Judul: Pengaruh Pupuk dan Interval Defoliasi terhadap Pertumbuhan dan Produksi Tanaman Torbangun (Coleus amboinicus Lour)
Abstrak: This research was conducted to measure the growth and the production of torbangun. The factors are defoliation rate and organic fertilizer . Defoliation was treated in two levels : once per 6 weeks (D1) and once per 9 weeks (D2). Fertilizer treatments were 100% broiler manure fertilizer (PK 3), 75% broiler manure fertilizer with PSB (Phosphate Solubilizing Bacteria) & AMF (Arbuscula Mycorrhizal Fungi) (PK 2), and 50% broiler manure fertilizer with PSB & AMF (PK 1). Each treatment was replicated for 6 times in 18 weeks. The first defoliation was conducted three times while the second defoliation was conducted twice. The measured variables are leaves amount, canopy height, leaf width, fresh weight of leaves, dried weight of leaves. The results showed that the interaction between PK 3 and D1 had the best effect in the increase of leaves amount. PK 3 and PK 2, individually, gave a good impact to the increase of canopy height. The other results showed that PK 2 gave the best impact to dried leaves weight (p<0.05)
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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: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix