Browsing by Author "Nugaliyadde, L."

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Bioactivity of leaf volatiles of Azadirachta indica A. Juss. and Murraya koenigii Spreng. against Sitophilus oryzae L.(Coleoptera: Curculionidae)
(National Science Foundation of Sri Lanka., 2002) Paranagama, P.A.; Abeysekera, K.H.T.; Nugaliyadde, L.; Abeywickrama, K.
Repellent activity, fumigant and contact toxicities of leaf volatiles of Azadirachta indica A. Juss. and Murraya koengii Spreng. were evaluated against Sitophilus oryzae L. In the dual choice repellency test with A indica leaf volatiles, significantly higher number of insects was repelled at doses above 100 mg, whereas volatiles of At. koenigii attracted insects at 25 mg dose and repelled at 300 mg dose. In the fumigant toxicity test 100% mortality was observed at the concentration of 32.5 mg/ml, 3 days after the treatment with 2 volatiles separately. The L C n values for fumigant toxicities were 13.5 and 22.5 mg/ml for A. indica and At. koenigii volatiles, respectively. In contact toxicity test, 100% mortality was observed immediately after 48 h contact exposure of insects at concentrations of 0375 and 0.125 mg/cm1 of A indica and At. koenigii respectively. The respective L C W values were 0.12 and 0.08 mg/cm1 for A. indica and At. koenigii leaf volatiles.
An e-pest surveillance and advisory system to empower farmers in managing rice pests and diseases in Sri Lanka
(International Research Conference on Smart Computing and Systems Engineering - SCSE 2018, 2018) Ponnamperuma Arachchi, J.; Bandara, D.M.B.N.; Perera, S.P.M.G.N.H.; Nilakshi, S.V.; Nugaliyadde, L.; Sisira Kumara, W.A.G.
An e-pest surveillance and advisory system called “Govi Vedaduru” was developed with two broad objectives in mind; to enable rice farmers in Sri Lanka to manage pest and disease problems efficiently and in a cost-effective manner and to facilitate relevant authorities with better monitoring and control of pest and disease incidents. Many farmers are not competent to identify pests and diseases related issues and decide the correct management practices themselves. They expect the assistance of the field officers of government agriculture extension services for this purpose. However, lack of officers and the knowledge gaps that exist among them hinder the achieving these expectations. Hence, farmers do not receive the correct advice in time and crop get damaged leading to higher production cost. The Govi Vedaduru mobile application was designed to provide an advisory service through smart phones enabling the farmers to obtain expert guidance from the Rice Research Stations of Department of Agriculture (DOA), in identifying their field problems and remedial measures to follow. A user friendly mobile interface was developed in local languages (initially Sinhala) to upload data about the pest and disease problems. The system was initially piloted in five areas (yaya) of rice cultivation representing two agro-ecological zones in Galle district in Sri Lanka. A follow up survey of the participant farmers indicated that they received timely, useful and trustworthy advice that helped them with correct remedial measures. The reports generated via web application with limited incident data showed the system’s capability of providing valuable information to relevant authorities for monitoring and planning purposes.
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.
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.
Inhibition of aspergillus flavus link and aflatoxin formation hy essential oils of cinnamomum xeylanicum (L) and cymbopogon nardus rendle
(Postgraduate Institute of Agriculture, University of Peradeniya: Peradeniya, 2002) Jayaratna, K.H.T.; Pranagama, P.A.; Abeywickrama, K.P.; Nugaliyadde, L.
The essential oils of Cinnamomum zeylanicum (L.) leaf and Cvmbopoeon nardus Rendle were tested for their fungistatic, fungicidal and qflatoxin suppressing efficacy against an isolate of Aspergillus flavus Link, isolated from rice. The mycelial growth and the aflatoxin formation in SMKY semi synthetic liquid medium in the presence of different concentrations of two test oils were monitored. At concentrations varying from 100 to 500 ppm of the essential oil of C. zeylanicum. the mycelial dry weight decreased from 0.49 to 0.01 g/50 ml. The percentage inhibition of the mycelial growth of A. flavus increased from 50 to 95 when treated with 1000 to 1800 ppm of C. nardus oil. The minimum lethal concentrations (MLCs) for the essential oils of C. zeylanicum leaf and C. nardus were 1000 and 4000 ppm, respectively. Aflutoxins were not present in the medium at or above the concentrations of400 and 600 ppm C zeylanicum leaf and C nardus oils, respectively
Inhibition of Aspergillus flavus Link and Anatoxin Formation by Essential Oils of Cinnamomum zeylanicum (L.) and Cymbopogon nardus Rendle
(Tropical Agricultural Research, 2002) Jayaratne, K.H.T.; Paranagama, P.A.; Abeywickrama, K.P.; Nugaliyadde, L.
K.H.T. Jayaratne, P.A. Paranagama, K.P. Abeywickrama1 and L. Nugaliyadde2
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.
Toxic effect of Volatiles from five plants on Sitotroga cerealella (Oliver) (Lepidoptera: Gelechiidae) in stored paddy
(Sri Lanka Association for the Advancement of Science, 2002) Paranagama, P.A.; Jayaratne, K.H.T.; Nugaliyadde, L.; Abeywickrama, K.P.