http://dr.lib.sjp.ac.lk/handle/123456789/3299 Wed, 07 Jan 2026 05:57:17 GMT 2026-01-07T05:57:17Z http://dr.lib.sjp.ac.lk/handle/123456789/4596 Eco-Friendly Alternatives for Storage Pest Management: Leaves of Ruta Graveolens (Aruda) as a Repellent against the Rice Weevil, Sitophilus oryzae L. Perera, A.G.W.U.; Karunaratne, M.M.S.C. In view of worldwide interest and greater public awareness in finding plant products as the most promising and ecologically safer alternatives for synthetic insecticides in post-harvest protection of stored rice, present study was undertaken to explore the potential of leaves of Ruta graveolens (Aruda) as a repellent against S.oryzae infestations. Leaf powder and solvent extracts of R. graveolens were evaluated for their contact and fumigant repellent properties against seven day old S. oryzae adults. In contact repellency test, weevils (20 each) were exposed to 1.0 g, 3.0 g, 5.0 g, and 7.0 g of leaf powder mixed with white raw rice grains in a modified cup bioassay apparatus. Fumigation repellency of leaf powder was tested using same dosages and the number of weevils in a fumigation-repellency chamber. Number of weevils that moved from the bioassay chamber was recorded one hour after weevil introduction. Leaves of R. graveolens were extracted in hexane, ethyl acetate, methanol, distilled water and different concentrations 10, 50, 100% (v/v) were assessed separately to evaluate repellent activity by means of an area preference bioassay. In all experiments, ten weevils or each were tested and the number repelled was recorded 30 minutes after weevil introduction. Highest contact and fumigant repellent effects were elicited by 7.0 g of leaf powder resulting 96% and 95% respectively, whilst lowest dose also produced more than 50% repellency indicating extremely strong repellent action of the plant powder. In comparison, aqueous extract exhibited the most potent repellent activity (91%) while other extracts were producing over 70% repellent effects on weevils at the concentration of 100% (v/v). Overall findings of the study suggest that both powder and extracts of R. graveolens leaves could be used as eco-friendly agents for post-harvest rice protection. Thu, 01 Jan 2015 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/4596 2015-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/3359 Preparation of Liquid Medicinal Soap Products Using Adhatoda Vasica (Adhatoda) Leaf Extracts Wijetunge, W.M.A.N.K.; Perera, B.G.K. Main objective of this research was to prepare medicinal soaps based on Adhatoda vasica. Optimum extraction conditions to obtain antibacterial and antioxidant active extracts from adhatoda were selected from a range of extraction conditions carried out using maceration, soxhlet extraction and sonication. The antibacterial activity of the extracts was determined by the disk diffusion assay against B.cereus, S.typhimurium, S.aureus and E.coli. The Folin Cioclteau (FC) assay and the DPPH radical scavenging assay were used to obtain the antioxidant capacity (AOC) and the percentage radical scavenging activity respectively. An antibacterial liquid soap and an antioxidant liquid soap were prepared using the adhatoda leaf extracts and these bioactivities of the prepared medicinal soaps were determined with respect to their control soaps. Furthermore, phytochemical analyses of the bioactive extracts were carried out to investigate the presence of different secondary metabolites. Methanolic soxhlet extract of adhatoda exhibited significant antibacterial activity against all the tested bacterial strains. The ethyl acetate soxhlet extract displayed the highest AOC of 109±2 μg PGE/mg by the FC assay and a 22±1% radical scavenging activity in the DPPH assay. These extracts were used to prepare the antibacterial and antioxidant adhatoda soaps respectively. Antibacterial adhatoda soap indicated significant antibacterial activity at a 50 mg/mL concentration against S. aureus compared to the control. According to the results of a thumb impression test, a reduction in the number of bacterial colonies was observed in the thumb impression of the hand washed with the new adhatoda antibacterial soap compared to the control. The antioxidant adhatoda soap displayed approximately three times better AOC (10±0 μg PGE/mg) relative to the control soap (3±0 μg PGE/mg). Incorporation of adhatoda extracts into soap products to enhance their medicinal properties has not been reported so far and the promising results of this study indicate the possibility of this approach. Wed, 26 Oct 2016 08:03:05 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3359 2016-10-26T08:03:05Z http://dr.lib.sjp.ac.lk/handle/123456789/3358 Effect of Potassium on Growth, Fruit Quality Improvements and Resistance to Anthracnose in Field Grown Capsicum (Capsicum Annum L. Cv. ‘Hungarian Yellow Wax’) Somapala, K.S.; Weerahewa, H.L.D.; Thrikawala, S. Postharvest losses of capsicum crop accounts for 30-40% of total crop production. It has been shown that postharvest losses of capsicums can be reduced significantly with the application of potassium due to improvements in disease resistance and fruit quality. The objective of this study was to investigate the effect of higher doses of potassium (K) on plant growth, yield and fruit quality parameters and resistance to anthracnose disease of capsicum cv. ‘Hungarian Yellow wax’. Three different levels of potassium, Department of Agriculture (DOA) recommended level [180g per bed (control)], double the level (360g per bed) and three times of the level (540g per bed) were applied to the soil in a Randomized Complete Block design. The same experiment was repeated in three farmer fields of Naula Grama Niladhari (GN) division in Dambulla Divisional Secretariat of Matale district of the central province of Sri Lanka. Plant growth parameters were measured at two week intervals, and fruit quality parameters (TSS, Ph, %TA), fruit physical parameters (length, width, pericarp thickness, fresh weight, firmness and cell wall thickness) were recorded. Finally the resistance to diseases of capsicum fruits was also tested by inoculation of Colletotrichum capsici to the fruits. This study concludes that application of higher doses of potassium improves some plant growth parameters (height and plant diameter at base), fruit physical parameters (fruit length, width , fresh weight, firmness and cell wall thickness). The tripled and doubled the dose of potassium application reduced anthracnose disease by over 75% and 95% respectively indicating that higher level of K could have a significant impact in reducing postharvest losses of capsicum in local conditions Wed, 26 Oct 2016 08:01:38 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3358 2016-10-26T08:01:38Z http://dr.lib.sjp.ac.lk/handle/123456789/3357 Evaluation of Groundwater Quality in Five Grama Divisions of Maharagama Urban Area Using Groundwater Quality Index (WQI) Rathnasri, P.A.S.A.; Manage, P.M. The Maharagama urban area is a heavily populated area in Colombo district. Groundwater in this area is having a great vulnerability for pollution by anthropogenic activities. The present study was carried out to monitor some important water quality parameters, to evaluate the quality of groundwater in the study area using a Water Quality Index (WQI) and to compare the water quality between Grama Niladari (GN) divisions in the study area. Five GN divisions (Jambugasmulla, Gangodawila south B, Wijerama, Navinna and Wattegedara) were selected for the study. 55 wells were sampled during the study. The resulted WQI values in groundwater ranged from 17.08 to 280.91. The results revealed that the water quality of the wells deviate from excellent to very poor quality. The nitrate concentration was high (>45mg/l) in some wells. Considering all the water quality parameters, the poorest water quality was recorded in Navinna GN division. It was observed that unregulated garbage dumping, uncontrolled application of organic and inorganic fertilizers, constructing toilet pits very close to wells and unregulated human settlements have been increasing in the study area. Wed, 26 Oct 2016 08:00:24 GMT http://dr.lib.sjp.ac.lk/handle/123456789/3357 2016-10-26T08:00:24Z