Judul: Keragaan Agronomi Varietas Padi di Kabupaten Bogor dan Kabupaten Subang Menggunakan Sistem Tanam Jajar Legowo 4:1
Abstrak: Peningkatan produksi padi dapat dilakukan dengan penggunaan varietas unggul didukung oleh sistem budidaya yang tepat dan lingkungan yang sesuai. Lokasi atau lingkungan tumbuh yang berbeda memiliki perbedaan kondisi agroekosistem sehingga dapat menyebabkan pertumbuhan dan produksi yang berbeda pada varietas yang dibudidayakan. Penelitian ini bertujuan mengetahui pengaruh lokasi terhadap keragaan agronomi dan produktivitas beberapa varietas padi yang ditanam menggunakan sistem tanam jajar legowo 4:1. Varietas yang digunakan yaitu Inpari 32, Inpari 33, Inpari 43, IPB 3S, IPB 9G, dan Batang Piaman. Rancangan yang digunakan adalah Rancangan Kelompok Lengkap Teracak (RKLT) dengan satu faktor varietas, kemudian dilakukan analisis gabungan antar lokasi percobaan. Lokasi tanam berpengaruh terhadap jumlah anakan, jumlah malai per rumpun, jumlah gabah total per malai, jumlah gabah bernas total per malai, dan bobot gabah kering giling (GKG). Varietas unggul baru (VUB) yang meliputi Inpari 32, Inpari 33, dan Inpari 43 memiliki ciri-ciri jumlah anakan banyak dengan jumlah gabah per malai kategori sedikit dan sedang, sedangkan padi tipe baru (PTB) memiliki ciri-ciri jumlah anakan sedikit dengan jumlah gabah per malai kategori sedang. Jumlah anakan, jumlah malai per rumpun, dan jumlah gabah per malai akan berpengaruh pada produksi padi., The effort for Increasing rice production could be achieved by planting high yielding varieties supported by implementing an appropriate cultivation system and suitable growing environments. Differetnt location or growing environment have different agroecosystem conditions could be differences growth and production of cultivated varieties. This study aimed to determine the effect of different location on agronomic performance and productivity of several rice varieties grown using “jajar legowo 4:1” system. The varieties used were Inpari 32, Inpari 33, Inpari 43, IPB 3S, IPB 9G, and Batang Piaman. It was arranged in Randomized Complete Block Design (RCBD) of one factor, namely variety, then a combined analysis was carried out between the experimental locations. Planting location affected the total stem, total panicle per clump, total grain per panicle, total pithy grain per panicle, and dry milled grain weight (GKG). The new superior varieties (VUB) which include Inpari 32, Inpari 33, and Inpari 43 have the characteristics of a large number of tillers with the number of grain per panicle in the category of few and medium, while the new type of rice (PTB) has the characteristics of a small number of tillers with the number of grain per panicle medium category. The number of tillers, number of panicles per clump, and number of grain per panicle will affect rice production.
Keyword: Agroecosystem, high yielding varieties, productivity

Judul: Multicanopy Cultivation of Four Rice Varieties with Jajar Legowo Planting Distances at KP Babakan Dramaga
Abstrak: Padi (Oryza sativa) merupakan salah satu tanaman pangan terpenting di Indonesia. Peningkatan konsumsi beras tidak sebanding dengan luas panen di Indonesia. Penelitian ini bertujuan mempelajari pengaruh sistem budidaya dan varietas terhadap peningkatan produksi padi di Kebun Percobaan Sawah Baru IPB, Babakan Dramaga. Penelitian ini menggunakan RKLT faktorial dengan dua faktor yaitu sistem budidaya (monokultur, multikanopi sisip 1, multikanopi sisip 2) dan varietas (INPARI 32, INPARI 33, INPARI 43, IPB 9G sebagai tanaman sisipan). Hasil penelitian menunjukkan bahwa terdapat interaksi kedua perlakuan yang berpengaruh pada tinggi tanaman saat berumur 8 MST, tinggi batang saat panen, sudut kemiringan daun bendera. Pengaruh tunggal sistem budidaya signifikan terhadap tinggi tanaman padi saat berumur 8 MST, jumlah anakan, panjang daun dan sudut kemiringan daun bendera, bobot kering tajuk dan bobot kering malai saat panen, jumlah malai per rumpun, jumlah gabah isi per malai, bobot gabah per rumpun. Pengaruh tunggal varietas signifikan terhadap tinggi tanaman, jumlah anakan, panjang daun dan sudut kemiringan daun bendera, bobot kering malai, panjang malai, jumlah gabah per malai, jumlah gabah isi per malai, bobot 1000 butir, dan bobot gabah per rumpun., Rice (Oryza sativa) is one of the most important food crops in Indonesia. The increase in rice consumption is not proportional to the harvested area in Indonesia. This study aims to study the effect of cultivation systems and varieties on increasing rice production in the Experimental Garden of Sawah Baru IPB, Babakan Dramaga. This study used a factorial RKLT with two factors, namely the cultivation system (monoculture, multi-canopy insertion 1, multi-canopy insertion 2) and varieties (INPARI 32, INPARI 33, INPARI 43, IPB 9G as insertion plant). The results showed that there was an interaction between the two treatments that affected plant height at 8 WAP, stem height at harvest, flag leaf tilt angle. The single effect of the cultivation system was significant on rice plant height at the age of 8 WAP, number of tillers, leaf length and angle of inclination of flag leaves, crown dry weight and panicle dry weight at harvest, number of panicles per clump, number of filled grain per panicle, grain weight per clump. The single varietal effect was significant on plant height, number of tillers, leaf length and angle of inclination of flag leaf, panicle dry weight, panicle length, number of grain per panicle, number of filled grain per panicle, 1000 grain weight, and grain weight per clump.
Keyword: insertion, interaction, monoculture, production, productivity

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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