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Item Effects of foliar and soil-applied liquid organic fertilizers on the growth of Basella alba L. and Centella asiatica L.(The Journal of Agricultural Sciences - Sri Lanka, 2021) Ranasinghe, R.H.A.A.,; Ratnayake, R.M.C.S.; Kannangara, B.T.S.D.P.Purpose: Environmental-friendly organic fertilizers reduce the adverse impacts of chemical fertilizers. This study was conducted to formulate organic liquid fertilizers using selected plant materials i.e., Tithonia diversifolia, Mikania scandens, Chromolaena odorata and Gliricidia sepium with selected organic wastes to compare the efficacies of foliar and soil-applications over the growth of leafy vegetables; Basella alba and Centella asiatica. Research Method: Selected plant materials were allowed to decompose for two months and thereafter fish waste was hydrolyzed separately with fruit wastes of Carica papaya, Ananas comosus and (1:1 w/w) mixture of both were mixed and nutrients analyzed. Fertilizers were foliar and soil-applied separately on C. asiatica and B. alba in RCBD in pot trials. Findings: Fertilizer formulated with decomposed plants + fish waste hydrolyzed with C. papaya significantly recorded the highest N (0.57%), P (0.06%) and highest growth of C. asiatica and B. alba over both soil and foliar applications followed by the fertilizer formulated with decomposed plants + fish waste hydrolyzed with C. papaya + A. comosus. Foliar-application of B. alba significantly showed the highest growth than the soil-application [shoot height (36.6±3.4 cm vs 30.0±1.5 cm), number of leaves per plant (21.7±1.4 vs 17.5±0.8) and plant fresh-weight (61.5±1.8 vs 55.6±0.9 g)] whereas, C. asiatica indicated no significant difference considering both fertilizer application methods. Research limitation: Pot experiments were carried out to provide uniform soil conditions for the experiment which was the main limitation compared to field trials. Originality/value: The formulated novel fertilizers could be utilized effectively in organic farming for safe and healthy leafy vegetables which reduce the adverse impacts of chemical fertilizers.Item Investigation of a best fitting mathematical model for the frequency of occurrence of Trichoderma harzianum in Hakgala Montane Forest in Sri Lanka(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Munasinghe, J.; Jayalath, J.T.D.; Kannangara, B.T.S.D.P.Trichoderma is a genus commonly found in the soils of all climatic zones. All most all the species of Trichoderma can produce antimicrobial antibiotics and are good competitors of fungal pathogens, which promote plant growth, enhance stress resistance and induce disease resistance in plants. Interactions between plants and Trichoderma are ecologically important. Moreover, this genus is economically much important because Trichoderma has been used as a biofertilizer and bio pesticide. In the present study, the attention is given to Trichoderma species: Trichoderma harzianum. The aim of this study was to detect a proper mathematical model to investigate the frequency of occurrence of fungus; Trichoderma harzianum in Hakgala Montane Forest in Sri Lanka at any period of time. Data for the frequency of occurrence of Trichoderma harzianum were collected at once in three months intervals from the decomposing leaf litter of Hakgala Montane Forest in a previous study. Significance of the data was checked using the ANOVA test. Data were tested with five mathematical models (Exponential, Logistic, Gompertz, Brody, Von Bertalanffy) and parameters estimated using the nonlinear least square method in R Studio software. The models were tested for goodness of fit using the adjusted coefficient of determination (R 2 ), Akaike’s information criterion (AIC) and Bayesian information criterion (BIC). The logistic model provided the best fit of the data due to the highest value of R 2 , lower values of AIC and BIC than other models. The developed logistic model revealed 0.549% for the growth rate of Trichoderma harzianum in Hakgala Montane Forest. Since the Hakgala Montane Forest is an undisturbed natural ecosystem with its equilibrium stage this proposed model can be used to investigate the frequency of Trichoderma harzianum at any time period even for future predictions.Item Effect of Trichoderma virens on vegetative and reproductive growth of Capsicum annuum cv. MI2 (green chilli)(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Sakalasooriya, S.M.C.P.; Kannangara, B.T.S.D.P.; Jayasekara, L.R.Plant Growth Promoting Fungi (PGPF) facilitate a favorable interaction with plants in the rhizosphere through several biological processes. PGPF play a significant role in phytostimulation, phytoremediation and biofertilization. The use of PGPF as a biofertilizer has steadily increased in sustainable agriculture to reduce the use of chemical fertilizers. The objective of the present study is to investigate the effect of Trichoderma virens on vegetative and reproductive growth of Capsicum annuum cv. MI2 (green chilli). The trials were conducted in a greenhouse in the botanical garden, University of Kelaniya. Six weeks-old seedlings of C. annuum cv. MI2 were transplanted in solarized potting medium prepared by mixing topsoil and compost (3:1), filled into grow bags. Four treatments (103 , 105 , 107 conidia/ mL) including control (treated with Urea, Triple superphostphate and Muriate of Potash) were carried out along with five replications. Potting medium was inoculated with the conidial suspensions at the time of transplanting, followed by four inoculations until the time of uprooting. At the completion of 10 weeks after transplanting, the plants were uprooted, measured and represented as a percentage increment compared to the control; for the vegetative (shoot height, number of leaves, leaf area, average leaf length, girth of tap root, total leaf chlorophyll, fresh and dry weights of shoot and root mass) and reproductive parameters (number of buds, flowers and pods) of C. annuum cv. MI2. The plants treated with 107 conidia of T. virens per mL showed a significant increase in growth parameters of shoot height (18.55%), leaf number (79.78%), fresh weight of shoot (122.4%), fresh weight of root (14.17 %) and a significant increase in reproductive parameters of, number of buds (18.18%), and number of pods (143.75%) compared to the control was observed. Moreover, the plants treated with 105 conidia of T. virens per mL showed a significant enhancement in the growth parameters, leaf area (17.63%), total chlorophyll content (8.87%) and dry weight of root (54.16%) compared to the control. Present study clearly indicated that C. annuum cv. MI2 show better vegetative, as well as reproductive growth performance, when treated with conidial suspensions of T. virens. Therefore, T. virens can be suggested as a potential biofertilizer for C. annuum cv. MI2.Item Potential of Trichoderma harzianum and Trichoderma virens in controlling Meloidogyne incognita on Basella alba(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Rajakaruna, R.M.N.P.; Kannangara, B.T.S.D.P.Meloidogyne incognita, the root knot nematodes are a widely spread group of plant pathogens that affect a variety of economically important plants. Even though chemical nematicides are used to control the nematodes at present, these nematicides pose a huge threat to the environment. Taking this fact into account usage of nematophagous fungi has gained popularity as a more ecofriendly approach to control nematodes. Trichoderma spp. has a great ability to control nematodes by using trapping mechanisms and by secreting nematicidal metabolites. The present study focuses on the potential of using Trichoderma harzianum and T. virens in controlling Meloidogyne incognita. Three weeks old healthy nematode free Basella alba L. (Indian spinach) seedlings were subjected to five different treatments; Soil, Soil+ Nematodes, Soil + Nematodes + Nematicides, Soil + Nematodes + T. harzianum and Soil + Nematodes + T. virens. Six replicate samples were considered for each treatment. The plants were maintained in a homogenous environment. Some below ground direct growth parameters including number of galls, length, fresh weight and the dry weight of the tap root were measured at one month intervals up to three months. As Meloidogyne incognita develop disease symptoms mainly in the root system of Basella alba plants the above ground indirect systems were not considered in the present study. The data collected were analyzed using MINITAB version 18 statistical software. At the end of the second sampling time, the plants grown on soil treated with nematodes alone had a significantly higher number of galls (72 ± 6.97) compared to those treated with nematodes + T. harzianum (7 ± 0.516) ,nematodes + T. virens (8 ± 0.211) and nematodes and nematicides (32 ± 6.98 ) . However a significant difference was not observed in the length of the tap root. This may be because length of the tap root is not directly affected by the Meloidogyne incognita infection. At the end of the third sampling time, the fresh weight (14.42 g ± 1.29) and the dry weight (10.67 g ± 0.29) of the roots of plants infected with nematodes, were significantly higher than the fresh weight(3.83 g ± 0.55 ) and dry weight(2.34 g ± 0.51) of the roots of plants grown in soil. This study clearly indicates that both T. harzianum and T. virens have a great potential to be used as biocontrol agents of the root knot nematode Meloidogyne incognita in Basella alba L. This present study can be further improved by investigating the mechanisms employed by Trichoderma harzianum and Trichoderma virens in controlling Meloidogyne incognita.Item Evaluation of nutrient and fiber content of selected invasive plants in Sri Lanka with a potential for preparing compost(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Hewavitharana, N.; Kannangara, B.T.S.D.P.; Jayasekera, L.R.; Senanayake, S.P.Based on availability, the amount of above ground bio-mass and the degree of use as compost in traditional farming systems Tithonia diversifolia, Chromolaena odorata, Mikania scandens, Lantana camara, Wedelia trilobata, Mimosa pigra and Panicum maximum were selected for nutrient analysis, with an attempt to investigate their potential to be utilized in preparation of cost effective, organic potting medium for cultivation of selected vegetables and ornamental plants. According to the preliminary surveys, Anuradhapura, Madawachchiya, Kandy, Gampaha, Kalutara and Kurunegala areas were selected for sample collection. Leaves and immature stem parts of the selected plants were analyzed by two samples per one location with three replicates. The total N, P and K contents were determined by Kjeldahl, vanadomolybdate and flame photometric methods respectively. Atomic absorption spectrophotometry was used for quantitative analysis of Mg, Ca, Cu Zn, and Fe. Crude fiber content was determined gravimetrically after chemical digestion and solubilization of the materials. Results obtained were statistically analyzed using SPSS statistics-22 software. The nutrient contents of T. diversifolia; N (3.28%), P (0.37%), K (2.50%), Mg (0.83%), Ca (4.92%), Cu (10 mg/kg), Zn (517 mg/kg) Fe (296 mg/kg) and M. scandens; N (3.44%), P (0.35%), K (3.30%) Mg (1.33%), Ca (3.39%), Cu (34 mg/kg), Zn (671 mg/kg), Fe (393 mg/kg) were significantly higher than that of other selected weeds. However, they showed significantly lower crude fiber contents 4.85% and 3.50% respectively. Although the nutrient content in P. maximum was significantly low N (1.27%), P (0.24%), K (1.44%) Mg (0.5%), Ca (1.55%), Cu (9 mg/kg), (Zn 181 mg/kg), Fe (267 mg/kg) and its crude fiber content (20.42%) was significantly higher than that of others. It can be concluded, T. diversifolia and M. scandens as plant materials which have higher amounts of nutrients. P.maximum which has higher content of crude fiber also can be incorporated in preparing compost in order to improve the physical properties of the potting medium.Item Analysis of naphthalene and phenanthrene degradation catabolic genes of phyllosphere bacterial strains, Alcaligenes faecalis and Alcaligenes sp. DN25(2015) Kannangara, B.T.S.D.P.; Undugoda, L.J.S.; Sirisena, D.M.The bacterial strains, Alcaligenes feacalis and Alcaligenes sp. DN25 which were isolated from the phyllosphere of four ornamental plant species, Ixora chinensis, Ervatamia divaricata, Hibiscus rosa-sinensis and Amaranthus cruentus in five highly polluted sites in Sri Lanka, showed the highest phenanthrene and naphthalene degradation ability. Transformation and plasmid curing results of them revealed, naphthalene and phenanthrene degradation ability of these bacterial strains were plasmid encoded character. The occurrence of naphthalene specific (nahR and nahU) genes and phenanthrene specific (phnAc and phnG) genes of these catabolic plasmids were analyzed by PCR using degenerate primers. According to the amplification results, plasmids of Alcaligenes faecalis and Alcaligenes sp. DN25 harbour nahR, nahU and phnG genes but, lack of phnAc gene. RFLP and sequence data of nahU and nahR amplicons revealed, both of these genes were homologous to these two bacterial strains. But, phnG gene of two phenanthrene and naphthalene degrading phyllosphere bacterial strains was coexistence as two distinct copies of alleles.Item Moss endophytes and polyaromatic hydrocarbon degradation(Sri Lanka Association for the Advancement of Science, 2015) Ambadeniya, A.R.P.D.U.K.R.; Undugoda, L.J.S.; Kannangara, B.T.S.D.P.Item Soil fungi of semi natural montane forest and adjacent pine plantation in Peacock hill, Pussellawa, in Nuwara Eliya district(Institute of Biology, Sri Lanka, 2015) Dharmasiri, R.G.K.; Kannangara, B.T.S.D.P.Item Antifungal effect of Croton aromaticus against Rhizopus spp. Isolated from banana and papaya(Institute of Biology, Sri Lanka, 2015) Wijesundara, S.A.G.T.L.; Kannangara, B.T.S.D.P.Item Endolichenic fungi in Usnia sp. From Hakgala Montane Forest in Sri Lanka as a Novel Source of Bioactive Natural Products(Proceedings of the international symposium on Natural Products Chemistry and its contribution to the economy, environment and the social well being, University of Peradeniya, Sri Lanka, 2010) Paranagama, P.A.; Kannangara, B.T.S.D.P.; Rajapaksha, R.S.C.G.