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Item Land and soil requirements for optimum growth and productivity of rubber under Sri Lankan conditions(Rubber Research Institute of Sri Lanka. Agalawatta, 2001) Samarappuli, L.Item Rubber plantations as self-sustaining agroforestry systems(Sri Lanka Forest Department:Battaramulla, 1995) Samarappuli, L.; Yogaratnam, N.Item Use of neutron moisture meter n soil-plant-water relation studeis of rubber (Hevea braziliensis)(University of Ruhuna Faculty of Agriculture. Kamburupitiya, 2000) Samarappuli, L.; Yogaratnam, N.; Hettiarachchi, R.; Karunadasa, P.; Mithrasena, U.Item Towards shorter immaturity and improved yields by mulching with rice straw(Rubber Research Institute. Agalawatta, 1992) Samarappuli, L.; Yogaratnam, N.; Samarappuli, P.; Mitrasena, U.In this study with immature Hevea brasiliensis, multing with paady straw around the base of the tree was found to be a better agronomic practice than growing leguminous cover crops such as Pueraria phaseoloides and Desmodium ovalifolium or allowing natural vegetation to grow in the inter-row area. Girthing had been much higher with mulching which resulted into reduction of the immature, unproductive period by approximately 18 and 12 month in comparison with naturals and creeping legumes respectively. In addition to early tapping, yield of latex was also higher during the early stages, increases in the region of 33perc. and 40perc. in comparison with creeping legumes and naturals respectively. The present value of the benefit achieved from mulching amount to Rs. 31,088/= per hectare of which Rs. 19,740/= is due to extra yield and the balance of Rs. 11,348/= is saving on inputs as a result of early maturity. Consequently, a net present value (NPV) of Rs. 7.8 million at national level can be achieved with the above practice at 50perc. level of adoptionItem The contribution of rubber plantations towards a better environment(Rubber Research Institute. Agalawatte, 1996) Samarappuli, L.Item Root development in Hevea brasiliensis(Rubber Research Instutite. Agalawatte, 1996) Samarappuli, L.Item Plastochron indexes in Hevea brasiliensis growth under two water regimes(Rubber Research Institute of Sri Lanka. Agalawatte, 1987) Samarappuli, L.Rubber (Hevea brasiliensis) plants were grown in two water regimes, so that one treatment (wet plants) received water every other day and other treatment (dry plants) received water every seventh day, during the experimental period. In wet plants, plastochron indexes (PI) advanced more rapidly with time and final leaf size was greater (9.6 cm average). Diminished water supply appears to affect the rate of development and the sequence of developmental events, as observed when plastochron index was plotted against time and when leaf length was plotted against plastochron index of wet and dry treatments. It appears that the plastochron index could be used as a scale for studies connected with the effects of water availability on the development of Hevea brasiliensis.Item Weed control in rubber plantations(Rubber Research Institute of Sri Lanka. Agalawatta, 1991) Yogaratnam, N.; Samarappuli, L.; Dissanayake, D.M.A.P.Item Litter accumulation from Mucuna bracteata cover crop and its effects on some soil chemical properties in rubber plantations(Rubber Research Institute. Agalawatta, 2010) Chathurika, S.; Samarappuli, L.; Mapa, R.B.Item Soil management practices in rubber plantations and their effects on the environment(Rubber Research Institute of Sri Lanka. Agalawatte, 1997) Samarappuli, L.; Yogaratnam, N.