Judul: Pests and Diseases of Lucky Bamboo (Dracaena sanderiana Sander ex Mast.) (Asparagales: Asparagaceae) in Sukabumi Regency
Abstrak: Bambu hoki merupakan tanaman hias dalam ruangan yang memiliki nilai ekonomi tergolong prospektif. Informasi mengenai hama dan penyakit bambu hoki di Indonesia belum banyak dilaporkan. Penelitian bertujuan memperoleh informasi mengenai hama dan penyakit serta insidensi dan keparahan penyakit penting pada tanaman hias bambu hoki di Kabupaten Sukabumi. Penelitian dilaksanakan pada bulan Februari hingga April 2022 di Desa Sudajaya Girang dan Klinik Tanaman IPB. Penelitian ini meliputi survei penentuan lokasi, wawancara kepada enam petani, pengamatan hama dan penyakit dengan diagonal sampling sebanyak 200 tanaman contoh, hama dan penyakit yang ditemukan kemudian diidentifikasi, laludihitung insidensi dan keparahan penyakit serta persentase dan intensitas serangan hama. Budi daya bambu hoki meliputi pengolahan tanah, penanaman, pemeliharaan tanaman, pemanenan, dan pengelolaan pascapanen. Hama pada bambu hoki yaitu keong semak (Bradybaena similaris), ulat penggulung daun (Bibasis sp.), dan kutu putih (Pseudococcus longispinus). Penyakit pada bambu hoki yaitu antraknosa (Colletotrichum sp.), busuk batang (Fusarium sp.), bercak daun Alternaria (Alternaria alternata), dan karat alga (Cephaleuros sp. dan Phycopeltis arundinacea). Insidensi dan keparahan penyakit antraknosa tertinggi berada di lahan B dengan rata-rata 64,2 dan 16,3%., Lucky bamboo is an indoor ornamental plant with a prospective economic value. Information about pests and diseases of lucky bamboo in Indonesia has not been widely reported. The objective of the research was to obtain information on pests and diseases and the incidence and severity of important diseases in ornamental plant lucky bamboo in Sukabumi Regency. The research was carried out from February to April 2022 at Sudajaya Girang Village and Plant Clinic IPB. The research includes a survey of location determination, interviews with six farmers, observation of pests and diseases by diagonal sampling with 200 plant samples, pests and diseases found and identified, then calculated the incidence and severity of disease as well as the percentage and intensity of pest attacks. Cultivation of lucky bamboo includes tillage, planting, plant maintenance, harvesting, and post-harvest management. Pests on lucky bamboo are Asian trampsnail (Bradybaena similaris), leaf roller (Bibasis sp.), and mealybug (Pseudococcus longispinus). Diseases on lucky bamboo are anthracnose (Colletotrichum sp.), stem rot (Fusarium sp.), Alternaria leaf spot (Alternaria alternata), and algal rust (Cephaleuros sp. and Phycopeltis arundinacea). The highest incidence and severity of anthracnose was in field B with an average of 64,2 and 16,3%.
Keyword: Colletotrichum sp., Fusarium sp., insidensi, keparahan, tanaman hias

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: 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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