Judul: Interaction of shade intensity and fertilization rate on growth and harvest of pohpohan (Pilea trinervia Wight)
Abstrak: Penelitian ini dilakukan untuk memperoleh tingkat naungan dan dosis pupuk yang sesuai untuk pertumbuhan dan hasil pohpohan. Penelitian dilakukan di Pusat Kajian Hortikultura Tropika IPB, Tajur dari Maret sampai Juli 2013. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) 2 faktor. Faktor pertama merupakan tingkat naungan, N0 (tanpa naungan), N1 (naungan 55%) dan N2 (naungan 75%). Faktor kedua merupakan dosis pemupukan P1 (0 kg ha-1), P2 (50 kg ha-1), P3 (100 kg ha-1), P4 (150 kg ha-1) dan P5 (200 kg ha-1). Tanaman pohpohan dipupuk pada umur 3, 6 dan 8 MST (Minggu Setelah Tanam) dengan pupuk dosis NPK 15-15-15 (N 15%: P2O5 15%: K2O 15%). Hasil percobaan menunjukkan bahwa naungan 55% mampu meningkatkan tinggi tanaman dan diameter batang. Jumlah daun, jumlah cabang dan bobot layak pasar meningkat secara kuadratik pada pemberian dosis optimum. Pohpohan lebih baik apabila ditanam pada tingkat naungan 55% dengan dosis pupuk 88.3 to 104.5 kg ha-1., The objective of this study was to find out the optimum percentage of shading and fertilizer rate on pohpohan. The research was conducted at Center for Tropical Horticulture Studies IPB, Tajur from March until July 2013. This research was arranged in a Randomized Completely Block Design 2 factors. The first factor was a level of shade, N0 (no shade), N1 (55% shade) and N2 (75% shade). The second factor was rate of fertilizer, at rates of P1 (0 kg ha-1), P2 (50 kg ha-1), P3 (100 kg ha-1), P4 (150 kg ha-1) dan P5 (200 kg ha-1). Pohpohan were fertilized in 3, 6 and 8 weeks after planting with NPK 15-15-15 (N 15%: P2O5 15%: K2O 15%). Result of the research showed that 55% shades increased the plant height and diameter of stem. Number of leaves, number of branches and of marketable yield were quadratically increased with fertilizer application. Poh-pohan plants prefered growing at shade 55% with NPK fertilization 88.3 to 104.5 kg ha-1. Key words: fertilizer, growth, indigenous vegetable, Pilea trinervia, shading
Keyword: naungan, pertumbuhan, Pilea trinervia, pupuk, sayuran indigenous

Judul: Pertumbuhan Setek Batang Pohpohan (Pilea trinervia Wight.) pada Umur Tanaman, Bagian Batang, dan Media Tanam yang Berbeda
Abstrak: Pohpohan (Pilea trinervia Wight.) is one of indigenous vegetables that grows in the mountain areas of West Java. Pohpohan in large quantities and in a short time can be done with cuttings of vegetative propagation, but it has not been developed at this time. The research was conducted at the Center for Tropical Horticulture Studies Experimental Field Tajur, Bogor, from January to July 2013. The research consisted of two experiments. The first experiment was to obtain the plant age of pohpohan that was good for the growth of stem cuttings pohpohan and the second experiment was to obtain the stem and growing media that was good for the growth of stem cuttings pohpohan. Treatment on first experiment was stem cutting pohpohan 3, 4, 5, and 6 months. Treatment of pohpohan 4 month showed the best of number of leaves and the increase of stem length. Stem cutting pohpohan 4 months on first experiment was gaved a treatment for second experiment, that was part of stem (tips, central, and base) and growing media (topsoil, rockwool, combination 1:1 of husk and compost, and vermicompost). There were 5 cuttings per treatment and 3 replications in this way a total was 720 cuttings. The experiment was laid out in Randomized Completely Block Design factorial.. The cutting pohpohan 4 month of stem tips were the best grown in husk and compost media with 11 number of leaves and 3.94 cm the increase of stem length. The cutting pohpohan of central stem were the best grown in husk and compost with 11 number of leaves and 2.67 cm the increase of stem length. The cutting pohpohan of base stem were best grown in husk and compost with 12 number of leaves and 2.38 cm the increase of stem length.
Keyword: rockwool, indigenous, husk, compost

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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