Judul: Induction of Growth and Flower Formation in Mexican Accessions of Jatropha curcas with Plant Growth Regulators.
Abstrak: Jarak pagar aksesi Meksiko dikenal tidak memiliki racun tetapi produksinya sangat rendah di Indonesia. Untuk itu perlu dilakukan upaya untuk memacu pertumbuhan dan pembungaan tanaman jarak pagar aksesi Meksiko dengan Zat Pengatur Tumbuh. Penelitian ini bertujuan untuk menentukan konsentrasi dan jenis zat pengatur tumbuh yang dapat memacu pertumbuhan dan pembentukan bunga betina tanaman jarak pagar aksesi Meksiko. Tiga Puluh (30) stek jarak Meksiko ditanam dalam polibag selama 3 minggu kemudian dipindah ke lubang tanam dan diberi pupuk kandang 5 kg serta NPK sebanyak 5-10 gram per lubang tanam. Perlakuan ZPT diberikan setiap minggu sesuai konsentrasi yang ditentukan dengan cara disemprotkan pada permukaan bagian bawah daun. Pengamatan dilakukan setiap 2 minggu dengan parameter jumlah kapsul per tanaman, jumlah biji, berat biji, tinggi tanaman, jumlah daun, jumlah cabang, dan diameter cabang per tanaman. Hasil pengamatan tinggi tanaman menunjukkan bahwa respon terlihat antara 16 Minggu Setelah Tanam (MST) sampai 20 MST. Jumlah daun pada perlakuan giberelin 100 ppm meningkat secara nyata hingga 20 MST dan setelah itu gugur. Pertambahan diameter batang tidak dipengaruhi oleh perlakuan ZPT. Jumlah cabang mengalami penambahan signifikan dengan pemberian Giberelin 100 ppm. Produksi biji tertinggi diberikan oleh tanaman dengan perlakuan Kinetin 50 ppm sampai umur 28 MST.
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Judul: Aplikasi zat pengatur tumbuh untuk menyerempakkan mekar bunga dan masak buah jarak pagar (Jatropha curcas L.)
Abstrak: One of the major constraints in Jatropha oil production is asynchronous fruit ripening, hence harvesting needs to be carried out accordingly which lead to drudgery. Therefore, an experimental study on the use of plant growth regulators was designed to induce synchronous blooming of pistilate flowers, and to promote synchronous fruits ripening. The study was conducted at the Jatropha Plantation of PT Indocement Tunggal Prakarsa Tbk Citeureup from October 2009 to August 2010. To induce synchronous blooming of pistilate flowers, Benzyl Amino Purine (BAP) and etephon were used, whereas etephon alone was used to promote synchronous fruits ripening. A completely randomized design was used in the first experiment that was carried in two steps. In the first step BAP at 0, 30, 35, 40, 45, 50 ppm and etephon at 10, 30, 50, 70 and 90 ppm were applied on early developing flower buds. In the second step 0, 30, 50, 70, 90 and 110 ppm BAP were used. The second experiment consisted of three steps. The first step was observation of seed development from 30 days after anthesis. A randomized complete block design was used in the second and the third steps. In the first step 0, 200, 400, 600, 800, 1000, and 1200 ppm of etephon were applied on fruits at 40 and 45 days after anthesis during the rainy season. In the second stage 0, 100, 200, 300, 400 ppm etephon were applied on fruits of the same maturation stages in the dry season. The result show that BAP tends to increase the number of female flowers in an inflorescence thus longer period of blooming. Application of etephon at 200 ppm on 40 day after anthesis shorten the fruit maturation hence more synchronous fruit ripening in rainy season, but not in dry season when fruits ripened synchronously. The quality of the seed and kernel were not affected by etephon application.
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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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