Judul: Pertumbuhan dan Produksi Daun Torbangun (Plectranthus amboinicus Spreng.) dengan Pemupukan Organik dan Pemangkasan
Abstrak: Torbangun is a nutritious crop that increase breast milk because it contains lactagogen. Most study of torbangun plants focuses on pharmacological characteristics of plant. There is a need for research in cultivation techniques using organic fertilizer and pruning. The purpose of this study was to investigate the effect of organic fertilizer and pruning on the growth and leaf production of torbangun plant. This study used randomized block design (RBD) in the first experiment with fertilizer factor and Split plot design in the second experiment with fertilizer and pruning. Both of the experiment used Tukey‟s (Honestly Significant Difference) test. Organic fertilization is divided into 5 levels: without fertilizer, cow manure+rock phosphate, cow manure+rice-hull ash, rock phosphate+rice-hull ash, and cow manure+rock phosphate+rice-hull ash. Pruning is consisted of 2 levels: without pruning and with pruning. The results showed that fertilization using cow manure + rock phosphate + rice-hull ash increased shoot fresh weight of 125.21% compared to without fertilization. Pruning reduced plant biomass and leaf number. Torbangun growth is slow, so harvesting should have been done in a longer interval.
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Judul: Evaluasi Kandungan Nutrien Daun Torbangun (Coleus amboinicus Lour.) Secara in Vitro Terhadap Pengaruh Interval Defoliasi dan Pupuk
Abstrak: Penelitian ini bertujuan untuk mengevaluasi kandungan nutrien daun torbangun secara in vitro terhadap pengaruh interval defoliasi dan penambahan pupuk ayam broiler yang berbeda level. Rancangan percobaan yang digunakan adalah rancangan acak kelompok pola faktorial 3x3 dengan 3 ulangan. Faktor perlakuan meliputi interval defoliasi (6 minggu, 9 minggu dan 12 minggu) dan penambahan level pupuk kandang ayam broiler 100%, 75% dengan FMA+MPF, 50% dengan FMA&MPF. Data dianalisis dengan analisis sidik ragam, perbedaan yang signifikan diuji menggunakan uji lanjut Duncan dengan SPSS. Parameter yang diamati kandungan mineral (P, Fe dan Ca), konsentrasi N-Protein, kecernaan bahan kering dan organik, konsentrasi amonia serta VFA total. Perlakuan interval defoliasi dan pemupukan berpengaruh nyata (P<0.05) terhadap nilai mineral (Fe, Ca dan P) serta kecernaan bahan kering. Perlakuan umur panen 12 minggu berpengaruh nyata (P<0.05) terhadap N-Protein, kecernaan bahan organik dan konsentrasi amonia. Interaksi antar perlakuan berpengaruh terhadap nilai mineral besi, kalsium dan kecernaan bahan kering.
Keyword: Coleus amboinicus L., kecernaan, mineral, pupuk, interval defoliasi

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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