Judul: Response of Growth and Production of 4  Varieties of Chili Pepper (Capsicum frutescens L.) to Fertilizer Type
Abstrak: The purpose of this experiment was to study the response of the type of fertilizer on the growth and production of four varieties of chili pepper. The research was carried out at the Tajur 2 Experimental Station, Tropical Horticultural Research Center, Bogor Agricultural University, from January to July 2021. This study used a Split Plot Experimental Design Completely Randomized Group Design (CRBD). The main plot consisted of four varieties of red chili pepper consisting of Bonita IPB (V1), Feira IPB (V2), Taruna (V3), and Cakra Putih (V4). Sub-plots are types of fertilizer consisting of, NPK (16-16-16) + foliar fertilizer (P1), NPK (15-15-15) (P2), and AB mix (P3). The results show the diversity of varieties on several observed characters. Bonita IPB variety was superior to the characters of harvest age and plant height. The characters of flowering age, stem diameter, leaf length and leaf width, fruit length and fruit diameter, fruit weight, number of fruit plant, and productivity of Bonita IPB variety were equivalent to the range of values in the variety description. Taruna variety was superior in terms of harvest age and plant height. Cakra Putih variety had the same harvest age and stem diameter as the variety description. Chili pepper plants treated with NPK fertilizer (16-16-16) + foliar fertilizer showed higher observed character values in stem diameter, number of branches, and leaf length. Other types of fertilizers had no effect on the observed characters. There was no difference in the response of varieties to the type of fertilizer tested.
Keyword: Bonita IPB, capsaicin, NPK, quantitative character, superior varieties

Judul: The Effects of Biocontrol Application on Production of Four Varieties of Chilli Pepper (Capsicum spp.) for Industries
Abstrak: Cabai rawit merupakan komoditas yang penting bagi masyarakat Indonesia. Penelitian ini bertujuan mengetahui pengaruh aplikasi biokontrol terhadap karakter produksi pada empat varietas cabai rawit sehingga didapatkan rekomendasi varietas cabai dengan karakter produksi terbaik dan agen biokontrol terbaik. Penelitian dilaksanakan pada bulan Desember 2018 sampai dengan bulan Juli 2019 di Kebun Percobaan 2 PKHT (Pusat Kajian Hortikultura Tropika) Institut Pertanian Bogor, Tajur, Bogor dan di Laboratorium Pasca Panen, Departemen Agronomi dan Hortikultura, Fakultas Pertanian IPB. Rancangan percobaan yang digunakan adalah Split Plot RKLT (Rancangan Kelompok Lengkap Teracak) dua faktor. Petak utama adalah varietas cabai rawit yang terdiri dari empat taraf yaitu Rinta (R1), Kara (R2), Lentera (R3), dan Dewata (R4). Faktor kedua menjadi anak petak adalah perlakuan biokontrol yang terdiri dari empat taraf yaitu tanpa biokontrol (P0), Prima Gard (P1), PGPR Rhizomax (P2), dan kombinasi antara Prima Gard dengan Rhizomax (P3). Karakter produksi varietas Rinta, Kara, Lentera dan Dewata dapat ditingkatkan dengan memberikan perlakuan Rhizomax secara tunggal atau dikombinaksikan dengan Primagard. Varietas Lentera memiliki karakter produksi terbaik diikuti oleh varietas Kara. Produktivitas cabai rawit varietas Lentera pada penelitian ini mencapai 11,07 ton ha-1. Perlakuan biokontrol juga efektif menekan kejadian penyakit yang menyerang selama penelitian berjalan., Cayenne pepper is an important commodity for the people of Indonesia. This study aimed to determine the effects of biocontrol applications on the production of four varieties of cayenne pepper so that the recommendations regarding chili varieties with the highest production and the best biocontrol agent could be obtained. The research was carried out from December 2018 to July 2019 at the PKHT 2 Experimental Station (Center for Tropical Horticulture Studies), IPB University, Tajur, Bogor and at the Post-Harvest Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University. The experimental design used was a two-factor split plot randomized complete block design. The main plot was the variety of cayenne pepper consisting of four levels, namely Rinta (R1), Kara (R2), Lentera (R3), and Dewata (R4). The second factor being a subplot was the biocontrol treatment consisting of four levels, namely without biocontrol (P0), Prima Gard (P1), PGPR Rhizomax (P2), and the combination of Prima Gard and Rhizomax (P3). The production of the Rinta, Kara, Lentera and Dewata varieties can be increased by giving Rhizomax treatment alone or in combination with Primagard. Lentera variety has the highest production followed by Kara variety. The productivity of Lentera chili varieties in this study reached 11,07 tons ha-1. The biocontrol treatment was also effective in suppressing the incidence of disease during the study.
Keyword: Plant Growth Promoting Rhizotobacter (PGPR), Pseudomonas sp., Bacillus sp., Cryptococcus sp.

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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