Judul: Pemuliaan tanaman lada (Piper nigrum L.) di Balai Penelitian Tanaman Rempah dan Obat Bogor
Abstrak: Praktek Lapang ini bertujuan selain untuk memperoleh pengalaman lapang, juga untuk mengetahui dan mempelajari kegiatan pemuliaan tanaman lada di Kelompok Peneliti (Kelti) Pemuliaan, Balai Penelitian Tanaman Rempah dan Obat (Balittro) Bogor. Kegiatan penelitian pemuliaan tanaman lada di Balittro yang telah, sedang, dan akan dilaksanakan cukup banyak. Kegiatan tersebut diantaranya koleksi, uji varietas, seleksi klon, dan upaya konservasi plasma nutfah lada. Tanaman lada koleksi Balittro saat ini berjumlah 38 varietas yang terdapat di dua kebun koleksi, yaitu 28 varietas di kebun koleksi Sukamulya, dan 28 varietas di kebun koleksi Kelti Pemuliaan Cimanggu Bogor. Uji varietas lada lebih ditekankan kepada uji resistensi terhadap penyakit busuk pangkal batang, yang disebabkan oleh cendawan Phytophthora palmivora. Seleksi klon dilakukan untuk mendeteksi kemurnian varietas dan untuk menemukan klon-klon yang berproduksi tinggi dan lebih seragam. Upaya konservasi plasma nutfah tanaman lada dilakukan dengan perbanyakan secara vegetatif maupun generatif.
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Judul: Tinjauan agroklimat terhadap budidaya tanaman lada ( Piper ningrum Linn. ) di kebun percobaan Petaling Bangka
Abstrak: Lada merupakan salah satu komoditi ekspor non migas yang diharapkan dapat meningkatkan devisa negara terutama pada saat-saat sekarang ini dimana nilai ekspor migas go- yah. Tanaman lada (Piper nigrum Linn.) tidak hanya termas suk tanaman tertua di Indonesia, tetapi juga merupakan sa- lah satu hasil rempah-rempah di kawasan Asia Timur. Perkembangan lada di Indonesia akhir-akhir ini berang- sur baik, terutama karena adanya usaha-usaha pembinaan un- tuk meningkatkan produksi lada melalui Bimas. Berbagai usaha yang telah dibina antara lain mengenai pemupukan dengan dosis dan cara yang tepat, penanggulangan kematian serta teknik-teknik pemeliharaan lainnya. Salah satu penyebab turunnya produksi lada di Indone- sia adalah serangan penyakit kuning disamping adanya sera- ngan penyakit busuk pangkal batang. Penyakit kuning meru- pakan penyakit yang paling berbahaya bagi pertanaman lada di daerah Bangka dan merusak hampir 32% areal pertanaman. Walaupun penelitian penyakit kuning ini sudah dimulai sejak ditemukannya, dan sudah banyak dilakukan cara penang- gulangannya, namun sampai saat ini masalah penyakit ini masih belum terpecahkan. Sedangkan dilain pihak kerugian yang disebabkannya semakin terasa, khususnya oleh petani- petani di Bangka. ...
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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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