Judul: Ornamental Bedding Plants Management of Vinca (Catharanthus roseus) and Celosia (Celosia argentea) in PT. Bina Usaha Flora, Cianjur, West Java
Abstrak: Kegiatan magang dilaksanakan pada bulan Januari – Mei 2021 di PT. Bina Usaha Flora, Cianjur, Jawa Barat. Kegiatan magang bertujuan meningkatkan pengetahuan dan keterampilan mengenai teknik pengelolaan produksi usaha tanaman hias, terutama tanaman hias hamparan, termasuk jadwal produksi mulai dari persiapan tanam hingga siap panen, dan kriteria panen tanaman Celosia argentea dan Catharanthus roseus. Kegiatan tambahan dalam magang yaitu mempelajari pengaruh aplikasi retardan paclobutrazol pada Celosia argentea untuk menghasilkan tanaman yang pendek dan seragam. Ketinggian Celosia argentea bisa mencapai 100 cm yang membuat tanaman mudah rebah dan kesulitan dalam transportasi. Pengukuran pertumbuhan pada vinca meliputi tinggi tanaman, jumlah cabang sekunder, jumlah bunga, dan diameter bunga. Pengukuran pertumbuhan Celosia argentea meliputi tinggi tanaman, jumlah daun, jumlah cabang sekunder, jumlah ruas, jumlah bunga, dan ukuran bunga. Kegiatan budidaya tanaman hias yang dilakukan meliputi persiapan media semai, persemaian, persiapan media tanam, pindah tanam, penyiraman, pemumpukan, pengendalian hama penyakit, dan panen. Hasil pengamatan kriteria panen tanaman Vinca menunjukkan hasil yang sesuai dengan kriteria perusahaan. Aplikasi retardan paclobutrazol pada konsentrasi 10 ppm dengan cara disiram pada media efektif dapat mengurangi tinggi tanaman Celosia dan memenuhi kriteria yang diinginkan perusahaan., The internship activities was carried out in January – May 2021 at PT. Bina Usaha Flora, Cianjur, West Java. This aims of the internship is to increase knowledge and skills about production management and cultural techniques in ornamental plants, particularly of bedding plants, including production schedule from planting preparation until ready to harvest, the harvest criteria of Celosia argentea and Catharanthus roseus. An additional activity was conducted during the internship, i.e. to study the effects of retardant paclobutrazol application in Celosia argentea in order to produce short and compact plants. Celosia argentea height could reach 100 cm which make them prone to lodging and more difficult to transport. Growth measurement on Vinca included plant height, number of branches, number of flowers, and diameter of flowers to determine harvest criteria. Growth measurement on Celosia argentea included plant height, number of leaves, number of branches, number of internodes, number of flowers, and diameter of flowers. Cultivation activities include preparation of nursery media, nurseries, preparation of planting media, transplanting, watering, fertilizing, controlling pests and diseases, and harvest. The harvest criteria of Vinca has been conducted in accordance with the company’s criteria. Retardant paclobutrazol application in Celosia at 10 ppm concentration with soil drench application is effective to produce short and compact plants and I have met the company’s criteria.
Keyword: Celosia, Harvest criteria, Retardant, Vinca

Judul: Pengelolaan Tanaman Hias Hamparan Famili Asteraceae dan Violaceae di PT. Bina Usaha Flora, Cianjur, Jawa Barat
Abstrak: Kegiatan magang dilaksanakan di PT. Bina Usaha Flora, Cianjur, Jawa Barat selama 3 bulan mulai Januari hingga April 2020. Kegiatan magang ini secara umum bertujuan meningkatkan pengetahuan, keterampilan teknis dan manajerial dalam produksi tanaman hias. Tujuan khusus pelaksanaan magang ini adalah memperoleh pemahaman dan keterampilan dalam proses budidaya, mengetahui kriteria panen, dan mengevaluasi kelayakan usaha tanaman hias hamparan famili Asteraceae dan Violaceae dengan analisis usahatani. Metode yang digunakan terdiri atas metode langsung melalui pengamatan langsung di lapangan serta wawancara dengan karyawan perusahaan dan metode tidak langsung melalui studi pustaka. Pengamatan meliputi tinggi tanaman, jumlah daun, jumlah kuntum bunga dalam satu tanaman, dan diameter bunga untuk menentukan kriteria panen famili Asteraceae dan Violaceae dan analisis usahatani. Proses budidaya yang dilakukan meliputi persemaian, persiapan media tanam, pindah tanam, pemupukan, penyiraman, pengendalian hama dan penyakit, serta panen. Kriteria panen hasil pengamatan menunjukkan hasil yang sesuai dengan kriteria perusahaan maupun literatur, kecuali untuk tinggi tanaman marigold kuning yang sedikit di bawah standar perusahaan. Nilai R/C rasio pada marigold, bunga matahari, dusty miller, dan pansy serta viola yaitu 1.65, 1.44, 1.69, dan 2.47. Hasil analisis usahatani pada seluruh komoditas memiliki nilai R/C rasio >1 yang menunjukkan bahwa usaha layak dijalankan dan bersifat menguntungkan.
Keyword: bunga matahari, dusty miller, kriteria panen, marigold, pansy, viola

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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