Judul: Pest and Disease Attacks, Pesticide Application, and Rice Production in Pekalongan City, Central Java
Abstrak: Tanaman padi (Oryza sativa L.) merupakan tanaman pangan pokok di Indonesia. Tanaman padi pada umumnya tidak dapat berproduksi secara optimal karena berbagai kendala, seperti kesuburan lahan, praktik budidaya, dan serangan hama dan penyakit tanaman. Serangan hama dan penyakit tanaman dapat menyebabkan kerugian yang sangat tinggi. Strategi pengendalian yang sering dilakukan oleh petani salah satunya melalui aplikasi pestisida sintetik. Penelitian ini bertujuan mengetahui jenis hama dan penyakit penting, luas serangan hama dan penyakit, jenis dan aplikasi pestisida, serta produktivitas tanaman padi di Kota Pekalongan, Jawa Tengah. Data serangan hama dan penyakit, penggunaan pestisida, dan produktivitas padi diperoleh dari Dinas Pertanian Kota Pekalongan serta literatur elektronik. Hama dan penyakit penting yang menyerang tanaman padi di Kota Pekalongan antara lain penggerek batang padi, wereng batang cokelat, keong mas, burung, tikus, penyakit kerdil rumput, dan hawar daun bakteri. Berdasarkan luas serangan OPT, wereng batang cokelat merupakan hama yang dominan menyerang tanaman padi di Kota Pekalongan. Terdapat 11 bahan aktif pestisida yang digunakan oleh petani padi di Kota Pekalongan, yang sebagian besar merupakan jenis insektisida. Insektisida Abacel 18 EC yang berbahan aktif abamektin merupakan insektisida yang rata-rata volume penggunaannya tinggi. Curah hujan juga menjadi salah satu faktor yang mempengaruhi produktivitas padi, semakin tinggi curah hujan, maka produksi padi semakin menurun. Tiga jenis pupuk,yaitu phonska, urea, dan SP-36 dan padi varietas IR-42 banyak digunakan oleh petani padi di Kota Pekalongan., Rice (Oryza sativa L.) is a primary food crop in Indonesia. Rice plants are generally unable to produce optimally due to various factors, such as soil fertility, cultivation pratices, weather, and plant pests and diseases. Pests and diseases could cause significant production losses and synthetic pesticide was one of the current prevention methods used by farmers. The aim of this study was reporting the main pests and diseases and their attacks, pesticides application, and the rice production in Pekalongan, Central Java. The data were obtained from Pekalongan Agricultural Office and some electronic references. There were seven main pests and diseases attacking the rice plants in Pekalongan, including rice stem borer, brown planthopper, birds, rats, golden snails, bacterial leaf blight, and grassy stunt virus disease. According to the area of pest attack, the brown planthopper was a dominant pest attacking rice plants. There were 11 pesticide active ingredients used by rice farmers, and most of which were insecticides. Abacel 18 EC (a.i abamectin) is an insecticide with a high average volume used. The rainfall was also become one of the factors affecting the rice productivity, the higher the rainfall, the lower the rice production. Three types of fertilizer, phonska, urea, and SP-36 are used by rice farmers in Pekalongan. Meanwhile, IR-42 was the commonly rice variety planted in Pekalongan.
Keyword: active ingredient, brown planthopper, rainfall

Judul: Inventarisasi Penyakit Tanaman Padi (Oryza sativa L.) di Kecamatan Lubuk Basung dan Tanjung Raya, Kabupaten Agam, Sumatra Barat
Abstrak: Tanaman padi merupakan salah satu komoditas pangan penting di dunia. Penurunan produksi padi di Indonesia dan khususnya Sumatra Barat disebabkan oleh beberapa faktor penyakit tanaman seperti cendawan, bakteri, virus, dan nematoda. Berbagai macam penyakit yang mengancam produksi komoditas tanaman pangan telah dilaporkan termasuk komoditas tanaman padi. Patogen dapat merusak bagian tertentu atau bahkan seluruh organ tanaman. Faktor lingkungan menjadi salah satu penyebab pemencaran penyakit pada tanaman padi. Tujuan dari penelitian ini mengamati dan melakukan penghitungan kejadian dan keparahan penyakit tanaman padi di Kecamatan Lubuk Basung dan Tanjung Raya, Kabupaten Agam, Sumatra Barat. Penelitian akan dilaksanakan dalam lima tahap yaitu wawancara petani, penentuan tanaman contoh, penghitungan insidensi dan keparahan penyakit, penghitungan produksi padi, serta analisis data. Penyakit tanaman padi yang ditemukan yaitu hawar daun bakteri (Xanthomonas oryzae pv oryzae), blas (Pyricularia oryzae), hawar daun pelepah (Rhizoctonia solani), pucuk putih (Aphelenchoides besseyi), bercak cokelat sempit (Cercospora oryzae), dan busuk bulir bakteri (Burkholderia glumae). Hasil penelitian menunjukkan bahwa seluruh lahan pengamatan ditemukan penyakit tanaman padi dengan lahan LB1, LB3, LB5, TR2, TR3, TR5 rata rata menunjukkan insidensi dan keparahan penyakit yang tinggi dibandingkan lahan pengamatan lainnya., Rice Plant is one of the most important food commodities in the world. The decline in rice production in Indonesia and especially West Sumatra is caused by several plant disease factors such as fungi, bacteria, viruses, and nematodes. Various diseases that threaten the production of food crop commodities have been reported, including rice commodities. Pathogens can damage certain parts or even entire plant organs. Environmental factors are one of the causes of the spread of disease in rice plants. The purpose of this study was to observe and calculate the incidence and severity of rice disease in Lubuk Basung and Tanjung Raya, Agam, West Sumatra. The research will be carried out in five stages, farmers interview, determining sample plants, calculating disease incidence and severity, calculating rice production, and analyzing data. Rice plant diseases found were bacterial leaf blight (Xanthomonas oryzae pv oryzae), blast (Pyricularia oryzae), sheath blight (Rhizoctonia solani), white tip (Aphelenchoides besseyi), narrow brown spot (Cercospora oryzae), and bacterial grain rot (Burkholderia glumae). The results showed that all of the observed rice plant diseases were found with LB1, LB3, LB5, TR2, TR3, TR5 fields on average showing a high incidence and severity of disease compared to other observation fields.
Keyword: dispersal, pathogen, rice production

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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