Judul: Development of a Radicle Emergence-Based Vigor  Evaluation Method for Long Bean (Vigna sinensis L.) Seeds Using Digital Image  Processing
Abstrak: Uji pemunculan radikula adalah metode alternatif yang menjanjikan untuk pengujian vigor benih secara cepat. Pengolahan citra digital merupakan suatu teknologi yang dapat digunakan dalam identifikasi mutu benih menggunakan metode pemunculan radikula yang lebih akurat dan waktu yang efisien. Penelitian bertujuan mengembangkan metode uji cepat vigor benih yang lebih efisien dan akurat dengan metode pemunculan radikula (radicle emergence) menggunakan pengolahan citra digital pada benih kacang panjang (Vigna sinensis L.). Penelitian dilakukan di Laboratorium Fisiologi dan Kesehatan Benih, Departemen Agronomi dan Hortikultura (AGH), Fakultas Pertanian, Institut Pertanian Bogor, pada bulan Oktober 2023 hingga Januari 2024. Penelitian ini menggunakan pengujian yang didasarkan pada tolok ukur daya berkecambah (DB), indeks vigor (IV), potensi tumbuh maksimum (PTM), kecepatan tumbuh (KCT), rataan waktu pemunculan radikula (MRET), serta pengujian vigor pada cekaman salinitas 0,35% dan 0,7%. Penelitian menggunakan rancangan kelompok lengkap teracak satu faktor dengan empat ulangan dengan suhu perkecambahan 25 ± 2 . Penelitian menggunakan sepuluh varietas benih kacang panjang dan pengamatan uji pemunculan radikula dilakukan mulai jam ke 46 hingga jam ke 58 setelah tanam. Penelitian ini menemukan bahwa pengolahan citra digital dapat digunakan secara efektif pada uji pemunculan radikula untuk pengujian vigor benih kacang panjang. Uji pemunculan radikula berkorelasi kuat positif dengan tolok ukur daya berkecambah, indeks vigor, dan kecepatan tumbuh, serta berkorelasi negatif dengan tolok ukur rataan waktu pemunculan radikula. Periode perkecambahan paling cepat yang dapat digunakan untuk pengujian uji pemunculan radikula adalah 52 jam. Penelitian ini menunjukkan potensi uji pemunculan radikula sebagai metode yang dapat diandalkan dan efisien untuk pengujian vigor benih kacang panjang, terutama ketika dikombinasikan dengan teknologi pengolahan citra digital., Radicle emergence test is a promising alternative method for rapidly evaluating seed vigor. Digital image processing is a technology that can be used to identify seed quality using the radicle emergence method that is more accurate and time efficient. This study aimed to develop an accurate and efficient radicle emergence method for long bean (Vigna sinensis L.) seed testing. The research was conducted at the Seed Physiology and Health Laboratory, Department of Agronomy and Horticulture (AGH), Faculty of Agriculture, Bogor Agricultural University, between October 2023 and January 2024. The study utilized tests that were based on benchmarks such as germination, vigor index (VI), maximum growth potential (MGP), germination speed, mean radicle emergence time (MRET), and vigor testing under 0.35% and 0.7% salinity stress. The study used a one-factor randomized complete group design with four replications with a germination temperature of 25 ± 2?. The study used ten varieties of broad bean seeds and the observation of radicle emergence test was conducted from hour 46 to hour 58 after sowing. This study found that digital image processing can be effectively used in conjunction with the radicle emergence test for seed vigor testing on long-bean seeds. The radicle emergence test showed strong positive correlations with germination, vigor index, and growth rate, and a negative correlation with mean radicle emergence time. The earliest possible germination period for radicle emergence assays was 52 hours. This study demonstrates the potential of the radicle emergence test as a reliable and efficient method for vigor testing of broad bean
Keyword: correlation, germination period, vigor, viability

Judul: Development of Rapid Vigor Test Using Radicle Emergence Method on Long Bean (Vigna sinensis L.)
Abstrak: Pengembangan pengujian mutu benih khususnya uji vigor diperlukan agar evaluasi mutu benih yang didapat lebih cepat, tepat, praktis, dan sesuai dengan kondisi lapangan. Uji pemunculan radikula [(radicle emergence (RE)] merupakan salah satu metode uji vigor yang telah divalidasi ISTA pada benih jagung, oilseed rape dan lobak. Penelitian ini bertujuan untuk mengembangkan metode uji RE pada benih kacang panjang dengan menentukan waktu pengamatan pemunculan radikula yang tepat serta mengkorelasikan uji RE dengan uji tolok ukur mutu fisiologis lainnya dan daya tumbuh benih di lapangan. Penelitian dilaksanakan di Laboratorium Ilmu dan Teknologi Benih dan Kebun Percobaan Cikabayan, Departemen Agronomi dan Hortikultura, Institut Pertanian Bogor, pada bulan Juni sampai dengan Agustus 2020. Benih yang digunakan adalah sembilan lot benih kacang panjang varietas KP-01 dan KP-12 yang memiliki tingkat viabilitas dan tanggal panen yang berbeda-beda, didapatkan dari PT. BISI International Tbk. Rancangan percobaan yang digunakan untuk pengujian RE adalah rancangan kelompok lengkap teracak (RKLT) faktor tunggal yaitu lot benih dengan pola pengamatan berulang pada jam ke-24, 27, 30, 33, 36, 39, dan 42 setelah pengecambahan. Pengujian mutu fisiologis dan daya tumbuh benih di lapangan juga menggunakan RKLT faktor tunggal. Hasil penelitian menunjukkan bahwa uji RE pada benih kacang panjang setelah dikecambahkan pada suhu 25± 2 °C dan diamati pada 33 jam ± 15 menit setelah pengecambahan, terbukti berkorelasi negatif sangat kuat dengan rataan waktu berkecambah., Development of seed quality tests, especially vigor tests, is needed so that the evaluation of the seed quality obtained is a faster, more precise, and simple method, and correlated with field conditions. Radicle emergence (RE) is one of the vigor testing methods that has been validated by ISTA for maize, oilseed rape and radish seeds. This research aimed to develop the RE test method on long bean seeds by determining the observation time of the RE test and correlating it with other seed physiological quality tests and seedling emergence tests in the field. The research was conducted at Seed Science and Technology Laboratory and Cikabayan Experimental Station, Department of Agronomy and Horticulture, Bogor Agricultural University from June to August 2020. The seeds used were nine lots of long bean seeds cv. KP-01 and KP-12 which had different levels of viability and harvesting ages, were obtained from PT. BISI International Tbk. The experimental design used for RE testing was a randomized completely block design (RCBD) using single-factor seed lots with repeated measurements at 24, 27, 30, 33, 36, 39, and 42 hours after sowing. An RCBD with a single factor (seed lots) was also used to test the seed’s physiological quality and seedling emergence in the field. The results showed that the RE test on long bean seeds after sowing at 25 ± 2 °C and observed after 33 hours ± 15 minutes was closely negatively correlated with mean germination time
Keyword: mean germination time, seed lot, seed physiological quality

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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