Judul: The Quality of Elephant Grass (Pennisetum purpureum) Different Types of Growth: Data Review
Abstrak: Hijauan pakan sangat penting dalam menyediakan nutrien bagi ternak, terutama pada sistem produksi yang mengandalkan hijauan sebagai pakan utama seperti pada peternakan rakyat. Komersialisasi hijauan pakan terkendala oleh tingginya variasi kualitas terutama akibat perbedaan tipe pertumbuhan. Pemahaman terhadap kualitas hijauan disebabkan perbedaan struktur tanaman sangat penting bagi peternak, agar porsi hijauan dipertimbangkan saat pemberian pada ternak. Kajian data kualitas hijauan dilakukan untuk mengetahui kualitas hijauan rumput gajah yang berbeda tipe pertumbuhan dan secara morfologi berbeda. Di Indonesia terdapat dua tipe rumput gajah yaitu tipe tinggi dan tipe pendek. Data yang digunakan dalam kajian ini adalah hasil analisis proksimat dan Van soest dari sampel hijauan rumput gajah tipe tinggi yaitu Pennisetum purpureum Schumach. dan rumput gajah tipe pendek kultivar Mott dwarf, yang diperoleh dari Balai Pengujian Mutu dan Sertifikasi Pakan Bekasi dan data yang diperoleh dari jurnal. Hasil kajian menunjukan kandungan bahan kering rumput gajah tipe pendek lebih tinggi dibandingkan dengan bahan kering rumput gajah tipe tinggi (23% vs 20%), sedangkan fraksi serat seperti serat kasar, NDF dan ADF pada hijauan rumput gajah tipe pendek lebih rendah dibandingkan fraksi serat hijauan rumput gajah tipe tinggi berturut turut (32% vs 29%, 70% vs 65%, 43% vs 39%) sehingga nilai kualitas hijauan (RFQ) hijauan rumput gajah tipe pendek lebih tinggi dibandingkan dengan nilai RFQ hijauan rumput gajah tipe tinggi (68 vs 57). Kesimpulan dari kajian ini adalah terkait bahan kering dan fraksi serat kualitas hijauan rumput gajah tipe pendek kultivar Mott lebih baik dibandingkan kualitas hijauan rumput gajah tipe tinggi., Forage is very important in providing nutrients for livestock, especially in production systems that rely on forage as the main feed such as on smallholder farms. The commercialization of forage is constrained by the high variation in quality mainly due to different types of growth. Understanding of forage quality due to differences in plant structure is very important for farmers, so that the portion of forage is considered when giving it to livestock study on forage quality data was conducted to determine the quality of napier grass forage with different growth types and different morphologies. In Indonesia, there are two types of napier grass, namely the tall type and the short type. The data used in this study are the results of proximate and van soest analysis of tall-type napier grass forage samples, namely Pennisetum purpureum Schumach. and short-type napier grass, cultivar Mott dwarf, which were obtained from the Quality Testing Center and Feed Certification-Bekasi and data obtained from journals. The results of the study showed that dry matter content of short-type napier grass was higher than those of tall-type napier grass (23% vs 20%), while fiber fractions such as crude fiber, NDF and ADF of short-type napier grass were lower than those of tall-type napier grass 32% vs 29%, 70% vs 65%, 43% vs 39%, respectively. It is therefore relative forage quality (RFQ) of short-type napier grass was higher than those of tall-type napier grass (68 vs 57). It is concluded that in relation to dry matter and fiber fraction, the quality of the short-type napier grass (cv. Mott) is better than those of
Keyword: kualitas hijauan relatif, kultivar Mott, Pennisetum purpureum, RFQ, Mott cultivar, Pennisetum purpureum, relative forage quality, RFQ

Judul: Yield Test Strain Mutant Elephant Grass (Pennisetum purpureum Schumach) in Lowlands
Abstrak: Rumput gajah (Pennisetum purpureum Schumach) cv. Ciawi Dua merupakan salah satu tanaman pakan ternak yang banyak dikembangkan di Indonesia sebagai sumber hijauan pakan ternak ruminansia. Namun demikian rumput jenis ini belum bisa beradaptasi baik pada lingkungan kekeringan tinggi yang umumnya terjadi di daerah dataran rendah sehingga daya hasil hijauan menurun karena kondisi lingkungan fisik tanah dan iklim yang tidak mendukung. Penelitian ini bertujuan untuk mengetahui potensi keunggulan galur-galur mutan rumput gajah. Bahan tanam yang diuji dalam penelitian ini adalah 7 galur mutan rumput gajah koleksi BB Biogen dan 1 galur mutan rumput gajah kultivar Ciawi Dua sebagai kontrol. Percobaan dilaksanakan di Dusun Ceruk Dendeng, Desa Lulut, Kecamatan Klapanunggal, Kabupaten Bogor, Jawa Barat dari bulan Juni sampai Oktober 2020. Variabel yang diamati adalah jumlah anakan, panjang batang, tinggi tanaman, jumlah daun, panjang daun, lebar daun, panjang ruas, diameter batang, bobot panen per tanaman, dan bobot panen total. Rancangan yang digunakan adalah rancangan kelompok lengkap teracak (RKLT) dengan satu faktor yaitu galur mutan. Hasil penelitian menunjukkan bahwa galur mutan kontrol/asli secara umum lebih baik daripada galur-galur mutan rumput gajah hasil pemuliaan in vitro berdasarkan seluruh aspek pengamatan. Galur M6 dan M5 berpotensi untuk dikembangkan lebih lanjut karena memiliki karakter yang lebih baik dibanding galur lainnya selain galur kontrol., The elephant grass (Pennisetum pupureum Schumach) cv. Ciawi Dua is one of the most developed forage crops in Indonesia as a source of feed for ruminants. However, this grass has not been able to adapt well to the drought environment which generally occurs in lowland areas so that crop yields can decrease due to unfavorable physical soil and climatic conditions. This study aimed to determine the potential advantages of elephant grass mutant lines. The genetic materials tested in this study were 7 mutant lines of BB Biogen elephant grass collection and 1 mutant line of elephant grass cultivar Ciawi Dua as a control. The experiment was carried out in Ceruk Dendeng Hamlet, Lulut Village, Klapanunggal District, Bogor Regency, West Java from June to October 2020. The variables observed were number of tillers, stem length, plant height, number of leaves, leaf length, leaf width, internode length, stem diameter, sample harvest weight, and total harvest weight. The research design used was a completely randomized group design with one factor, namely mutant line. The results showed that the control/native mutant lines were generally better than the elephant grass mutant lines from in vitro breeding based on all aspects of observation. Two lines have the potential to be developed further because they have better characters than other lines besides control line.
Keyword: mutant line, forage, elephant grass

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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