Judul: The Effect of Cow Manure on the Growth of Beneng Taro (Xanthsoma undipes K.Koch)
Abstrak: Talas beneng merupakan komoditas komersial baru yang luas areal pertanamannya semakin meningkat. Namun demikian, teknis budidaya khususnya terkait pemupukan masih belum banyak diketahui. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian dosis pupuk kandang sapi terhadap pertumbuhan talas beneng (Xanthosoma undipes K.Koch). Penelitian dilaksanakan di Kebun Percobaan Leuwikopo IPB mulai April sampai Desember 2021. Aksesi yang digunakan adalah aksesi talas beneng Banten (A1), talas beneng Bondowoso (A2), dan talas pakan Nusa Tenggara Timur (A3). Perlakuan dosis pupuk kandang sapi pertanaman yaitu 0 kg (P1), 3,06 kg (P2), dan 6,11 kg (P3) per meter persegi setara dengan kandungan C-organik tanah 1,79%, 2,94%, dan 4,09%. Penelitian ini menggunakan rancangan kelompok lengkap teracak (RKLT) split blok. Hasil penelitian menunjukkan bahwa aksesi A1 merupakan aksesi terbaik pada pertumbuhan vegetatif meliputi tinggi tanaman, panjang petiole, diameter corm, jumlah daun, dan luas daun. Aksesi A2 memiliki laju fotosinesis, dan laju transpirasi tertinggi diantara aksesi yang lain. Pemberian dosis pupuk P3 menghasilkan tinggi tanaman, panjang petiole, dan diameter corm terbaik. Dosis pupuk P3 mampu meningkakan bobot basah, bobot kering, dan jumlah akar. Aksesi A2 dengan perlakuan P3 memiliki hasil produksi umbi terbaik sebesar 11,85 ton ha-1., Beneng taro is an emerging commodity as indicated by increasing production area. However, cultivation method especially fertilizer application is still scarce. This study aimed to evaluate the effect of cow manure application on the growth of beneng taro (Xanthosoma undipes K. Koch). The research was conducted in Leuwikopo Experimental Farm, IPB from April to December 2021. This research used 3 accessions i.e Banten beneng taro (A1), Bondowoso beneng taro (A2), and East Nusa Tenggara taro (A3). Cow manure was applied at level of 0 kg (P1), 3.06 kg (P2), and 6.11 kg (P3) per meter square corresponding to Corganic soil 1,79%, 2,94%, and 4,06%, respectively. This study used randomized complete block design (RCBD) of split block. The results showed that accession A1 had the best vegetative growth including plant height, petiole length, corm diameter, number of leaves, and leaf area. Accession A2 had the highest rate of photosynthesis and transpiration rates. The P3 treatment resulted in the best in plant height, petiole length, and diameter of the corm. Also, the P3 treatment was able to increase the fresh weight, dry weight and number of roots, irrespetive of accessions. Accession A2 with P3 treatment had the best tuber production yield of 11,85 tons ha-1.
Keyword: aksesi, C-organik, hasil, pertumbuhan vegetatif, pupuk kandang sapi

Judul: Pengaruh Pupuk Kandang dan NPK pada Tanaman Suweg, Talas, dan Iles-Iles
Abstrak: Tuber crops play important role in food security status in Indonesia. In order to increase productivity, study was conducted on suweg, taro, and iles-iles treated with manure and NPK fertilizers. Research was carried out in Cikabayan, University Farm of IPB from December 2009 to July 2010. Tubers were planted under 50% shading net. Split plot design with two factors was used in this reseach. Goat manure with three levels, i.e., 0 ton/ha, 5 ton/ha, dan 10 ton/ha was determined as main plot. As subplot, NPK fertilizers, was applied at four levels, i.e., zero, 100:60:80 kg/ha, 125:60:100 kg/ha, and 150:60:120 kg/ha. The results showed that there was interaction between manure and NPK on leaf number, petiole height, petiole diameter, and fresh mass of suweg. Aplication of 10 tons/ha of manure without NPK produced the highest fresh mass of suweg corm. Interaction was significant for leaf number and petiol height of taro and iles-iles, and petiol diameter and rachis length of iles-iles. There was not interaction between manure and NPK fertilizer for fresh mass corm of both taro and iles-iles.
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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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