Judul: Pengaruh Penambahan Media Tanam terhadap Keberhasilan Aplikasi Pangkas Akar dan Inokulasi Fungi Ektomikoriza pada Bibit Melinjo
Abstrak: Root pruning has been known to fix root’s root system and enhancing ectomycorrhiza colonization in 2 months old melinjo seeds, but during 6 months of observation, it is not giving any significant effect to enhance growth of seedlings. This research aimed to determine the effect of replenishment of planting media and time of observation to the success rate of ectomycorrhiza fungal infection and the growth of inoculated melinjo seedlings after 8 months. Planting media replenishment affected the growth of roots and shoots of the observed melinjo seedlings. Planting media replenishment shown its influence to the growth of melinjo seedlings at the 3rd month of after weaned. Root pruning is no longer giving a significant effect, either to ectomycorrhiza colonization or melinjo seedlings growth. Fungi’s ectomycorrhiza inoculation enhance the growth of melinjo seedlings.
Keyword: Bogor Agricultural University (IPB), Ectomycorrhiza, Gnetum gnemon, Planting media, Root pruning

Judul: Keberhasilan Aplikasi Pangkas Akar dan Inokulasi Fungi Ektomikoriza pada Bibit Melinjo (Gnetum gnemon).
Abstrak: Aplikasi pangkas akar dan inokulasi fungi ektomikoriza pada bibit melinjo dapat meningkatkan kolonisasi ektomikoriza tetapi belum dapat meningkatkan pertumbuhan bibit melinjo selama 6 bulan inokulasi. Tujuan penelitian ini ialah mengetahui pengaruh penambahan media tanam dan waktu pengamatan terhadap keberhasilan aplikasi pangkas akar dan inokulasi fungi ektomikoriza pada bibit melinjo. Rancangan percobaan yang digunakan dalam penelitian ini adalah rancangan petak terbagi, sumber inokulum sebagai petak utama terdiri atas 3 taraf (kontrol, bibit bermikoriza, inokulum tanah). Tingkat pangkas akar sebagai anak petak yang terdiri atas 3 taraf (0%, 30%, dan 50%). Pengamatan dilakukan pada bulan ke-9, 10, 11 setelah bibit diinokulasi. Penambahan media tanam dan penambahan waktu pengamatan dapat meningkatkan keberhasilan aplikasi pangkas akar dan inokulasi fungi ektomikoriza terlihat dari pertumbuhan bibit melinjo. Inokulasi fungi ektomikoriza mulai memberikan pengaruh terhadap pertumbuhan bibit melinjo pada bulan ke-9 setelah inokulasi. Kombinasi tingkat pangkas akar 50% dengan inokulasi menggunakan inokulum tanah memberikan interaksi yang terbaik pada peubah banyaknya cabang akar baru yang terbentuk pada bulan ke-9 setelah inokulasi. Pada bulan ke 11 setelah inokulasi ditemukan tubuh buah Scleroderma sp. pada bibit melinjo yang diinokulasi fungi ektomikoriza.
Keyword: ektomikoriza, inokulasi, melinjo, pangkas akar, scleroderma

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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