Judul: Knowledge, Attitude, and Practice of Farmers in  Tobacco Pest and Disease Management in Banyudono, Boyolali Regency
Abstrak: Tembakau memegang peranan penting sebagai komoditas ekspor di Indone sia. Namun demikian, hama dan penyakit seringkali membatasi produksi temba kau. Penelitian ini bertujuan memperoleh informasi mengenai pengetahuan, sikap, dan tindakan petani dalam pengelolaan hama dan penyakit tanaman tembakau di Kecamatan Banyudono, Kabupaten Boyolali. Penelitian dilakukan dengan metode survei langsung kepada 60 petani tembakau dengan menggunakan kuesioner ter struktur untuk mendapatkan data primer. Sementara itu, data sekunder diperoleh dari pemerintah daerah. Data yang diperoleh disajikan secara deskriptif dan diana lisis dengan menggunakan χ2 (chi-square). Pengetahuan petani tentang budi daya tembakau berasal secara turun-temurun dari orang tua. Hama dan penyakit utama budi daya tembakau adalah Spodoptera litura, Myzus persicae, Aphis gosypii, Helicoverpa sp., Bemisia sp., penyakit kerupuk (Tobacco leaf curl virus), lanas (Phytohpthora nicotiane), dan patik daun (Cercospora nicotinae). Serangan hama dan penyakit tersebut dapat menyebabkan penurunan kualitas tembakau. Hub ungan antara usia, pendidikan, pengalaman usaha tani, dan keanggotaan gapoktan menunjukkan bahwa pengetahuan petani berhubungan dengan tingkat pendidikan petani. Sikap petani berhubungan dengan usia dan pendidikan, sedangkan tinda kan petani berhubungan dengan tingkat pengalaman usaha tani dan keanggotaan gapoktan., Tobacco plays role as important export commodity in Indonesia. This re search was aimed to obtain informations about the knowledge, attitude, and prac tice of of tobacco pests and diseases management in Banyudono District, Boyolali Regency. This research was done by conducting direct survey to 60 tobacco farm ers using structured questionnaires to collect primary data, while a data was ob tained from local government. The data obtained were presented descriptively and analyzed using χ2 (chi-square). Farmers' knowledge about tobacco cultivation comes from generation to generation from their parents. Major pests and diseases of tobacco plants were Spodoptera litura, Myzus persicae, Aphis gosypii, Heli coverpa sp., Bemisia sp., leaf curl disease (Tobacco leaf curl virus), black shank (Phytohpthora nicotiane), and frog-eye disease (Cercospora nicotinae). These pests and diseases reduced tobacco quality. The relationship among age, educa tion, farming experience, and the membership of farmer group, showed that the farmers’ knowledge was closely related to their formal education background. Farmers’ attitude was correlated with age and formal education, while farmers’ practice was correlated with farming experience and the membership of farmer group
Keyword: cultivation, farmer characteristics, IPM

Judul: Knowledge, Attitudes, and Practices of Corn Farmers in the Management of Plant Pest Organism in Pesisir selatan District, West Sumatra
Abstrak: Serangan hama dan penyakit pada tanaman jagung mengakibatkan menurunnya produksi jagung bahkan dapat menyebabkan gagal panen. Penelitian ini bertujuan mengetahui pengetahuan, sikap, dan tindakan petani dalam budi daya jagung di Kabupaten Pesisir Selatan dan upaya menanggulangi OPT yang berkaitan dengan karakter petani dalam mengelola hama dan penyakit pada tanaman jagung. Penentuan responden dilakukan secara terpilih (purposive sampling) berdasarkan populasi penduduk yang bekerja sebagai petani jagung di kecamatan tersebut. Jumlah responden sebanyak 60 petani jagung dari tiga kecamatan yaitu Kecamatan Ranah Pesisir, Linggo Sari Baganti, dan Lengayang. Jenis dan sumber data yang digunakan dalam penelitian ini adalah data primer dan data sekunder. Data primer diperoleh melalui wawancara secara langsung dengan petani responden menggunakan panduan kuesioner terstruktur, sedangkan data sekunder diperoleh dari Badan Penyuluh Pertanian Kabupaten Pesisir Selatan. Hasil penelitian menunjukkan bahwa kurangnya pengetahuan petani terhadap PHT dan petani di Kabupaten Pesisir Selatan sangat bergantung pada penggunaan pestisida sintetik dalam mengelola OPT. Tindakan petani dalam mengelola hama dan penyakit juga dipengaruhi oleh faktor kebiasaan cara bertani secara turun temurun dan pengaruh dari petani lain. Perlu dilakukan kegiatan penyuluhan kepada petani mengenai cara pengelolaan OPT pada petani di Kabupaten Pesisir Selatan., Pests and diseases that attack corn crops resulted in a decrease in corn production and caused crop failure. This study aimed to determine the knowledge, attitudes, and Practices of corn farmers in Pesisir Selatan Regency related to Integrated Pest Management (IPM) on corn plants. Respondents were selected by purposive sampling based on the population as corn farmers in the sub-district. The respondents were 60 corn farmers from three sub-districts, namely Ranah Pesisir, Linggo Sari Baganti, and Lengayang sub-districts. The types and sources of data used in this study were primary and secondary data. Primary data were obtained through direct interviews with respondents using a structured questionnaire guidance, while secondary data were obtained from the Agricultural Extension Agency in Pesisir Selatan Regency. The research showed that there is a lack of knowledge of farmers on IPM, and the farmers in Pesisir Selatan Regency are very dependent on the use of synthetic pesticides in managing plant pests and deseases. Farmers' practices in managing pests and diseases were influenced by farming habits from generation to generation as well as other farmers. It is necessary to carry out outreach activities to farmers on how to manage pests for farmers in Pesisir Selatan Regency.
Keyword: corn pests and deseases, interview, IPM, survey

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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