Judul: Pemanfaatan Kitosan dan Media Organik untuk Pertumbuhan dan Produktivitas Tanaman Cabai Merah (Capsicum annum L.) di Screenhouse
Abstrak: Indonesian farmer incapable of fulfilling chili demands due to low productivity. Chitosan are capable of increasing productivity and inducing disease resistance against various pathogens. This research conducted to meet the best concentration of chitosan when combined with soil and manure as fertilizer. The combinations of soil and manure were 70%:30% (P1), 50%:50% (P2), and 30%:70% (P3), and the plants were sprayed with variation of chitosan concentration (0, 2, 4, 6, and 8 ml/L). The measured parameters were plant heights, number of leaves, stem diameters, number of flowers and fruits, and fruit weights. Only number of flowers and fruits, and fruit weights showed significant results based on Duncan test 5%. The combination of P2 medium with 2 ml/L of chitosan was the best combination for increasing flowers in week 13th (10) and fruit in week 15th (24.33) significantly. The combination of P2 medium with 4 ml/L of chitosan was the best combination for increasing fruit weights in week 18th (75.67 gr) significantly. Chitosan can also increase plant recovery time when damaged by disease.
Keyword: Bogor Agricultural University, 50:50 of soil and manure composition, chitosan concentration, chili plant productivity

Judul: Efektivitas Penggunaan Pupuk Organik yang diperkaya Mikrob Aktivator dalam Mengatur Keseimbangan Tajuk dan Akar Tanaman Cabai (Capsicum annuum. L)
Abstrak: The aim of this research was to evaluate the effect of enriched biofertilizer in some dosed for balancing shoot and root growth of red chili (Capsicum annuum. L) to support productivity and for biocontrol of pest and disease. The activator microbes used in this research belongs to Plant Growth Promoting Rhizobacteria (PGPR), consist of : Azospirillum sp. (Strain NS01), Azotobacter sp. (Strain HY1141), Bacillus subtilis (Strain HU48), and Pseudomonas beteli (Strain ATCC1986IT). The experiment was carried out in green house by Completley Randomize Design Method that consist of 6 treatments and 9 replications. The treatments were soil with unriched biofertilizer in 2:1 dosed (P1), soil with enriched biofertilizer in 2:1 dosed (P2), soil with unriched biofertilizer in 3:1 dosed (P3), soil with enriched biofertilizer in 3:1 dosed (P4), soil with anorganic fertilizer (NPK) and soil without any fertilizer (Ko). The result showed that application of enriched biofertilizers by activator microbes increased macro nutrients C, N, P, K, Ca and Mg in biofertilizers, increased growth and balancing of red chili. Application of enriched biofertilizers also increased imunity of red chili from pest and disease.
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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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