Browsing by Author "Ratnayake, R. M. C. S."

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Addition of two Trichoderma species with organic fertilizer paste - A boon for crop yield of Abelmoschus esculentus L. cv. MI 5
(Faculty of Graduate Studies, University of Kelaniya Sri Lanka, 2022) Kalpani, N. N.; Kannangara, B. T. S. D. P.; Ratnayake, R. M. C. S.
Sustainable agriculture is a farming technique that minimizes environmental impacts while providing a tenable yield. The use of organic amendments as an alternative to inorganic treatments has more significant potential to establish a self-sustaining, less expensive, and environmentally friendly agricultural system. The amalgamation of organic fertilizer with bio-controlling microorganisms is more beneficial than individual application in cropping land to enhance crop productivity. The present study was aimed to examine the influence of an organic fertilizer paste enriched with Trichoderma spp. to enhance the growth performances and yield of Abelmoschus esculentus L. cv. MI 5. The organic fertilizer paste was prepared by aerobic digestion of air-dried and powdered immature twigs of the following plants; Annona glabra, Clidemia hirta, Chromolaena odorata, and Pongamia pinnata (2.0 kg each) in distilled water (42.0 L) for a month. Bio-controlling agents Trichoderma harzianum (KT852821.1) and Trichoderma virens (KP985643.1) were formulated in solid carrier material (compost, straw, clay, and cow urine; 2:1:1:1) separately. The pot trial consisted of six treatments of liquid organic fertilizer enriched with Trichoderma spp. (T10H, T10V, T20H, T20V, T25H, and T25V, where 10, 20, and 25 denote 10%, 20%, and 25% of C. odorata, A. glabra, C. hirta, and P. pinnata extract combined with H as T. harzianum and V as T. virens) with 15 replicates in a completely randomized block design. One-week-old A. esculentus L. cv. MI 5 seedlings were soil treated for 3 months (1st week - 5 mL, 2nd week - 10 mL, 3rd week - 15 mL, 4th week - 20 mL, and 100 mL). The positive and negative controls were commercial fertilizer (Maxicrop) and tap water, respectively. Shoot growth performances, root growth performances, average fresh weights, and average dry weights, and the amount of harvest of A. esculentus L. cv. MI 5 were measured after 3 months of the plantation. One-way ANOVA statistical method, along with Tukey’s multiple comparison tests were used to identify the significant differences (P≤0.05) in growth parameters among treatments using MINITAB (Version 17). T10H treatment (10 % diluted C. odorata, A. glabra, C. hirta, and P. pinnata extract only incorporated with T. harzianum) recorded significantly (P≤0.05), the highest average plant shoot height (163.6±5.40 cm), number of leaves (39±2), stem circumference (5±0.19 cm), average leaf area (309.56±1.2 cm2), root length (38±2.20 cm), the girth of the root (5.24±0.32 cm), number of lateral roots (59±2.08), fresh weight of the entire plant (146.13±16.79 g/plant), fresh weight of the root (35.53±5.82 g/plant), average dry weight of the whole plant (17.61±1.79 g/plant), dry weight of the shoot biomass (13.1±1.42 g/plant), dry weight of the root biomass (4.19±0.09 g/plant), the average number of pods per plant (30±0.24), and average fresh weight of pods (39.83±2.14 g). Therefore, T10H treatment can be successfully used as the best organic fertilizer paste enriched with T. harzianum to enhance the growth and yield of Abelmoschus esculentus L. cv. MI 5.
Allelopathic effects of Prosopis juliflora (Sw.) Dc. on selected crops and native plants
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Jayasinghe, J. A. C. P.; Ratnayake, R. M. C. S.
Allelopathic effects of exotic plant species in natural and agricultural ecosystems have received increasing attention because of their negative impacts on native plant growth and reduction of crops yields. It was hypothesized that leaf extracts of P. juliflora have allelochemicals that could inhibit seed germination and seedling growth of the selected plants. The objective of the study was to investigate the allelopathic effects of the Prosopis juliflora leaves on seed germination and seedling growth of selected crops (Eleusine coracana, Vigna radiata) and native plants (Manilkara hexandra, Calophyllum inophyllum). The stock extract (100 gL-1) was preparedfrom P. juliflora leaves collected from Bundala National Park after five days of digestion in deionized water. The stock solution was used to prepare dilution series for applications (10.0 gL-1, 25.0 gL- 1, 50.0 gL-1, and 75.0 gL -1). The above concentrations of P. juliflora leaf extracts were separately tested for percentage seed germination, shoot lengths, root lengths, and seedling growth of the selected plant species with distilled water as the control. Seed germination percentages, root lengths, and shoot lengths results of the test species were analyzed using One-way ANOVA followed by Tukey’s test at p=005. The findings indicate that with the increasing concentration of P. juliflora leaf extracts, seed germination and seedling growth of E. coracana, V. radiata were significantly reduced. The negative effects were more visible in E. coracana than V. radiata. The lowest germination percentage of E. coracana (0.0 %) was observed when seeds were treated with 100 gL-1 and 75 gL-1 and C. inophyllum seeds were also not germinated in those concentrations. Manilkara hexandra seeds were not germinated in all concentrations of P. juliflora leaf extracts. Allelopathy was concentration-dependent and with increasing concentration of P. juliflora leaf extract, seed germination and seedling growth of C. inophyllum significantly reduced (One-way Anova, p=0.05). Hence it showed that Prosopis juliflora aqueous leaf extracts have an allelopathic effects on the seed germination and seedling growth of the selected crops and the native plants. Therefore, allelopathic effects of the aqueous leaf extracts P. juliflora need to consider in forest management and agriculture.
Analysis of the spatial relationship between land surface temperature and vegetation cover in Gampaha District, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Amarasooriya, A. B. C. I.; Ratnayake, R. M. C. S.; De Silva, W.
Land Surface Temperature (LST) provides important information about the land surface’s physical properties and climate. Natural phenomena and anthropogenic activities, particularly urbanization, can alter LST. Besides, population increase, and urbanization are among the most widely reported drivers of vegetation cover change. As such, it is essential to investigate vegetation cover changes to identify vulnerable areas and implement sustainable management strategies to protect the environment. The present study evaluated the relationship between LST on vegetation change in the Gampaha district. Landsat 8 OLI /TIRS data of the study area from 2013 to 2015 were utilized to prepare vegetation maps and investigate LST. The thermal infrared bands of Landsat 8 were used to calculate the LST. Normalized Difference Vegetation Index (NDVI) was used to explore the vegetation change of the study areas. The result revealed that LST increased from 2013 to 2015. The maximum LST was reported from areas surrounding the Gampaha city (i.e., the maximum temperatures for 2013 and 2015 were 30.63°C and 35.02°C, respectively). The highest NDVI values reported for 2013 and 2015 were 0.62 and 0.52, respectively. Vegetation cover types of Gampaha district were classified into three categories based on the NDVI values (i.e., -0.1 to 0.2 non-vegetation, 0.2 to 0.3 sparse vegetation and 0.3 to 0.6 moderate vegetation). Interestingly, the current study revealed considerable changes in areas of vegetation cover classes over the study period. In 2013, the study area was found to be dominated by moderate vegetation (67.16 %) followed by sparse vegetation (27.92 %) and nonvegetation (4.92 %). However, between 2013 to 2015, the extent of moderate vegetation significantly declined from 67.16 % to 61.67 %, whereas sparse vegetation increased significantly from 27.92 % to 32.03 % (p < 0.01). Correlation analysis revealed a negative correlation between NDVI and LST, suggesting an increase in LST resulting in the decline of the vegetation cover change in Gampaha district. The results of this study may support urban planners, and respective authorities in making appropriate decisions to mitigate the environmental impacts of urban development activities in Gampaha district.
Anatomy and chromium tolerance of green leafy vegetable, Alternanthera sessilis and its sympatric weed, Alternanthera philoxeroides
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Siriwardhana, K. H. W.; Ratnayake, R. M. C. S.
Heavy metals can be readily taken up by crop roots and can be accumulated at high levels in edible parts. Elevated levels of heavy metal in edible parts of vegetables can affect human health. Some food plants in Sri Lanka act as hyper-accumulators. Alternanthera sessilis (“Mukunuwenna”) is a commonly used leafy vegetable and its co-species Alternanthera philoxeroides (“Alligator weed”) is a weed and known as hyper-accumulators. A. sessilis bunches available in vegetable markets are commonly mixed with A . philoxeroides. Chromium (Cr) is a heavy metal and its maximum allowable limit in food is 2.3 mg/kg (FAO/WHO). The objectives of the present study were to determine the ability to tolerate chromium in A . sessilis and A . philoxeroides and their anatomical variations. Pot experiments were done by growing healthy plantlets of both Alternathera species in garden soil treated with Cr concentrations of 0, 10, 15, 20, 30 and 40 mg/kg. 30 pots per treatment were used and three plants were planted in each pot. Growth parameters of plants were measured after two weeks. All the data obtained were statistically analyzed using MINITAB (Version-18) statistical software package. The one way analysis of variance (ANOVA, p < 0.05), Tukey’s pairwise comparison tests was employed to make out the significant differences. While A . philoxeroides bear hollow cylinder in their stems, A . sessilis stems are filled with pith cells. In leaves, clustered vascular bundles are seen in A . philoxeroides, whereas single isolated vascular bundles are seen in A . sessilis . While the highest shoot height and fresh weight of A . sessilis were at 15 mg/kg Cr concentration, that of A . philoxeroides were recorded at 20 mg/kg Cr treatment. In A . philoxeroides, the highest internode length was recorded at the 20 mg/kg of Cr treatment. But, in A . Sessilis, the highest internode length was recorded in the control. Although the plant growth of two Alternanthera species was increased with increasing Cr in soil, above 40 mg/kg of Cr causeed growth reduction in both species. While chlorosis of the plants was recorded in A . sessilis, wilting of plants were observed in A . philoxeroides at 40 mg/kg of Cr concentrations. Interestingly, A . philoxeroides showed a higher level of Cr tolerance without a considerable growth reduction compared to A . sessilis . As A . philoxeroides grows healthier than A . sessilis in an environment with high levels of Cr, it may be of health risk if A . philoxeroides is being consumed due to the possibility of accumulated Cr.
Effect of a novel organic liquid fertilizer on the growth of Abelmoschus esculentus (okra)
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Prabath, S. A. D. M.; Ratnayake, R. M. C. S.; Wimalasekara, R.
Inorganic fertilizers are widely used to provide nutrients to crops, but their excessive use adversely impacts both the ecosystem and human health. This research aims to produce a novel liquid organic fertilizer (LOF) using easily available ingredients and evaluate its effectiveness for the growth and yield of Abelmoschus esculentus (Okra). The entire plant of Mimosa pigra (Giant sensitive tree) (fresh weight - 10 kg) was used along with Musa sp. (Banana) peels (fresh weight - 2 kg), powdered Eppawala rock phosphate (1 kg) and latex of Carica papaya (Papaya) (500.0 mL). A stock solution was prepared by mixing these ingredients with 20 L of well water and the mixture was allowed for aerobic digestion for six weeks. Then different concentrations of LOF were prepared from the stock solution at 5% (T1), 10% (T2), 15% (T3) and, 20% (T4). These prepared LOF were separately tested on the growth and yield of A. esculentus with well water as the control and commercially available LOF (Maxi crop) as standard under field conditions. Data collection started three weeks after applying the fertilizer and continued up to the ninth week. Fertilizer was applied weekly as the foliar application. The following parameters were measured: plant height, number of leaves, leaf area, stem circumference, time for the first flowering, number of flowers, time for first fruit formation, number of fruits per plant, total fruit weight per plant, circumference of the fruits and length of fruits. The data were analysed by one-way ANOVA. The mean values of plant height (25.7 ± 4.6 cm), number of leaves (23.0 ± 3.2), leaf area (120.0 ± 56.0 cm2), number of flowers (7 ± 2.51), number of fruits per plant (4 ± 1.9), total fruit weight (125.6 ± 51.3 g), length of the fruit (20.7 ± 1.6 cm), number of filled seeds per fruit (286.2 ± 183.7) and circumference of the fruits (4.5 ± 3.1 cm) of A. esculentus plants that treated with 10% concentration of LOF was significantly higher than those of the control as well as the commercial LOF. Early flowering (40.8 ± 1.5 days) was observed in the plants of T2 compared to the standard (53.0 ± 14.1 days) and the control (65.0 ± 1.4 days). It also shows the same pattern for the time taken for first fruit formation (T2; 50.8 ± 1.5 days, standard; 63.0 ± 14.1 days, control; 76.5 ± 0.7 days). The T2 treatment which has a 10% concentration, has shown a significant positive impact on the increase of the growth and yield of A. esculentus compared to the standard and control. Hence, the study recommends using a10% concentration of the synthesized LOF to enhance the growth and yield of okra.
Effect of organic amendments for growth enhancement of ornamental cactus: Mammillaria prolifera (P. Mill.)
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Ranathunga, R. M. T. K.; Ratnayake, R. M. C. S.
Cactus is a popular group of house plants in the world due to their attractive morphology. Among the ornamental cacti, Mammillaria prolifera (P. Mill.) is widely cultivated in different geographical regions of the world. Chemical fertilizers are excessively applied in cacti nurseries and their toxic traces such as arsenic, chromium, cadmium, and mercury accumulate in water resources and soil causing environmental pollution. This study aimed to evaluate the effect of a novel organic liquid fertilizer (OLF) to enhance the growth of M. prolifera, as a substitute for chemical fertilizers. The OLF was prepared by aerobically digesting a mixture of Tithonia diversifolia leaves, coconut husk ash, rock phosphate, and dried cow dung in 6.0 L of water for six weeks. 5%, 15%, and 25% OLF concentrations were used as the OLF treatments along with “Lonzin” as the chemical liquid fertilizer (CLF). Samesized M. prolifera stems were transplanted in 10 cm diameter pots filled with a cactus growth medium prepared by mixing coarse sand, sand, and compost. After one month of growing, M. prolifera plants were randomly assigned to OLF treatments and CLF treatment with 15 replicates. Treated plants were placed in a plant house at 27 0C temperature and 60% relative humidity. All the treatments were applied once a week for six months. After six months of the experiment, the height and width of the mother stem, number of phylloclades, number of flowers, time for first flowering, and root length were measured. Data were analyzed using, analyzed by one-way ANOVA at α = 0.05 and Turkey pairwise comparison test using “R” software (version 4.2.2). Plants treated with 5% OLF showed significantly better growth metrics including mean height (6.760 ± 0.942 cm), width (2.013 ± 0.344 cm), number of phylloclades (12.33 ± 5.1) number of flowers (2.07 ± 0.99) and root length (7.061 ± 1.24 cm) while no significant differences were observed between the 15% OLF, 25% OLF, and CLF treatments. M. prolifera plants treated with 25% OLF recorded the lowest mean duration (15.3 ± 4.2 weeks) for the first flower formation due to the appropriate nutrient content for flowering. Based on the growth performance data, 5% OLF treatment significantly enhanced the growth of M. Prolifera plants. Hence, 5% OLF concentration can be considered as the optimum concentration for the growth enhancement of M. prolifera cactus.
Effects of Mimosa pigra and Panicum maximum extracts on the productivity of Aloe vera
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Bandaranayake, A. R. B. W. M. C. D.; Ratnayake, R. M. C. S.
Aloe vera has a huge market demand locally and internationally for numerous uses. Organic A. vera farming is popular among farmers. Nutrition rich invasive alien plant species can be used for the preparation of organic liquid fertilizers (OLF). In this study, extracts of Mimosa pigra and Panicum maximum, and Musa fruit peels were used to prepare organic liquid fertilizer and it was conducted to evaluate the effects of three concentrations of the above organic liquid fertilizer on the growth and yield performance of A. vera under field conditions. Overall, there were five treatments as T1 - (0.50 g/mL of OLF), T2 – (0.75 g/mL of OLF), T3 – (1.00 g/mL of OLF) with TC (control – no fertilizer), and TS (standard – used cow dung, the typical fertilizer applied by farmers for A. vera). The pots were filled with a soil medium that contained sand, garden soil and compost (3:1:1 ratio). A. vera plants were placed under the shade of Gliricidia sepium to provide partial shade conditions. The growth and yield parameters of A. vera plants measured were plant height, leaf length, leaf width, leaf thickness, the volume of leaves, number of leaves, number of offsets, fresh weight of leaves, fresh gel weight of leaves, and percentage of gel recovery. Data were collected four months after transplantation and the data were statistically analyzed using one–way ANOVA. The T2 showed the significantly highest growth performances: length of leaves (26.34±2.21 cm), the volume of leaves (14.76 cm3±3.37), fresh weight of leaves (33.80±4.55 g/plant), fresh gel weight of leaves (24.40±4.50 g/plant), and percentage of gel recovery (67.90%±5.57) of A. vera (One–way ANOVA). These values significantly differed from TC and growth performance higher in A. vera with the application of all concentrations of organic liquid fertilizer compared to TS that used by farmers. Since T2 resulted in the highest performance for the economically important growth parameters of A. vera, the study revealed that it is the best cultivation practice for A. vera. The results have confirmed that M. pigra and P. maximum can be used for the formulation of organic liquid fertilizer for effective growth of Aloe vera as an eco- friendly, low-cost organic liquid fertilizer for the growers.
An ethnobotanical approach to control Typha angustifolia: A case study from Sri Lanka
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Madushani, K. P. K.; Amarasinghe, M. D.; Ratnayake, R. M. C. S.; Dahanayaka, D. D.G. L.
Typha is a cosmopolitan genus that is infamous globally for having nuisance plant species. In Sri Lanka, Typha angustifolia is distributed in both coastal and inland wetlands, including lagoons, paddy fields, and small reservoirs. Pervasive effects of Typha include hindrance to fishing activities, navigation, agriculture, human health, and ecosystem functions, especially provision of habitats for wading birds in coastal lagoons. The present study attempted to formulate an ethnobotanical strategy to control the distribution of Typha in Embilikala lagoon in Bundala National Park in Hambantota District in Southern Sri Lanka. T. angustifolia edible plant parts were tested for antioxidant activity to promote it as a phytonutrient that boosts the overall health of the body. Hexane, methanol, and aqueous extracts of leaf, leaf base, rhizome, and pollen of Typha were analyzed with DPPH and ABTS bioassays for the presence of antioxidants. Leaves were tested for their quality as raw material for making paper using the mould and deckle pouring method and couching technique. Methanol was found to be superior to hexane and deionized water as a solvent for both the assays. Leaf base (99.5±5.3 μg/mL) and rhizome (65.3±0.6 μg/mL) of T. angustifolia showed higher radical scavenging activity, and in some instances, higher than that of standard butylated hydroxytoluene (BHT) (119.3±4.5 μg/mL), indicating their potential as sources of bioactive compounds that can reduce free radicals. Contents of heavy metals (Arsenic: 0.338±0.040, Cadmium: 0.628±0.146, Chromium: 63.641±1.30, Lead: 15.657±1.70 ppb) in the rhizomes were below the standard permissible level (100.0 ppb). Pulp made with Typha leaves alone and a mixture of Typha (95%) and wastepaper (5%) were used successfully to produce writable paper. Findings suggest that T. angustifolia, which is widely considered as an invasive plant and marginally utilized currently, has a promising potential to be exploited as food and raw material to introduce new livelihoods to rural communities. This ethnobotanical approach may potentially be used to control the distribution of T. angustifolia in wetlands where it is found in invasive proportions.
Forecasting phenological model for tropical forest species: Monoon coffeoides
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Wellassa, P. W. G. S. R.; Ratnayake, R. M. C. S.; Liyanage, U. P.
Monoon coffeoides is a forest plant growing a tropical intermediate forest and pollinated by a native species of weevils in Sri Lanka. The longtime survival of both M. coffeoides and weevils is governed by its flowering and fruiting phenology. Due to a lack of phenological information implementation of proper conservation and management measures are not possible. The main purpose of this study is to analyze phenological parameters, namely, flower buds, open flowers, leaf flushing, leaf dropping, immature fruits and mature fruits of the Monoon coffeoides, to identify their correlation and variation patterns. Further, forecasting of these parameters are important in future forest management. Hence, the study has been extended to investigate the ability to forecast the parameters. Unsupervised learning techniques such as K-means clustering under Data mining are applied to identify similar behaviors among 50 trees of Monoon coffeoides. Silhouette width test was used to validate the cluster accuracy. Further, the Cross-correlation analysis was used to identify the relationships between series of phenological parameters with following delay periods as lag phases. The analysis resulted, the delay between flower buds and open flowers is 2 weeks, the delay between leaf flushing and mature fruits is 17 weeks, the delay between open flowers and immature fruits and between immature fruits and mature fruits is 5 weeks. Additionally, it was identified that the flowering and fruiting periods are varied from January to May and from March to August respectively. As the next step, phenological parameters and climate factors have been forecasted using univariate time series models. The accuracy was tested using standard tests: R-squared, Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE) and Mean Absolute error (MAE). The best-fitted models for each of these parameters are; flower buds: ARMA(2,3)-GARCH(1,1), open flowers : ARMA(2,3)- GARCH(1,1), mature fruits : ARIMA(1,1,1)-GARCH(1,1), immature fruits : ARMA(1,4)- GARCH(1,1), leaf dropping : ARMA(1,1), leaf flushing : ARMA(1,1)-GARCH(1,1), average temperature : ARIMA(1,2,1) and rainfall : ARMA(3,1) respectively. All the models were significant to forecast the values and thereby, these models can be used to forecast phenological parameters.
Formulation of a low-cost organic fertiliser paste from selected invasive plants enriched with Trichoderma species for the cultivation of Raphanus sativus
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) Kalpani, N. N.; Kannangara, B. T. S. D. P.; Ratnayake, R. M. C. S.
Excessive use of synthetic fertilisers is a significant drawback in modern agriculture, and it has several negative outcomes; unfavourable environmental effects and adverse impacts on human health and agriculture. The present study was conducted to produce an organic fertiliser paste from alien invasive plants enriched with either Trichoderma harzianum or Trichoderma virens. Fresh leaves and immature twigs of selected invasive plants, namely, Annona glabra, Clidemia hirta, and Chromolaena odorata, and a native plant Pongamia pinnata were randomly collected from the vicinity of the Gampaha District, sun-dried, and powdered. The materials (2.0 kg each) were mixed, and the mixture was digested with distilled water (42.0 L) for a month to form organic fertiliser. Previously isolated and identified Trichoderma harzianum (KT852821.1) and Trichoderma virens (KP985643.1) were formulated in a mixer of solid carrier materials (compost, straw, clay, and cow urine; 2:1:1:1, moisture content - 40 %) separately. From the stock solution (100 % w/v) of organic fertiliser paste, a concentration series of organic fertiliser (10 %, 20 %, and 25 %) was prepared and enriched with one of the above Trichoderma spp. They were used in six treatments (T10H, T10V, T20H, T20V, T25H, and T25V, where treatments indicated by H included T. harzianum while V included T. virens). Growth and yield of Raphanus sativus (Raddish) were investigated by applying the above treatments with tap water as the negative control and commercially available liquid organic fertiliser (“Maxicrop”) as the standard, using pot trials in a randomized block design with 15 replicates for each treatment. Raphanus sativus seedlings were treated weekly for 02 months as follows: 1st week - 5 mL, 2nd week - 10 mL, 3rd week – 15 mL, 4th week -20 mL, and 100 mL. Data obtained for the growth parameters of R. sativus were analysed statistically using one-way ANOVA with Minitab 17. As per the results, T10H treatment (10 % diluted C. odorata, A. glabra, C. hirta, and P. pinnata extract only incorporated with T. harzianum) recorded significantly (P≤0.05), the highest average number of leaves (23±1), leaf area (111.6±7.4 cm2), the height of the leaf biomass (6.1±0.35 cm), average leaf length (28.01±0.98 cm), root length (20.73±0.74 cm), the average girth of the root (13.11±0.65 cm), average dry weight of the whole plant (15.2±0.62 g/plant), dry weight of the shoot biomass (8.95±0.41 g/plant) and dry weight of the root biomass (4.78±0.29 g/plant) compared to the standard and the negative controls. Therefore, out of the six organic fertiliser combinations used in the experiment, T10H treatment can be recommended as the best organic fertiliser paste to maximize the yield of Raphanus sativus.
Formulation of novel organic liquid fertilizer for growth enhancement of ornamental cactus: Opuntia microdasys (Lehm.) Pfeiff
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Ranathunga, R. M. T. K.; Ratnayake, R. M. C. S.
The ornamental plant industry is one of the world's most commercially significant plant-based industries. Among the ornamental plants, cacti are popular due to their attractive plant morphology. Opuntia microdasys (Lehm.) Pfeiff. is an expensive and popular house plant in Sri Lanka, and it is grown at large scales to fulfill the high market demand. Growers use excessive amounts of phosphorous-rich chemical fertilizers to enhance the growth of cacti, and they may cause both human and environmental health issues either directly or indirectly. This study aimed to formulate an organic liquid fertilizer (OLF) to provide nutrients for O.microdasys as an alternative to chemical fertilizers. Hence, the study evaluated the effect of a novel OLF and its optimum concentration for the growth performances of O. microdasys. To prepare the OLF, fresh Tithonia diversifolia leaves, dried cow dung, coconut husk ash, and powdered rock phosphate (1.5:1.25:1.25:1 ratio) were aerobically digested in well water (6.0 L) for six weeks at 27 °C. Same-sized, O. microdasys cladodes were grown in 5 cm diameter plastic pots (one cladode per each) containing cacti growth medium (coarse sand, river sand, and compost in a 4.1.1 ratio). One month after growth, O. microdasys plants were treated with 5%, 15%, and 25% of the concentrations of OLF once a week with 15 replicates. Chemical liquid fertilizer (CLF) "Lonzin" was used as the positive control, and well water was the negative control. Treated O. microdasys plants were arranged in a randomized block design in a plant house, and the pots were rotated clockwise every two weeks to obtain adequate sunlight. The growth performances of the O. microdasys plants were evaluated after six months by measuring the plant height, number of cladodes, cladode's length, width, and root length. All the data were subjected to the One-way ANOVA at p = 0.05 followed by Tukey pairwise comparison tests using the R statistical software. The lowest mean height (7.6 ± 1.0 cm), number of daughter cladodes (1.3 ± 0.8), root length (7.8 ± 1.9 cm), cladode's length (4.0 ± 0.8 cm), and cladode's width (2.7 ± 0.3 cm) of O. microdasys plants were recorded by the negative control. The growth performances of the O. microdasys plants under OLF treatments were significantly higher (One-way ANOVA, p < 0.05) than the CLF. Among the concentrations tested, the 5% OLF concentration significantly enhanced the plant height (12.7 ± 1.8 cm), number of daughter cladodes (3.6 ± 1.4), cladode's length (5.0 ± 0.8 cm) and cladode's width (3.6 ± 0.7 cm). Therefore, 5% OLF can be recommended as the optimum OLF concentration for the growth enhancement of O. microdasys.
Growth performance of Basella alba (Spinach) exposed to liquid fertilizer prepared using invasive alien species; Clidemia hirta and Chromolaena odorata
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Senevirathna, M. A. T. M.; Ratnayake, R. M. C. S.
Inorganic fertilizers are popular in supplying plant nutrients, but their excessive use adversely affect human health and ecosystems. The present study was aimed to study the effect of organic liquid fertilizer prepared from the foliage of Clidemia hirta and Chromolaena odorata with the combination of leaves of Pongamia pinnata and fruits of Phyllanthus emblica and Carica papaya. Different concentrations (25, 50, 75 and 100 gL-1) of both extracts separately tested on the growth and yield of Basella alba with tap water as the control and commercially available liquid organic fertilizer (Maxicrop) as a standard under field conditions. Two weeks old B. alba seedlings were treated (300 mL of each treatment with seven replicates) thrice a week for 50 days. Collected data of the growth parameters of B. alba were analyzed by using one-way ANOVA. According to the results, mean values of number of leaves (19), leaf area (128.16 cm2), shoot height (93.1 cm), fresh weight of shoot (100.9 g/plant) and root (9.29 g/plant) of C. hirta 100 gL-1 in (CHM 100) treatment was significantly higher (P= 0.05) than those of the standard (leaves- 8, leaf area-48.78 cm2, shoot height-28.57 cm, fresh weight of shoot- 19.71 g/plant and root weight- 2.91 g/plant); and the control (leaves 7, leaf area-52.04 cm2, shoot height-23.86 cm, shoot weight-13.71 g/plant and root weight- 2.91 g/plant). In C. odorata 75 gL-1 (COM 75) treatment was having the highest mean values of the number of leaves (20), shoot height (86.4 cm), stem girth (5.17 cm) and fresh weight of shoot biomass (113.7 g/plant) and significantly higher than that of the standard (leaves 8, shoot height- 23.57 cm, stem girth-3.66 cm and shoot biomass- 19.57 g/plant) and for those of the control. As CHM 100 and COM 75 were shown the highest growth performance of B. alba, both organic liquid fertilizer mixtures can be recommended for B. alba cultivation in Kurunegala district.
Influence of mucilage of Aloe vera (L.) Burm.f, Hibiscus rosa-sinensis (L.), Abelmoschus esculentus (L.) Moench and Neolitsea cassia (L.) Kosterm on seed germination and seedling growth of Vigna radiata (L.)
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Ranathunga, R. M. T. K.; Nadungamuwa, D. M. H. S. K.; Ratnayake, R. M. C. S.
Crop seed germination is one of the fundamental determinants of agricultural productivity and a process influenced by various biotic and abiotic factors. Understanding and optimizing seed germination immensely helps to enhance crop yields and ensure food security via better crop establishment and growth. This study aimed to identify the most effective botanical mucilage extract for enhancing the germination and seedling growth of Vigna radiata among various leaf and pod extracts. Pure leaf mucilage of Aloe vera (T1), Hibiscus rosa-sinensis. (T2), Neolitsea cassia (T3), and mature pod mucilage of Abelmoschus esculentus (T4) were used as the treatments along with uncoated V. radiata seeds as the control (T0). Leaves of T1 – T3 and mature pods of T4 were collected, washed, ground, and the paste was squeezed to obtain pure mucilage extracts. Surfaced sterilized V. radiata seeds were immersed in the T1 – T4 for ten minutes and placed in sterilized petri dishes layered with moistened filter paper. They were incubated at 27 oC under a relative humidity of 83 %. The number of germinated seeds was counted daily and the mean germination rate (MGR), germination time (MGT), germination index (MGI), germination energy (MGE), and coefficient of velocity of germination (MCVG) of V. radiata were calculated. The root and hypocotyl lengths of seedlings were measured during the final data collection. Six replicates were performed for each treatment and control with 120 V. radiata seeds. Based on the number of germinated seeds, T3 was identified as the least active mucilage extraction, and the same experiment was repeated with 1:1 diluted mucilage extraction (T5) under the same conditions. Data were analyzed using one-way ANOVA (at α = 0.05) and PCA in 'R' software. T2 significantly enhanced seed germination recording the highest MGI (19.1 ± 0.88), MCVG (98.3 ± 2.89 %), and lowest MGT (0.7 ± 0.05 days) while T3 reduced both germination and seedling growth (p < 0.05). According to PCA, both A. vera and H. rosa sinensis were identified as the most effective treatments. T3 and T4 were identified as the least effective and moderately effective extracts respectively. The extract of A. vera was 24.31% more effective and the extract of H. rosa-sinensis was 42.25% more effective in promoting the rapid germination of V. radiata seeds compared to the control. The study concluded that H. rosa-sinensis and A. vera can be used to enhance V. radiata seed germination as lowcost alternatives to chemical seed germination enhancers.
Influence of Pinus caribaea and Alstonia macrophylla invasion on floristic composition of the buffer zone in Kottawa forest
(Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Dias, M. A.; Ratnayake, R. M. C. S.
Kottawa forest is an isolated patch of lowland rain forest and its buffer zone is threatened by invasive alien plants ((IAS). Among IAS, wind dispersed seeds of both Alostonia macrophylla and Pinus caribaea may invade the forest gaps in the core area of Kottawa forest. The present study aimed to assess the influence of IAS at the buffer zone of the Kottawa forest in relation to the floristic composition of the area. Vegetation sampling was done using randomly selected 11 plots (10 m x 20 m) representing the forest (0.14 km2) buffer zone area. The girth at breast height (GBH), density, and frequency of plant species were enumerated. The species composition of the forest was completed by identifying the other species found outside the plots. The important value index (IVI = relative density + relative frequency + relative dominance) of species > 10 cm GBH was calculated. The percentage contribution of endemic, exotic and indigenous species to the floristic composition of the area was enumerated and it revealed that 55.1% endemic, 14.3% exotic and 30.6% native species. Pinus caribaea, Gyrinops walla, Dillenia retusa, Artocarpus nobolis, Cinnamomum verum, Alstonia macrophylla and Carissa carandas are the dominantplant species in the buffer zone. Agrostistachys hookeri, Shorea congestiflora and Dipterocarpus hispidus are the dominant endemic tree species found in the area. The most dominant species with highest relative basal area are P. caribaea and Artocarpus nobolis. the most abundant species with high relative density (11.8) is G. walla Both P. caribaea (IVI - 33.5) and A. macrophylla (IVI - 2.7) considered as IAS. The present study provides baseline information on the potential risk of A. macrophylla invasion and wide distribution of P. caribaea for native flora in Kottawa buffer zone. Therefore, the study suggests importance of managing further spread of P. caribaea and A. macrophylla in the buffer zone of the Kottawa forest with appropriate forest management practices such as assisted natural regeneration.
Influence of the pollinator on the yield of Luffa cylindrical (Cucurbitaceae) - an under-utilized vegetable.
(. 4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka., 2019) Dandeniya, D. A. M. N.; Ratnayake, R. M. C. S.; Kumari, S. A. S. M.
Luffa cylindrica is a cucurbit known as sponge gourd or “Niyan wetakolu”. Although under-utilized, L. cylindrica is rich in nutrients. Few studies have been conducted on its reproductive biology and the effects of pollinators on the crop yield. To fill this information gap, the present study was designed to investigate pollination ecology and the effect of pollinators on yield parameters of L. cylindrica. Experiment was carried out in the Regional Agriculture Research and Development Center, Makandura. Floral morphology, floral phenology, pollen histochemistry, effective pollinators, stigma receptivity and anther dehiscence of L. cylindrica were studied. Measurement of yield parameters were collected from the plants grown in a pollinator proof plant house and plants were allowed to pollinate naturally. Fruit weight, number of fruits, fruit length, fruit yield and circumference of the fruits were measured from plants in each of three plots (4.5 x 3 m). All the agronomic conditions were provided according to recommendations of department of agriculture (spacing, irrigation, fertilization and pest management etc.). Flowers were unisexual and bloomed at around 4.30 to 5.00 am. and stigma were receptive for six hours from the time of blooming (till 11.00 a.m.). Anther dehiscence was commenced prior to flower blooming. Pollens were globular with three germ pores and contained starch, but lipids and proteins were absent. The effective pollinator and the most frequent floral visitor identified was Apis cerana (Honey bee). Pollination syndrome indicated that L. cylindrica was xenogamous and entomophilous. Mean number of fruits/ plot was significantly higher in open pollination of L. cylindrica (42 fruits/plot) compared to one fruit/plot in pollinator proof plant house (P = 0.001). The yield of open pollination was 7.71 t /ha which was significantly higher than 2.52 t/ha yield in pollinator proof plant house. Results proved that melittophily has a significant positive effect on increasing fruit yield of L. cylindrica and decline of pollinators has significantly reduced the fruit yield. Therefore, conservation of pollinators is essential as it is a vital ecosystem service and it directly affects food scarcity and biodiversity
Investigation of a suitable formulation for Trichoderma harzianum in different compositions of solid carrier materials at two temperatures
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Kalpani, N. N.; Kannangara, B. T. S. D. P.; Ratnayake, R. M. C. S.
In sustainable agriculture, the application of Trichoderma spp. is a widely accepted, eco-friendly method. But, in the commercialization process, the effectiveness of Trichoderma spp. as a biological control agent, plant growth promoter, and as a decomposing agent affectsthe selection of the carrier material and the formulationprocedure. The present investigation was carried out in an attempt to develop an effectiveorganic carrier material using abundant natural solid materials in which the viability and the effectiveness of T. harzianum could be maintained for a sufficient duration at an optimum temperature for product stabilization. Previously isolated and identified T. harzianum (KT852821.1), which can enhance the growth of many crops (e.g.: Pisum sativum, Cucumis sativus, Solanum lycopersicum, and Tulipa gesneriana), was selected for the present investigation. Five carrier formulations were made using different compositions of compost, straw, clay, and cow urine. Inocula taken from pure cultures of T. harzianum grown on PDA media were introduced separately into sterilized polypropylene bags containing different proportionsof carrier materials. They were then incubated at 25°C for 7 days and then stored at room temperature (28°C) and in the refrigerator (4°C) for 12 months. Viability was determined at frequent intervals of 2, 6, 9, and 12 months for the formulations kept at 28℃ and 4℃ separately. Colony-forming units per gram of substrate were calculated following the dilution plate method in 10 replications for each formulation. Among the five different formulations used for formulating T. harzianum, the formulationconsisting of compost 50%, straw 25%, clay 12.5%, and cow urine 12.5% (V/W) stored at 4°C for a 12-month time period, proved to be significantly the most effective composition for the commercialization of T. harzianum, which gave a colony count of 6.99 log CFU/g whereas the other formulations provided the values of 6.36 log CFU/g, 6.26 log CFU/g, 6.91 log CFU/g, and 6.45 log CFU/g. The present investigation highlighted the significance of using the formulation consisting of compost 50%, straw 25%, clay 12.5%, and cow urine 12.5% (V/W) to develop T. harzianum as a commercialproduct.
Monomorphic enantiostyly and reproductive biology of Osbeckia octandra and Melastoma malabathricum
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Ratnayake, R. M. C. S.
Although stylar polymorphism of angiosperms plays a significant role in pollination, few studies have been conducted on stylar polymorphism in relation to reproductive success in tropical plants. To fill this knowledge gap, the present study was designed to investigate stylar polymorphism of two selected Melastomataceae plants; Osbeckia octandra (Heen Bovitiya) and Melastoma malabathricum (Kata Kalu Bowitiya) with respect to their reproductive success. Data on floral level phenology, stylar polymorphism, floral visitors, breeding systems and fruiting success of two species were collected by gathering field data from Hantana, Pilikuththuwa and Meethirigala forests. Floral level phenological data collection was done at the peak flowering stages in 20 tagged individuals for both species in each site. Statistical analysis was done using One-way ANOVA at p=0.05. Floral morphology and breeding system data (pollen-ovule ratio, and out crossing index) revealed that both species are xenogamous and entomophilous. The pollination syndrome is melittophily and buzz pollination is required for anther dehiscence with poricidal pollen dispersal in both species. Even though, both species exhibited monomorphic enantiostyly, mirror image flowers were present only in O. octandra. Though pollination and fruiting success of both O. octandra and M. malabathricum do not significantly influence by enantiostyly, it helps xenogamy to maintain long term sustainability of the species. The effective pollinators of O. octandra and M. malabathricum were Amegilla spp. and Xylocopa spp. respectively. Anther dimorphism of M. malabathricum indicates labor division by yellow anthers for feeding and purple anthers for pollination. Percentage of pollen germination in purple anthers was significantly higher than that of the yellow anthers (p=0.05). Late stage flexistyly ensures selfing and enhance reproductive potential, if crossing is not successful. Information gathered from this study will be useful to strengthen the scientific understanding in reproductive biology of tropical plants and facilitate the future hybridization and breeding designs to improve the ornamental value of the species
Optimizing growth conditions for vegetative propagation of Near Threatened (NT) epiphytic Cactus Rhipsalis baccifera sub sp. Mauritiana (DC.) Barthlott. (Cactaceae)
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Senanayaka, S. G. M. S. D.; Ratnayake, R. M. C. S.; Senanayake, R. A. S. P.; Attanayake, A. M. A. S.
The Cactaceae family exhibits a diverse range of adaptations, making it popular among horticulturists and Cactus growers. Rhipsalis baccifera sub sp. mauritiana (DC.) Barthlott., an epiphytic cactus, is valued both as an ornamental plant and a medicinal plant. As it is categorized as a “nearly threatened species” (National Red List, 2020) steps must be taken for conservation. Prior studies have not determined the use of commercial growth hormones, the use of naturally available growth media such as compost, soil, and wood, and the effect of shade to increase the successful establishment of stem cuts. We hypothesized that there is an effect of growth hormones, media type and shade level on the growth of the plant. Therefore, this research aimed to determine the optimal shade, growth media, and hormone combination for the vegetative propagation of R. baccifera due to the scarcity of information. Freshly plucked twigs of R. baccifera were utilized as explants for vegetative propagation experiments. Six soil combinations that include Compost (Co), Brick Powder (BP) + Powdered Roof Tile (RT) (1:1), Soil (S) + Co (1:1), S + Sand (Sa) (1:1), S + Co + Sa + BP (2:1:1:1), and S + Co + BP (3:3:2) were assessed to identify the most suitable growth medium for vegetative propagation. R. baccifera planted in each combination was grown in shade net houses with the following shade levels (80%, 60%, and 40%) at room temperature for three months. The successful growth media (Co) and 80% shade level were subsequently employed. It included 16 treatments with 10 replicates randomly for each treatment (160 total), incorporating four types of new growth media that include Co as the base component (Co, Co + S, Co + Wood, and Co + S + Wood) and three types of growth hormones (powder form Rapid Root, Clonex®, a commercial liquid fertilizer). The growth hormone level was 0.3% w/w. The control treatment included no growth hormones. Fresh stem cuttings with a few nodes about 6 cm in length were planted in the above media. Watering was conducted once a week over a three-month period. The length of the plant was recorded at the end of each month as the growth increment parameter. Upon statistical analysis (p=0.05), it was found that there was no significant difference between the average growth rate for any growth media type (p≥0.05), and therefore the inclusion of “compost” in any growth media combination resulted in the best growth. Additionally, the powdered growth hormones "Rapid Root" (5.5±0.4 cm) and "Clonex®" (7.2±0.4 cm), proved to be the most effective, compared to the control (0.9±0.2 cm) for stem cuttings (p<0.05). This study successfully identified optimal conditions for the vegetative propagation of R. baccifera sub sp. mauritiana that includes compost as a growth media and powdered hormone types Rapid Root or Clonex® as the growth hormone, at 80% shade. The findings contribute practical insights for the cultivation of nearly threatened species of Rhipsalis baccifera.
Optimizing Solanum lycopersicum seed germination using Aloe vera gel extraction
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Alvis, T. P. G. N. T.; Sudeshini, K. D. P. V.; Ratnayake, R. M. C. S.
Solanum lycopersicum. L is an important crop plant that is highly used in consumption. A high seed germination rate is essential for the efficient establishment of S. lycopersicum. Seed germination can be enhanced using commercially available chemicals including growth regulators, vitamins, and antioxidants. In addition, natural biostimulants are used for seed germination enhancement as an environmentally friendly alternative to chemicals. In this study the effect of Aloe vera gel extraction on S. lycopersicum seeds was evaluated. Five concentrations (0%, 20%, 40%, 60%, 80%, and 100%) of A. vera gel extractions were prepared. One hundred eighty healthy S. lycopersicum seeds were selected and surface sterilized. They were then immersed in sterile distilled water for two hours. Ten seeds were placed on each petri dish layered with filter paper moistened with 2.5 mL of the corresponding A. vera treatment separately. The respective A. vera gel extractions were added every two days. Three replicates were conducted for each treatment. Treated seeds were incubated at 27 °C for six days and seed germination was recorded daily. Mean Germination Rate (MGR), Mean Germination Time (MGT), Mean Germination Index (MGI), and Mean Coefficient of Velocity of Germination (MCVG) were calculated. One-way ANOVA and Tukey pairwise tests were applied for data analysis at α = 0.05 level. Based on the results, 80% of A. vera gel extraction recorded the highest germination rate for S. lycopersicum seeds (14.43 ± 2.12 %) compared to the 0% A. vera treatment. It has significantly increased the germination rate of S. lycopersicum compared to the other treatments (One-way ANOVA, p < 0.05). The lowest mean germination time was recorded by 80% A. vera treatment. Based on the germination rates, 80% treatment was 8.25 % more effective than the control (0% A. vera). Aloe vera gel extraction (80%) can significantly enhance the S. lycopersicum seed germination by increasing the germination speed and hence it can be recommended to the field application.
A Study on Career Aspirations of Undergraduates in Sri Lanka
(Faculty of Commerce and Management Studies University of Kelaniya, Sri Lanka, 2020) Ratnayake, R. M. C. S.; Elvitigala, D. Y. C
Studying career aspiration among undergraduates has become an important topic since undergraduates face numerous challenges after completing their university degree especially when seeking for suitable employment opportunities. This study investigates the “career aspiration” in the context of current Sri Lankan Undergraduates, identify the factors that affect different career aspirations of undergraduates and the key issues faced by undergraduates regarding their career aspirations separately. To achieve the research objectives, the study was devised using descriptive qualitative approach. Data were collected from 50 undergraduates in 04 solitary universities as per the sample and from 03 graduates to conduct case studies based on their successful stories for validation purpose through semi structured interviews. The analysis of collected data is done by thematic analysis method by using NVivo 8 qualitative analysis software. The results of the study indicated that the subjective norms, perceived behavioral control and attitude are the factors which affect different career aspirations of the undergraduates in Sri Lanka. In most situations attitude had a positive relationship with the career aspiration, and it had an influence on other two constructs. Finally, key issues were identified as lack of experiences, competition, political changes, and lack of monetary facilities and all the respondents agree with the statement that the identified issues become great influence to career aspiration. This research is a significant source for the policy makers and decision makers in manipulating the university education system of the island and the universities can meaningfully contribute towards career development of undergraduates.