Browsing by Author "Senarathne, S.H.S."

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    Comparison of different weed management systems and their effects on yield of coconut plantations in Sri Lanka
    (2003) Senarathne, S.H.S.; Samarajeewa, A.D.; Perera, K.C.P.
    The influence of five different weed management systems on nut yield of coconut were evaluated to determine an economical and effective method of controlling weeds in coconut plantations in the low country, dry zone in Sri Lanka. Treatments imposed included slashing and mulching around the palms with slash (T1), slashing and removing the slash (T2), application of glyphosate (N-(phosphonomethyl)-glycine) alone at 1.44 kg ai ha - 1 (T3), application of glyphosate alone at 2.88 kg ai ha - 1 (T4) and cover cropping with Pueraria phaseoloides (T5). All treatments were applied twice a year, except for the cover cropping treatment, T5. Based on a reduction in weed biomass, treatments T3, T4 and T5 were found to be significantly effective over other treatments. Coconut yield was increased significantly ( P < 0.05) in glyphosateapplied plots at both tested rates. Control of weeds with the lower concentration of glyphosate (1.44 kg ai ha - 1 ) resulted in a 25% increase in nut yield over the uncontrolled weed plots. At this rate, it was found to be the most effective and economical method of controlling weeds in coconut plantations. Cover cropping with Pueraria phaseoloides was effective in controlling weeds in the long-term, but was not economical compared with the glyphosate application
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    Impact of Glyphosate on Weed Biomass and Growth. of Coconut Seedlings in Nurseries
    (2010) Senarathne, S.H.S.; Perera, K.C.P.
    The effects of five different weed management systems on growth of coconut seedlings were evaluated to detennine an economical and effective method for controlling weeds in coconut nurseries in the low country ofthe wet zone in Sri Lanka. The treatments comprised ofmanual weeding (TI)' application ofglyphosate at 1.44 kg ai/ha (T2), 1.08 kg ailha (T3), 0.72 kg ailha (T') and 0.36 kg ailha (Ts) applied at three-month intervals. Treatments 1 and 2 significantly reduced the weed biomass when compared to other treatmetns. The growth of coconut seedlings (in tenns pf height and girth) increased significantly (P<0.05) with the application of glyphosate at 1.08 kg ailha (T) at the end of the nursery growth period. At the higher concentration (1.44 kg ailha) the growth of seedlings was reduced at the latter part of the experiment. Therefore, the most costeffective treatment ofcontrolling we.eds in the study was to apply glyphosate at the rate of 1.08 kg ailha (31 of commercial mixturelha). Manual weeding was neither effective no economical.
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    Utilization of Different Plant Species available in Coconut Plantation to Produce Nutrient Rich Vermicompost
    (2015-06) Senarathne, S.H.S.; Ilangamudali, I.M.P.S.
    Vermicomposting is a well known technology that produces a valuable organic fertilizer from organic waste. Weeds in coconut plantations are good organic sources for vem1icompost production. The experiment was carried out to evaluate the quality of vermicompost produced by different weed or plant species commonly available in coconut plantations and also to evaluate the effect of these residues on the earth worm activity in the vermicomposting process. Vermicomposts were produced using different plant or weed species collected from coconut plantations in combination with cattle manure. The highest N content and worm growth was found in the vermicompost produced using Puereria phasioloides, Gliricidia sepium and Tithonia diversiJofia. The highest P content was recorded in vermicompost samples produced using Tithonia diversiJolia and Panicum maximum. Tithonia diversijolia, Pliereria phasioloides and GlirJc idia sepium showes significantly higher K content than the other plant species residues. Organic Carbon content was significantly high in vermicompost made with Tithonia diversiJolia, Gfiricidia sepium, Tephrosia pwpurea, Chromoleana odorata, PaniclInt maximum and Hyptis suaveolens. Worm mUltiplication rate was significantly lower % by Lantana camara, Chromofeana odorata, Hyptis suaveolens and Vernonie zeylanica substrates, possibly due to chemical compounds present in these plant species. The results shows that Gliricidia sepillll1, Puereria phasioloides and Tithonia diversiJolia are the best species for velm icomposting when compared with other weed species in coconut plantations.