Judul: Pengaruh Pupuk Fosfor terhadap Pertumbuhan Vegetatif dan Generatif Rosela (Hibiscus sabdariffa L.)
Abstrak: Penelitian ini dilakukan untuk mengetahui pengaruh pupuk fosfor terhadap pertumbuhan vegetatif dan generatif rosela. Penelitian dilakukan di Kebun Percobaan Cikabayan, IPB pada bulan Februari hingga Juni 2009. Penelitian menggunakan rancangan acak lengkap. Perlakuan yang digunakan yaitu dosis pupuk fosfor yang terdiri atas lima taraf meliputi 0 g SP- 18/polibag, 10 g SP-18/polibag, 20 g SP-18/polibag, 30 g SP-18/polibag, dan 40 g SP-18/polibag. Setiap perlakuan diulang sebanyak tiga kali sehingga terdapat 15 satuan percobaan. Bahan tanam yang digunakan ialah benih rosela merah. Benih ditanam pada media tanam berupa campuran tanah dan pupuk kandang dengan perbandingan 5:1 pada polibag berukuran 10 kg sebanyak ¾ volume polibag. Jarak tanam yang digunakan ialah 1 m x 1,5 m. Dosis fosfor yang digunakan sesuai perlakuan, sedangkan dosis N dan K masing-masing sebanyak 30 g urea/polibag dan 15 g KCl/polibag. Aplikasi pupuk P dan K pada 4 MST, sedangkan pupuk N diaplikasikan pada 4 dan 10 MST.
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Judul: Kajian Pemupukan fosfor Terhadap Pertumbuhan dan Produksi Antosianin Dua Aksesi Rosela (Hibiscus sabdariffa L.).
Abstrak: Roselle (Hibiscus sabdariffa L.) is a common herb plant that contain high anthocyanin. This research on roselle was conducted in 2009 at Cikabayan Research Center, IPB. The purpose of the research was to study the effect of phosphorus fertilizer on anthocyanin content in two lines of roselle. This research used Split Plot Design with two factors and three replications. The main plot was lines of roselle i.e. red and purple.The sub plot was dosage of phosphorus i.e: 0, 18, 36, and 54 kg P2O5/ha. At 16 days after planting, calyx was taken to analyze anthocyanin content with spectrophotometer using Sims and Gamon (2002) method. The result of this study showed that dosage of phosphorus has no significant effect for several vegetative and generative variables on both of red and purple lines, but it has significant effect for the number of secondary branch per plant at 11 week after planting (WAP), the number of leaf per plant at 9 WAP, fresh weight of shoot per plant, and dry weight of fruit. The study also has very significant effect for the number of height per plant at 11 WAP, the number of primary branch per plant at 7 WAP, dry weight of shoot per plant, fresh and dry weight of total shoot per slot (20m2), as well as fresh and dry weight of calyx per slot (20m2). The optimum content of anthocyanin per calyx and production of anthocyanin per plant found on purple lines and 54 kg P2O5/ha that were 3.68 mmol/g and 6.85 mol/plant.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology