Institutional Repository

U n i v e r s i t y of P e r a d e n i y a

The Institutional Repository of the University of Peradeniya is the University's digital gateway to scholarly knowledge and research excellence. Established as the next phase of the Digital Library initiative launched by the University Library in 2011, it preserves, showcases, and provides open access to the intellectual output of the University community.

Through a rich collection of research articles, conference proceedings, theses, dissertations, and other scholarly works, the repository enhances the visibility, accessibility, and long-term preservation of knowledge, extending the global reach and impact of the University of Peradeniya’s academic and research contributions.

Photo by @ITD,Main Library

Communities in DSpace

Select a community to browse its collections.

Now showing 1 - 5 of 5

Recent Submissions

Phylogenetic analysis of indigenous dwarf cattle population in Sri Lanka
(University of Peradeniya, Sri Lanka, 2023-09-20) Silva, G.L.L.P.; Wijebandara, K.G.C.B.; Kurukulasuriya, M.S.
The Sri Lankan indigenous cattle population is under a threat of genetic admixing in the context of production-oriented breeding policies. Genetic differentiation of existing populations and identifying the uniqueness are important for the sustainable utilization of the indigenous genetic resources in attempts taken to curb loosing adaptive genetic characteristics of house populations. Hence, this research was conducted to construct phylogenetic structure to identify the placement of the phenotypically short, local non descriptive cattle population in Northern Province of Sri Lanka (Northern Local Cattle; NLC) compared to selected Sri Lankan local cattle populations and different populations of genus Bos. A total of 11 DNA sequences with 708 bases long segments of mtDNA D-loop region were generated from genetically unrelated Sri Lankan local cattle populations which includes five samples of NLC population, three samples of Lankan cattle and three samples of Thawalam cattle. Molecular variance analysis recorded 14 variable sites among local cattle populations producing eight singleton variable sites and six parsimony informative sites. Six of the eight singleton variable sites were unique to NLC population which is relatively a high polymorphism. The 11 DNA sequences of local cattle were aligned with 23 cattle D-loop sequences from countries in the region available in the National Center for Biotechnology Information database to analyze evolutionary development and diversification. The phylogenetic tree assigned the NLC population under the distinct clade of Bos indicus with close evolutionary divergence of two South Indian dwarf cattle populations (Kasaragod and Trinket) which are in geographical proximity with each other. This observation suggests a genomic inheritance of NLC population could be traced back to South Indian cattle. Thus, the clearly distinguishable short body morphology in NLC population might be a result of their genomic inheritance from the South Indian dwarf cattle populations as well as the generations of isolated breeding.
Evaluation of impact of climatic factors on tea yield -a case study in Badulla Region
(University of Peradeniya, Sri Lanka, 2023-09-20) Samarakoon, T.S.M.D.M.; Jeewanthi, P.W.; Ranawana, S.R.W.M.C.J.K.
Tea, Camellia sinensis is a perennial plant grown for decades sustaining various climatic conditions. The physiological activities of tea plants, including their growth and development, are significantly influenced by climatic parameters such as rainfall, temperature, sunshine hours, and relative humidity. Responses of tea plants for climatic parameters vary region wise. Therefore, this study was carried out to determine the impact of climatic parameters on tea yield in the Badulla region. Thirty years of climate and tea yield data were collected from Ury Estate, Badulla, and TRI Advisory and Extension Center, Uva and trend analysis was performed to determine changes in tea yield in response to climatic parameters. Lag periods were taken into consideration to analyze the effect of climatic conditions from previous months on tea yield. Three models were developed for green leaf yield, using Multiple Linear Regression, Generalized Linear Model, and Deep Learning. The linear relationship between tea yield and climatic parameters was identified through correlation analysis. The trend analysis showed significant trends with respect to different climatic parameters. Both green leaf and made tea yields have decreased over the years, due to climate change. Sunshine hours gave the highest positive correlation at a 5% significance level (P ≤ 0.05) with both green leaf and made tea yield (r = 0.40 and r = 0.45). Average temperature also showed correlations (r= 0.336 and r=0.383) with green leaf and made tea yield respectively. Of the three models developed, the Deep Learning model demonstrated the best performance, exhibiting the least error value and the highest correlation (r=0.73) between actual and fitted values. Hence this model can be effectively utilized to predict tea yields based on changes in climate parameters of the studied locations of this study.
Impact of threshing method on black pepper pericarp and processing procedures on fungal infection of black pepper (Piper nigrum L.)
(University of Peradeniya, Sri Lanka, 2023-09-20) Lakmali, H.M.R.P.; Liyanage, T.; Subasinghe, H.M.P.A.; Kirthisinghe, J.P.
Black pepper (Piper nigrum L.) can be used in human foods for flavoring, and to incorporate aroma. Good Agricultural Practices can reduce the toxigenic fungi growth and dissemination in the post-harvest process of black pepper. Mechanical damage to the plant material during post-harvest manipulation may increase the possibility of subsequent fungal contamination. Therefore, the study aimed to find the damage percentage of the black pepper fruit's pericarp due to the facilitation of different threshing methods and the potential of fungal infections on black pepper due to the facilitation of different processing procedures in the processing chain. Three types of threshing methods, two types of blanching, and two types of drying methods were used as treatments. To determine the damage percentage of the black pepper, physical counting was used and to determine the fungal infection rate, the Serial dilution method and agar plate method were used. Minimum pericarp damage (17.62%) resulted in the hand-picked sample and maximum pericarp damage (93.89%) resulted in machine threshed sample. The fungal infection rate was significantly lower (1.4 x 104 Colony forming units/ml) in hand-picked samples compared to other treatments (Foot Threshed: 1.5 x 104 Colony forming units/ml, Machine Threshed: 4.6 x 104 Colony forming units/ml), because the damage to the spikes and the pericarp of the pepper fruits were minimal. The fungal infection rate was significantly higher in sun-dried and without-blanched samples as it took much time to dry the pods (Sun-dried- without blanching: 4.7 x 104 colony forming units/ml and machine-dried and blanched: 0.22 x 104 colony forming units/ml). Therefore, hand threshing, blanching, and machine drying were the best practices in the black pepper processing chain. If practiced machine threshing and foot threshing, it is essential to follow blanching and machine drying to minimize fungal infection.
Acceptability of liquid fertilizer produced from sewage sludge in wastewater treatment plants by Sri Lankan community
(University of Peradeniya, Sri Lanka, 2023-09-20) Perera, B.S.Y.; Sajitthan, S.; Witharana, A.; Rajapakse, E.P.; Illangasinghe, I.M.W.K.
Wastewater recycling is an important resource efficiency pillar in a sustainable city. Several countries are resolving the safe senatorial issue with the expansion of wastewater treatment while introducing a new issue on the handling and disposal of sewage sludge (SS). Hydrothermal carbonization (HTC) is a thermochemical technique for processing high moisture biomass at a specified temperature and autogenous pressure. This study investigates the social acceptability of liquid fertilizer from hydrothermal carbonization of SS (LFHTC) by Sri Lankan community. A questionnaire survey was used to collect relevant data from selected organic fertilizer distributors/sellers, users of organic and chemical fertilizers, and organic food consumers who represent the community after conducting a stakeholder analysis. The purposive sampling method was used. A total of 105 responses were received from 3 categories of respondents. Furthermore, the reasons for accepting or rejecting the LFHTC in the market, as well as the properties that need to be included in LFHTC for commercialization, were explored. The responses were as: 75% of organic fertilizer distributors accept future sales of the LFHTC, 84% of fertilizer users show the acceptance of using LFHTC for their cultivations, and 74% of organic food consumers show willingness to consume foods made with LFHTC. The highest percentage of fertilizer distributors/sellers have accepted considering that LFHTC would be an environmentally friendly product. Based on the responses of fertilizer users, the highest percentage of them accepted that the LFHTC would be environmentally friendly and its practices in other countries has produced successful outcomes. The distributors/sellers and users who have rejected the LFHTC, believed the lack of trust in the quality of the SS product. Also, the survey results emphasized that fertilizer users pay too much attention on fertilizer properties such as the nutrient level (N, P, K) when purchasing, the easiness of use and the price.
Evaluating the effect of soil amendments to reduce ralstonia solanacearum population density in a potato-cultivated soil in the up country intermediate zone (IU3) of Sri Lanka
(University of Peradeniya, Sri Lanka, 2023-09-20) Rajapakshe, B.N.K.; Ranasinghe, C.; Chathuranga, K.P.H.; De Costa, D.M.
Reducing the initial inoculum density of the pathogen, Ralstonia solanacearum in soil is an effective strategy to control the bacterial wilt of potato. The present study evaluated the potential of locally available soil amendments for reducing the density of R. solanacearum in potato-grown soils reported to have wilt infection. Four soil amendments were used namely half-burn paddy husk, rice husk biochar, and radish and mustard plant residues at a rate of 2 kg/m2 on fresh weight basis. Fresh wild sunflower (Tithonia diversifolia) leaves (2 kg/m2) with Urea (20 g/m2) and CaO (200 g/m2 ) was used as an already identified soil amendment effective for wilt pathogen. A treatment with no soil amendment served as the control. Potato var. Granola was planted two weeks after the incorporation of the soil amendments. The field experiment was arranged as a randomized block design with three replicates. Soil samples were collected five times (i.e. before the addition of soil amendments, at the time of planting, and one, two, and three months after planting (i.e. harvesting)) and plated on TZC medium by dilution plate technique. The virulent pathogen density in soil was calculated based on the colony morphology of R. solanacearum on the TZC medium. The density of the virulent R. solanacearum in soil varied significantly (p<0.05) due to the interaction effect of sampling times and treatments. Half-burn paddy husk, Tithonia+ Urea + CaO (TUC) and radish residues reduced the virulent pathogen density significantly from the time of planting until the harvesting stage. At harvesting, the lowest pathogen density was reported by the TUC amendment. Mustard residues reduced the pathogen density from one month after planting. Rice husk biochar significantly reduced the pathogen density, except for two months after planting. The study confirmed the tested soil amendments' effectiveness in reducing bacterial wilt.