Judul: Pengaruh varietas kedelai, mulsa jerami dan aplikasi PGPR terhadap penyakit pustul bakteri dan kelimpahan bakteri rizosfer
Abstrak: Bacterial pustule caused by Xanthomonas axonopodis pv. glycines is one of important bacterial diseases of soybean in Indonesia. The development of alternative control of the disease is required to support Integrated Pests and Diseases Management for sustainable agriculture. This research was conducted to observe the effect of straw mulch, Plant Growth Promoting Rhizobacteria (PGPR) on the incidence of bacterial pustule disease and the abundance of chitinolytic bacteria, heat tolerant bacteria, and fluorescence bacteria on two soybean varieties. All of the factors as combinations were not significant to affect the value of total area under disease progress curve (AUDPC) of bacterial pustule. Factor that significantly affected the values of AUDPC was varieties. Gepak Kuning variety has lowest AUDPC value compare to Anjasmoro variety. In addition, combination of Gepak Kuning variety and straw mulch showed AUDPC value. Abundance of fluorescence bacteria on soybean rhizosphere treated with PGPR is significantly higher compared with those on plants without PGPR. The other treatments and their combination did not significantly affect the abundance of rhizosphere bacteria.
Keyword: 

Judul: Studies on the effectivity of several enviromental friendly pest management components to bacterial pustule on soybean
Abstrak: Ecological approach of plant disease management is needed to enhance the sustainable agriculture in Indonesia. Bacterial pustule disease has been known as an important soybean disease because of its potential to reduce soybean yield in Indonesia. The causal agent of the disease is Xunthomonus uxonopodzs pv. glycmes. To control the pustule disease, series of experiments were done to determine the effect of combination of the culture system and using biocontrol agents or botanical bactericide on the disease severity and yield of soybean. The researches have been conducted at the Bacteriology Laboratory of Plant Pest and Disease Department, the Agriculture Faculty, the Chemistry Laboratory of Mathematics and Natural Science Faculty, the Bioprocess Engineering Laboratory of Biotechnology Research Centre and Cikarawang Experimental Station, Bogor Agricultural University. The works have been done from June 2000 until December 2002. The results of this work showed that (I) the liquid formulation of P. fluorescens GI 34 in molasses 1% retarded Xa. pv glycznes up to 60 days after storage by the exudation of siderofor, hydrogen cyanida, and biosurfactant and that of B subtzlzs BBO 1 also retarded Xu. pv glycznes by the exudation of biosurfactant, (2) the matoa leaf extract with gallic acid 8.2 mg/g leaf fresh weight in the concentration of 20 % in water gave the highest retardation to the bacterial pustule, (3) the combination of intercropped system soybean-corn with the application of biocontrol agents gave the highest retardation effect : decreasing the infection rate from 0.11 unit/days to 0.06 unit/days in dry season and decreased the infection rate from 0.13 unit/days to 0.07 unit/days in wet season, (4) the combination of intercropped system soybean-corn with the application of biocontrol agents gave the highest income (Rp 1,765,000.00/ha in dry season and Rp 1,363,000.00/ha in wet season)., Di Indonesia, pengendalian penyakit tanaman yang bersifat ramah lingkungan diperlukan untuk mendukung sistem pertanian berkelanjutan. Penyakit pustule bakteri merupakan penyakit penting yang mengakibatkan rendahnya produksi kedelai di Indonesia. Penyebab penyakit pustule bakteri adalah Xanthomonas axonopodis pv. Glycines. Untuk mengendalikan penyakit pustule bakteri kedelai dilakukan suatu seri percobaan untuk mengevaluasi pengaruh kombinasi pola tanam dengan aplikasi bakteri biokontrol atau bakterisida botani terhadap keparahan penyakit dan produksi kedelai.
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: