Judul: Yield Trial of 38 New Plant Type Rice in Low Dose Fertilization
Abstrak: Padi merupakan tanaman pangan yang digunakan sebagai pemenuhan kebutuhan karbohidrat utama masyarakat Indonesia. Peningkatan produktivitas padi diperlukan melalui pemuliaan tanaman padi tipe baru untuk memenuhi kebutuhan padi nasional. Penelitian ini bertujuan menguji galur-galur padi sawah tipe baru pada kondisi pemupukan dosis rendah. Penelitian dilaksanakan di Kebun Percobaan IPB Sawah Baru Desa Babakan, Kecamatan Dramaga, Kabupaten Bogor, Jawa Barat sejak Bulan April sampai Juli 2021. Penelitian menggunakan rancangan kelompok lengkap teracak (RKLT) faktor tunggal yaitu terdiri atas 38 galur dan satu varietas pembanding dengan dua ulangan. Hasil analisis ragam pada galur-galur uji memiliki daya hasil yang tidak berbeda nyata dengan varietas pembanding. Namun, terdapat 3 nomor galur yang memiliki daya hasil lebih tinggi serta memiliki karakter agronomi yang lebih baik daripada varietas Ciherang. Galur-galur tersebut adalah IPB187-F-37-1-2 (6,26 ton ha-1), IPB193-F30-2 (6,22 ton ha-1) dan IPB189-F-132-1-1 (6,20 ton ha-1), sedangkan varietas Ciherang sebagai pembanding memiliki daya hasil sebesar 5,87 ton ha-1., Rice is a food crop that is used to fulfill the main carbohydrate needs of the Indonesian people. Increasing rice productivity is needed through breeding of new types of rice plants to meet the national rice needs. This study aimed to evaluate promising lines of rice under low-dose fertilization conditions. The experiment was conducted at the Sawah Baru Experimental Station IPB, Babakan Village, Dramaga, Bogor, West Java, started from April to July 2021. The study used of randomized complete block design (RCBD) single factor consisting of 38 lines and one check variety with two replications. The results showed that yield of the lines evaluated were no significantly different from the check varieties. However, there were 3 lines that had the higher yield and had better agronomic characters than the Ciherang variety. These lines are IPB187-F-37-1-2 (6.26 ton ha-1), IPB193-F-30-2 (6.22 ton ha-1) and IPB189-F-132-1-1 (6.20 ton ha-1), while the Ciherang variety check has a yield of 5.87 tons ha-1.
Keyword: agronomic character, new plant type, yield power

Judul: Yield Trial of New Plant Types Rice Line from Five Populations at Low Dose Fertilization Conditions
Abstrak: Pengujian galur padi merupakan tahap untuk mendapatkan genotipe unggul untuk menghasilkan suatu varietas baru. Penelitian bertujuan menguji daya hasil dan keragaan 37 galur padi sawah bermalai lebat pada kondisi pemupukan dosis rendah. Percobaan dilakukan di Kebun Percobaan IPB Sawah Baru, Bogor menggunakan rancangan kelompok lengkap teracak (RKLT) faktor tunggal dengan dua ulangan. Galur yang diujikan terdiri atas 37 galur padi tipe baru dari lima populasi beserta 2 varietas pembanding yaitu Inpari 32 dan Ciherang. Hasil analisis menunjukkan bahwa galur-galur yang diuji memiliki produktivitas yang setara atau tidak berbeda nyata dengan varietas pembanding. Galur yang memiliki potensi produktivitas lebih tinggi daripada pembanding yaitu IPB193-F-31-1-1 (6,58 ton ha-1), IPB189-F-17-3-2 (6,26 ton ha-1), IPB187-F-117-2-1 (6,74 ton ha-1), dan IPB193-F-4-1-3 (6,28 ton ha-1), sedangkan produktivitas dari varietas pembanding Inpari 32 dan Ciherang sebesar 5,34 ton ha-1 dan 4,40 ton ha-1., Yield trial is one of stage to obtain superior genotypes to produce a new varieties. The research aimed to evaluate the yield and performance of 37 heavy panicle paddy rice lines under low-dose fertilization conditions. The experiment was conducted at the Experimental Station of IPB University, Bogor, using a single factor randomized complete block design (RKLT) with two replications. The lines evaluated consisted of 37 new rice lines from five populations along with 2 check varieties, namely Inpari 32 and Ciherang. The results of the analysis showed that the tested lines had the same productivity or had no significant effect on the check varieties. Lines that have higher productivity potential than the check varieties are IPB193-F-31-1-1 (6.58 tons ha-1), IPB189-F-17-3-2 (6.26 tons ha-1), IPB187-F-117-2-1 (6.74 tons ha-1), IPB193-F-4-1-3 (6.28 tons ha-1), while the productivity of the check varieties Inpari 32 and Ciherang were 5.34 and 4.40 tons ha-1, respectively.
Keyword: new plant type rice, potential genotype, yield trial

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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