Judul: Optimasi Pupuk Magnesium pada Tanaman Kelapa Sawit (Elaeis guineensis) Belum Menghasilkan Umur Dua Tahun.
Abstrak: The aims of this research were to study growth response of immature oil palm age of two years and to determine optimum rate of magnesium fertilizer. This experiment was conducted at the IPB-Cargill Palm Oil Teaching Farm, Jonggol, Bogor from March 2014 to February 2015. The experimental design used in this research was a randomized complete block design with 3 replications. Kieserite fertilizer consist of four levels i.e. without Kieserite (control), 625, 1250, 2500 g of Kieserite fertilizer year-1. The result of this research showed that Kieserite had not affected on height of oil palm, diameter of stem, number of leaflet, length of leaflet, leaf area, and physiological parameters.
Keyword: magnesium, oil palm, optimizing fertilizer, response

Judul: Optimasi Pupuk Kalium dan Magnesium pada Tanaman Kelapa Sawit (Elaeis guineensis Jacq.) Belum Menghasilkan Umur Tiga Tahun.
Abstrak: Aplikasi pupuk dengan dosis yang tepat sangat penting dilakukan pada tanaman kelapa sawit. Tujuan penelitian ini adalah untuk mempelajari respons morfologi, fisiologi, dan produksi serta menentukan dosis optimum pupuk K dan Mg pada tanaman kelapa sawit TBM 3. Penelitian dilaksanakan di Kebun Pendidikan dan Penelitian Kelapa Sawit Jonggol IPB-Cargill, Kecamatan Jonggol, Kabupaten Bogor dari bulan September 2015 sampai Maret 2016. Penelitian terdiri atas dua percobaan terpisah dengan menggunakan satu faktor Rancangan Kelompok Lengkap Teracak (RKLT). Percobaan optimasi pupuk K (percobaan 1) terdiri atas 5 taraf (0, 225, 450, 675, dan 900 g K2O tanaman-1 semester-1) dengan 3 ulangan, sedangkan percobaan optimasi pupuk Mg (percobaan 2) terdiri atas 4 taraf (0, 62,5, 125, dan 250 g MgO tanaman-1 semester-1) dengan 3 ulangan. Perlakuan pupuk kalium meningkatkan pertumbuhan tanaman secara kuadratik terhadap panjang pelepah ke-17. Dosis optimum pupuk kalium adalah 594 g K2O tanaman-1 semester-1. Perlakuan pupuk magnesium tidak memberikan pengaruh nyata terhadap peubah morfologi, fisiologi, dan produksi tanaman kelapa sawit TBM 3.
Keyword: fisiologi, morfologi, pelepah, respons, taraf

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