Judul: Pertumbuhan Tanaman, Produksi dan Mutu Benih Kacang Panjang sebagai Respon terhadap Pupuk Urea dan KNO3
Abstrak: Nitrogen dapat diberikan dalam bentuk nitrat atau amonium. Kalium nitrat merupakan sumber nitrogen dalam bentuk nitrat, sementara Urea dalam bentuk amonium. Penelitian ini bertujuan mendapatkan informasi pertumbuhan tanaman, produksi, dan mutu benih kacang panjang dari tanaman yang diberi pupuk N berupa KNO3 dan Urea. Penelitian dilaksanakan dalam rancangan petak terbagi dengan rancangan lingkungan acak kelompok. Jenis pupuk sebagai petak utama (KNO3 dan Urea) dan dosis N sebagai anak petak (50%, 100%, dan 150% rekomendasi). Penanaman dilakukan di Desa Darmaraja pada bulan April hingga Juni 2021. Pengujian mutu benih dilakukan di Laboratorium Penyimpanan dan Pengujian Mutu Benih IPB. Hasil penelitian menunjukkan jenis pupuk N dan dosis yang berbeda tidak mempengaruhi pertumbuhan dan perkembangan tanaman kacang panjang. Pupuk KNO3 dan dosis N tinggi (150% rekomendasi) meningkatkan hasil benih. Mutu fisiologis benih kacang panjang KP-1 tidak dipengaruhi oleh jenis pupuk N dan dosis yang diberikan. Pupuk KNO3 pada dosis yang lebih tinggi meningkatkan bobot kering dan ukuran benih., Nitrogen can be provided in the form of nitrate or ammonium. Potassium nitrate is a source of nitrogen in the form of nitrate, while Urea is in the form of ammonium. This study aims to obtain information on plant growth, production, and quality of yard-long bean seeds from plants fed with N fertilizers in the form of KNO3 and Urea. The experiment was arranged in a split-plot design with the completely randomized block design as an environmental design. The main plot was the type of N fertilizer (Urea and KNO3) and the subplots are fertilizer doses (50%, 100%, and 150% of the recommendation). Planting was carried out in Darmaraja Village from April to June 2021. Seed quality testing was carried out at the IPB Seed Storage and Quality Testing Laboratory. The results showed that the type of N fertilizer and the different doses did not affect the growth and development of yard-long beans. KNO3 fertilizer and high N dose (150% recommendation) increase seed yield. The physiological quality of KP-1 long bean seeds was not affected by the type of N fertilizer as well as the dose. KNO3 fertilizer at higher doses increased seed dry weight and seed size.
Keyword: KP-1, seed physical quality, viability, vigor

Judul: Impact of N, P, K Fertilization and Pruning to Increase Cowpea (Vigna unguiculata L.) Seed Production and Quality
Abstrak: Penelitian bertujuan mengidentifikasi untuk memperoleh pengaruh pemupukan N, P, K dan pemangkasan terhadap peningkatan produksi dan mutu benih kacang tunggak (Vigna unguiculata L.). Penelitian menggunakan rancangan perlakuan Split Plot dalam Rancangan Kelompok Lengkap Teracak (RKLT), masing-masing dengan tiga ulangan. Petak utama adalah pemangkasan yang terdiri dari tanpa pangkas (P0) dan pangkas (P1), sedangkan anak petak adalah tiga dosis pupuk N, P, K yang terdiri dari D1 (Urea 100 kg ha-1, SP-36 200 kg ha-1, KCl 150 kg ha-1), D2 (Urea 100 kg ha-1, SP-36 250 kg ha-1, KCl 175 kg ha-1), dan D3 (Urea 100 kg ha-1, SP-36 275 kg ha-1, KCl 200 kg ha-1). Pemupukan N, P, K dan pemangkasan tidak berpengaruh terhadap karakter vegetatif yaitu daya tumbuh, jumlah cabang, dan tinggi tanaman, serta komponen produksi seperti produksi petak-1, jumlah polong tanaman-1, bobot benih tanaman-1, jumlah benih polong-1, bobot polong tanaman-1, dan bobot 1000 butir benih, namun berpengaruh nyata terhadap interaksi bobot 1000 butir benih. Kedua perlakuan juga berpengaruh nyata pada komponen mutu benih seperti daya berkecambah, indeks vigor, dan Berat Kering Kecambah Normal (BKKN), tetapinamun tidak berpengaruh nyata terhadappada kecepatan tumbuh dan potensi tumbuh maksimum. Secara umum, perlakuan tersebut dapat diterapkan untuk meningkatkan mutu benih dalam produksi benih kacang tunggak., This study investigated the effect of N, P, K fertilization and pruning treatment to increase cowpea yield and seed quality. The experiment was arranged in a split-plot with a randomized complete block design, with three replications. The main plot was pruning treatment, i.e. pruning and control, while the subplot was three fertilizer doses of N, P, K i.e. 100 kg ha-1 Urea – 200 kg ha-1 SP-36 – 150 kg ha-1 KCl (D1), 100 kg ha-1 Urea – 250 kg ha-1 SP-36 – 175 kg ha-1 KCl (D2), and 100 kg ha-1 Urea – 275 kg ha-1 SP-36 – 200 kg ha-1 KCl (D3). N, P, K fertilization and pruning treatment didn’t affect to vegetative characters such as seed germinated in the field, branches number, and plant height. Both treatments also didn’t affect yield components such as yields plot-1, pods number plant-1, seeds weight plant-1, seeds number pod-1, pods weight plant-1, and 1000 seeds weight, but significantly affected interaction of the 1000 seeds weight. A significant effect of both treatments was observed on seed quality such as seed germination, vigor index, and normal seedling’s dry weight, however, didn’t affect other character such as germination speed and maximum growth potential. Generally, the treatments could be applied to increase the seed quality in cowpea seed production.
Keyword: cowpea, fertilizer dose, seed viability, pruning, cultivation technique

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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