Judul: Pengaruh media simpan, ruang simpan dan lama penyimpanan propagul terhadap viabilitas benih Rhizophora apiculata
Abstrak: Kondisi hutan mangrove di Indonesia yang semakin rusak membutuhkan usaha rehabilitasi. Untuk kegiatan penanaman berskala besar seringkali benih harus didatangkan dari daerah lain yang membutuhkan waktu yang cukup lama untuk transportasinya. Pengiriman bibit dalam bentuk semai sangat tidak efisien sehingga perlu dikembangkan metode pengiriman bibit dalam bentuk propagul. Masalah yang timbul adalah karena propagul R. apiculata merupakan benih rekalsitran sehingga pada kadar air tertentu yang relatif tinggi maka benih cenderung mudah untuk berakar dan bila kadar air rendah maka benih mati atau viabilitasnya menurun. Tujuan penelitian ini adalah untuk mengetahui pengaruh ruang simpan. media simpan dan lama penyimpanan terhadap viabilitas benih R. apiculata. Penelitian dilaksanakan di rumah kaca Balai Teknologi Perbenihan Kehutanan dan Perkebunan. Ciheuleut Bogor selama empat bulan yaitu mulai akhir Januari sampai akhir Mei 2000. Prosedur kerja penelitian ini terdiri dari tahap persiapan (wadah simpan, ruang simpan, media simpan dan media perkecambahan). pengunduhan propagul, seleksi benih. penyimpanan benih. penyemaian, pemeliharaan dan pengambilan data. Adapun data yang diambil adalah Persentase Berakar (PB) benih selama periode simpan. kadar air benih (KA). daya berkecambah (DB). nilai perkecambahan (NP), kecepatan tumbuh (KT) dan nisbah pucuk akar (NPA) semai R. apiculata. Disamping itu sebagai data penunjang juga diukur kadar air media simpan. berat 1000 benih serta panjang rata-rata dan diameter rata-rata hipokotil. Rancangan percobaan yang digunakan dalam penelitian ini adalah rancangan acak lengkap (RAL) faktorial 5 x 2 x 2 dengan 3 kali ulangan. Adapun perincian faktor-faktomnya adalah sebagai berikut: Faktor A (lama penyimpanan ) terdiri dari a0 (0 minggu), at (1 minggu). a2 (2 minggu). a3 (3 minggu) dan a4 (4 minggu); faktor B (ruang simpan ) terdiri dari bl (ruang AC suhu 19"C- 20°C. RH: 60 %-61%) dan b2 (ruang kamar: suhu 26°C-28°C. RH: 80%-85%) dan faktor C (media simpan) terdiri dari cl (sabut kelapa: KA awal 61.41%) dan c2 (serbuk gergaji: KA awal 37.39%).
Keyword: Seed storage

Judul: Pengaruh media simpan, ruang simpan, dan lama penyimpanan terhadap viabilitas Propagul Rhizophora stylosa Griff.
Abstrak: Indonesia as an archipelagic country has a coastline and partly overgrown with mangrove forest which is the dominant type of coastal areas. However, at present the mangrove forests have been degraded which causes a decrease in forest potency. The effort that can be done to improve the return potential of these mangrove forests is by rehabilitation of mangrove forest. Rhizophora sp., including the type of Rhizophora stylosa Griff., is a pioneer tree species in the mangrove forest which has an important meaning in the mangrove forest etablishment. The main problem of this type of R. stylosa that is the seed classified into the recalcitrant ones. Therefore, the technique of seed storage is a very important activity to be developed for supporting the success of mangrove rehabilitation activities that have been degraded. The purpose of this study is to discover the influence of storage media, storage room, and time of storage on the propagule viability of R. stylosa, and to compare the R. stylosa propagule germination potential between cutting test and directly propagule germination test results. The research was conducted at the greenhouse and Silviculture Laboratory, Faculty of Forestry IPB and Seed Technology Research Institute Laboratory (BPTP), Bogor. This study used a factorial experiment with completely randomized design (CRD) factorial 5x2x2 with 3 replicates. The details of the factors are: factor A (time of storage) consists of A0 (0 weeks), A1 (1 week), A2 (2 weeks), A3 (3 weeks), and A4 (4 weeks); factor B (storage room) consists of B1 (AC room) and B2 (living room); and factor C (storage media), consists of C1 (sawdust) and C2 (coconut husk). The data collected is propagule viability, the percentage of rooted propagule, moisture content of propagule, propagule germination, germination value of propagule, the growth rates of propagule and shoot and seedling root to ratio of R. stylosa. Based on these results, it is known that the influence of interaction between treatment storage time, storage room, and storage media caused a significant difference to variable germination propagule R. stylosa. The influence of interaction between storage time and storage media caused significant differences on germination, germination value, the growth rates of propagule, and seedling root to shoot ratio of R. stylosa. The influence of interaction between storage room and storage media caused significant differences to the percent of rooted propagule R. stylosa. In this study, coconut husk media storage that is placed in the air conditioner room capable to maintaining the viability of R. stylosa propagule until the time of storage for 4 weeks. The result of estimation R. stylosa propagule viability with cutting test is relatively similar with the directly propagule germination test results.
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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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