Judul: Mikobiota pada Buah Pisang: Pengaruhnya terhadap Fusarium semitectum, Cendawan Penyebab Busuk Buah
Abstrak: Fusarium semitectum is a pathogenic fungus causing fruit rot of banana fruits. Biological control agents have been used as an alternative to control postharvest diseases. The objective of this study was to test antagonistic potential of mycobiota of banana fruits against F. semitectum. This pathogenic fungus was isolated from banana fruits cultivar lampung collected from three traditional markets in Municipality of Bogor using direct plating method. The test fungi were isolated using dilution method followed by pour plate method. Test of antagonism was carried out using direct opposition method. Pathogenicity test of F. semitectum and test fungi were carried out by inoculating the fungal isolates on banana fruits. Among the 5 isolates of F. semitectum, isolate PBI.3 showed the highest pathogenicity. Seventeen isolates of test fungi were isolated from banana fruits, consisted of 14 filamentous fungal and 3 yeast isolates. Test of antagonism gave 4 antagonist fungal isolates which inhibited the growth of F. semitectum PBI.3 in a range of 70-100%, they consisted of Aspergillus niger, Cercosporella sp., Plectosphaerella sp., and Trichoderma hamatum respectively. The last three of them did not cause any diseases of banana fruits, consequently they can be used as biocontrol agents.
Keyword: Bogor Agricultural University (IPB), Fusarium semitectum, fruit rot disease, banana, antagonistic fungi

Judul: Analisa introduksi mikroorganisme antagonis untuk pengendalian hayati penyakit layu (Fusarium oxysporum f. sp. cubense) pada pisang (Musa sapientum L)
Abstrak: Layu fusarium yang disebabkan oleh cendawan tular tanah Fusarium oxysporum Schlecht f. sp. Cubense (E. F. Smith) Snyd. & Hans. Merupakan penyakit yang saat ini telah menjadi masalh utama di berbagai pertanaman pisang. Beberapa tehnik pengendalian telah dilakukan, namun belum ada yang efektif mengendalikan penyakit. Alternatif pengendalian lain yang relatif belum banyak dilakukan di Indonesia adalah introduksi mikroorganisme antagonis untuk pengendalian penyakit. Oleh karena itu telah dilakuakn percobaan yang bertujuan untuk menganalisis keefektifan mikroorganisme antagonis (Trichoderma sp., Gliocladium fimbriatum, F. O. non patogenik, Peseudomonas fluorescens, dan Bacillus subtilis) dalam mengendalikan layu fusarium pada pisang
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: