Judul: Potential of Endophytic Fungi Originated for Rice and Grasses for Controling Brown planthopper Nilaparvata lugens (Stal) (Hemiptera: Delphacidae).
Abstrak: Wereng cokelat adalah hama padi terpenting di Indonesia. Pengendalian wereng cokelat dapat dikembangkan dengan berbagai metode. Cendawan endofit berpotensi sebagai agen biokontrol serangga. Penelitian ini bertujuan mengetahui potensi cendawan endofit dalam mengendalikan wereng cokelat. Cendawan endofit diisolasi dari padi dan rumput-rumputan di sekitar Bogor. Sebanyak 12 isolat hasil isolasi, 7 isolat asal padi dan 5 asal rumput-rumputan. Berdasarkan hasil uji patogenisitas, terdapat 5 isolat adalah nonpatogen. Uji selanjutnya dengan menggunakan 4 isolat cendawan endofit, yaitu Acremonium sp., Nigrospora sp.1, Nigrospora sp.2, Nigrospora sp.3. Penggunaan cendawan Nigrospora sp.4 dari koleksi Klinik Tanaman sebagai kontrol positif. Benih padi direndam ke dalam suspensi konidia cendawan endofit selama dua jam dan diperam selama 24 jam. Bibit padi dipindahkan ke ember setelah tanaman berumur 3 minggu setelah semai. Bibit padi disemprot dengan suspensi cendawan endofit seminggu setelah tanam. Tujuh hari setelah inokulasi cendawan endofit, sebanyak 10 nimfa wereng cokelat instar satu diintroduksi ke tanaman padi dan diamati setiap hari selama 7 hari untuk mencatat kelangsungan hidup nimfa. Dalam percobaan lain, 5 pasang wereng cokelat dewasa diintroduksi ke tanaman padi (28 hari setelah tanam) dan diamati setiap minggunya selama 6 minggu. Semua isolat cendawan endofit yang diuji dalam percobaan ini menyebabkan kematian nimfa dan menurunkan populasi wereng cokelat., Brown planthopper (BPH) is the most important rice pest in Indonesia. We developed many methods to control this planthopper. Endophytic fungi have the potential as biocontrol agents of insects. This study aims to determine the potential of endophytic fungi in controlling BPH. Endophytic fungi were collected from rice and grasses in Bogor. A total of 12 isolates were isolated, 7 from rice and 5 from grasses. Based on test, 5 isolates were nonpathogenic. We used 4 of these isolates for the experiments, Acremonium sp., Nigrospora sp.1, Nigrospora sp.2, Nigrospora sp.3. We also used Nigrospora sp.4 from Klinik Tanaman collection as positive control. Rice seeds were dipped in endophytic conidia fungal suspension for two hours, and then ripened for 24 hours. Rice seedlings were transferred to the planting baskets 3 weeks after sowing. Rice seedlings were sprayed with endophytic fungal suspension a week after planted. Seven days after inoculation of endophytic fungi, 10 first-stage BPH nymphs were introduced and observed daily for 7 days to record nymphs survival. In the other experiment, 5 pairs of adult were introduced in to the rice plants (28 days after treatment) and observed weekly for six weeks. All of endophytic fungi isolates tested in these experiments caused nymphs death and population suppression of BPH.
Keyword: biological control, Nigrospora, population, resistent

Judul: Testing the Effectiveness test of Several Entomopathogenic Fungi Against the Brown Planthopper, Nilaparvata lugens Stal (Hemiptera: Delphacidae) in Rice Nurseries
Abstrak: Wereng batang cokelat (WBC), Nilaparvata lugens Stal merupakan hama penting tanaman padi yang dapat menyerang semua fase pertumbuhan tanaman dari fase vegetatif (pembibitan) hingga generatif. Salah satu pengendalian hama dapat dilakukan dengan menggunakan agens hayati, seperti cendawan entomopatogen. Penelitian ini bertujuan untuk mengetahui keefektifan cendawan Beauveria sp. dan Metarhizium sp, yang dikembangkan LPHP Banyumas, serta produk komersial, Symbio berbahan aktif cendawan Lecanicillium lecanii SYW-TG2 dan Nigrospora sp. SYW-CG1 dalam mengendalikan telur, nimfa, dan imago WBC. Penelitian disusun dalam Rancangan Acak Kelompok (RAK) dengan 4 perlakuan dan 5 ulangan. Perlakuan terdiri dari isolat Beauveria sp. (B), Metarhizium sp. (M), Produk Symbio (PS), dan kontrol (K) dengan konsentrasi yang digunakan 108 konidia/ml. Data yang diperoleh diolah menggunakan analysis of variance (ANOVA) dan dilanjutkan dengan uji Tukey dengan taraf 5%. Hasil penelitian menunjukkan inokulasi cendawan dapat menyebabkan keabnormalan telur WBC, menunda kemunculan nimfa, dan menurunkan populasi imago. Perlakuan PS merupakan perlakuan terbaik dalam menyebabkan keabnormalan telur hingga 59,29% dan menunda kemunculan nimfa. Sedangkan perlakuan Metarhizium sp. merupakan perlakuan terbaik dalam menurunkan persentase anakan padi terinfestasi telur dan menurunkan populasi imago WBC
Keyword: pestisida hayati, patogen serangga, perendaman benih, penyemprotan

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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