Judul: Production Management of Peperomia (Peperomia sp.), Begonia (Begonia sp.), Bromelia (Neoregelia schultesiana), and Hortensia (Hydrangea macrophylla) in PT Melrimba Mitra, West Java
Abstrak: Kegiatan magang dilaksanakan pada bulan Maret – Juli 2021 di PT. Melrimba Mitra, Kab. Bogor, Jawa Barat. Kegiatan magang bertujuan untuk meningkatkan pengalaman, wawasan, serta kemampuan teknis dalam pengelolaan tanaman hias khususnya peperomia, bromelia, begonia sebagai tanaman hias pot dan hortensia sebagai tanaman hias lanskap. Kegiatan teknis pengelolaan tanaman hias mencakup jadwal produksi mulai dari persiapan tanam hingga siap panen dan kriteria panen tanaman. Pengamatan tanaman Peperomia obtusifolia, Neoregelia schultesiana, dan Hydrangea macrophylla meliputi jumlah daun dan tinggi tanaman. Pengukuran tanaman Peperomia argyreia dan Peperomia caperata meliputi jumlah tunas. Pengukuran Begonia ‘orococo’ meliputi panjang daun, lebar daun, dan jumlah daun. Kegiatan budi daya tanaman hias yang dilakukan meliputi persiapan media tanam, pembibitan, penyiraman, pemupukan, pengendalian hama penyakit, panen, dan pascapanen. Hasil pengamatan pada tanaman Peperomia obtusifolia, Neoregelia schultesiana, dan Begonia ‘orococo’ yang menggunakan metode perbanyakan setek batang tergolong cepat sehingga selama periode magang tanaman tersebut memenuhi kriteria perusahaan, sedangkan Peperomia caperata dan Peperomia argyreia yang diperbanyak dengan menggunakan metode setek daun memiliki pertumbuhan yang lambat sehingga selama periode magang tanaman tidak memenuhi kriteria panen perusahaan. Hydrangea macrophylla memiliki umur panen rata-rata sekitar 15 MST sehingga periode pengamatan selama 8 minggu tidak dapat mengamati tanaman sampai panen. Hasil analisis usahatani dengan asumsi luasan 200 m2 beserta greenhouse lengkap dan manajemen yang sudah ada pada Peperomia obtusifolia, Peperomia argyreia, Peperomia caperata, Begonia ‘orococo’, dan Neoregelia schultesiana menghasilkan pendapatan yang lebih tinggi dari pengeluaran., The internship activities was carried out in March – July 2021 at PT. Melrimba Mitra, Bogor, West Java. The aims of the internship is to increase experience, knowledge, and skills in production management in ornamental plants, particularly of peperomia, bromelia, begonia as ornamental pot plant and hortensia as ornamental landscape plant. The technical activities in production management including production schedule from planting preparation until they are ready to harvest and fulfil the harvest criteria. Growth measurement on Peperomia obtusifolia, Neoregelia schultesiana, and Hydrangea macrophylla included number of leaves and plant height. Growth measurement on Peperomia caperata and Peperomia argyreia included number of shoots. Growth measurement on Begonia ‘orococo’ included the length of leaf, width of leave, and number of leaves. Cultivation activities include preparation of planting media, nurseries, watering, fertilizing, controlling pests and diseases, harvest, and post-harvest. The results of observation on Peperomia obtusifolia, Neoregelia schultesiana, and Begonia ‘orococo’ using stem cuttings propagation method which is relatively fast so that during internship period the plants met the company’s harvest criteria, while Peperomia caperata and Peperomia argyreia propagated using the leaf cuttings method had slow growth. So that during the internship period the plants did not meet the company’s harvest criteria. Hydrangea macrophylla has an average harvest age of about 15 WAP so that the observation period of 8 weeks cannot observe the plant until harvest period. The result of farming analysis using 200 m2 assumption area with complete greenhouse and existed management of Peperomia obtusifolia, Peperomia argyreia, Peperomia caperata, Begonia ‘ orococo’, and Neoregelia schultesiana produce more income than the output.
Keyword: harvest criteria, leaf cuttings, ornamental landscape plant, ornamental pot plant, stem cuttings

Judul: Cultivation, Harvesting, and Post-harvest of Philodendron giganteum, Philodendron selloum, and Philodendron xanadu at PT PDMA, Bogor, West Java
Abstrak: Kegiatan magang dilaksanakan di PT Pesona Daun Mas Asri (PDMA) selama empat bulan yang dimulai dari 18 Januari hingga 17 Mei 2021. Tujuan kegiatan magang adalah meningkatkan pengetahuan, pengalaman, dan keterampilan kerja mahasiswa secara teknis maupun manajerial khususnya dalam budidaya, panen, dan pascapanen daun potong Philodendron giganteum, Philodendron selloum, dan Philodendon xanadu pada PT PDMA. Metode yang digunakan dalam kegiatan magang adalah metode langsung dengan melakukan dan mengambil data di lapangan dan tidak langsung dengan studi literatur dan pengambilan data dari dokumentasi PT PDMA. Berdasarkan hasil kegiatan magang diketahui bahwa budidaya Philodendron dilakukan pada bedengan yang berada di shadehouse menggunakan paranet dengan tingkat naungan 75%. Perbanyakan masing-masing tanaman untuk penyediaan bibit dilakukan dengan cara stek batang dengan jarak tanam 40 x 40 cm. Pemupukan dilakukan sebanyak dua kali setiap bulan menggunakan campuran 1 Kg NPK dan 500 g urea per bedeng berukuran 32 x 1,5 m dengan metode sebar rata. Hasil pengamatan menunjukkan pertumbuhan daun Philodendron dengan rata-rata pertambahan tinggi tanaman tiap minggu sebesar 1,4 cm pada Philodendron selloum serta 1,8 cm pada Philodendron giganteum dan Philodendron xanadu. Kriteria daun yang siap dipanen berdasarkan panjang daun ≥ 15 cm dan lebar daun ≥ 10 cm yang dipanen menggunakan gunting panen. Perlakuan pascapanen terdiri dari pembersihan, sortasi, pengkelasan, pengemasan, dan penyimpanan. Penyimpanan daun potong menggunakan air pada medium kapas basah. Pemasaran dilakukan langsung ke pelanggan yang terbagi menjadi end user dan trader., The internship activity was conducted at PT Pesona Daun Mas Asri (PDMA) for four months starting from 18th January until 17th May 2021. This internship aimed to improve student technical and managerial knowledge, work experience, and skills, especially in cultivation, harvest, and post-harvest of Philodendron giganteum, Philodendron selloum, dan Philodendon xanadu at PT PDMA. The data is collected through direct observation by conducting and taking the data in the field and indirect methods by literature study and documentation taken from PT PDMA. Based on the result of the internship, it is known that Philodendron cultivated on beds in shadehouses from a paranet with a shade rate of 75%. Each plants propagated by stem cutting for nursery. The plant spacing for each plants is 40 x 40 cm. Fertilization done twice in a month using 1 Kg NPK and 500 g urea per beds sized 32 x 1,5 m with broadcasting method. The observation resulted Philodendron growth increase 1.4 cm for Philodendron selloum and 1.8 cm for Philodendron giganteum and Philodendron xanadu. The foliage harvesting criteria based on foliage length ≥ 15 cm and foliage width ≥ 10 cm that harvested with scissor. The post-harvest phase consists of cleaning, sorting, grading, packaging, and storage. Cut foliage storage method use wet cotton as a medium of water. The company marketing done directly to the customer that divided into trader and end user.
Keyword: daun potong, Philodendron, produksi, tanaman hias, cut foliage, ornamental plant, production

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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