Judul: Concentration and Soaking Time in GA3 Solution for Breaking Dormancy of Bambara Groundnut
Abstrak: Dormansi benih pada kacang bambara seringkali menjadi kendala dalam pengujian mutu benih kacang bambara, sehingga perlu dilakukan pematahan dormansi. Percobaan dilakukan untuk mendapatkan konsentrasi dan waktu perendaman GA3 yang efektif untuk mematahkan dormansi pada benih kacang bambara. Percobaan dilaksanakan di Laboratorium Ilmu dan Teknologi Benih IPB dan green house Cikabayan. Penelitian dilaksanakan pada bulan Juli sampai dengan September 2021. Percobaan disusun secara faktorial dengan dua faktor yaitu konsentrasi GA3 dan waktu perendaman GA3. Faktor konsentrasi GA3 terdiri atas 5 taraf, yaitu 0 ppm, 50 ppm, 100 ppm, 200 ppm dan 300 ppm. Faktor waktu perendaman GA3 terdiri atas 3 taraf yaitu 6 jam, 12 jam, dan 24 jam. Rancangan percobaan yang digunakan yaitu Rancangan Acak Lengkap (RAL). Hasil percobaan menunjukkan bahwa perlakuan pematahan dormansi benih kacang bambara menggunakan perendaman dalam waktu dan konsentrasi larutan GA3 mampu meningkatkan viabilitas dan vigor benih kacang bambara. Perlakuan perendaman benih selama 6 jam dengan konsentrasi GA3 50 ppm meningkatkan viabilitas benih kacang bambara berdasarkan peubah daya berkecambah yaitu 79,33 % dan potensi tumbuh maksimum yaitu 82,67 %. Perlakuan perendaman benih selama 24 jam dengan konsentrasi GA3 100 ppm meningkatkan vigor benih kacang bambara berdasarkan peubah indeks vigor yaitu 50,67 % dan kecepatan tumbuh yaitu 11,67 %., Seed dormancy in bambara groundnut is often the constraint in testing the quality of bambara groundnut bean seed, so it is necessary to break dormancy. The objective of this research was to get effective concentration and soaking time in GA3 solution for breaking dormancy of bambara groundnut. The research was conducted at Laboratory of Seed Science and Technology IPB and Cikabayan green house from July to September 2021. The experiment was arranged in a factorial with two factors, namely concentration of GA3 and soaking time in GA3. The factor concentration of GA3 consists of five levels, namely 0 ppm, 50 ppm, 100 ppm, 200 ppm and 300 ppm. The factor soaking time in GA3 solution consist of three levels, namely 6 hours, 12 hours, and 24 hours. The experiment was arranged in a Completey Randomize Design (CRD). The results showes that the treatment of breaking dormancy of bambara groundnut using soaking time and concentration of GA3 solution was able to increase the viability and vigor of bambara groundnut. The treatment of soaking the seeds for 6 hours with a concentration of GA3 50 ppm increased the viability of bambara groundnut based on the normal germination variable of 79.33 % and the maximum germination potential of 82.67 %. The treatment of soaking seeds for 24 hours with a concentration of GA3 100 ppm increased the vigor of bambara groundnut based on the vigor index of 50.67 % and the growth rate of 11.67 %
Keyword: GA3, Viability, Vigor

Judul: Hydration Dehydration Treatment Of Bambara Groundnuts (Vigna subterranea L. Verdc) Seed Vigor
Abstrak: Upaya yang dapat dilakukan untuk meningkatkan produktivitas kacang bambara antara lain adalah menjamin ketersediaan benih bermutu, namun terdapat kendala dalam penyediannya. Penelitian ini bertujuan mempelajari pengaruh hidrasi-dehidrasi sebagai perlakuan invigorasi terhadap viabilitas dan vigor benih kacang bambara (Vigna subterranea L. Verdc). Penelitian ini dilaksanakan pada bulan Juni hingga Agustus 2019 di Laboratorium Pengujian Benih, Departemen Agronomi dan Hortikultura, Institut Pertanian Bogor. Percobaan dirancang menggunakan rancangan acak lengkap (RAL) dengan dua faktor. Percoban dilakukan pada lanras Tasikmalaya. Faktor pertama adalah lot benih dipanen Maret 2019, lot benih dipanen Oktober 2017. Faktor kedua adalah perlakuan hidrasi-dehidrasi yang terdiri atas 5 taraf, yaitu kontrol, (perendaman dalam air selama 12 jam lalu dikeringkan 4 jam) pada suhu 28 o C-30 o C, suhu 38 o C-40 o C, suhu 28 o C-30 o C, suhu 38 o C-40 o C. Perlakuan hidrasi-dehidrasi mampu meningkatkan vigor benih kacang bambara dengan peningkatan nilai indeks vigor dari 15,9% menjadi 27% dan kecepatan tumbuh dari 9%etmal -1 menjadi 11%etmal -1., Effort that can be done to increase the productivity of bambara groundnuts include ensuring the availability of quality seeds, but there are obstacles in the process of providing the seeds. This research aims to study the effect of hydration- dehydration as an invigoration treatment on vigor and viability of two lots of bambara groundnut seeds (Vigna subterranea L. Verdc.). This research was conducted from June to August 2019 at Seed Testing and Storage Laboratory, Department of Agronomy and Horticulture, IPB University. The experiment was designed using a completely randomized design (CRD) with two factors. The experiment was conducted on the Tasikmalaya landraces. The first factor is the seed lot, harvested in March 2019, harvested in October 2017. The second factor is hydration-dehydration consisting of five levels, namely control, (soaking in water for 12 hours and then dried for 4 hours) at temperature 28 o C-30 o C, at temperature 38 o C-40 o C, at temperature 28 o C-30 o C, at temperature 38 o C-40 o C. Hydration-dehydration treatment was able to increase seed vigor of bambara groundnut seeds by increasing the vigor index value from 15.9 % to 27% and the speed of germination from 9%etmal -1 to 11%etmal -1 .
Keyword: Invigoration, Bogor Groundnuts, Seed deterioration, Viability

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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