Judul: Induksi Pertunasan pada Umbi Tanaman Sedap Malam (Polianthes tuberosa L.) dengan Pengasapan dan Aplikasi Zat Pengatur Tumbuh
Abstrak: Increasing flower production of Polianthes is hindered by limited supply of bulb. Newly harvested bulb shows after ripening phenomenon, in which new bulbs are not readily sprouting. Farmers usually air or sun-dried the bulbs followed by curing above the kitchen stove for 1-3 months to induce sprouting. It is therefore necessary to accelerate sprouting. The purpose of this research was to study if bulbs of different sizes will sprout at the same time and if sprouting could be accelerated. The research was conducted at the Laboratory of Seed Science and Technology, Department of Agronomy and Horticulture, IPB Darmaga during November 2010 - February 2011. The research consisted of two experiments. In the first experiment bulbs were grouped into small (0.5 < Ø < 1.5 cm), medium (1.5 < Ø < 2.5 cm) and large ( Ø > 2.5 cm) sizes and subjected to air-drying or curing for six days. Each treatment was replicated four times with 20 bulbs for each experimental unit. In the second experiment sprouting was induced using BAP, GA3 or cured as three different set of experiments. The concentrations of BAP were 0, 100, 200, 300 ppm, whereas GA3 were 0, 50, 100, 150, and 200 ppm. Curing was carried out for 0, 2, 4, 6 days. The result showed that larger bulb produced higher number of sidebulb, so did curing as opposed to air-drying. The large bulb produced higher percentage of sprouting bulb than medium and small bulb. The larger the bulb the earlier they sprout. Result from the second experiment showed that the higher concentration of BAP give higher number of sidebulbs and earlier sprouting. Bulbs treated with BAP at 300 ppm uniformly sprouted within one week after treatment. However, it was not significantly different from BAP at 200 ppm. Use of GA3 up 100 ppm affected number of sidebulb and shoot length but did not affect percentage of sprouting bulbs. Use of curing did not affect number of sidebulb, shoot length as well as percentage of sprouting bulbs.
Keyword: 

Judul: Percepatan pematahan dormansi subang gladiol (Gladiolus hybridus) dengan aplikasi zat pengatur tumbuh
Abstrak: The main constraint of gladiolus cut flower production is the limited planting material. The availability of ready to plant corms is hindered by the long period of dormancy. The objective of the research was to ivestigate the effect of plant growth regulators (PGR) in breaking the dormancy of gladiolus corms cv. Nabila. The first experiment was carried out in two steps. In the first step NAA was combined with BAP. The concentration of NAA were 0, 50, 100, 150 ppm whereas BAP were 0, 50 100, 150 ppm. In the second step GA3 was combined with BAP. The concentration of GA3 were 0, 50, 100, 150 ppm whereas BAP were 0, 50 100, 150 ppm. The Randomized Complete Block Design with one factor was used in the first experiment with five replication. In the second experiment the best combination of PGR from the first experiment were selected and applied to corms with different storage periode (0, 2, 4, 6, 8 weeks). The Randomized Complete Block Design with two factor and five replication was used. The results of the first experiment showed that all treatment using NAA, GA3, BAP hastened the rooting and sprouting of the corms therefore breaking the dormancy. Considering the efficiency of dormancy breaking techniques, the treatment NAA 100 ppm and GA3 50 ppm were selected for the second experiment. The results of the second experiment showed that NAA 100 ppm and GA 50 ppm were similarly effective for breaking dormancy of the corms. The newly harvested and two weeks old corms rooted and sprouted earlier than the corms that had been longer in storage.
Keyword: 

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.
Keyword: