Judul: Perbandingan Pengelolaan Tanaman Berbasis PHT dan Konvensional Pada Tanaman Jagung (Zea mays ) di Nganjuk , Jawa Timur.
Abstrak: One of factors that results in suboptimum productivity of corn is lack of good management and cultivation, and the presence of plant pests and diseases. Several attempts to improve the productivity of corn has been developed continuously, including the use of natural agents such as Plant Growth Promoting Rhizobacteria (PGPR) and fungal biocontrol agents as control component in IPM. The objective of this study was to compare IPM based corn crop management involving PGPR and bicontrol agents with conventional method on plant growth, yield, and pest/diseases occurence. Field observations of the crop pests and diseases, and their intensity and severity were conducted as well as measurements of plant height, girth, number of leaves, and number of cobs. Interview with the farmer was also done. The use of PGPR containing mixture of Pseudomonas fluorescens and Bacillus polymixa combined with application of Trichoderma sp., Verticillium sp., and organic fertilizer to meet IPM concepts resulted in maintaining optimum plant height, number of leaves, and number of cobs. The plant also showed to acquire resistance against pests and diseases. In general, the IPM based plant management gives better performance of growth and yield and lower occurence of corn pest and diseases than that of conventional method. The cost for growing corn based on IPM was higher than that conventional method, however, gave more yield benefit. IPM approach is concluded to be more profitable than conventional method.
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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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