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: Pengayaan pupuk organik dengan pupuk hayati untuk meningkatkan efisiensi penggunaan hara, pertumbuhan, dan produksi tanaman cabai, The Enrichment of Organic Fertilizer with Biofertilizer to Improve Nutrient Use Efficiency, Growth, and Yield of Red Chili).
Abstrak: Red chili production in Indonesia is low due to low soil productivity. Soil productivity can be increased by using biofertilizer. Biofertilizer can improve plant growth, yield, and soil quality. The aim of this study was to study influence of enriched compost and ordinary compost to increase nutrient use efficiency, growth, and yield of red chili. This study used biofertilizer which consisted of Bacillus subtilis (strain HU48), Pseudomonas beteli (strain ATCC1986IT), Azotobacter sp. (strain HY1141), and Azospirillum sp. (strain NS01). The experiment was conducted in the field using randomized block design (RBD) with two factors and three replications. The first factor was organic fertilizer that consisted of ordinary compost (O1), enriched compost (O2), and compost added biofertilizer when planted (O3). The second factor was inorganic fertilizer that consisted of 50% dosage of NPK and 100% dosage of NPK. The plants were grown on plots of 3 m x 3 m with a plant distance about 50 cm x 60 cm. The observed parameters were nutrient use efficiency, plant growth, and yield. The results showed that biofertilizer increased plant nutrient uttilization efficiency, plant growth, and yield by 65 %, 59%, and 126%, respectively. The combination of enriched compost and 50% dosage of NPK (O2A1) had the highest plant nutrient uttilization efficiency, plant growth, and yield than the other treatment.
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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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