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Item 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.Item 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.Item Isolation and identification of litter decomposing fungi in Nagacholai Forest Reserve, Mullaitivu, Sri Lanka(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Bopitiya, B. D. S. S.; Dewangani, H. G. N.; Perera, H. W. K.; Premachandra, J. A. H. P.; Senevirathna, M. A. T. M.; Kalpani, N. N.; Kodituwakku, T. D.; Kannangara, S.Nagacholai Forest Reserve, which was disturbed by local terrorism before 2009, is located in Mullaitivu District in the Northern Province of Sri Lanka. It is a tropical dry zone forest, administrated by the Department of Forest Conservation, Sri Lanka. Litter-fall and subsequent nutrient release from decomposing litter are crucial processes that regulate the nutrient availability and the nutrient cycling in soil, as well as the plant growth in forest ecosystems. Litter decomposition rates of forest ecosystems are governed by both biotic and abiotic factors. Therefore, the present study was conducted to study soil characteristics such as pH and electrical conductivity and to isolate and identify the litter decomposing fungi of the Nagacholai forest. Soil and litter were collected randomly by placing 0.5 m X 0.5 m size quadrats on the forest floor. The pH and electrical conductivity of each soil sample were determined by following standard methods. Litter decomposing fungi were isolated from leaf discs (1 mm X 1 mm) obtained from the collected litter following washing and plating method using sterilized distilled water. Pure cultures of isolated fungi were maintained at 28 °C in PDA and morphologically identified using identification keys. The low moisture content in the soil was reflected by brown colour, sandy-podzolic soil. The high proportion of less decomposed, dense litter layer reflected the low decomposition rate due to decelerated soil microbial activity and low water availability. Soil pH was within the range of 6.34 – 6.80 and electrical conductivity at 30 °C varied between 1.23 – 1.57 mS cm-1. Five different fungal species were isolated in high frequencies (50%>) from leaf litter, while four of them were identified up to the genus level based on their vegetative and reproductive morphology (i.e. Mucor sp., Aspergillus sp., Candida sp. and Pestalotiopsis sp.). The remaining unidentified species produced white colour colonies and branched, hyaline, septate hyphae without showing any sexual reproductive structure. Mucor, Aspergillus and Pestalotiopsis are some of the common fungal decomposers found in most of the forests of different climatic zones. However, Candida is a filamentous yeast, which is not frequently reported as a decomposer in terrestrial ecosystems, but found to be a member of the normal soil microflora in forests as secondary sugar fungi. Therefore, Mucor, Aspergillus and Pestalotiopsis could be identified as the most prominent genera of litter decomposing fungi in the Nagacholai forest. Nevertheless, this preliminary study needs to be elaborated further to confirm their identity up to species level using molecular techniques