Judul: Population Dynamics of the Rice Stem Borer in Kiarasari Village, Subang District
Abstrak: The rice stem borer is one of the most important rice pests in Indonesia. Three species of rice stem borer are found in Subang Regency, including the yellow rice stem borer (Scirpophaga incertulas), the striped rice stem borer (Chilo suppressalis), and the pink rice stem borer (Sesamia inferens). This study aims to determine the population dynamics of rice stem borer species in Kiarasari Village, Compreng District, Subang Regency. Rice stem borers were collected using an Insect Light traps 0.4 watt LED trap lamp, then counted and identified to determine the species. The research was conducted from January to October 2022. Lightrap was placed in three parts of the rice fields based on the compass point, west, east and north. The dominant rice stem borer was the yellow rice stem borer (92.2%). Other types of rice stem borer are pink rice stem borer (4.4%) and striped rice stem borer (3.5%). There was a difference in the average number of rice stem borer adults caught in each wind direction. The number of catches of the yellow rice stem borer was higher when the lamp traps were placed in the north, west and east directions compared to the striped rice stem borer and the pink rice stem borer. The development of rice stem borer populations can be affected by wind speed, temperature, and humidity., Penggerek batang padi merupakan salah satu hama tanaman padi yang penting di Indonesia. Penggerek batang padi yang ditemukan di Kabupaten Subang ada tiga jenis yaitu penggerek batang padi kuning (Scirpophaga incertulas), penggerek batang padi bergaris (Chilo suppressalis), dan penggerek batang padi merah muda (Sesamia inferens). Penelitian ini bertujuan untuk mengetahui dinamika populasi spesies penggerek batang padi di Desa Kiarasari, Kecamatan Compreng, Kabupaten Subang. Penggerek batang padi dikumpulkan dengan lampu perangkap LED Insect Lightrap 0,4 watt, kemudian dihitung dan diidentifikasi untuk menentukan spesiesnya. Penelitian dilakukan pada bulan Januari hingga Oktober 2022. Lightrap ditempatkan di tiga bagian pesawahan berdasarkan arah mata angin, yaitu barat, timur, dan utara. Penggerek batang padi yang dominan adalah penggerek batang padi kuning (92,2%). Jenis penggerek batang padi lainnya adalah penggerek batang padi merah jambu (4,4%) dan penggerek batang padi bergaris (3,5%). Terdapat perbedaan rata-rata jumlah imago penggerek batang padi yang tertangkap pada setiap arah mata angin. Jumlah tangkapan penggerek batang padi kuning lebih banyak tertangkap pada semua penempatan lampu perangkap dibandingkan dengan penggerek batang padi bergaris dan penggerek batang padi merah jambu. Kecepatan angin, suhu, dan kelembapan udara dapat berpengaruh terhadap perkembangan populasi penggerek batang padi.
Keyword: Padi, Penggerek Batang Padi, Perangkap Cahaya, Arah Mata Angin

Judul: Perilaku Petani dalam Pengendalian Hama Terpadu Penggerek Batang Padi Kuning di Kecamatan Ciasem Kabupaten Subang
Abstrak: Hama penggerek batang kuning (Scirpophaga incertulas) telah menurunkan produksi padi di Indonesia secara signifikan sehingga diperlukan metode pengendalian yang tepat berdasarkan pengendalian hama terpadu (PHT). Penelitian ini bertujuan untuk mendapatkan informasi dan menganalisis pengetahuan, sikap, dan praktik petani responden terhadap pengendalian hama penggerek batang padi di Kecamatan Ciasem, Kabupaten Subang, serta karakteristik agroekosistemnya. Penelitian ini dilaksanakan pada bulan Maret hingga Juni 2023. Lokasi pengamatan tersebar di tiga desa dengan tingkat kerusakan hama yang berbeda dan total petani yang dipilih sebanyak 60 petani. Metode wawancara menggunakan kuesioner terstruktur untuk memperoleh data. Data yang diperoleh kemudian diolah dengan menggunakan MICROSOFT EXCEL 2013 dan dilakukan uji ?2 (Chi-square) untuk melihat hubungan antara karakteristik petani dengan pengetahuan, sikap, dan tindakan dalam pengelolaan tanaman padi pada tingkat a = 5%. Hasil penelitian menunjukkan bahwa petani di lahan dengan tingkat serangan ringan memiliki pengetahuan, sikap, dan tindakan yang lebih baik dibandingkan dengan petani di lahan dengan tingkat serangan sedang dan berat, Yellow stem borer (Scirpophaga incertulas) reduce rice production in Indonesia significantly so appropriate control methods based on integrated pest management (IPM) are needed. This study aims to obtain information and analyze knowledge, attitudes, and practice of respondent farmers towards the management of rice stem borer in Ciasem District, Subang Regency, and the characteristics of agroecosystem as well. This research was conducted from March to June 2023. The observation locations spreaded over three villages with different levels of pest damage and a totally 60 farmers were selected. Interview methods using structured and instructured questionnaires implemented to obtain data. Obtained data was then processed using MICROSOFT EXCEL 2013 and the ?2 (Chi-square) test was conducted to see the relationship between farmer characteristics with knowledge, attitudes, and actions in rice plant management at the a = 5% level. The results showed that farmers in the field with mild infestation had better knowledge, attitudes, and practice compared to the field with moderate and severe infestation.
Keyword: Penggerek batang padi, PHT, Survei, Rice stem borer, 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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