Judul: The Main Pest of Pepper Plants in the Village of Dusun Besar, sub-district of Pulau Maya, Kayong Urata Regency, Kalimantan Barat
Abstrak: Lada (Piper ningrum L.) merupakan salah satu komoditas ekspor yang penting di Indonesia setelah karet, kopi, teh, dan kelapa sawit. Penelitian ini dilakukan untuk mengetahui jenis-jenis hama utama tanaman lada dan kerusakan akibat serangannya di Desa Dusun Besar, Kecamatan Pulau Maya, Kabupaten Kayong Utara, Kalimantan Barat. Penelitian dilakukan pada bulan Maret hingga Juli 2021. Pengamatan hama tanaman lada dilakukan di enam kebun lada di daerah bukit di Desa Dusun Besar, yang masing-masing memiliki 50 tanaman lada dengan pemilik kebun yang berbeda. Hama utama yang menyerang tanaman lada adalah kumbang penggerek batang Lophobaris piperis (Coleoptera: Curculionidae), kepik penghisap bunga Diconocoris hewetti (Hemiptera: Tingidae), dan kepik penghisap buah Dasynus piperis (Hemiptera: Coreidae). Tingkat kerusakan tertinggi disebabkan oleh serangan D. piperis yang mencapai 47,81%. populasi D. piperis banyak ditemukan pada kebun 1 yaitu sebanyak 120 ekor dan terendah pada kebun 4 yaitu sebanyak 55 ekor. Populasi D. hewetti paling banyak ditemukan pada kebun 4 yaitu 19 ekor dan paling rendah pada kebun 6 sebanyak 14 ekor. Rata-rata kelimpahan D. piperis pada bagian bawah 42,5, bagian tengah 37,5, dan bagian atas 12,8. Kelimpahan hama D. piperis pada bagian bawah dan tengah tidak berbeda nyata, tetapi keduanya nyata lebih tinggi dibandingkan dengan pada bagian atas. Rata-rata kelimpahan D. hewetti rendah, dan tidak berbeda nyata antara tajuk bagian bawah, tengah, maupun atas. Kata kunci: hama utama, lada, pengamatan hama, Pepper (Piper ningrum L.) is one of export commodities that important in Indonesia after rubber, coffee, tea, and palm oil. This study was conducted to determine the main types of pepper pests and the damage caused by their attacks in Dusun Besar Village, Pulau Maya district, Kayong Utara Regency, West Kalimantan. Studies were conducted from March to July 2021 in the Dusun Besar. Observations of pepper plant pests were carried out in six pepper platations in the hill area of Dusun Besar Village, each with a total 50 pepper plants with different plantation owners. The main pest that attacks pepper plants were the stem borer Lophobaris piperis (Coleoptera: Curculionidae), the flower-sucking ladybug Diconocoris hewetti (Hemiptera: Tingidae), and the fruit-sucking ladybug Dasynus piperis (Hemiptera: Coreidae). The highest level of damage was caused by D. piperis attack, which reached 47.81%. The population of D. piperis was monthly found in plantation 1, which was 120 individuals and the lowest population was 55 individuals. The highest population of D. hewetti was found in plantation 4 with 19 individuals and the lowest in plantation 6 with 14 individuals. D. piperis averaged 42.5 at the bottom 37.5 and 12.8 at the top. The abundance of D. piperis at the bottom and middle was not significantly different, but both were higher than at the top. The average abundance of D. hewetti was at the bottom at 1.8, the center 2.5, and top at 1.2. The mean abundance of D. hewetti was low, and there was no significant difference between the lower, middle, and upper canopy. Keywords: main pests, pepper, pest observation
Keyword: Main pest, Pepper, Pest observation

Judul: Potensi Sebaran Hama Penggerek Batang dan Penyakit Busuk Pangkal Batang Lada di Kabupaten Lampung Utara
Abstrak: Lada adalah salah satu komoditas ekspor Indonesia di bidang perkebunan mengalami penurunan hasil yang salah satunya dapat disebabkan oleh faktor serangan hama dan penyakit. Pertumbuhan dan perkembangan hama dan penyakit salah satunya dapat dipengaruhi iklim suatu daerah. Penelitian ini bertujuan menganalisis potensi sebaran hama penggerek batang (Lophobaris piperis) dan penyakit busuk pangkal batang lada (Phytophthora capsici) berdasarkan nilai Ecoclimatic Index (EI), serta mengetahui potensi kerugian akibat hama penggerek batang (Lophobaris piperis) dan penyakit busuk pangkal batang lada (Phytophthora capsici) di Kabupaten Lampung Utara. Ecoclimatic Index (EI) merupakan luaran Model Climex berdasarkan karakteristik fisik spesies dan faktor iklim Kabupaten Lampung Utara pada tahun 2009-2018. Nilai EI hama penggerek batang dan penyakit busuk pangkal batang lada tergolong sesuai hingga sangat sesuai. Potensi sebaran tertinggi hama penggerek batang dan penyakit busuk pangkal batang lada berlokasi di Kecamatan Sungkai Jaya. Potensi sebaran terendah hama penggerek batang berlokasi di Kecamatan Kotabumi Selatan dan penyakit busuk pangkal batang lada berlokasi di Kecamatan Kotabumi Selatan dan Abung Tinggi. Secara umum, potensi sebaran bulanan hama penggerek batang dan penyakit busuk pangkal batang lada memiliki pola yang sama, dimana pola fluktuasi bulanan tinggi pada musim hujan. Potensi kerugian hasil lada berbanding lurus dengan luas serangan hama penggerek batang dan penyakit busuk pangkal batang lada. Serangan yang tinggi dapat menyebabkan kerugian hasil yang tinggi., Pepper is one of Indonesia's agricultural export commodities, which has been experiencing a decrease in yield, partly due to factors such as pest and disease attacks. The growth and development of pests and diseases can be influenced by the climate of an area. This study aims to analyse the potential distribution of pepper stem borer pest (Lophobaris piperis) and pepper stem base rot disease (Phytophthora capsici) based on the Ecoclimatic Index (EI) value, and determine the potential losses due to pepper stem borer pest (Lophobaris piperis) and pepper stem base rot disease (Phytophthora capsici) in North Lampung Regency. Ecoclimatic Index (EI) is the output of the Climex Model based on the physical characteristics of species and climatic factors of North Lampung Regency in 2009-2018. The EI values of pepper stem borer pests and pepper stem base rot disease are classified as suitable to highly suitable. The highest potential distribution of pepper stem borer pests and pepper stem base rot disease is located in Sungkai Jaya sub-district. The lowest potential distribution of pepper stem borer pests is located in Kotabumi Selatan sub-district and pepper stem base rot disease is located in Kotabumi Selatan and Abung Tinggi sub-districts. In general, the potential monthly distribution of stem borer pests and pepper stem base rot disease has the same pattern, where the monthly fluctuation pattern is high in the rainy season. The potential yield loss of pepper is directly proportional to the extent of pepper stem borer infestation and pepper stem base rot disease. High infestation can lead to high yield losses.
Keyword: Black Pepper, Climex, Ecoclimatic Index, Lophobaris Piperis, Phytophthora Capsici

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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