Judul: Studi Pembiakan Vegetatif Intsia bijuga (Colebr.) O.K. Melalui Grafting
Abstrak: Pembiakan vegetatif dengan cara grafting merupakan suatu alternatif untuk pemuliaan pohon merbau [Instia bijuga (Colebr.) O.K]. Salah satu keuntungan dari grafting ialah banyak digunakan untuk produksi bibit yang akan ditanam di kebun benih dan bermanfaat untuk penyelamatan kandungan genetik tanaman merbau. Metode grafting yang dipakai adalah Top Cleft Grafting dan menggunakan rancangan acak lengkap (RAL) dengan dua faktorial. Faktor pertama adalah perlakuan rootstock berdiameter 4-6 mm dan rootstock berdiameter 6.1-8 mm. Faktor kedua adalah perlakuan jenis fase scion yang mengalami fase dorman dan fase aktif. Berdasarkan analisis sidik ragam diketahui bahwa perlakuan rootstock dan perlakuan jenis fase scion tidak berpengaruh nyata terhadap persentase keberhasilan sambungan Merbau dan persentase ketahanan penyakit. Tetapi interaksi perlakuan rootstock dan jenis fase scion berpengaruh nyata terhadap persentase ketahanan penyakit. Berdasarkan hasil penelitian diketahui bahwa rata-rata persen keberhasilan sambungan Merbau adalah 21.67%.
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Judul: Studi Keberhasilan Grafting Jati (Tectona grandis L.f)
Abstrak: Jati merupakan salah satu jenis kayu komersial yang banyak diminati. Jati yang unggul dapat dipertahankan dengan teknik vegetatif grafting. Salah satu kendala pada grafting yaitu inkompatibilitas batang atas (scion) dan batang bawah (rootstock). Oleh karena itu, diperlukan penentuan umur pohon induk, umur dan kondisi scion sebagai bahan grafting. Penelitian ini bertujuan menguji sumber scion terhadap keberhasilan grafting jati. Percobaan pertama menggunakan scion yang cenderung tua dan tidak diketahui umurnya. Percobaan kedua menggunakan scion berumur 8 hari. Percobaan ketiga menggunakan scion dari bibit Jati Plus Perhutani berumur 8 bulan. Penelitian dilakukan di Taman segitiga Departemen Silvikultur (DSVK) dan Rumah Kaca DSVK IPB pada bulan April hingga Juni 2022. Prosedur penelitian diawali dengan pemilihan rootstock, pemilihan scion, penyambungan, pemeliharaan, hingga analisis data. Penyambungan dilakukan dengan metode sambung sisip dan top cleft grafting pada percobaan pertama dan kedua. Percobaan ketiga hanya menggunakan metode top cleft grafting. Rancangan yang digunakan adalah RAL (rancangan acak lengkap) satu faktor dengan perlakuan A (teras rumah kaca) dan B (dalam rumah kaca). Data dianalisis dengan software SAS 9.0. Hasil penelitian menunjukkan percobaan pertama dan kedua mengalami kegagalan total. Adapun percobaan ketiga total persentase keberhasilan sebesar 20,84%., Superior teak can be maintained with vegetative grafting techniques. One of the obstacles to grafting is the incompatibility of scions and rootstocks. Therefore, it is necessary to determine the age of the seed trees, the age and condition of the scion as a grafting material. This study aims to test the source of scion against the success of teak grafting. The first experiment used a scion which tends to be old and its age is unknown. The second experiment used an 8-day-old scion. The third experiment used scion from 8-month-old Perhutani Jati Plus seedlings. The study was conducted in the Triangular Park of the Silviculture Department (DSVK) and the DSVK IPB Greenhouse in April to June 2022. The procedure begins with rootstock selection, scion selection, splicing, maintenance, and data analysis. Splicing is carried out by the method of connecting the insert and top cleft grafting in the first and second experiments. The third experiment used only the top cleft grafting method. The design used was a one-factor RAL (complete random design) with treatment A (greenhouse terrace) and B (in greenhouse). The data was analyzed with SAS 9.0 software. The results showed that the first and second experiments failed miserably aand third experiment, the total success percentage was 20.84%.
Keyword: grafting, jati, rootstock, scion

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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