Judul: Pemanfaatan Limbah Substrat Jamur Tiram dan Penambahan Sumber Nutrisi pada Budidaya Jamur Tiram Putih
Abstrak: Oyster mushroom or Pleurotus ostreatus (Jacq:Fr) Kummer is a type of wood-rot fungi commonly found in nature. White oyster mushroom has been widely marketed in the form of fresh or was processed like mushrooms chips. Substrates commonly used for the development of oyster mushroom cultivation is sawdust of Falcata. The more number of oyster mushroom cultivation gave the more waste of its substrate, while this waste still has nutrients that can be re-used for the cultivation of oyster mushroom. The objective of this study was to study the effect of the use of waste oyster mushroom substrate and liquid organic fertilizer to the growth and yield of oyster mushroom cultivation. Stages in this research consisted of substrate creation, seeding or inoculation, caring and observation of fungal development, and chemical composition analysis. The observations were the growth during the vegetative phase and reproductive phase, the character of the fruit body morphology, and the chemical composition analysis results of oyster mushroom fruiting bodies. The composition media of 75% spent mushroom substrate mixed with 25% of new mushroom substrate gave the best result on growth and mushroom yields. Concentration of 0.2% and 0.5% liquid organic fertilizer gave best yields. Besides the media and genetic factors, environmental factors such as temperature, humidity, and light affected the growth and yield of oyster mushroom.
Keyword: Pleurotus, oyster mushroom, mushroom substrate, mushroom cultivation, liquid organic fertilizer, Bogor Agricultural University (IPB)

Judul: Growth and Production Of Oyster Mushroom (Pleurotus spp.) on Media Containing Sengon Wood, Coffee Skin, and Straw
Abstrak: Jamur tiram merupakan salah satu kelompok jamur kayu yang dapat dimakan (edible). Pemanfaatan limbah hasil kehutanan dan pertanian seperti serbuk gergaji kayu sengon, kulit kopi, dan jerami menjadi salah satu yang dapat dimanfaatkan sebagai media tanam dalam kultivasi jamur tiram guna memaksimalkan limbah yang ramah lingkungan. Penelitian bertujuan untuk menganalisis pengaruh media yang mengandung kayu sengon, kulit kopi, dan jerami terhadap pertumbuhan dan produksi jamur tiram. Penelitian menggunakan Rancangan Acak Lengkap (RAL) faktor tunggal dengan 3 perlakuan media yaitu formula 1 (kayu sengon dan kulit kopi), formula 2 (kayu sengon dan jerami), dan kontrol (kayu sengon). Hasil penelitian menunjukkan bahwa fase vegetatif jamur paling singkat diperoleh pada media formula 2 (15-18 hari). Fase generatif jamur yang membutuhkan waktu paling cepat masa panen diperoleh pada media kontrol (9-11 hari). Total bobot basah jamur terbesar dan nilai efisiensi biologis tertinggi diperoleh pada media kontrol (229,10 g) dengan nilai efisiensi biologis 79,0% pada jamur tiram putih (Pleurotus ostreatus) dan (331,70 g) pada jamur tiram cokelat (Pleurotus cystidiosus) dengan nilai efisiensi biologis 114,4%., Oyster mushroom is a group of edible wood mushrooms. Utilization of forestry and agricultural waste such as sawdust from sengon wood, coffee husks, and straw is one that can be used as a planting medium in oyster mushroom cultivation in order to maximize environmentally friendly waste. This study aims to analyze the effect of media containing sengon wood, coffee skin, and straw on the growth and production of oyster mushrooms. The study used a single factor completely randomized design (CRD) with 3 media treatments, namely formula 1 (sengon wood and coffee husk), formula 2 (sengon wood and straw), and control (sengon wood). The results showed that the shortest fungal vegetative phase was obtained in formula 2 media (15-18 days). The fungal generative phase wich required the fastest time to harvest was obtained in control media (9-11 days). The highest total wet weight of mushrooms and the highest biological efficiency value obtained on control media (229,10 g) with a biological efficiency value of 79,0% on white oyster mushroom (Pleurotus ostreatus) and (331,70 g) on brown oyster mushroom (Pleurotus cystidiosus) with a biological efficiency value of 114,4%.
Keyword: brown oyster mushroom, coffee husk, sengon wood, straw, white oyster mushroom.

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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