Judul: Application of Gandasil D Foliar Fertilizer on the Growth and Yield of Four Accessions of Katuk (Sauropus androgynus (L.) Merr.)
Abstrak: Katuk memiliki banyak manfaat dan berpotensi memenuhi kebutuhan pangan keluarga. Penelitian ini mengevaluasi pengaruh perbedaan aksesi dan aplikasi pupuk daun Gandasil D terhadap pertumbuhan dan produksi tanaman katuk (Sauropus androgynus (L.) Merr.). Perlu dilakukan penelitian untuk mengetahui keragaman aksesi dan pengaruh aplikasi pupuk daun terhadap pertumbuhan dan produksi terbaik. Rancangan yang digunakan adalah petak tersarang dengan dua perlakuan pupuk (kontrol, dipupuk daun) tersarang dalam empat aksesi (Ciaruteun Ilir 1, Pager Jangkung 1, Ciaruteun Ilir 2, Pager Jangkung 2). Aksesi Ciaruteun Ilir 1 dan Aksesi Pager Jangkung 1 secara umum menunjukkan pertumbuhan dan produksi yang lebih besar dari aksesi lainnya. Aksesi Ciaruteun Ilir 1 menunjukkan hasil paling tinggi pada parameter jumlah cabang dan panjang cabang panen. Aksesi Ciaruteun Ilir 1 menghasilkan bobot panen per bedeng lebih banyak dari aksesi Ciaruteun Ilir 2 dan aksesi Pager Jangkung 2 tetapi tidak berbeda dengan aksesi Pager Jangkung 1. Aksesi Pager Jangkung 1 menunjukkan jumlah daun dan jumlah cabang yang lebih banyak dari aksesi Pager Jangkung 2 tetapi tidak berbeda dengan aksesi Ciaruteun Ilir 1 dan aksesi Ciaruteun Ilir 2. Aksesi Ciaruteun Ilir 1 dan aksesi Pager Jangkung 1 menunjukkan estimasi bobot panen per hektar yang lebih tinggi dari aksesi lainnya, yaitu masing-masing sebesar 1333,8 kg ha-1 dan 1131,6 kg ha-1. Penambahan pupuk daun Gandasil D mampu meningkatkan pertumbuhan dan produksi tanaman katuk. Pengaruh interaksi Aksesi Ciaruteun Ilir 1 dan dipupuk daun menunjukkan panjang cabang panen yang paling tinggi., Katuk (Sauropus androgynus (L.) Merr.) has numerous benefits and potential to meet family food needs. This study evaluates the effects of different accessions and foliar application of Gandasil D fertilizer on the growth and production components of katuk. Research is needed to understand the diversity of accessions and the impact of foliar fertilizer application on optimal growth and production. A nested plot design was used with two fertilizer treatments (control, foliar fertilized) nested within four accessions (Ciaruteun Ilir 1, Pager Jangkung 1, Ciaruteun Ilir 2, Pager Jangkung 2). Results showed that Ciaruteun Ilir 1 and Pager Jangkung 1 generally have higher growth and yield compared to other accessions. Accession Ciaruteun Ilir 1 showed the highest results in the parameters of the number of branches and the length of harvested branches. This accession produced a higher harvest weight per bed than Accession Ciaruteun Ilir 2 and Accession Pager Jangkung 2, but there was no significant difference compared to Accession Pager Jangkung 1. Accession Pager Jangkung 1 exhibited a greater number of leaves and branches compared to Accession Pager Jangkung 2 but showed no significant difference compared to Accession Ciaruteun Ilir 1 and Accession Ciaruteun Ilir 2. Accession Ciaruteun Ilir 1 and Accession Pager Jangkung 1 demonstrated an estimated harvest weight per hectare that was higher than the other accessions, with 1333.8 kg ha-1 and 1131.6 kg ha-1, respectivelyAdding foliar application of Gandasil D significantly increased growth and production of katuk. Effect of interaction between Ciaruteun Ilir 1 and foliar fertilized resulted in highest harvest branch length.
Keyword: aksesi, pupuk daun, katuk, accession, foliar fertilizer, Sauropus androgynus

Judul: Effect of Water Strees and Leaf Fertilization Interval on the Growth of Katuk (Sauropus androgynous L.) Plants
Abstrak: Katuk (Sauropus androgynus L.) merupakan salah satu jenis sayuran indigenous di Indonesia yang dapat memenuhi kebutuhan nutrisi manusia dan digunakan sebagai obat-obatan herbal. Tanaman yang mengalami cekaman air memerlukan tambahan unsur hara dalam mendukung proses pertumbuhan, salah satunya dengan cara pemupukan. Penelitian bertujuan mengetahui pengaruh cekaman air dan interval pemupukan daun terhadap pertumbuhan tanaman katuk. Rancangan percobaan yang digunakan adalah rancangan split-plot dalam rancangan kelompok lengkap teracak (RKLT) yang terdiri atas 2 faktor yaitu interval pemupukan daun sebagai petak utama dan cekaman air sebagai anak petak. Interval pemupukan daun terdiri dari 3 taraf, yaitu P0 (tanpa pemupukan), P1 (2 minggu sekali), dan P2 (4 minggu sekali) . Faktor cekaman air terdiri dari 4 taraf, yaitu C1 (40% kapasitas lapang (KL)), C2 (60% KL), C3 (80% KL ), dan C4 (100% KL). Penelitian dilakukan dengan 3 ulangan yang diperoleh dari 12 kombinasi, sehingga terdapat 36 satuan percobaan. Cekaman air tidak berpengaruh nyata terhadap pertumbuhan tanaman katuk. Waktu pemupukan daun berpengaruh nyata terhadap parameter jumlah cabang, jumlah daun, dan bobot panen dengan interval 2 minggu sekali. Waktu pemberian pemupukan optimal Interaksi antara cekaman air dan pemupukan daun tidak berpengaruh terhadap pertumbuhan tanaman katuk., Katuk (Sauropus androgynus L.) is one of the indigenous vegetables in Indonesia that can meet human nutritional needs and is used as herbal medicine. Plants experiencing water stress require additional nutrients to support the growth process, one of which is fertilization. The study aimed to determine the effect of water stress and foliar fertilization interval on the growth of katuk plants. The experimental design used was a split-plot design in a completely randomized group design (RKLT) consisting of 2 factors: leaf fertilization interval as the main plot and water stress as a subplot. The foliar fertilization interval consisted of 3 levels, namely P0 (without fertilization), P1 (2 weeks), and P2 (4 weeks). The water stress factor consists of 4 levels, namely C1 (40% field capacity (KL)), C2 (60% KL), C3 (80% KL), and C4 (100% KL). The study was conducted with three replications obtained from 12 combinations so that there were 36 experimental units. Water stress did not significantly affect the growth of katuk plants. The time of foliar fertilization had a significant effect on the parameters of the number of branches, number of leaves, and harvest weight at intervals of 2 weeks. Optimal fertilization time The interaction between water stress and foliar fertilization did not affect the growth of katuk plants.
Keyword: Fertilization interval, growth, katuk, water stress

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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