Judul: Inventarisasi Penyakit Tanaman Bambu di Kebun Raya Bogor
Abstrak: Bambu di Indonesia ada sekitar 157 spesies dan lebih dari 50% merupakan jenis bambu yang dapat dimanfaatkan. Adanya penggunaan bambu diharapkan dapat mengurangi penggunaan kayu yang akhirnya dapat mengurangi penebangan hutan. Bambu rentan terhadap berbagai penyakit dan gangguan lainnya. Penelitian ini bertujuan menginventarisasi penyakit dan mengidentifikasi patogen pada tanaman bambu. Penelitian ini dilakukan di Kebun Raya Bogor dengan mengamati 19 spesies tanaman bambu. Pengambilan sampel tanaman sakit dilakukan pada bagian yang bergejala seperti akar, batang, daun, dan rebung. Dari sampel tersebut dilakukan isolasi dan identifikasi patogen yang ditemukan yang pelaksanaannya di Laboratorium Mikologi Tumbuhan, IPB University. Studi pustaka dilakukan dari beberapa sumber seperti jurnal dan buku untuk melengkapi informasi tentang penyakit pada tanaman bambu. Hasil dari pengamatan ditemukan cendawan Penicillium sp. (daun), Rhizoctonia solani (batang), dan Amylosporus campbellii (akar) pada jenis bambu Gigantochloa apus. Cladosporium sp. juga ditemukan pada batang bambu jenis Dendrocalamus asper. Penyakit lain yang menginfeksi tanaman bambu berdasarkan studi pustaka diantaranya rot of emerging culm (Fusarium moniliforme), sapu (Epichloe bambusae), dan branch die-back (F. pallidoroseum) pada batang. Penyakit pada bagian daun yaitu karat daun (Dasturella divina), embun hitam (Meliola bambusicola), dan embun jelaga (Capnodium sp.). Bagian akar yaitu rhizome bud rot (Pythium middletonil) dan decay of rhizome, root and basal culm (Ganoderma lucidum). Informasi ini dapat dijadikan sebagai acuan dalam merancang tindakan pengendalian penyakit pada bambu., Bamboo types in Indonesia are about 157 species and more than 50% of them are bamboo that can be utilized. The use of bamboos are expected to reduce the use of wood which could ultimately reduce deforestation. Bamboo is susceptible to various diseases and other disorders. This study aims to record the diseases and identify the pathogens of bamboo plants. This research was conducted at Bogor Botanical Gardens by observing 19 species of bamboo plants. Sampling of diseased plants was done on symptomatic plant such as roots, stems, leaves, and bamboo shoots. From these samples, isolation and identification of pathogens were perform, which was conducted at Laboratory of Plant Mycology, IPB University. Literature studies were carried out by cites several sources such as journals and books to complement information about diseases of bamboo plants. The result of this study found Penicillium sp. (leaf), Rhizoctonia solani (stem), and Amylosporus campbellii (root) on bamboo Gigantochloa apus species. Cladosporium sp. also found on bamboo Dendrocalamus asper stems. Other diseases that infect bamboo plants based on literature studies include emerging calm rot (Fusarium moniliforme), witches broom (Epichloe bambusae), and Branch die-back (F. pallidoroseum) on the stem. Disease on the leaves is leaf rust (Dasturella divina), Black mildew (Meliola bambusicola), and Sooty mould (Capnodium sp.). Diseases of the root part are rhizome bud rot (Pythium middletonil) and decay of rhizome, root and basal culm (Ganoderma lucidum). This information can be used as a reference for designing disease control measures of bamboo
Keyword: A. campbellii, bambu, Cladosporium sp., Penicillium sp., R. solani

Judul: Investigation on Chemical and Biological Properties of Bamboo Rhizosphere as Disease Suppressive Soil
Abstrak: Bamboo can growth in many places in Indonesia with high diversity. There are 60 species from 200 species bamboo in Southeast Asia with high adaptation. Bamboo rhizosphere known as disease suppressive soil. The objectives of this research were to: (i) study the influence of bamboo rhizosphere on disease suppressive soil phenomenon based chemical and biological soil properties, (ii) study the functional diversity of bamboo rhizosphere on disease suppressive soil. This research was conducted from July 2014 to April 2015. Bamboo rhizosphere samples were taken at depth 0-20 cm from three locations in the district of Bogor, West Java province. There were four bamboo species successfully examined, namely: Gigantochloa apus, Dendrocalamus asper, Scyzosthachyum longispiculatum, and Bambusa vulgaris. This research was conducted in two parts; (i) bioassay in the greenhouse to determine the influence of bamboo rhizosphere on plant growth and the disease incidence,(ii) laboratory investigation of microbiological aspects of bamboo rhizosphere, including: total of microbes, P and K solubilizing microbes, N2 fixing bacteria, chitinolytic bacteria, total of indole acetic acid (IAA) and antibiosis microbes of bamboo rhizosphere. The research result showed that chemical and biological properties of bamboo rhizosphere influent the increasing of plant growth and suppressing soil borne pathogen. Microbes in the rhizosphere of bamboo has a high diversity. Microbes in the rhizosphere of bamboo has a better ability to promote plant growth and suppress the growth of P. palmivora relative than non bamboo rhizosphere. Effectiveness of bamboo rhizosphere as disease suppressive soil determined by chemical properties, including: low pH; high Cation Exchange Capacity, high C-organic, P2O5 in the soil, and biological properties, including: high total bacteria, high functional microbes (chitinolitic bacteria, N-fixing bacteria, P solubilizing bacteria), high total of IAA, and abundance of microbes antibiosis. This research suggests the use of bamboo rhizosphere soil as a papaya nursery medium.
Keyword: bamboo rhizosphere, Phytophthora palmivora, microbes

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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