Judul: Growth of Cuttings and Production of G0 Potato (Solanum tuberosum L.) Tubers of IPB CP1 and Atlantic Varieties in the Midlands
Abstrak: IPB CP1 merupakan salah satu varietas kentang yang dikembangkan IPB untuk memenuhi kebutuhan bahan baku industri keripik kentang. Produksi benih kentang di dataran menengah dengan varietas yang sesuai merupakan upaya untuk meningkatkan area produksi benih sehingga produksi benih kentang industri secara nasional dapat meningkat. Penelitian ini bertujuan mengetahui pertumbuhan setek dan produksi benih umbi G0 kentang varietas IPB CP1 dan varietas Atlantik di dataran menengah. Penelitian dilakukan di rumah kasa yang berlokasi di Desa Bojong Koneng, Sentul, Kabupaten Bogor. Penelitian menggunakan faktor perlakuan genotipe kentang yaitu kentang varietas IPB CP1 dan varietas Atlantik dengan tiga ulangan. Satuan percobaan berupa petakan berukuran 75 x 90 x 20 cm, berisi media cocopeat. Pengamatan dilakukan terhadap tinggi tanaman, jumlah daun, jumlah buku, bobot basah dan bobot kering umbi, bobot basah tajuk, bobot kering tajuk, umur berbunga, dan produksi umbi per tanaman. Setek kentang genotipe IPB CP1 di dataran menengah tumbuh lebih adaptif dan memiliki ketahanan hidup yang lebih baik dibandingkan varietas Atlantik. Varietas IPB CP1 menghasilkan bobot umbi yang lebih tinggi dibandingkan varietas Atlantik., The IPB CP1 is one of the potato varieties developed by IPB to fulfill the need of material of potato chip industry. Production of potato seeds in the midlands with suitable varieties is an effort to increase the seed production area, therefor the national production of potato seeds increases. This study aims to study the growth of cuttings and production of tubers of G0 potato varieties IPB CP1 and Atlantic varieties in the midlands. The research was conducted in a screenhouse located in Bojong Koneng, Sentul, Bogor Regency. The experiment used two potato genotypes, var. IPB CP1 and Atlantic. The experimental unit was a plot measuring of 75 x 90 x 20cm, containing cocopeat media. The variable observed in the experiment were plant height, number of leaves and nodes, fresh and dry weight of the shoots and the tubers, time of flowering, and tuber yield per plant. Potato cuttings of the IPB CP1 genotype grew more adaptive and had better survival than the Atlantic varieties in midlands. The IPB CP1 variety produced a higher tuber weight than the Atlantic variety.
Keyword: benih kentang, kentang industri, keripik kentang

Judul: Growth and Production of G0 Potato (Solanum tuberosum L.) Seed Tuber of IPB CP3 in Greenhouse and Screenhouse in the Medium Altitude
Abstrak: Kentang (Solanum tuberosum L.) adalah komoditas hortikultura yang memiliki nilai ekonomi tinggi. Indonesia masih mengimpor benih kentang karena produksi benih dalam negeri tidak mencukupi. Keterbatasan produksi benih kentang industri, salah satunya kentang varietas IPB CP3 disebabkan oleh keterbatasan luas lahan di dataran tinggi. Untuk meningkatkan produksi benih, perlu dilakukan pemanfaatan lahan di dataran menengah dengan menggunakan varietas yang sesuai. Penelitian ini bertujuan membandingkan pertumbuhan dan produksi benih umbi G0 kentang varietas IPB CP3 dari stek yang ditanam di dalam rumah kaca dan rumah kasa di dataran menengah. Stek pucuk berumur 2 minggu setelah tanam yang sudah berakar ditanam pada polybag yang berisi media cocopeat. Setiap satuan percobaan terdiri atas 20 tanaman dengan 3 ulangan, sehingga di dalam rumah kaca atau rumah kasa terdapat 60 tanaman. Panen dilakukan pada umur 90 hari setelah tanam. Parameter yang diamati adalah tinggi tanaman, jumlah buku, jumlah daun, jumlah umbi, bobot basah serta bobot kering tajuk dan umbi. Hasil penelitian menunjukkan bahwa rumah kaca dan rumah kasa memberikan pengaruh yang signifikan terhadap pertumbuhan dan produksi benih umbi G0 kentang IPB CP3. Pertumbuhan tanaman dan produksi benih umbi G0 kentang varietas IPB CP3 di dalam rumah kasa secara signifikan lebih baik daripada rumah kaca., Potato (Solanum tuberosum L.) is a horticultural commodity with high economic value. Indonesia is still importing potato seeds due to insufficient seed production. The lack of seed tuber production for potato chips is due to the limited land area in high-altitude regions. It is necessary to produce seed tubers in the medium altitude with suitable varieties. The study aims to compare the growth and production of G0 potato seed tubers of IPB CP3 variety planted in greenhouse and screenhouse in the medium altitude. Two weeks old of the rooted shoot-cuttings were transferred into polybags containing cocopeat media. Each experimental unit consists of 20 plants with 3 replications, therefore there are 60 plants in greenhouse and screenhouse. The potato seed tubers were harvested at 90 days after planting. The parameters observed were plant height, number of nodes, number of leaves, number of tubers, fresh and dry weight of the plant shoot and tubers. The research showed that greenhouse and screenhouse had a significant effect on the growth and production of G0 potato seed tubers of IPB CP3. The growth and production of G0 potato seed tubers of the IPB CP3 variety in screenhouse is significantly better than that in greenhouse.
Keyword: greenhouse, potato chips, screenhouse, shoot-cuttings, sipitri

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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