Judul: Respon Kombinasi Pupuk Organik dan Anorganik terhadap Produksi dan Kualitas Hasil Panen Katuk (Sauropus androgynous (L.) Merr.)
Abstrak: Katuk (Sauropus androgynus (L.) Merr.) adalah salah satu tanaman indigenous yang berpotensi untuk menjadi sayuran daun bernutrisi tinggi dan memiliki manfaat antibakteri, antianemia, antiinflamasi, memperlancar ASI, pewarna alami, serta ramuan obat tradisional. Penelitian ini bertujuan untuk mengetahui respon kombinasi pupuk organik dan anorganik pada produksi dan kualitas hasil panen tanaman katuk serta dosis optimumnya. Penelitian ini dilaksanakan pada bulan Juni-November 2020 di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor, Jawa Barat. Percobaan dilakukan dengan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktor Split Plot dengan pupuk urea sebagai petak utama dan pupuk kandang sebagai anak petak. Pupuk urea terdiri dari tiga taraf perlakuan, yaitu N1 (100 kg ha-1), N2 (200 kg ha-1), dan N3 (300 kg ha-1). Pupuk kandang terdiri dari dua taraf, yaitu P1 (20 ton ha-1) dan P2 (30 ton ha-1). Penelitian dilakukan dengan empat ulangan sehingga diperoleh enam kombinasi dengan 24 satuan percobaan. Hasil penelitian menunjukkan bahwa terdapat interaksi pupuk urea dan pupuk kandang pada peubah bobot daun layak konsumsi, bobot basah daun, bobot kering daun, dan bobot panen per petak. Kombinasi pupuk urea dan pupuk kandang pada N1P1 (100 kg ha-1 urea + 20 ton ha-1 pukan), N3P1 (300 kg ha-1 urea + 20 ton ha-1 pukan), dan N1P2 (100 kg ha-1 urea + 30 ton ha-1 pukan) terbukti meningkatkan bobot basah daun, bobot kering daun, dan bobot panen petak. Pada percobaan dengan dua kali pemanenan ini dapat menggunakan kombinasi N1P1 (100 kg ha-1 urea + 20 ton ha-1 pukan) untuk praktik budidaya katuk yang efisien dan hemat biaya., Katuk (Sauropus androgynus (L.) Merr.) is one of the indigenous plants that has the potential to become a leaf vegetable with high nutrition and has antibacterial, antianemic, anti-inflammatory benefits, facilitates breast milk, natural dyes, and traditional medicinal ingredients. This study aims to determine the response of the combination of organic and inorganic fertilizers on the production and quality of katuk crop yields and the optimum dose. This research was conducted in June-November 2020 at the Leuwikopo Experimental Station, IPB, Dramaga, Bogor, West Java. The experiment was carried out using a Completely Randomized Block Design (CRBD) with Split Plot factor with urea as the main plot and manure as the sub-plots. Urea fertilizer consisted of three treatment levels, namely N1 (100 kg ha-1), N2 (200 kg ha-1), and N3 (300 kg ha-1). Manure consists of two levels, namely P1 (20 tons ha-1) and P2 (30 tons ha-1). The study was conducted with four replications so that six combinations were obtained with 24 experimental units. The results showed that there was an interaction between urea fertilizer and manure on the variables of leaf weight suitable for consumption, leaf wet weight, leaf dry weight, and harvest weight per plot. Combination of urea and manure in N1P1 (100 kg ha-1 urea + 20 tons ha-1 manure), N3P1 (300 kg ha-1 urea + 20 tons ha-1 manure), and N1P2 (100 kg ha-1 urea + 30 tons ha-1 manure) was shown to increase leaf wet weight, leaf dry weight, and plot harvest weight. In this experiment with two harvests, a combination of N1P1 (100 kg ha-1 urea
Keyword: katuk, kualitas hasil panen, produksi, pupuk kandang, urea

Judul: Response of Shade and Fertilizer Dosage on Growth and  Yield of Katuk (Sauropus androgynus (L.) Merr.).
Abstrak: Katuk (Sauropus androgynus (L.) Merr.) adalah salah satu jenis sayuran indigenous di Indonesia yang memiliki potensi untuk dikembangkan sebagai sayuran alternatif untuk memenuhi kebutuhan nutrisi. Penelitian ini bertujuan untuk mengetahui pengaruh intensitas naungan dan dosis pupuk yang sesuai guna meningkatkan pertumbuhan dan hasil produksi katuk. Percobaan dilakukan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktor Split plot dengan petak utama adalah naungan dan anak petak adalah dosis pemupukan. Intensitas naungan terdiri dari 4 taraf, yaitu N0 (tanpa naungan), N1 (naungan 55%), N2 (naungan 65%), dan N3 (naungan 75%). Dosis pemupukan juga terdiri dari 4 taraf, yaitu P1 (50 kg ha-1), P2 (100 kg ha-1), P3 (150 kg ha-1), dan P4 (200 kg ha-1). Penelitian dilakukan dengan 3 ulangan sehingga diperoleh 16 kombinasi, dengan 48 satuan percobaan. Hasil penelitian menunjukkan tidak terdapat interaksi antara naungan dan dosis pemupukan. Perlakuan tunggal dosis pemupukan tidak memberikan pengaruh terhadap seluruh parameter pengamatan. Perlakuan naungan berpengaruh terhadap seluruh peubah pengamatan kecuali pada diameter batang saat pengamatan 2 MST dan 3 MST. Bobot panen komersial yang dipanen pada 8 MST mencapai hasil optimum pada aplikasi naungan 65%. Kata kunci: paranet, sayuran indigenous, dan sayuran komersial, Katuk (Sauropus androgynus (L.) Merr.) is one of the indigenous vegetables in Indonesia which has the potential to be developed as an alternative vegetable to meet nutritional needs. This study aims to determine the effect of shade intensity and appropriate dose of fertilizer to increase growth and yield of katuk production. The experiment was carried out using a completely randomized block design (RKLT) with split plot factors with the main plot being shaded and sub-plots being the dose of fertilization. Shade intensity consisted of 4 levels, namely N0 (without shade), N1 (55%), N2 (65%), and N3 (75% shade). The fertilization dose also consisted of 4 levels, namely P1 (50 kg ha-1), P2 (100 kg ha-1), P3 (150 kg ha-1), and P4 (200 kg ha-1). The study was conducted with 3 replications so that 16 combinations were obtained, with 48 experimental units. The results showed that there was no interaction between shade and fertilization dose. Single treatment of dose fertilization did not give effect on all parameter of observation. Shade treatment affected all observation variables except for stem diameter at 2 WAP and 3 WAP. Commercial harvest weights harvested at 8 WAP achieved optimum yields at 65% shading applications. Keywords: commercial vegetable, indigenous vegetable, and paranet
Keyword: commercial vegetable, indigenous vegetable, paranet

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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