Journal of the Rubber Research Institute of Sri Lanka
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Item An investigation on oil of rubber seed (Hevea brasiliensis)(Rubber Research Institute. Agalawatte, 1996) Njoku, O.U.; Ononogbu, I.C.; Owusu, A.J.Y.Oil from seeds of hevea brasiliensis traditionally used as thickening agent for saurce preparation was isolated, and its physical and chemical characteristics determined. Saponification yielded saturated and unsaturated fatty acids which were seperated by preferential crystallization using organic solvents. Methanol, Ethnol, Hexane and Acetone were found effective solvents inthis regard. Gas liquid chromatography (GLC) revealed large amounts of C18 fatty acids as well as traces of other fatty acids. The iodine values show that the solvents used in this study gave excellent yields of fatty acids with acetone being the most effective as a crystallization solvent to oil ratio 3:1 at 5 oC.Item The effects of the basic medium and the carbohydrate content on shoot cultures of Hevea brasiliensis(Rubber Research Institute. Agalawatte, 1996) Seneviratne, P.; Flegmann, A.W.; Wijesekera, G.A.S.Woody Plants Medium (WPM) was superior to murashige and skoog medium (M S), which showed better axillary bud growth of both juvenile and mature shoot materials. The effect was more pronounced in later passages, in particular, on the survival rate of the cultures. Most of the cultures grown on M S medium did not survive more than 24-28 weeks, while on WPM medium cultures survived for more than one and a half years, until the experiment was terminated. The level of sucrose in the medium also had an effect on the growth of the primary axillary shoots, specially the length and the leaf growth. The length of primary axillary shoots incresed with the increasing levels of sucrose in the medium up to 10 per cent with clonal materials. Explants did not survive beyond 8 weeks when the medium was not supplied with sucrose.Item In vitro evaluation of fungicides against rubber isolate of Thanatephorus cucumeris and management of Thanatephorus foot rot of Hevea seedlings(Rubber Research Institute. Agalawatta, 1997) Jayasinghe, C.K.; Fernando, E.B.; Fernando, B.I.Thanatephorus cucumeris, the causal agent of target leaf spot disease of Hevea also attacks the hypocotyls of germinated seeds and cause damping off and foot rot of seedling in Hevea nurseries in Sri Lanka. Sixteen fungicides were screened for their abilities to reduce the saprophytic growth of T.cucumeris on agar and in soil while five fungicides were tested to control foot rot of Hevea seedlings in pots. Five fungicides (benomy 1,Metalaxyl 8% + mancozeb 64%, tebuconazole, thiram and tridemorph) were found to be effective in inhibiting fungal growth 100% (EC 100 %) on agar at a very low concentration of 50 ug/ml. Three fungicides,viz.captan,mancozed,oxadixyl 10% + propineb 56%, pencycuron,propineb and triadimenol) showed EC 100 between 200-800 ug/ml.However,only four fungicides (benomyl,pencycuron,propineb and tebuconazole)reached the EC 100 within the tested range when assessed in the presence of soil indicating that these are the potential fungicides in management of rubber isolate of T.cucumeris. In pot culture trials two fungicides,pencycuron and benomy1 were found to be effective in controlling the disease.However,the disease was completely checked by traditional burning of soil.Item Susceptibility of different leaf stages of Hevea to Corynespora cassiicola(Rubber Research Institute. Agalawatta, 2010) Fernando, T.H.P.S.; Jayasinghe, C.K.; Wijesundera, R.L.C.; Siriwardena, D.Item Feasibility of rubber (Hevea brasiliensis Muell.Arg.) cultivation in Eastern province of Sri Lanka with the peasant community(Rubber Research Institute. Agalawatta, 2010) Iqbal, S.M.M.; Rodrigo, V.H.L.; Karunathilake, P.K.W.Item Impact of creeping vegetable cover crops on weed flora composition during the early growth of Hevea (Natural rubber) saplings in a tropical rain forest zone(RRI. Agalawatta, 2009) Okore, I.K.; Akpobome, F.A.Item Laboratory tests to assay responses of rubber (Hevea brasiliensis)genotypes to Phytophthora meadii(Rubber Research Institute. Agalawatta, 2009) Jayasuriya, K.E.; Wijesundera, R.L.C.Item Effect of different light regimes on above and below ground development of Hevea brasiliensis during early stage of growth(Rubber Research Institute. Agalawatta, 2009) Senevirathna, A.M.W.K.; Karunatillake, P.K.W.; Pathirana, P.D.; Rodrigo, V.H.L.Item A comparative study of Colletotrichum species causing anthracnose in Hevea(Rubber Research Institute. Agalawatta, 2009) Jayasinghe, C.K.; Fernando, T.H.P.S.; Jayawardana, N.Item Effect of potassium on growth, yield and mineral composition of young Hevea brasiliensis(Rubber Research Institute of Sri Lanka. Agalawatte, 1995) Iqbal, S.M.M.; Yogaratnam, N.