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Item Suppression and management of Meloidogyne incognita in soil using Trichoderma harzianum NFCF160 and Trichoderma virens Isf-77(Malaysian Journal of Microbiology, 2022) Rajakaruna, N.; Undugoda, L.; Kannangara, S.; Abeywickrama, K.Aims: Meloidogyne incognita adversely affects numerous crop plants worldwide. Therefore, the modern world has been moving towards biocontrol methods to prevent nematode attacks. This study was aimed to (i) investigate the potential use of Trichoderma harzianum NFCF160 and T. virens Isf-77 in managing M. incognita in soil and (ii) identify trapping mechanisms employed by both Trichoderma strains to suppress M. incognita. Methodology and results: Three weeks old, Basella alba L. plants were subjected to five different treatments. The above and below ground growth parameters and the galling indices of these plants were measured every four weeks for three sampling times. Trapping mechanisms employed by Trichoderma strains were examined following plate assays. Plants treated with T. harzianum NFCF160 and T. virens Isf-77 had significantly higher values for the total number of leaves (34 ± 2.84) and (27 ± 2.61), fresh weight of the shoot (81 ± 9.51 g) and (91 ± 9.70 g), dry weight of the shoot (71 ± 5.24 g) and (62 ± 5.81 g), respectively eight weeks after inoculation of M. incognita. Significantly low galling indices (2 and 2) were recorded in B. alba treated with Trichoderma strains. Both Trichoderma strains exhibited various nematode-trapping mechanisms, such as non-constricting rings and adhesive spores. Conclusion, significance and impact of study: This investigation highlighted the potential of both Trichoderma strains as biocontrol agents to control M. incognita effect in sustainable agriculture.Item Morphological and molecular identification of fungi for their association with postharvest fruit rots in some selected citrus species(2022) Jayasekara, A.; Daranagama, A.; Kodituwakku, T.D.; Abeywickrama, K.Purpose: The availability of fresh Citrus fruits is limited by their susceptibility to invasion by microbial pathogens which leads to cause serious postharvest losses. The present study was carried out to isolate and morphologically identify postharvest fungal associations from selected Citrus fruit species (C. sinensis, C. limon, C. crenatifolia and C. medica) and to confirm their identity by molecular characterization. Research method: Postharvest fungal associations of selected Citrus fruit species were isolated, and identification was done based on morphological characteristics. Confirmation of fungal associations was done through phylogenetic analysis of newly generated ITS sequencing data. Further, frequency of occurrence of each fungal isolate was calculated in three different districts in Sri Lanka. Findings: From the morphological and molecular identification, Collectrichum fructicola, Collectrichum gloeosporioides, Lasiodiplodia theobromae, Aspergillus niger and Pestalotiopsis sp. were recorded from C. sinensis. Neofusicoccum parvum, Collectrichum gigasporium and Aspergillus clavatus were isolated from C. crenatifolia. Further, Lasiodiplodia theobromae and L. pseudotheobromae were the only fungal association isolated from C. limon and C. medica fruit species, respectively. It is worthwhile noting that this is the first report of association of the C. gigasporium and Pestalotiopsis sp. from Citrus fruits in Sri Lanka. Research limitations: Since this research was mainly focused on the isolation and identification of the potential fungal associations, pathogenicity evaluation could not be carried out. Originality/Value: Findings of potential disease causative agents in citrus will be valuable for agriculture sector, to adopt and practice effective strategies to minimize postharvest losses of citrus fruits.Item Dip treatment of Aloe vera gel and Aloe vera in combination with cinnamon essential oils on stem-end rot of mango cv. ‘Karthakolomban’(2022) Karunarathna, N. S. N.; Abeywickrama, K.; Kodituwakku, T. D.This study was conducted to investigate the applicability of Aloe vera gel alone and mixed with cinnamon leaf and bark oil in controlling stem-end rot (SER) and extending the shelf life of mango cv. ‘Karthakolomban’. Mangoes were subjected to dip treatments of Aloe vera gel and Aloe vera gel in combination with cinnamon bark oil (2.0 μL/mL) and cinnamon leaf oil (2.0 μL/mL) and their pathological, physicochemical, sensory properties, and percentage shriveling were evaluated after a 10 d storage period at 12-14℃. Dip treatment of Aloe vera gel + cinnamon oils and Aloe vera gel reduced SER by 3.0 - 6.0%. Physicochemical and sensory properties did not show drastic alterations among all treatments and controls. Mangoes subjected to Aloe vera gel + cinnamon oil treatments demonstrated 0% shriveling. Uncoated fruits showed the highest shriveling. The findings highlight that Aloe vera gel may have a better prospect in the preservation and quality maintenance of mango in combination with cinnamon oils.Item Physiological disorders of selected Citrus fruit species in Sri Lanka and their effect on fruit quality(JOURNAL OF HORTICULTURE AND POSTHARVEST RESEARCH, 2021) Jayasekara, A.; Abeywickrama, K.; Daranagama, A.; Kodituwakku, T.Purpose: This study was conducted to identify the physiological disorders and their symptoms of selected Citrus fruit species (C. sinensis, C. limon and C. crenatifolia). Furthermore, it was aimed to determine whether physicochemical and sensory properties were affected by physiological disorders. Research method: Citrus fruits with physiological disorders were observed separately for visible changes and characters were recorded and photographed. Moreover, Citrus fruits with physiological disorders were analyzed for physicochemical and sensory properties. Findings: Many physiological disorders were recorded from three Citrus fruit species including chilling injury, sun burn, stem-end rind breakdown, oleocellosis, rind disorder, puff and crease, granulation, wind injury, peteca, fruit splitting and fruit cracking. Based on the overall result of sensory analysis, it can be concluded that most of the physiological disorders in studied Citrus species appear on the peel but not adversely affect the edible internal portion of the fruits. Physicochemical properties of C. limon are not adversely affected by physiological disorders whereas C. sinensis and C. crenatifolia are affected by physiological disorders. Limitations: Availability of selected Citrus fruit species throughout the year is limited due to their seasonality. Originality/Value: This study provides novel information about the physiological disorders of some Citrus species in Sri Lanka and other parts of Asia and a future potential exists in controlling these disorders to provide healthy and quality fruits to the market.Item In vitro and in vivo Application of Eco-friendly Treatments to Control Postharvest Stem-end Rot of Naturally Infected Avocado (cv. Pollock)(The Journal of Agricultural Sciences - Sri Lanka, 2021) Nilmini, R.K.; Kodituwakku, T.D.; Abeywickrama, K.; Kuruppu, M.Purpose: Stem-end rot (SER) is an endophytic fungal infection of avocado causing significant postharvest losses, affecting its marketability. This study was conducted to identify effective concentrations of selected eco-friendly essential oils and chemicals to control SER pathogens by conducting in vitro bioassays and to develop treatments to control SER in naturally infected avocado (cv. Pollock) using less hazardous alternatives to synthetic fungicides. Research Method: In vitro disc volatilization and poison food bioassays were conducted to identify inhibitory concentrations of some essential oils and chemicals against SER pathogens. Avocado fruits were subjected to eco-friendly fumigation and dip treatments and their pathological, physicochemical and sensory properties were assessed after 7 days of storage at 15 °C. Findings: Disc volatilization bioassay revealed that 5 µL/plate clove oil was most effective against Lasiodiplodia theobromae, Diaporthe nelumbonis and Fusarium oxysporum. According to Poisoned food bioassay, 5% (w/v) sodium bicarbonate and 0.07% (v/v) acetic acid were highly effective against the test pathogens. SER incidence of avocado fruits has been successfully delayed for 7 days after subjecting to fumigation treatment with clove oil and dip treatments with sodium bicarbonate and acetic acid, followed by storage at 15 °C. None of the treatments adversely affected physicochemical and sensory properties of avocado. Originality/Value: Treatments could be further improved by conducting a medium-scale in vivo trial to obtain good quality avocado with higher consumer acceptance.Item Pathogenicity of Stem-end Rot Associated Fungi Isolated from Karthakolomban Mango and Their Control by Spray and Fumigation Treatments with Selected Essential OilsPathogenicity of Stem-end Rot Associated Fungi Isolated from Karthakolomban Mango and Their Control by Spray and Fumigation Treatments with Selected Essential Oils(The Journal of Agricultural Sciences - Sri Lanka, 2020) Kodituwakku, T. D.; Abeywickrama, K.; Karunanayake, K. O. L. C.Purpose: Stem-end rot (SER) is a major disease of mango that causes serious postharvest losses. Application of fungicides is environmentally unsound and is being practiced currently in its control. This study was conducted to develop essential oil treatment systems as eco-friendly strategies to control SER of Karthakolomban mango and to determine the pathogenicity of several SER associated fungi. Research Method: Pathogenicity of four fungal isolates in SER was assessed by inoculating them on Karthakolomban mango fruits. Karthakolomban mango fruits were subjected to spray and fumigation treatments using four essential oils and their pathological, physicochemical and sensory properties were evaluated after a 8-day storage at 12 – 14 ºC. Findings: Lasiodiplodia theobromae, Pestalotiopsis sp., Phomopsis sp. and Xylaria feejeensis were the major SER pathogens of mango. X. feejeensis was identifi ed as a SER pathogen for the fi rst time in Sri Lanka. Spray and fumigation treatments conducted using basil, clove, cinnamon leaf and cinnamon bark oils eff ectively controlled SER of Karthakolomban mango stored at 12 – 14 ºC for 8 days. Mango sprayed with 1.6 μL/mL cinnamon bark oil has displayed no SER after induced ripening. None of the treatments caused drastic alterations in physicochemical and sensory properties of mango. Research Limitations: Storage period of mango was restricted to 8 days due to the initiation of natural ripening which was the major limitation to achieving a further enhanced shelf life. Originality/value: The treatment strategies developed by this research could be commercialized as biosafe SER control strategies in reducing postharvest losses of mango in the local and international trade.Item Aloe vera gel and cinnamon essential oils-incorporated Aloe vera on stem-end rot control of mango (cv. Karthakolomban) using dip treatment(Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Karunarathna, N.S.N.; Abeywickrama, K.Stem-end rot (SER) is a major post-harvest disease of mango worldwide. Naturally occurring biologically active compounds from plants are expected to be more suitable and less harmful than synthetic fungicides. Current research was carried out to investigate the applicability of Aloe vera gel and cinnamon bark oil and cinnamon leaf oil-incorporated Aloe vera gel in controlling SER and extending post-harvest shelf life of mango (cv. Karthakolomban). Dip treatments of A. vera gel and cinnamon bark oil (2.0 μL/mL) and cinnamon leaf oil (2.0 μL/mL) incorporated A. vera gel were carried out for 90-day old mango fruits and their pathological, physicochemical, sensory properties and percentage shriveling were evaluated after 10-day storage at 12-14 ℃. After the initial dip treatment trial, a scaling up experiment was conducted using the best treatments where treated and control mangoes were placed in ventilated corrugated fiberboard boxes instead of plastic trays to store mango at 12-14 ℃. Statistical analysis of the results was carried out using MINITAB 18 statistical software. Data with respect to physicochemical properties were analyzed using One-way ANOVA and Tukey’s multiple comparison test. Kruskal Wallis non-parametric test was used to analyze data with respect to pathological, shriveling and sensory properties. Dip treatments of Aloe vera gel in combination with cinnamon leaf and bark oils reduced SER severity of mango to 3.0% in both trials once fruits were subjected to induce ripening. A. vera gel treatment reduced SER severity of mango to 6.0%. A. vera gel, cinnamon bark and leaf oil-incorporated A. vera gel treatments significantly reduced SER severity of mango in comparison to the negative control (distilled water) which showed SER severity of 19.0%. Physicochemical properties namely total soluble solids, titratable acidity, pH, firmness and weight loss of A. vera gel and gel plus oil treated mangoes were similar to the negative control fruits according to the statistical analysis. Percentage shriveling of mango subjected to A. vera gel treatments was reduced to 0- 0.4% compared to the uncoated control fruits which indicated a shriveling of 1.6%. Sensory properties of mango did not demonstrate any drastic alteration between all treatments. Current ecofriendly treatment strategies could be introduced to horticulture industry to reduce post-harvest loss of mango in local trade, during transportation and exportation via air cargo within 10 days.Item Nutritional quality of Cavendish banana (Musa acuminata, AAA) as affected by basil oil and determination of basil oil residues by GC-MS(Journal of Science, Faculty of Science, University of Kelaniya, 2019) Siriwardana, H.; Abeywickrama, K.; Kannangara, S.; Jayawardena, B.The effectiveness of basil oil on the nutritional properties of Cavendish banana and chemical composition of basil oil and oil residue levels of treated banana fruits were evaluated in this study. Cavendish banana hands were treated with 1% alum (w/v), 1% alum (w/v) + 0.4% Ocimum basilicum (basil) oil, distilled water (control) and packaged in Low Density Polyethylene (LDPE) bags and stored at a cold room at 12-14ºC. After two weeks of cold storage banana were induced ripened and nutritional contents of treated Cavendish banana were determined. Gas Chromatography - Mass Spectrometry (GC-MS) was instrumental in identifying the chemical constituents of basil oil as well as residues in basil oil treated Cavendish banana peel after two weeks of storage at 12-14ºC.Item Nutritional quality of Cavendish banana (Musa acuminata, AAA) as affected by basil oil and determination of basil oil residues by GC-MS(Journal of Science of the University of Kelaniya Volume:10, 2019) Siriwardana, H.; Abeywickrama, K.; Kannangara, S.; Jayawardena., B.The effectiveness of basil oil on the nutritional properties of Cavendish banana and chemical composition of basil oil and oil residue levels of treated banana fruits were evaluated in this study. Cavendish banana hands were treated with 1% alum (w/v), 1% alum (w/v) + 0.4% Ocimum basilicum (basil) oil, distilled water (control) and packaged in Low Density Polyethylene (LDPE) bags and stored at a cold room at 12-14ºC. After two weeks of cold storage banana were induced ripened and nutritional contents of treated Cavendish banana were determined. Gas Chromatography - Mass Spectrometry (GC-MS) was instrumental in identifying the chemical constituents of basil oil as well as residues in basil oil treated Cavendish banana peel after two weeks of storage at 12-14ºC.1 Nutritional properties of basil oil treated Cavendish banana showed no adverse changes compared to control. Methyl chavicol (estragole) was the most abundant component (74.44%) of basil oil followed by linalool (15.01%). GC-MS data revealed that negligible amount of residues of basil oil retained in treated Cavendish banana after 14 days. Basil oil treatment and subsequent modified atmosphere packaging of Cavendish banana is recommended as an ecofriendly strategy for air freight or long distance transport over land.Item Nutritional quality of Cavendish banana (Musa acuminata, AAA) as affected by basil oil and determination of basil oil residues by GC-MS.(Journal of Science 2019, Department of Botany, University of Kelaniya, Sri Lanka, 2019) Siriwardana, H.; Abeywickrama, K.; Kannangara, S.; Jayawardena, B.The effectiveness of basil oil on the nutritional properties of Cavendish banana and chemical composition of basil oil and oil residue levels of treated banana fruits were evaluated in this study. Cavendish banana hands were treated with 1% alum (w/v), 1% alum (w/v) + 0.4% Ocimum basilicum (basil) oil, distilled water (control) and packaged in Low Density Polyethylene (LDPE) bags and stored at a cold room at 12-14ºC. After two weeks of cold storage banana were induced ripened and nutritional contents of treated Cavendish banana were determined. Gas Chromatography - Mass Spectrometry (GC-MS) was instrumental in identifying the chemical constituents of basil oil as well as residues in basil oil treated Cavendish banana peel after two weeks of storage at 12-14ºC.1 Nutritional properties of basil oil treated Cavendish banana showed no adverse changes compared to control. Methyl chavicol (estragole) was the most abundant component (74.44%) of basil oil followed by linalool (15.01%). GC-MS data revealed that negligible amount of residues of basil oil retained in treated Cavendish banana after 14 days. Basil oil treatment and subsequent modified atmosphere packaging of Cavendish banana is recommended as an ecofriendly strategy for air freight or long distance transport over land.
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