Journal of the Rubber Research Institute of Sri Lanka
Permanent URI for this collectionhttps://dl.nsf.gov.lk/handle/1/8676
Browse
138 results
Search Results
Item The efficiency use of phosphatic fertilizer in relation to the phosphorus fixing capacities of the rubber soils(Rubber Research Institute. Agalawatta, 1977) Silva, C.G.; Kumarakulasuriya, S.; Wickramasinghe, L.J.Item Studies on inoculation of cover legumes for improving nitrogen fixation(Rubber Research Institute. Agalawatta, 1977) Waidyanatha, U.P. De S.; Pathiratne, L.S.S.; Ariyaratne, W.A.Many rhizobial strains were screened for their nodulating ability against Pueraria, Centrosema, Calopogonium and Desmodium spp. using seedlings grown in nutrient agar. Pueraria in pots but not in the field. This is probably due to natural populations of rhizobia in the soil which were able to successfully compete with the introduced strains in nodulating on the legume. There was evidence that indigenous rhizobia themselves formed effective nodule and fixed nitrogen.Item Nutrition and fertilizer use in Hevea and associated covers in peninsular Malaysia - a review(Rubber Research Institute. Agalawatta, 1977) Pushparajah, E.The paper reviews some of the latest findings on nutrition of Hevea and effects of fertilizer on latex properties. It also considers work on increased efficiency in use of fertilisers. The latter includes studies on effect of fertilisers on soil properties and availability of fertiliser residues. The use of appropriate covers and their management to increase their efficiency is considered. Additionally, the influence of the covers on the nitrogen nutrition of Hevea is discussed. The information available indicates that the applications of inorganic N fertilisers could be avoided for up to 8-109 years of tapping, with consequent economic benefits.Item How can we most rapidly increase the production of natural rubber(Rubber Research Institute. Agalawatta, 1977) Bonner, J.Item Field performance of young coffee seedlings and cuttings intercropped with rubber(Rubber Research Institute. Agalawatta, 1988) Rodrigo, V.H.L.; Nugawela, A.; Kariyawasam, L.S.; Aluthhewage, R.K.Coffee may be planted either using seedlings or cuttings. Anyhow, a comparative study of their field establishment and performance has not been made. Iin this study seedlings and cuttings of Coffea canephora intercropped with rubber were compared for their field stablishment and growth. It is evident that there is no difference in the success of their field establishment. The dry matter yield determinants of plants, i. e. light intercept ion, conversion efficiency and rate of loss of dry matter, estimated by total leaf area, CO2 assimilation rate and dark respiratory rate respectively, are also similar in both seedlings and cuttings. This is confirmed by the similar mean total dry weight of a seedlings and a cuttings. The partitioning of assimilates is more towards root development in the cuttings and is evident by the significantly high root dry weight and the root/shoot ratio. The percentage of assimilates partitioning towards the growth of aerial parts is less in the cuttings, i. e. 52 and 67perc. for cuttings and seedlings respectively. Despite of similar light levels, the CO2 assimilation rates are lower in the afternoon in both seedlings and cuttings. The perc. deeline is 23.5 and 18.6perc. for seedlings and cuttings respectively.Item Shoot tip culture as a method of micropropagation of Hevea(Rubber Research Institute. Agalawatta, 1988) Gunatilleke, I.D.; Samaranayake, C.Shoot tips of Hevea from aseptically grown seeedlings were established in culture on Murashige and Skoog (MS) liquid medium with half strenth salts, supplimented with BAP +IBA or MS solid medium, with full strenth salts with and without BAP + IBA. BAP was found to be better for axillary bud proliferation and growth than the other cytokinines. Proliferation of buds improved with successive subcultures. A multiplication rate of 30 + 2 shoots per explant was obtained with threee subcultures in 165 daysItem Effect of potassium and magnesium on growth of young Hevea brasiliensis(Rubber Research Institute. Agalawatta, 1988) Weerasuriya, S.M.; Yogaratnam, N.The effect of potassium and magnisium fertilisers on growth of young Hevea brasiliensis were studied using clones PB 86, RRIC 100, RRIC 103, and RRIC 121 with the objective of determining the requirement of these elements during the early phase of establishment of these clones. Three commercial fertilisers were evaluated as of magnesium. Potassium requirement of clone PB 86 during the first year was found to be approsimately 33g K/plant/year. It was found that clones. RRIC 100 and RRIC 121 needed higher amount of K than PB 86 for normal growth. Potassium application caused an overall reduction in growth of clone RRIC 103 where the soil K level was 0.07 me./100g suggesting that this level is adequate for this clone during its first year of growth. Total dry weight was significantly increased when Mg application was increased from 11 to 22g/plant/year in clone RRIC 103 but such effects were not seen in clones PB 86, RRIC 100 and RRIC 121Item Secondary characters and their association with latex yield in Hevea brasiliensis(Mull Arg.)(Rubber Research Institute. Agalawatta, 1988) Olapade, E.O.Ten Hevea clones developed at the Rubber Research Institute Of Nigeria (RRIN) and a control clone RRIM 600 were evaluated for their latex yield after six months of tapping. The mean dry latex yield recorded for each clone was correlated with their Juvenile secondary characters i. e Height, Girth and Plant Vigour at 18 months. Significant variability was exhibited by the clones in terms of yield with clone C 83 having the highest mean latex yield of 42.15 g/t/t/ while clone C 202 had the least mean yield of 22.73 g/t/t. The secondary characters i. e Hewight, Girth and Vigour were significantly positively correlated to themselves but all negatively correlasted to latex yield. However a spurious correlation was established between latex yield and the secondary characters. The implication of the results are discussedItem An analysis of growth patterns of Hevea clones(Rubber Research Institute. Agalawatta, 1988) Margret, H.A.W.; Abeyasekera, S.; Jayasekera, N.E.M.Four girth measurements collected over four years, before tapping from ten Hevea clones grown in two sites have been analysed to study the growth pattern. Year to year variation in both sites was mainly due t linear component of growth. Growth of individual clones too was mainly due to linear effect. But some clones in one site showed significant quadratic and or cubic component. This was due to non linear growth of plants in some plots. Ten clones have been groued (a) according to the when averaged over four years so that clones within a group have the same average girth and (b) on the gradient of the regression fitted to the girth measurement increasing over the four years. RRIC 52 had the fastest growth in both sites. RRIC 103 had the same growth rates in both sites suggesting that it has a greater stability to local environmental changes.Item Effect of leaf litter on direct and indirect mobilization of P from apatite(Rubber Research Institute. Agalawatta, 1987) Pathiratne, L.S.S.; Waidyanatha, U.P. De S.; Peries, O.S.Leaf litter as direct and indirect means of improving P availability from apatite was tested. Application of leaf litter impo=roved the P uptake by indicator crops but did not influence the availability of P from applied apatite.