Judul: Karakterisasi Morfologi Beberapa Genotipe Kentang (Solanum tuberosum) yang Dibudidayakan di Indonesia
Abstrak: The research was conducted at Cikajang Garut West Java from March 2013 until July 2013. The purpose of this research is characterize of vegetative and generative character some genotypes of potato cultivated in Indonesia qualitatively and quantitatively. The genotypes of Potato used consisted of three comparator (Granola, Atlantic, South Sulawesi) and seven tested genotypes (Intan, Bengkulu, Jambi, Bukit Tinggi, Wonosobo, Blis, and Mikraset). Observations consist of a plant height, stem (diameter and color), leaves (number of leaves, color, shape, and size), flowers (flowering time, shape, and color), time of harvest, tubers (the number of tuber, weight, shape, size, color, and moisture content). The research result showed genotype Jambi and Intan has a higher yield than the comparison. Ten genotypes of potato that is used is divided into 3 groups. The first group consists of Jambi, Atlantic, Bukit Tinggi, and Mikraset. The second group consists of Granola, Intan, South Sulawesi, Blis and Wonosobo. The third group is a group that does not have in common with the three comparator namely Bengkulu. Genotypes Bengkulu have the purple stem and red skin of tuber, so it can potentially to do registration of varieties.
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Judul: Preliminary Result Test of Potato Genotype (Solanum tuberosum L.) in Garut District, West Java
Abstrak: Kentang (Solanum tuberosum L.) merupakan salah satu sumber karbohidrat yang diminati masyarakat, tetapi produksi dan produktivitas nasional masih rendah karena penyediaan benih bermutu masih kurang. Upaya untuk meningkatkan produksi kentang adalah dengan mengembangkan varietas baru berdaya hasil tinggi. Penelitian ini bertujuan untuk mengevaluasi daya hasil beberapa genotipe kentang IPB di Kabupaten Garut, Jawa Barat. Penelitian dilaksanakan di Desa Girijaya, Kecamatan Cikajang, Kabupaten Garut, Jawa Barat pada bulan November 2020 sampai Maret 2021. Penelitian menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) factor tunggal yaitu genotipe dan tiga ulangan sebagai kelompok. Bahan tanam yang digunakan yaitu genotipe kentang PKHT-2020-006, PKHT-2020-010, PKHT-2020-012, PKHT-2020-016, PKHT-2020-017, PKHT-2019-021, serta kentang varietas medians dan granola sebagai pembanding. Hasil penelitian menunjukan bahwa genotipe PKHT-2020- 012 dan PKHT-2019-021 memiliki produktivitas lebih tinggi dari varietas pembanding. Genotipe lain yang memiliki produktivitas tidak berbeda dengan varietas pembanding adalah genotipe PKHT-2020-010., Potatoes (Solanum tuberosum L.) are one of carbohydrates source which is interested, but its national production and yield are still low. Efforts to increase potato production are by developing new varieties with higher yield. This study aimed to evaluate the yield potential of IPB genotypes potato in Garut district, West Java. The study was conducted in Girijaya Village, Cikajang District, Garut Regency, West Java in November 2020 to March 2021. This study uses a completely randomized Complete Group Design (RKLT) namely genotypes and three replications as a group. The planting material used are the potato genotype PKHT-2020-006, PKHT-2020-010, PKHT-2020-012, PKHT-2020-016, PKHT2020-017, PKHT-2019-021, as well as Medians and Granola potato varieties as a comparison. The results showed that genotypes of PKHT-2020-012 and PKHT2019-021 had the highest productivity than the comparison varieties. The others genotype that have productivity not different with comparison varieties is genotype of PKHT-2020-010.
Keyword: genotype, productivity, yield potential 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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