Judul: Keragaan dan Stabilitas Hasil 14 Genotipe Tomat (Solanum lycopersicum L.) di Empat Lingkungan Dataran Rendah
Abstrak: Tomat (Solanum lycopersicum L.) merupakan salah satu komoditas hortikultura penting di Indonesia. Budidaya tanaman tomat umumnya dilakukan di dataran tinggi. Namun, belakangan ini areal penanaman tomat dataran tinggi terbatas karena terjadi persaingan penanaman komoditas pertanian lain dan banyaknya daerah konservasi yang terletak di dataran tinggi. Oleh karena itu, perlu dilakukan perluasan areal tanam tomat ke daerah dataran rendah. Perluasan areal tanam ke dataran rendah menyebabkan adanya perbedaan kondisi lingkungan sehingga varietas yang dikembangkan tidak berproduksi optimum. Oleh karena itu, usaha pemuliaan tomat unggul dataran rendah perlu dilakukan dengan kegiatan uji daya hasil tomat genotipe unggul di beberapa lokasi dataran rendah. Penelitian mencakup (1) kegiatan uji daya hasil di empat lokasi dataran rendah, (2) analisis stabilitas hasil dengan menggunakan pendekatan parametrik dan (3) analisis stabilitas hasil dengan menggunakan pendekatan nonparametrik. Berdasarkan kegiatan yang dilakukan didapatkan kesimpulan: (1) Berdasarkan metode stabilitas parametrik, genotipe yang memiliki produktivitas yang tinggi menurut konsep stabilitas statis adalah IPBT78 dan menurut konsep stabilitas dinamis adalah IPBT64. Produktivitas IPBT78 dan IPBT64 masing–masing adalah 22.71 dan 22.97 ton ha–1. (2) Berdasarkan pengujian kestabilan dengan menggunakan 14 parameter analisis stabilitas parametrik dan nonparametrik, genotipe IPBT34, IPBT33, IPBT60 dan IPBT3 memiliki frekuensi kestabilan di atas lima kali, yaitu masing-masing 11 kali, 10 kali, 7 kali dan 6 kali. (3) Pendekatan nonparametrik dengan metode Thennarassu dan metode Nassar & Huehn merupakan metode stabilitas yang bersifat statis, akan tetapi pada penelitian ini pola stabilitas yang dihasilkan setara dengan konsep stabilitas parametrik yang bersifat dinamis.
Keyword: keragaman, genotipe, tomat, multilokasi, stabilitas, parametrik, nonparametrik, stabilitas statis, stabilitas, dinamis

Judul: Uji Daya Hasil 12 Genotipe Tomat (Solanum lycopersicum L.) di Dataran Rendah (Tajur, Bogor).
Abstrak: Development of tomato which is adaptive in lowland is important because land availability in the highlands being limited. The study aims to test and compare the yield and quality of 10 genotypes with two compared varieties grown in the lowlands. The study uses Randomized Completely Block Design one factor with three replications. Materials used are 10 potential tomato genotypes and 2 compared varieties, Intan and Ratna. Observations were conducted on 13 qualitative characters which include hypocotyl color, growth type, leaf types, leaf attitude, leaflets attitude, infloresence type, flower color, fruit shape, fruit blossom end shape, color of immature fruit, color of ripe fruit, flesh color, shape of pistil scar, and 17 quantitative characters which includes plant height, leaf size, pedicel length, number of locules, number of inflorescence, number of flowers per inflorescence, fruit set, number of fruit per plant, days to flowering, days to harvesting, fruit size, flesh thickness, weight per fruit, fruit weight per plant, productivity, fruit hardness, total soluble solid (PTT). The results showed that tested genotypes have different character in leaf attitude, fruit shape, and fruit blossom end shape compared with varieties Intan and Ratna. Genotype that can be continued for multilocation field trials is F8 005001-4-1-12-3-17-3 genotype because it has a length fruit (5.55 cm), flesh thickness (0.69 cm), pedicel length (3.1 cm), and leaf width (33.48 cm) better than the two compared varieties, yields (45.24 ton/ha) and fruit set (70.8%) as well as both compared varieties, weight per fruit (73.03 g ), fruit diameter (4.99 cm), and PTT (1.58 oBrix) better than varieties Ratna, and plant height (76.77 cm), fruit number per plant (39), fruit weight per plant (1 413.70 g), and fruit hardness (1.35 kgf cm-2) higher than varieties Intan.
Keyword: genotype, lowland, productivity field trial, Solanum lycopersicum L., tomato

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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