Judul: Pengaruh Iba dan GA3 terhadap Pertumbuhan Bibit Karet (Hevea brasiliensis Muel. Arg.) Stump Mata Tidur (OSLO) di Pembibitan
Abstrak: Percobaan ini bertujuan untuk melihat pengaruh pemberian indolebutyric acid (IBA) dan gibberelic soid (GAs) terhadap pertumbuhan bibit karet stump mata tidur (OSLO) di pembibitan. Di samping itu ingin diketahui konsentrasi optimum zat pengatur tumbuh tersebut yang dapat memberikan pertumbuhan yang baik dan seragam.
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Judul: Pengaruh zat pengatur tumbuh ethepon, IBA dan NAA terhadap pertumbuhan bibit stum mata tidur (Oslo) karet (Hevea brasiliensis Muel. Arg.)
Abstrak: Penelitian ini dilakukan untuk mengetahui pengaruh zat pengatur tumbuh Ethepon, IBA dan NAA terhadap pertumbuhan bibit stum mata tidur karet yang dilaksanakan di kebun percobaan IPB, Cikabayan pada akhir bulan Agustus 2000 sampai Februari 2001. Penelitian ini menggunakan Rancangan Acak Kelompok yang disusun secara faktorial dengan dua faktor. Faktor pertama adalah perlakuan Ethepon dengan merek dagang Ethrel, yaitu 30 ppm/stum (E1), 40 ppm/stum (E2), 50 ppm/stum (E3) dan 60 ppm/stum (E4). Sedangkan faktor kedua adalah perlakuan IBA, NAA dengan merek dagang Rootone-F, yaitu: 50 mg/stum (R1), 100 mg/stum (R2), 150 mg/stum (R3), 200 mg/stum (R4). Kedua perlakuan diberikan secara bersamaan pada awal sebelum tanam, masing-masing kombinasi perlakuan diulang tiga kali setiap satuan percobaan terdiri atas 5 tanaman sehingga jumlah tanaman yang digunakan adalah 240 tanaman. Pengamatan dilakukan terhadap peubah waktu pecah tunas, mata okulasi yang tumbuh, panjang tunas, diameter tunas, tinggi payung daun pertama, jumlah daun, panjang akar, berat kering akar, berat kering batang dan berat kering daun. Hasil penelitian menunjukkan bahwa perlakuan Ethepon berpengaruh nyata terhadap panjang tunas, tinggi payung daun pertama dan jumlah daun dan perlakuan Ethepon 50 ppm memberi hasil yang terbaik. Perlakuan IBA dan NAA hanya berpengaruh nyata terhadap panjang akar dan perlakuan IBA dan NAA 200 my memberi hasil yang paling baik. Interaksi perlakuan Ethepon, IBA dan NAA berpengaruh nyata terhadap panjang tunas, diameter tunas dan berat kering daun dan perlakuan Ethepon 40 ppm, IBA dan NAA 100 mg memberi hasil yang paling baik…dst
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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