Judul: Peran Vernalisasi dan Zat Pengatur Tumbuh dalam Peningkatan Pembungaan dan Produksi Biji Bawang Merah di Dataran Rendah dan Dataran Tinggi
Abstrak: The aim of this research was to observe the effect of vernalization and growth regulator in increasing flowers and true shallot seed yield in lowland and highland. This reaserch was conducted at lowland, Dramaga (250 masl, t=25- 260C, rainfall: 105-548 mm/month, RH:71-87%), and highland, Cipanas (1250 masl, t=20-210C, rainfall 204-479 mm/month, RH:80-87%). Shallot bulb 5-7 g was used as planting material. This research was conducted in two experiments. In the first experimental completely Randomized Block Design with two factors was used. The first factor was vernalisation, i.e.without vernalisation (V0) and vernalisation at 10 0C for thirty five days (V1) s, and the second factor was GA3 concentration, i.e. 0 ppm (G1), 100 ppm (G2), and 200 ppm (G3). In the second experiment, NAA at concentration of 0 (A1), 50 (A2), 100 (A3) and 200 ppm(A4) was used. Before planting, the bulbs was vernalized and submerged in 200 ppm GA3 solution for one hour. NAA is given by spraying to the plants aged 3 and 5 weeks after planting. The result showed that vernalization and GA3 affected flowering and TSS production. In lowland, combination of vernalization and 200 ppm GA3 increased flowering 233 times compared to the control and increased one-half times compared to the vernalization treatment without GA3 and in highland it increased four times compared to the control and one-half times compared to the vernalization without GA3. Combination of vernalization and 200 ppm GA3 resulted in the TSS production 3.93 g/m2 (39.3 kg/ha) in lowland and 4:41 g/m2 (44.1 kg/ha) in highland. Aplication of 200 ppm GA3 without vernalization and combination of vernalization until 200 ppm GA3 produced > 80% germination in lowland and highland. Aplication of 50 ppm NAA increase 24% flowering, 4.80 g or equal to 48.00 kg/ha TSS production with 87% germination. The result also show that vernalization can be substituted by GA3 aplication to enhance flowering and TSS production in highland however in lowland as well as high land area a combination of vernalization and GA3 was the best treatment.
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Judul: Effects of Gibberellic Acid (GA3) to Growth, Yield Component, and Yield on Shallot (Allium cepa var. aggregatum) Bima Brebes Variety
Abstrak: Penggunaan ZPT giberelin merupakan faktor pendukung yang memberikan kontribusi dalam peningkatan produktivitas bawang merah. Penelitian ini bertujuan untuk mempelajari pengaruh GA3 pada bawang merah varietas Bima Brebes, dan mendapatkan dosis optimum yang dapat meningkatkan produktivitas. Penelitian ini dilaksanakan pada bulan Maret sampai Mei 2020 di Kabupaten Brebes. Penelitian dilakukan dengan cara foliar spray GA3 dengan 0–2,5 dosis dalam volume semprot 400 L air pada tanaman bawang merah varietas Bima Brebes. Rancangan yang digunakan adalah Rancangan Kelompok Lengkap Teracak faktor tunggal 4 ulangan, terdiri dari 6 perlakuan dosis masing-masing yakni 0; 0,5; 1,0; 1,5; 2,0; dan 2,5 dosis GA3. Hasil penelitian menunjukkan bahwa 0,5–2,0 dosis GA3 secara nyata berhasil meningkatkan tinggi tanaman, bobot 10 umbi, bobot kering per tanaman dan bobot per petak yang memengaruhi dugaan hasil per hektar. Dosis optimum dari hasil analisis regresi menunjukkan pada peubah bobot 10 umbi yakni 1,54 dosis GA3., The use of gibberellin as a growth regulator is a supporting factor that contributes to the productivity of shallots. This research aimed to study the effects of GA3 on Bima Brebes shallots variety, and to get the optimal doses so that it is expected to increase productivity. This research was conducted from March to May 2020 in Brebes Regency. This research used foliar spray of GA3 with 0–2,5 doses in 400 L of water spray volume to Bima Brebes shallots variety. This research used Randomized Complete Block Design in single factor of 4 blocks, consists of 6 doses treatment which 0; 0,5; 1,0; 1,5; 2,0; and 2,5 doses GA3. The results showed that 0,5–2,5 GA3 doses significantly increased plant height, 10 tubers weight, dry plant weight and weight per plot which affected the estimated yield per hectare. The optimum doses from regression analysis results showed on variable of 10 tubers weight is 1,54 GA3 doses.
Keyword: Bima Brebes, foliar spray, GA3, sets, shallots

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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