Judul: Pengaruh Cendawan Endofit terhadap Biologi dan Statistik Demografi Wereng Batang Cokelat
Abstrak: Endophytic fungi is an endosymbiont that lives within host plant tissues without causing any visible symptom of disease. This type of fungus are important as mediators in plant-herbivore interactions. Endophytic fungi are known to enhance resistance of host plant against insect herbivores mainly by productions of various alkaloid-based defensive compounds in the plant tissue or through alterations of plant nutritional quality. This study was conducted as an attempt to gain information on the effect of Nigrospora sp4 on the biology and life history of of brown plant hopper (BPH). Nigrospora sp4 culture (in powder form), were provided by Plant Clinic of Bogor Agriculture University, and was used to inoculate the fungi to the rice seeds. The effect of endophyte infected and endophyte-free plants were measured on the survival and development of Nilaparvata lugens Stál, a major pest in rice. Endophyte infected plants showed resistance to N. lugens in the form of significant increase in eggs and early nymphs mortality. Another effect of endophytic fungi which was also observed on this study were nymphal development, life cycle, preovipositional period as well as age at first reproduction. The overall result showed that Nigrospora sp4 has an affect toward population growth of N. lugens in laboratory scale and artificial inoculation of endophytes could be a useful method to protect rice plants from N. Lugens. This result could be used to develop alternative ecologically safe control strategies.
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Judul: Pengaruh cendawan endofit terhadap hama dan pertumbuhan tanaman padi di lapangan
Abstrak: Cendawan endofit merupakan cendawan yang hidup dalam jaringan tanaman, tanpa menimbulkan gejala penyakit pada tanaman inangnya. Penelitian bertujuan mengetahui pengaruh cendawan endofit terhadap hama dan pertumbuhan tanaman padi di lapangan. Perlakuan yang digunakan adalah perendaman benih padi varietas Ciherang menggunakan suspensi cendawan endofit dengan kerapatan 10 cfu/ml. Cendawan endofit yang digunakan yaitu Nigrospora, Penicillium, dan Acremonium. Sebagai pembanding digunakan tanaman yang tidak diberi perlakuan cendawan endofit dan tanaman yang diberi perlakuan pestisida. Penelitian terdiri dari sembilan perlakuan dan setiap perlakuan terdiri dari tiga ulangan, disusun dalam Rancangan Acak Kelompok (RAK). Pengamatan yang dilakukan terdiri dari dua pengamatan yaitu pengamatan hama dan pertumbuhan padi. Parameter yang diamati pada pengamatan hama meliputi tingkat serangan hama penggerek batang merah jambu dan belalang serta populasi kepinding tanah. Pada pengamatan pertumbuhan padi yang diamati meliputi pertumbuhan bibit (panjang bibit, panjang akar, dan daya perkecambahan), tinggi tanaman, jumlah anakan, berat bulir, jumlah bulir, dan jumlah anakan prduktif serta bobot panen. Data yang diperoleh dianalisis dengan ANOVA pada taraf 5% dan uji lanjut Duncan. Perlakuan cendawan endofit meningkatkan pertumbuhan bibit padi. Padi yang diberi perlakuan cendawan endofit menunjukkan pertumbuhan bibit, akar bibit dan daya perkecambahan yang berbeda dibandingkan kontrol. Perlakuan cendawan endofit secara umum tidak berpengaruh nyata terhadap tingkat serangan hama dan pertumbuhan tanaman. Kata kunci: Cendawan endofit, Nigrospora, Penicillium, Acremonium
Keyword: Cendawan endofit, Nigrospora, Penicillium, Acremonium

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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