Judul: Flower Induction of Marigold ‘Sudamala  Barak’ (Tagetes patula) with Plant Growth Regulator
Abstrak: Tagetes patula merupakan tanaman multifungsi, terutama pada bagian bunganya. Salah satu varietas dalam negeri yang potensial dikembangkan adalah Sudamala Barak, namun varietas ini memiliki umur berbunga yang lama yaitu 13-15 minggu sejak ditanam. Penelitian ini bertujuan mengetahui pengaruh ZPT (zat pengatur tumbuh) BAP (benzyl amino purine), GA3 (gibberellin acid), dan PBZ (paclobutrazol) terhadap respon pembungaan tanaman marigold ‘Sudamala Barak’ serta mengetahui konsentrasi terbaiknya. Penelitian dilaksanakan di dalam rumah kaca Kebun Percobaan Leuwikopo, IPB pada bulan September 2023 hingga Maret 2024. Penelitian ini menggunakan rancangan kelompok lengkap teracak dengan satu faktor yaitu jenis serta konsentrasi ZPT. Terdapat 10 taraf perlakuan yang terdiri dari kontrol (tanpa ZPT), BAP (50, 100, 150 ppm), GA3 (100, 200, 300 ppm), dan PBZ (50, 100, 150 ppm). Pengamatan meliputi karakter generatif dan vegetatif. Hasil penelitian menunjukkan pemberian ZPT berpengaruh nyata terhadap jumlah bunga, bobot total bunga, panjang tunas, panjang daun, dan panjang anak daun. Persentase tanaman berbunga tertinggi ditemukan pada perlakuan GA3 200 ppm (66,6%). Pengaruh ZPT terhadap karakter generatif menunjukkan GA3 200 ppm menghasilkan jumlah bunga dan bobot total bunga terbesar dibandingkan seluruh perlakuan lainnya. Hasil percobaan ini menunjukkan bahwa GA3 200 ppm berpotensi menginduksi pembungaan T. patula ‘Sudamala Barak’. Pada karakter vegetatif, pemberian BAP memberikan pengaruh yang netral kecuali pada BAP 150 ppm menghambat pemanjangan tunas, sementara GA3 mendorong pemanjangan tunas, dan PBZ menghambat pertumbuhan vegetatif., Tagetes patula is a multifunctional plant, especially in its flower parts. One potential domestic variety to be developed is Sudamala Barak, however this variety has a long juvenile period, which lasts for 13-15 weeks since planting. This study aimed to determine the effect of PGRs (plant growth regulation) BAP (benzyl amino purine), GA3 (gibberellic acid), and PBZ (paclobutrazol) on the flowering response of the marigold 'Sudamala Barak' and to determine the best concentrations. The research was conducted in the greenhouse of Leuwikopo Experimental Station, IPB University from September 2023 to March 2024. The experiment applied a completely randomized design with one factor, PGRs. There were 10 treatment levels consisting of control (without PGRs), BAP (50, 100, 150 ppm), GA3 (100, 200, 300 ppm), and PBZ (50, 100, 150 ppm). Observations included generative and vegetative characters. The results showed that the application of PGRs significantly affected the number of flowers, total flower weight, length of formed shoots, leaf length, and leaflet length. The highest percentage of plant flowering was found on GA3 200 ppm (66,6%). GA3 200 ppm treatment also produced the largest number of flowers and total flower weight compared to all other treatments. This experiment results imply that GA3 200 ppm has the potential inducer to induce flowering in T. patula ‘Sudamala Barak’. In the vegetative characteristics, the application of BAP had a neutral effect except at 150 ppm, where it inhibited shoot elongation, while GA3 promoted shoot elongation, and PBZ inhibited vegetative growth.
Keyword: benzyl amino purine, flower mechanism, gibberellic acid, paclobutrazol, production

Judul: Growth and Flowering Response of Two Clones of Marigold (Tagetes erecta L.) to Frequency of Pinching and Fertilization
Abstrak: Marigold (Tagetes erecta L.) merupakan tanaman herba hias yang berasal dari famili Asteraceae. Bunga marigold memiliki bentuk yang unik serta warna yang indah sehingga biasa digunakan sebagai tanaman hias dalam pot maupun sebagai karangan bunga. Marigold memiliki potensi untuk dikembangkan karena memiliki nilai ekonomis yang tinggi dan bunganya memiliki banyak kegunaan. Salah satu tindakan budidaya yang dapat meningkatkan pertumbuhan dan kualitas bunga adalah dengan perlakuan pinching dan pemupukan. Penelitian dilaksanakan pada bulan Desember 2022 - Juni 2023 di Kebun Percobaan CV. Benih Dramaga, Kecamatan Dramaga, Kabupaten Bogor. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktorial dengan taraf dua faktor yaitu frekuensi pinching dan frekuensi pemupukan AB mix. Faktor pertama adalah frekuensi pinching dari tiga taraf yaitu: 1 hari sekali (A1), 2 hari sekali (A2), dan 3 hari sekali (A3). Faktor kedua adalah frekuensi pemupukan dari dua taraf yaitu 2x/minggu (B1) dan 3x/minggu (B2). Pupuk yang digunakan pada penelitian ini adalah pupuk AB mix. Varietas marigold yang digunakan yaitu Sudamala Emas 1 sebagai tanaman utama dan Maharani sebagai tanaman pembanding. Hasil penelitian dari pengaruh frekuensi pinching, frekuensi pemupukan serta interaksi pinching dan pemupukan menunjukan pengaruh yang tidak berbeda nyata terhadap tinggi tanaman, jumlah bunga per tanaman, bobot bunga per tanaman, bobot bunga per kuntum, diameter bunga, dan Umur 50% berbunga., Marigold (Tagetes erecta L.) is an ornamental herbaceous plant from the Asteraceae family. Marigold flowers have a unique shape and beautiful colors so they are usually used as ornamental plants in pots or as flower bouquets. Marigolds have the potential to be developed because they have high economic value and the flowers have many uses. One of the cultivation measures that can improve the growth and quality of flowers is pinching and fertilizing. The research was carried out in December 2022 - June 2023 at the CV. Benih Dramaga, Perumahan IPB Alam Sinarsari Dramaga, Kecamatan Dramaga, and Kabupaten Bogor. This research used a factorial Randomized Complete Block Design (RCBD) with two factor levels, namely pinching frequency and AB mix fertilization frequency. The first factor was the frequency of pinching from three levels, namely: once a day (A1), once every 2 days (A2), and once every 3 days (A3). The second factor was the frequency of fertilization at two levels, namely 2x/week (B1) and 3x/week (B2). The fertilizer used in this research was AB mix fertilizer. The marigold variety used was Sudamala Emas 1 as the main variety and Maharani as the comparison. The results of the study of the effect of pinching frequency, fertilization frequency and the interaction of pinching and fertilization showed an effect that was not significantly different from plant height, number of flowers per plant, flower weight per plant, flower weight per flower, flower diameter, and 50% flowering time.
Keyword: marigold, pinching, pemupukan

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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