilczek) to mulches from different hedgerow tree species under fertilized and unfertilized conditions in the mid-country intermediate zone of Sri Lanka. Sri Lankan Journal of Agricultural Science 37: 1-20.

†Anandacoomaraswamy, A., De Costa, W.A.J.M., Shyamalie, H.W. and Campbell, G.S. (2000). Factors controlling transpiration of mature field-grown tea and its relationship with yield. Agricultural and Forest Meteorology 103: 375-386.

De Costa, W.A.J.M. and Rozana, M.F. (2000). Effects of shade and water stress on growth and related physiological parameters at seedling stage of five forest tree species. Journal of the National Science Foundation of Sri Lanka 28: 43-62.

De Costa, W.A.J.M., Abeysinghe, W.A.M.W.K.S.B. and Chandrapala, A.G. (2000). Relationship between stomatal conductance and leaf water potential in selected forest tree species growing under different levels of natural shade in the mid-country wet zone. Journal of the National Science Foundation of Sri Lanka 28: 63-78.

†De Costa, W.A.J.M. and Chandrapala, A.G. (2000). Effects of different tree species on growth and yield of mung bean (Vigna radiata (L.) Wilczek) grown in hedgerow intercropping systems in Sri Lanka. Journal of Agronomy and Crop Science 184: 43-48.

†De Costa, W.A.J.M. and Chandrapala, A.G. (2000). Environmental interactions between different tree species and mung bean (Vigna radiata (L.) Wilczek) in hedgerow intercropping systems in Sri Lanka. Journal of Agronomy and Crop Science 184: 145-152.

†De Costa, W.A.J.M. and Shanmugathasan, K.N. (1999). Effects of irrigation at different growth stages on the vegetative growth of mung bean (Vigna radiata (L.) Wilczek) in dry and intermediate zones of Sri Lanka. Journal of Agronomy and Crop Science 183: 137-143.

†De Costa, W.A.J.M. and Shanmugathasan, K.N. (1999). Effects of irrigation at different growth stages and source-sink manipulations on  yield and yield components  of mung bean (Vigna radiata (L.) Wilczek) in dry and intermediate zones of Sri Lanka. Journal of Agronomy and Crop Science 183: 111-117.

†De Costa, W.A.J.M., Shanmugathasan, K.N. and Joseph, K.D.S.M. (1999). Physiology of yield determination of mung bean (Vigna radiata (L.) Wilczek) under different irrigation regimes in the dry and intermediate zones of Sri Lanka. Field Crops Research 61: 1-12.

De Costa, W.A.J.M. (1998). Prediction of the effects of drought on grain yield and  radiation use efficiency of rice (Oryza sativa L.) using a simulation model. Journal of the National Science Council of Sri Lanka 26 (2): 101-123.

†De Costa, W.A.J.M. and Perera, M.K.K.W. (1998). Effects of bean population  and row arrangement on the productivity of chilli / dwarf bean (Capsicum annuum / Phaseolus vulgaris L.) intercropping in Sri Lanka. Journal of  Agronomy and Crop  Science 180: 53-58.

Hettiarachchi, M.P., De Costa, W.A.J.M. and Jayasekara, S.J.B.A. (1998). Factors responsible for productivity of food legumes: Findings of a farmer survey in the Kurunegala District, Sri Lanka. Tropical Agricultural Research and Extension 1 (2): 165-168.

†De Costa, W.A.J.M., Dennett, M.D., Ratnaweera and U. Nyalemegbe, K. (1997). Effects of different water regimes on field-grown determinate and indeterminate faba bean (Vicia faba L.). I. Crop development, canopy growth and dry matter production. Field Crops Research  49: 83-93.

†De Costa, W.A.J.M., Dennett, M.D., Ratnaweera, U. and Nyalemegbe, K. (1997). Effects of different water regimes on field-grown determinate and indeterminate faba bean (Vicia faba L.). II. Seed yield, yield components and harvest indices. Field Crops Research 52: 169-178.

De Costa, W.A.J.M., Becher, M. and Schubert, S. (1997). Effects of water stress and its relief on nitrogen fixation of common bean (Phaseolus vulgaris L.). Journal of the National Science Council of Sri Lanka 25 (2): 83-94.

De Costa, W.A.J.M. and Liyanage, L.P. (1997). Effects of potassium and water availability on water use efficiency of different varieties of common bean (Phaseolus vulgaris L.). Journal of the National Science Council of Sri Lanka 25 (4): 241-254.

Shanmugathansan, K.N., De Costa, W.A.J.M. and Joseph, K.D.S.M. (1996). Effects of irrigation at different growth stages on yield and yield components of soybean (Glycine max (L.) Merr.) grown in the low country dry zone of Sri Lanka. Tropical Agricultural Research  8: 1-10.

Ranasinghe, R.A.D.T.K., De Costa, W.A.J.M. and Sangakkara, U.R. (1996). Productivity of intercropped maize (Zea mays) x yard-long bean (Vigna unguiculata) as affected by planting time and variety of the legume. Tropical Agricultural Research  8: 11-19.

De Costa, W.A.J.M and Ariyawansa, S.K. (1996). Effects of water stress on water use efficiency of different varieties of common bean (Phaseolus vulgaris L.). Journal of the National Science Council of Sri Lanka 24 (4): 253-266.

De Costa, W.A.J.M. and De Zoysa, G.J.K. (1995). Effects of Water Stress on Root and Shoot Growth of Soyabean (Glycine max (L) Merill) and Rice (Oryza sativa). Sri Lanka Journal of Agricultural Science 32: 134-142.

Thattil, R.O. De Costa, W.A.J.M. Ubayasena, W.L.C. and L.L.U.L. Alwis (1994). Investigation of optimum spacing in Bush Bean (Phaseolus vulgaris) using a two-way parallel row systematic spacing design. Sri Lanka Journal of Agricultural Science 31: 93-103.

†Dennett, M.D., Nyalemegbe, K. and De Costa, W.A.J.M. (1993). Growth, water use and nitrogen fixation of determinate and indeterminate cultivars of Vicia faba L. under contrasting soil moisture regimes. Aspects of Applied Biology 34: 269-278.

De Costa, W.A.J.M. and Dennett, M.D. (1992). Is canopy light extinction coefficient a species-specific constant? Tropical Agricultural Research 4: 123-137.

Thattil, R.O. and De Costa, W.A.J.M. (1988). A spacing experiment on Maize x Mung Bean intercropping system using a three-way systematic design. Tropical Agriculturist 144: 109-122.

 

BOOK CHAPTERS, BOOKS & MONOGRAPHS

• Text books
  
  De Costa, W.A.J.M. (2001).  Plant Water Relations: Principles and Applications.  576 pp.  [ISBN 955-96814-4-3].  (2^nd Printing in 2004).
  
  De Costa, W.A.J.M. (2000). Principles of Crop Physiology: Towards an Understanding of Crop Yield Determination and Improvement.  545 pp. [ISBN 955-96814-1-9].  (2^nd Printing in 2004).
  
   
• Other books
  
  De Costa, W.A.J.M. (1999). Climate Change: Impact on Agriculture and Forestry. 137 pp. [ISBN 955-96814-0-0]
  
  De Costa, W.A.J.M. (2000). Acacia: A Highly Versatile Set of Multipurpose Tree Species. 33 pp. [ISBN 955-96814-2-7]
  
  Hettiarachchi, M.P., De Costa, W.A.J.M. and Jayasekara, S.J.B.A. (2000). An Evaluation of the Success of Varietal Improvement Programmes of Selected Food Legumes in Sri Lanka. 158 pp. [ISBN 955-96814-3-5]
  
   
• Book Chapters

   

  De Costa, W.A.J.M. (2020).  Increasing climate resilience of cropping systems in Sri Lanka.  (In) Agricultural Research for Sustainable Food Systems in Sri Lanka, R.P. De Silva et al. (Eds): Springer Nature (Singapore). pp. 107-157. ISBN: 978-981-15-3672-4, 470089_1_En, (6).

   

  De Costa, W.A.J.M. and Weerathunga, W.A.M.T. (2017).  Climate financing: an emerging avenue for the banking sector of Sri Lanka. (In) The 29^th Volume of the Anniversary Convention of the Association of Professional Bankers – Sri Lanka. Volume 29: pp. 55-76.  

  http://www.apbsrilanka.org/articales/29_ann_2017/4_29th_conv_a_Prof. W. A. J. M. De Costa.pdf.

   

  De Costa, W.A.J.M. (2011).  Integrated Development through Advances in Science and Technology: Essential Insights for Bankers.  (In) Banking Foresight; Shaping Integrated Development.  Publication to Commemorate The 23^rd Anniversary Convention of the Association of Professional Bankers – Sri Lanka. pp. 67-88. Association of Professional Bankers, Colombo [ISBN 978-955-1095-08-6].  

   

  De Costa, W.A.J.M., Mohotti, A.J. and Wijeratne, M.A. (2009).  Tea: Ecophysiology of Growth and Production.  (In) Ecophysiology of Tropical Tree Crops.  Fabio DaMatta (Ed), pp. 325-368. Nova Science Publishers, New York, USA. [ISBN 978-1-60876-392-4]

   

  De Costa, W.A.J.M., Chandrapala, A.G., Surenthran, P and Dharmasiri, L.G.N. (2008).  A case study on the potential of contour hedgerow intercropping for sustainable crop production on sloping highlands in humid and sub-humid zones of Sri Lanka.  (In) Ecological Basis of Agroforestry.  D.R. Batish, R.K. Kohli, S. Jose and H.P. Singh (Eds).  pp. 109-155. Taylor & Francis Publishers, Boca Raton, Florida, USA.  [ISBN-978-1-4200-4327-3]

  
  De Costa, W.A.J.M., Amaratunge, K.S.P. and Udumullage, R.S. (2006).  Transpiration characteristics of some homegarden tree species in Central Sri Lanka.  (In) Tropical Homegardens: A Time-Tested Example of Sustainable Agroforestry..  B.M. Kumar and P.K.R. Nair (Eds). pp. 251-267.  Springer Science, Dordrecht, The Netherlands. [ISBN-978-1-4020-4947-7]
  
  De Costa, W.A.J.M. (2000).  Chloroxylon swietenia.  (In) Forestry Compendium, Global Edition. CAB International, Wallingford, UK.
  
  De Costa, W.A.J.M. (2000).  Erythrina subumbrans.  (In) Forestry Compendium, Global Edition. CAB International, Wallingford, UK.
  
  De Costa, W.A.J.M. (1999). Curriculum development in Agriculture: A case study from Sri Lanka. (In) Towards a Shared Vision for Higher Education: Cross-cultural insights and projects - Volume II. (Eds). S. Amini, M. Fremerey and M. Wesseler. pp. 121-144. Institute for Socio-Cultural & Socio-Economic Studies, University of Kassel, Germany. [ISBN 3-88122-839-X]
  
   
• Commissioned Reports
  
  Waidyanatha, U.P. de S., De Costa, W.A.J.M., Weerahewa, H.L.J., Karunanayake, L. (2017).  Review of Research and Development of the Rubber Research Institute of Sri Lanka. Consultant Report prepared for the Rubber Research Institute of Sri Lanka. 124 pp.
  
  Waidyanatha, U.P. de S., De Costa, W.A.J.M., Sanderatne, N.H., Marambe, B. and Fernando, B.R.L. (2010).  Review of Research and Development of the Department of Agriculture, Sri Lanka. Consultant Report prepared for the National Research Council, Presidential Secretariat, Government of Sri Lanka. 218 pp.
  
  De Costa, W.A.J.M. (2003).  Review of Activities of the Science and Technology Institutions of Sri Lanka.  Specialist Consultant Report prepared for the National Science and Technology Commission, Ministry of Scientific Affairs, Sri Lanka.  366 pp.
   
• Edited Conference Proceedings
  
  De Costa, W.A.J.M., Nissanka, S.P., Mohotti, A.J. and Weerakoon, W.M.W. (2009).  Proceedings of the First National Conference on Global Climate Change and Its Impacts on Agriculture, Forestry and Water in the Tropics. 10 – 11 September 2009, Kandy, Sri Lanka. The CDM Study Centre, University of Peradeniya, Sri Lanka.  58 pp.
  
  De Costa, W.A.J.M. (2008).  Crop Science Student Research Abstracts.  Proceedings of the Final Year Students Research Session.  Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Peradeniya. 116 pp.
  
  Eeswara, J.P., De Costa, W.A.J.M., Weerakkody, W.A.P. and Pushpakumara, D.K.N.G. (2007).  Crop Science Student Research Abstracts.  Proceedings of the Final Year Students Research Session.  Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Peradeniya. 118 pp.
  
  Marambe, B., Sangakkara, U.R., De Costa, W.A.J.M. and Abeysekara, A.S.K. (2007).  Proceedings of the 21^st Asian Pacific Weed Science Society (APWSS) Conference, 2-6 October 2007, Colombo, Sri Lanka.  706 pp.
  
  Gunasena, H.P.M. and De Costa, W.A.J.M. (2002).  (Eds.) Recent Developments in Conservation and Use of Medicinal Plants.  Proceedings of the Eleventh Workshop on Multi-Purpose Trees. 24 July, 2002, Kandy, Sri Lanka.  [ISBN 955-9224-05-0]
   

CONFERENCE PROCEEDINGS

• Full length papers in peer-reviewed conference/symposium proceedings
  
  Pathiranage, S.R.W., Wijeratne, M.A. and De Costa, W.A.J.M. (2019). Evaluation of the impacts of mechanical harvesting on tea yield (Cultivar TRI 2027) in the low country of Sri Lanka In: Proceedings of the seventh symposium on plantation crop research (2). Towards achieving sustainable development goals in the plantation sector. Rodrigo, V.H.L., Wijesuriya, B.W., Edirisinghe, D.G. and Nayanakantha, N.M.C. (Eds). Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta. pp 79-86.
  
  Pathiranage, S.R.W., Wijeratne, M.A. and De Costa, W.A.J.M. (2018).  Physiological effects of mechanized harvesting of tea and ways to overcome its impacts.  pp. 29-42.  (In) K.M. Mohotti (Ed), Proceedings of the 236^th Meeting of the Experiments and Extension Forum, Tea Research Institute of Sri Lanka. 3^rd August, 2018, Talawakelle, Sri Lanka.  
  
  De Costa, W.A.J.M. (2016).  Impacts of climate change on the long-term variation in the water balance of different rainfall seasons in selected locations in Sri Lanka. pp. 335-349. (In) S.P. Nissanka and U.R. Sangakkara (Eds.) Proceedings of the First National Conference on Global Climate Change and its Impacts on Agriculture, Forestry and Water in the Tropics. 10-11 September 2009, Kandy, Sri Lanka. 
  
  Pathiranage, S.R.W., Wijeratne, M.A. and De Costa, W.A.J.M. (2016). Physiological aspects governing yield variation under manual and mechanical harvesting of clonal tea. In: Proceedings of the sixth symposium on plantation crop research. Plantation agriculture towards national prosperity. V.R.M.Vidanaarachhi, Herath, H.M.I.K., M.K. Meegahakumbura, A.D.N.T. Kumara and M.K.F.Nadeesha (Eds.). Coconut Research Institute, Lunuwila, Sri Lanka. pp 93-100.
  
  Weerakoon, W.M.W. and De Costa, W.A.J.M. (2016).  Impact of climate change on rice production in Sri Lanka.  pp. 41-64. (In) S.P. Nissanka and U.R. Sangakkara (Eds.) Proceedings of the First National Conference on Global Climate Change and its Impacts on Agriculture, Forestry and Water in the Tropics. 10-11 September 2009, Kandy, Sri Lanka. 
  
  Silva, T.U.K., Senevirathna, A.M.W.K., Seneviratne, P., De Costa, W.A.J.M., Samarasekara, R.K. and Deshapriya, H.A.U. (2016).  Impact of different latex harvesting systems on bark consumption, yield and economic lifespan of rubber plantations in Sri Lanka.  pp. 125 - 133.  (In) Proceedings of the sixth symposium on plantation crop research. Plantation agriculture towards national prosperity. V.R.M.Vidanaarachhi, Herath, H.M.I.K., M.K. Meegahakumbura, A.D.N.T. Kumara and M.K.F.Nadeesha (Eds.). Coconut Research Institute, Lunuwila, Sri Lanka.
  
  Wijeratne, T.L., De Costa, W.A.J.M. and Wijeratne, M.A. (2014).  Carbon sequestration potential of tea plantations in Sri Lanka as an option for mitigating climate change; a step towards a greener economy.  pp. 205 - 212.  (In) A. P. Keerthipala (Ed.) Proceedings of the Fifth Plantation Crop Research - "Towards a Green Plantation Economy", 15-17 October 2014, Colombo.  Sugarcane Research Institute, Uda Walawe, 70190, Sri Lanka.
  
  Bandara, N.P.S.N., Nuberg, I.K. and De Costa, W.A.J.M. (2014). Rain partitioning in a low-elevation tea field in Sri Lanka: Understanding the interception and evaporation losses in tea fields.  pp. 99 - 104.  (In) A. P. Keerthipala (Ed.) Proceedings of the Fifth Plantation Crop Research - "Towards a Green Plantation Economy", 15-17 October 2014, Colombo.  Sugarcane Research Institute, Uda Walawe, 70190, Sri Lanka..
  
  De Costa, W.A.J.M., Murray-Tortarolo, G., Harper, A. and Sitch, S. (2013).  Capacity for carbon sequestration and climate change mitigation in different ecologically-distinct zones of Sri Lanka.  (In) Proceedings of the International Conference on Climate Change Impacts and Adaptations for Food and Environment Security – “Sustaining Agriculture under Changing Climate”, 30 – 31 July 2013, Colombo, Sri Lanka.  pp. 137 – 151.  H.P.M. Gunasena, H.A.J. Gunathilake, J.M.D.T. Everard, C.S. Ranasinghe and A.D. Nainanayake (Eds.) Coconut Research Institute, Lunuwila, Sri Lanka.
  
  Sitch, S. Mercado, L., Anav, A., Murray-Tortarolo, G. and De Costa, W.A.J.M. (2013).  Changes in climate, atmospheric composition and land-atmosphere interactions across the South-Asian Region.  (In) Proceedings of the International Conference on Climate Change Impacts and Adaptations for Food and Environment Security – “Sustaining Agriculture under Changing Climate”, 30 – 31 July 2013, Colombo, Sri Lanka.  pp. 21 – 37.  H.P.M. Gunasena, H.A.J. Gunathilake, J.M.D.T. Everard, C.S. Ranasinghe and A.D. Nainanayake (Eds.) Coconut Research Institute, Lunuwila, Sri Lanka.
  
  De Costa, W.A.J.M., Suranga, H.R. and Wahala, W.M.P.S.B. (2011).  Estimated carbon sequestration rates of selected tropical lowland wet evergreen forests of Sri Lanka.  Proceedings of the International Conference on the Impact of Climate Change on Agriculture, 20 December, 2011.  (Eds.) M. Wijeratne, N.S.B.M. Atapattu, W.W.D.A. Gunawardena, P.W.A. Perera and N.Y. Hirimuthugoda.  pp. 264-274.  Faculty of Agriculture, University of Ruhuna, Sri Lanka.
  
  Karthika, S. and De Costa, W.A.J.M. (2011).  Impacts of climate change on the annual and seasonal water balance of selected locations representative of different agro-ecological regions of Sri Lanka.  Proceedings of the International Conference on the Impact of Climate Change on Agriculture, 20 December, 2011.  (Eds.) M. Wijeratne, N.S.B.M. Atapattu, W.W.D.A. Gunawardena, P.W.A. Perera and N.Y. Hirimuthugoda.  pp. 183-192.  Faculty of Agriculture, University of Ruhuna, Sri Lanka.
  
  H.I.U. Caldera, De Costa, W.A.J.M., Wijeratne, M.A. and Ranwala, S.M.W. (2011).  Response of stomatal characters of Sri Lankan tea cultivars to environmental change.  Proceedings of the International Conference on the Impact of Climate Change on Agriculture, 20 December, 2011.  (Eds.) M. Wijeratne, N.S.B.M. Atapattu, W.W.D.A. Gunawardena, P.W.A. Perera and N.Y. Hirimuthugoda.  pp. 114-123.  Faculty of Agriculture, University of Ruhuna, Sri Lanka.
  
  Wijeratne, T.L., De Costa, W.A.J.M., Woodward, F.I., Lomas, M. and Wijeratne, M.A. (2011).  Predicted impacts of climate change on the tea yields of different elevation zones of Sri Lanka during the 21^st century.  Proceedings of the International Conference on the Impact of Climate Change on Agriculture, 20 December, 2011.  (Eds.) M. Wijeratne, N.S.B.M. Atapattu, W.W.D.A. Gunawardena, P.W.A. Perera and N.Y. Hirimuthugoda.  pp. 292-301.  Faculty of Agriculture, University of Ruhuna, Sri Lanka.
  
  Gamage, D.A.S., Basnayake, B.F.A., De Costa, W.A.J.M., and Wijewardena, N.K. (2011).  Biochar-coated urea as a slow releasing fertilizer and evaluation of Nitrogen, Phosphorus and Potassium leaching.  Proceedings of the International Conference on the Impact of Climate Change on Agriculture, 20 December, 2011.  (Eds.) M. Wijeratne, N.S.B.M. Atapattu, W.W.D.A. Gunawardena, P.W.A. Perera and N.Y. Hirimuthugoda.  pp. 176-182.  Faculty of Agriculture, University of Ruhuna, Sri Lanka.
  
  Weerakoon, W.M.W., De Costa, W.A.J.M. and Nissanka, S.P. (2010).  Review of the Impacts of climate change on rice in Sri Lanka. (In) pp. 219 - 241. Proceedings of the 4^th Rice Congress, 2-3 December, 2010, Gannoruwa, Sri Lanka. D.M.N. Dissanayake, A.P. Bentota, R.S.K. Keerthisena and D.S. de Z. Abeysiriwardena (Eds). Rice Research and Development Institute, Department of Agriculture, Sri Lanka.
  
  Zahra, A.R.F., De Costa, D.M. and De Costa, W.A.J.M. (2010).  Identification of candidate genes for salt tolerance in rice.  (In) pp. 69 - 97. Proceedings of the 4^th Rice Congress, 2-3 December, 2010, Gannoruwa, Sri Lanka. D.M.N. Dissanayake, A.P. Bentota, R.S.K. Keerthisena and D.S. de Z. Abeysiriwardena (Eds). Rice Research and Development Institute, Department of Agriculture, Sri Lanka.
  Tennakoon, P.L.K., Gunaratne, G.P., De Costa, W.A.J.M. and Hettiarachchi, L.S.K. (2010).  Critical nitrogen (N), potassium (K) and magnesium (Mg) levels for early growth of clonal tea (Camellia sinensis (L.) O. Kuntz) under glasshouse conditions in sand culture.  Proceedings of the 3^rd Symposium on Plantation Crop Research, Colombo, Sri Lanka.  pp. 200-213.
  
  De Costa, W.A.J.M., Wijeratne, M.A., Herath, D.R.K.B.K. Herath and Gamage, A.J. (2008).  Carbon trading and its relevance to the tea industry of Sri Lanka.  Proceedings of the 217^th Experiments and Extension Forum of the Tea Research Institute of Sri Lanka.  pp. 6-24.  Tea Research Institute of Sri Lanka, Talawakelle.
  
  De Costa, W.A.J.M. (2000).  Decomposition and nutrient release from green manures of different tree species in three agroecological zones of Sri Lanka.  (In) Green Manuring and Fodder Tree Species For Crop-Livestock Productivity Improvement. (Ed.) H.P.M. Gunasena. Proceedings of the eleventh regional workshop on multipurpose tree species, Kandy, Sri Lanka. Held on 22 December, 2000. pp. 1-34.
  
  Hitinayake, H.M.G.S.B., De Costa, W.A.J.M., Dharmawardena, M.I.U.D.S. and Wedathanthri, H.P. (2000).  Key ecological features and distribution of plant species showing apparent invasive behaviour at Udawattekele forest reserve.  (In) Proceedings of the Symposium on “Alien Invasive Species of Sri Lanka: Impact on Ecosystems and Management”.  B. Marambe (Ed.).  pp. 51-57.  Ministry of Forestry and Environment and National Agricultural Society of Sri Lanka.
  
  De Costa, W.A.J.M. and Jayaweera, K.G.D. (1996). Radiation use efficiency and above-ground biomass production of selected forest tree species. (In) Management and Sustainable Utilization of Forest Resources. Proceedings of the Second Annual Forestry Symposium, 1996. (Eds. H.S. Amarasekara, D.M.S.H.K. Ranasinghe and W. Finlayson). pp. 96-103. Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
  
  Hitinayake, H.M.G.S.B., De Costa, W.A.J.M. and Jayaweera, K.G.D. (1996). Food trees in multi-layered homegardens in different agro-ecological regions of Kandy district. (In) Multipurpose Trees for Food Security. (Ed.) H.P.M. Gunasena. Proceedings of the seventh regional workshop on multipurpose tree species, Kandy, Sri Lanka. Held on 24-26 October, 1996. pp. 252-264.
  
  Anandacoomaraswamy, A., De Costa, W.A.J.M., Gawarammana, M.D.W. and Navaratna, D.M.S. (1996).  Effect of soil moisture stress on physiological parameters of young tea.  Proceedings of the 193^rd Experiments and Extension Forum of the Tea Research Institute of Sri Lanka.  pp. 17-35.  Published by the Tea Research Board of Sri Lanka.
   
• Abstracts
  
  R.M.C. Madhumali, W.M.P.S.B. Wahala, H.K.N. Sanjeewani, D.P. Samarasinghe, and W.A.J.M. De Costa (2020).  Inter-relationships between canopy openness and vegetation diversity in tropical rainforests of Sri Lanka across a wide altitudinal gradient.  Proceedings of the 10^th Annual Research Session of the Sabaragamuwa University of Sri Lanka, 16 December 2020.  pp. 58.
  
  Wettasinghe, B.T., Caldera, H.I.U., De Costa, W.A.J.M., Sanjeewani, H.K.N., Samarasinghe, D.P., Jayasinghe, H.D. and Wijethunga, W.M.G.A.S.T.B. (2020). Variation of stomatal anatomy of genus Syzygium in tropical forests along an altitudinal gradient in Sri Lanka. Proceedings of the Annual Sessions of the Institute of Biology, Sri Lanka. 25-26 September 2020.  (In Press).
  
  Gunasekara, S.P., Sanjeewani, H.K.L., Samarasinghe, D.P., Madhumali, R.M.C., Suriyagoda, L. and De Costa, W.A.J.M. (2020).  Variation of fine root biomass in Sri Lankan tropical rainforests with altitude.  Proceedings of the Faculty of Agriculture Undergraduate Research Symposium, Faculty of Agriculture, University of Peradeniya. 16 July 2020. pp. 211.
  
  Ranasinghe, R.U.D.A., Sanjeewani, H.K.N., Wijethunga, W.M.G.A.S.T.B., Samarasinghe, D.P., Madhumali, R.M.C. and De Costa, W.A.J.M. (2020).  Variation of wood density in different tree species found in the tropical rainforests in Sri Lanka. Proceedings of the Faculty of Agriculture Undergraduate Research Symposium, Faculty of Agriculture, University of Peradeniya. 16 July 2020. pp. 212.
  
  Wickramasinghe, M.S.K., Abeysiriwardena D.S. De Z., Senadheera, S.A.D.P. and De Costa, W.A.J.M. (2020).  Screening of a diverse range of rice (Oryza sativa L.) genotypes for drought tolerance.  Proceedings of the Faculty of Agriculture Undergraduate Research Symposium, Faculty of Agriculture, University of Peradeniya. 16 July 2020. pp.45.
  
  De Silva, A.L.C., De Costa, W.A.J.M. and Senarathna, H.A.K.N.N. (2019). The varietal variation in photosynthesis and transpiration efficiency at initial growth stage of sugarcane at elevated atmospheric CO₂ and temperature. pp. 99. In: A. Chandra, M. Swapna, R. Manimekalai, P. Singh, A.K. Tiwari and G. P. Rao (ed) Proceedings of the International Conference of Sugarcon-2019, Green Technologies for Sustainable Development of Sugar and Integrated Industries. ICAR-Indian Institute of Sugarcane Research, Lucknow, Uttar Pradesh, India.
  
  Sanjeewani HKN, Samarasinghe DP, Jayasinghe HD, Gardiyawasam PH, Wahala WMPSB, Wijetunga WMGASTB, Ukuwela KDB, Gomes P, and De Costa WAJM (2019). 'Variation in above-ground carbon stock of selected tropical rainforests of Sri Lanka along an altitude gradient', Proceedings of the Rajarata International Research Conference (RIRC 2019), University of Rajarata, Sri Lanka, PG 119, 6-7 November 2019, p199, ISSN 2235-9710.
  
  Sanjeewani HKN, Samarasinghe DP, Jayasinghe HD, Gardiyawasam PH, Wahala S, Wijethunga A, Ukuwela K, and De Costa J (2019). 'Species composition and Diversity in two selected lowland tropical rainforests in Sri Lanka and their relationships to temperature and precipitation', Proceedings of the 24th International Forestry and Environment Symposium, University of Sri Jayewardenepura, Sri Lanka, Volume 24, 11-12 October 2019, p09, ISSN 2235-9427.
  
  De Costa, W.A.J.M., Abhayapala, K.M.R.D., Malaviarachchi, M.A.P.W.K., Kumar, J.B.D.A.P., Fonseka, R.M., Suriyagoda, L.D.B. and De Costa, D.M. (2018).  Impacts of climate-resilient and eco-friendly crop management practices on yields of a representative range of crops grown across a natural temperature gradient in tropical South-Asia.  p. 29, (In) Proceedings of the 2^nd International Conference on Climate Change. E. Lokupitya (Ed.), 15-16 February, 2018, Colombo, Sri Lanka, The International Institute of Knowledge Management, Sri Lanka.
  
  Ragika, P., De Costa, W.A.J.M. and Wijeratne, T.L. (2018). Evaluation of potential high-shade tree species for low-grown tea (Camellia sinensis L.) during the initial plucking stage.  Proceedings of the Faculty of Agriculture Undergraduate Research Symposium, Faculty of Agriculture, University of Peradeniya. 12 January 2018. pp.44.
  
  Senaratne, H.A.K.N.N., De Costa, W.A.J.M. and De Silva, A.L.C. (2018). Response of physiological processes and parameters related to early growth of sugarcane under elevated carbon dioxide and temperature.  Proceedings of the Faculty of Agriculture Undergraduate Research Symposium, Faculty of Agriculture, University of Peradeniya. 12 January 2018. pp.70.
  
  De Costa, W.A.J.M. (2016). Adaptation of Sri Lankan agriculture to climate change: Some thoughts on our strengths and weaknesses.  Proceedings of the Open University Research Sessions – 2016. 17- 18 October 2016, Colombo, Sri Lanka. pp. xv.
  
  Silva, T.U.K.,  Senevirathne, A.M.W.K.,  Senevirathne, P. and Costa, W.A.J.M. (2016). Different latex harvesting systems and their impact on bark consumption and economic lifespan of rubber plantations in Sri Lanka. “International symposium on Agriculture and Environment 2016”, University of Ruhuna, Matara, Sri Lanka. Pp. 33-35.
  
  Malika, L.Y., De Costa, W.A.J.M., Deshabandu, K.H.S.T. and Weerakoon, W.M.W. (2016). Proceedings of the Faculty of Agriculture