Judul: Daya Gabung Lima Galur Murni Jagung (Zea mays L.) serta Penampilan dan Tingkat Heterosis Hibridanya
Abstrak: Penelitian ini dilakukan untuk mengetahui daya gabung lima galur murni jagung yang dibentuk oleh Pusat Studi Pemuliaan Tanaman (PSPT) IPB, serta penampilan dan tingkat heterosis hibridanya. Percobaan dilaksanakan di Kebun Percobaan IPB Sindang Barang pada bulan Desember 1999 hingga April 2000. Bahan yang digunakan dalam penelitian ini yaitu 17 genotipa jagung yang terdiri dari 5 galur murni, 10 hibrida hasil kombinasi persilangan antar galur murni, serta 2 varietas pembanding (Semar-3 dan Bisma). Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) faktor tunggal (genotipa) dengan 3 ulangan, sehingga seluruhnya terdapat 51 satuan percobaan.
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Judul: Evaluasi Daya Gabung Galur-Galur Inbrida Jagung (Zea mays L.) dan Potensi Hasil Hibridanya
Abstrak: Produksi jagung dapat ditingkatkan melalui penggunaan varietas hibrida unggul. Salah satu syarat untuk merakit varietas hibrida unggul yaitu tersedianya galur-galur murni yang memiliki daya gabung yang baik. Penelitian ini bertujuan mengevaluasi keragaan potensi hasil dan sifat agronomi lainnya dari 30 hibrida jagung serta mengestimasi nilai daya gabung umum dan daya gabung khusus galurgalur tetuanya. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo dan Laboratorium Pemuliaan Tanaman, Departemen Agronomi dan Hortikultura, IPB mulai bulan September 2019 hingga Januari 2020. Percobaan menggunakan rancangan kelompok lengkap teracak (RKLT) faktor tunggal dengan tiga ulangan. Terdapat 32 hibrida jagung yang dievaluasi, terdiri atas 30 hibrida uji hasil persilangan antara 15 galur IPB dengan 2 galur Balitsereal, dan dua varietas hibrida komersial (BISI-2 dan NK 6172) sebagai pembanding. Hasil penelitian menunjukkan bahwa genotipe berpengaruh nyata terhadap daya tumbuh, umur berbunga jantan, umur berbunga betina, anthesis silking interval (ASI), tinggi tanaman, tinggi tongkol utama, diameter batang, panjang tongkol, diameter tongkol, jumlah baris biji, bobot tongkol, bobot biji per tongkol, bobot 1,000 biji, rendemen hasil, dan hasil pipilan kering. Hibrida uji yang memiliki hasil pipilan tertinggi adalah P88xMr14, tidak berbeda nyata dengan varietas BISI-2 dan NK 6172. Galur P88 juga memiliki daya gabung umum tertinggi untuk hasil. Hasil pipilan kering berkorelasi positif nyata terhadap tinggi tongkol dan diameter tongkol.
Keyword: daya gabung, heritabilitas, korelasi, line x tester

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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