Botany
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Item Repellency and toxicity of four essential oils to Sitophilus oryzae L. (Coleoptera: Curculionidae)(2004) Paranagama, P.A.; Abeysekera, K.H.T.; Nugaliyadde, L.; Abeywickrama, K.P.Item Isolation and identification of fungi from mushroom composts and evaluation their biological activity(1999) Wickremasinghe, R.; Abeywickrama, K.P.; Abeythunga, D.T.U.Item An integrated treatment of basil oil (Ocimum basilicum) and alum with modified atmosphere to control crown rot disease in Embul banana(2009) Abeywickrama, K.P.; Wijerathna, C.; Herath, H.; Sarananada, K.H.A study was undertaken with the objective of developing environmental friendly integrated treatment strategies for controlling crown rot disease in Embul banana. The fungicidal potential of 1% alum (sodium aluminium sulphate) was observed in vitro. Findings indicate that alum+basil oil (0.16% or 0.20% v/v) treated 80, 85, 90 day mature Embul banana fruits were relatively free from crown rot dis-ease after subjecting to modified atmosphere packaging (MAP) and storage at optimum temperature. Crown rot disease severity of 85-day mature and vacuum packed 1% alum (w/v) washed banana was lower and comparable to carbendazim (bavistin) treatment. After ripening, there was no significant difference in physico-chemical properties (titratable acidity, total soluble solids, pH, fruit firmness) of all treated fruits compared to the control. Sensory properties were slightly affected as compared to un-treated fruits. MAP and vaccum packaging in combination with alum and/ or basil oil spray treatments at 12-140C could extend the storage life of Embul banana upto 32 days which could be recommended for sea shipment.Item Effect of the essential oils of Cymbopogon citratus, C. nardus and Cinnamomum zeylanicum on pest incidence and grain quality of rough rice (paddy) stored in an enclosed seed box(WFL Publisher, 2003) Paranagama, P.A.; Abeysekera, T.; Nugaliyadde, L.; Abeywickrama, K.P.The protective effect of the essential oils of Cymbopogon citratus, C. nardus and Cinnamomum zeylanicum leaf on paddy stored in wooden boxes lined with aluminium foil were evaluated. After 168 days of storage in oil treated boxes Sitotroga cerealella population was significantly lower in oil treated paddy than the control. The 1000 grain weight was higher in all three treatments (21.1 - 22.9 g) compared to the control (19.8 g). Percentage grain damage was lower in C. citratus and C. nardus treated paddy than the control. The percentage seed germination was not significantly different from that of the control in oil treated paddy though, in C. citratus treatment the seed germination was reduced. The milling quality of paddy was not affected by the essential oil treatment however; the flavour and stickiness of cooked rice was enhanced when treated with C. zeylanicum and C. citratus oils.Item Fungicidal and anti-aflatoxigenic effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus flavus Link. isolated from stored rice(The Society for Applied Microbiology, 2003) Paranagama, P.A.; Abeysekera, K.H.T.; Abeywickrama, K.P.; Nugaliyadde, L.Aims: To develop a natural fungicide against aflatoxigenic fungi, to protect stored rice, using the essential oil of lemongrass. Methods and Results: Aspergillus flavus Link. was isolated from stored rice and identified as an aflatoxigenic strain. Lemongrass oil was tested against A. flavus and the test oil was fungistatic and fungicidal against the test pathogen at 0Æ6 and 1Æ0 mg ml)1, respectively. Aflatoxin production was completely inhibited at 0Æ1 mg ml)1. The results obtained from the thin layer chromatographic bioassay and gas chromatography indicated citral a and b as the fungicidal constituents in lemongrass oil. During the fumigant toxicity assay of lemongrass oil, the sporulation and the mycelial growth of the test pathogen were inhibited at the concentrations of 2Æ80 and 3Æ46 mg ml)1, respectively. Conclusion: Lemongrass oil could be used to manage aflatoxin formation and fungal growth of A. flavus in stored rice. Significance and Impact of the Study: Currently, fungicides are not used to control fungal pests or mycotoxin production on stored rice. Rice treated with the essential oil of lemongrass could be used to manage fungal pests as well as the insect pests in stored rice. The essential oil is chemically safe and acceptable to consumers, as synthetic chemical fungicides can cause adverse health effects to consumers.Item Studies on the composition and biodegradation of cane molasses distillery slop of the Sevanagala sugar factory(Sri Lanka Association for the Advancement of Science, 1991) Chandrasena, G.; Widanapathirana, G.S.Item Effect of Sodium chloride (NaCl) salinity on some physiological traits of rice (Oryza sativa L.)(Sri Lanka Association for the Advancement of Science, 1991) Ranasinghe, A.; Peiris, B.Item Floristic composition of the undergrowth at a selected site in Hurulu forest reserve (sigiriya)(Sri Lanka Association for the Advancement of Science, 1991) Perera, B.M.S.; Solangaarachchi, S.M.Item Intraspecific neighbor effects on the growth and morphological plasticity of Salvinia molesta(Natural Resources, Energy and Science Authority of Sri Lanka, 1995) Solangaarachchi, S.M.; Hapuarachchi, H.T.Item Isolation and characterization of cellulolytic bacteria from decomposing rice straw(Natural Resources, Energy and Science Authority of Sri Lanka, 1995) Sirisena, D.M.; Manamendra, T.P.