Judul: Optimization of Inoculation Time and FMA Level on Alfalfa Plants (Medicago sativa L.)
Abstrak: Alfalfa merupakan tanaman subtropis yang sulit beradaptasi di daerah tropis. Penelitian ini bertujuan mengevaluasi efektivitas pemberian fungi mikoriza arbuskula (FMA) berdasarkan waktu inokulasi dan level terhadap pertumbuhan tanaman alfalfa (Medicago sativa L.). Rancangan percobaan berupa Rancangan Acak Lengkap (RAL) faktorial 2 x 6 dengan 20 ulangan. Faktor I yaitu waktu inokulasi, meliputi persemaian dan pembibitan. Faktor F yaitu level FMA, meliputi kontrol positif, 0 g FMA (A50F0), 5 g FMA (A50F5), 10 g FMA (A50F10), 15 g FMA (A50F15), dan 20 g FMA (A50F20). Hasil penelitian menunjukkan waktu inokulasi dan level FMA berpengaruh nyata (P<0,05) terhadap morfologi tanaman. Tanaman dengan inokulasi FMA memberikan respon yang baik terhadap kolonisasi FMA, berat segar dan kering tanaman alfalfa. Kesimpulan bahwa inokulasi FMA efektif meningkatkan produktivitas tanaman alfalfa (kolonisasi akar, tinggi, jumlah daun, jumlah tangkai daun, jumlah cabang, diameter batang, berat segar dan kering, serta warna daun) dibanding kontrol dan tanpa FMA. Inokulasi FMA pada periode persemaian cenderung lebih efektif. Inokulasi FMA level 20 g pada periode persemaian memberikan hasil yang baik secara konsisten., Alfalfa is a subtropical plant that is difficult to adapt to the tropics. This study aims to evaluate the effectiveness of arbuscular mycorrhizal fungi (FMA) application based on inoculation time and level on alfalfa plant growth (Medicago sativa L.). The experimental design is a 2 x 6 factorial completely randomized design (CRD) with 20 replications. Factor I is the time of inoculation, including nursery (I1) and seedling (I2). Factor F is FMA level, including positive control (A100F0), 0 g FMA (A50F0), 5 g FMA (A50F5), 10 g FMA (A50F10), 15 g FMA (A50F15), and 20 g FMA (A50F20). The results showed that inoculation time and FMA level had a significant effect (P<0.05) on plant morphology. Plants with FMA inoculation gave a good response to FMA colonization, fresh and dry weight of alfalfa plants. It is concluded that FMA inoculation effectively increases alfalfa plant productivity (root colonization, height, number of leaves, number of petioles, number of branches, stem diameter, fresh and dry weight, and leaf color) compared to control and without FMA. FMA inoculation in the nursery period tends to be more effective. FMA inoculation level of 20 g in the nursery period gave consistently good results.
Keyword: alfalfa, fungi, inokulasi, mikoriza arbuskula

Judul: The Effectiveness of Arbuscular Mycorrhizal Fungi (AMF) Results of Different Fortification and Fertigation Techniques on Indigofera zollingeriana (Miq.) Plants Field Scale
Abstrak: Penelitian ini dilakukan untuk mengevaluasi efektivitas FMA hasil fortifikasi dan teknik fertigasi berbeda pada tanaman Indigofera zollingeriana skala lapang. Metode penelitian ini menggunakan rancangan acak kelompok (RAK) berdasarkan perbedaan teknik produksi inokulum fungi mikoriza arbuskula pada tanaman indigofera yang meliputi 6 perlakuan (Inokulum FMA dengan fortifikasi AB mix 1000ppm;2000ppm;3000ppm fertigasi datar, Inokulum FMA dengan fortifikasi AB mix 1000ppm;2000ppm;3000ppm fertigasi bertingkat) dan 5 ulangan. Parameter yang diukur terdiri dari tinggi tanaman (cm), jumlah daun, jumlah ranting, jumlah cabang, lingkar batang (cm), pH tanah, warna daun dan tingkat infeksi FMA. Hasil tingkat kolonisasi akar (yang sama tinggi ≥ 80%) dari semua teknik fertigasi dan teknik fortifikasi. Perlakuan IFB2 (Inokulum FMA dengan fortifikasi AB Mix 2000 ppm pada fertigasi bertingkat) menghasilkan jumlah daun dan warna daun yang lebih baik dibandingkan perlakuan lainnya., This research was conducted to evaluate the effectiveness of mycorrhizal inoculum resulting from fortification and different fertigation techniques on Indigofera zollingeriana plants. field scale. This research used a randomized block design (RAK) method based on differences in production techniques of arbuscular mycorrhizal fungi inoculum on indigofera plants which included 6 treatments (AMF inoculum with AB mix fortification 1000ppm; 2000ppm; 3000ppm flat fertigation, AMF inoculum with fortification AB mix 1000ppm;2000ppm;3000ppm graded fertigation) and 5 replicates. Parameters measured consisted of plant height (cm), number of leaves, number of twigs, number of branches, plant circumference (cm), soil pH, leaf color, and colonization of AMF infection. The result of root colonization rate (which was equally high 80%) of all fertigation and fortification techniques. The IFB2 treatment (FMA Inoculum with 2000 ppm AB Mix fortification in graded fertigation) resulted in a better number of leaves and leaf color compared to other treatments.
Keyword: Efektivitas, Arbuscula Mycorrhizal Fungi, Indigofera zollingeriana

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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