Judul: Application of Phosphorous Fertilizer for Increasing Growth and Production of Some Parijoto (Medinilla speciosa Blume) Accessions
Abstrak: Buah parijoto (Medinilla speciosa Blume) banyak digunakan sebagai bahan baku pembuatan obat, oleh karena itu dibutuhkan peningkatan produksi buah. Salah satu pupuk yang dapat meningkatkan produksi buah adalah fosfor, namun belum terdapat dosis pemupukan P optimal pada parijoto. Penelitian bertujuan mendapatkan dosis pupuk fosfor (P) yang tepat untuk meningkatkan pertumbuhan dan produksi beberapa aksesi parijoto. Penelitian dilakukan pada bulan Januari 2023 hingga Juni 2023 di Agribusiness and Technology Park, IPB Dramaga, Bogor, Jawa Barat. Penelitian menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) split-plot dengan empat ulangan. Faktor aksesi sebagai petak utama terdiri atas tiga aksesi yaitu Bogor, Kudus, dan Nganjuk. Dosis pupuk per polybag sebagai anak petak terdiri atas P0 (tanpa P2O5), P1 (1,8 g P2O5), P2 (3,6 g P2O5), P3 (5,4 g P2O5), P4 (7,2 g P2O5), P5 (9,0 g P2O5). Pemupukan dilakukan satu minggu sekali. Hasil penelitian menunjukkan bahwa aksesi Nganjuk memiliki tinggi tanaman tertinggi, namun pertumbuhan vegetatif yang lain pada seluruh aksesi menunjukkan hasil yang sama. Respon hubungan antara aksesi dengan dosis pupuk P menunjukkan kurva linear. Bobot buah per tanaman tertinggi aksesi Bogor dan Nganjuk didapat pada dosis pemupukan 7,2 g P2O5, dan aksesi Kudus pada dosis pemupukan 5,4 g P2O5. Semakin tinggi dosis pupuk P dapat menyebabkan waktu pembungaan yang lebih cepat akan tetapi bunga yang dihasilkan tidak maksimal. Terdapat interaksi antara aksesi dengan dosis pupuk P terhadap bobot buah per tanaman, jumlah buah per tandan, dan bobot 10 butir., Parijoto fruit (Medinilla speciosa Blume) is widely use as a raw material for medicine production. Therefore, there is a need to incrase fruit production. One of the fertilizers that can enhance fruit production is phosphorus, but the optimal P fertilization dosage for parijoto has not been determined yet. The research aimed to obtain the appropriate phosphorus (P) fertilizer dosage to enhance the growth and production of several parijoto accessions. The study was conducted from January 2023 to June 2023 at Agribusiness and Technology Park, IPB Dramaga, Bogor, West Java. The research used a Split-Plot Randomized Complete Block Design (RCBD) with four replications. The accession factor as the main plot consisted of three accessions: Bogor, Kudus, and Nganjuk. The fertilizer dosage per polybag, as the subplot, consisted of P0 (without P2O5), P1 (1.8 g P2O5), P2 (3.6 g P2O5), P3 (5.4 g P2O5), P4 (7.2 g P2O5), P5 (9.0 g P2O5). Fertilization was carried out once a week. The results showed that Nganjuk accession had the tallest plant, but the growth of other vegetative aspects in all accessions showed similar results. The response of the relationship between accession and P fertilizer dosage showed a linear curve. The highest fruit weight per plant for the Bogor and Nganjuk accessions was obtained at a P2O5 fertilization dosage of 7.2 g, and for the Kudus accession it was at a fertilization dosage of 5.4 grams of P2O5. A higher dose of P fertilizer could lead to earlier flowering, but the resulting flower were not optimal. There was an interaction between accession and P dosage on fruit weight per plant, number of fruits per brunch, and weight 10 grains.
Keyword: dosage, flowering time, fuit production, medical plant, weed

Judul: Growth and Production of Bitter Gourd 'Opal F1' and 'Oktan F1' with Various Doses of Single Anorganic Fertilizer N, P, and K
Abstrak: Paria (Momordica charantia L.) merupakan salah satu komoditas tanaman sayuran dari famili Curcubitaceae, merupakan tanaman herba semusim, merambat, dan memiliki rasa yang pahit. Tanaman paria mengandung senyawa fitokimia yang bermanfaat untuk kesehatan manusia, seperti triterpenoid, flavonoid, senyawa fenolik, alkaloid, dan saponin. Terdapat beberapa varietas paria yang sudah dibudidayakan di Indonesia antara lain dari PT. East West Seed Indonesia (Ewindo), misalnya varietas Opal F1 dan Oktan F1. Penentuan dosis optimum untuk kedua varietas perlu diuji untuk pencapaian pertumbuhan dan produksi yang optimal. Oleh karena itu dilakukan penelitian ini di Kebun Percobaan IPB Cikarawang, Dramaga, Bogor yang dimulai bulan Januari hingga April 2023. Penelitian terdiri atas 2 set percobaan terpisah, yaitu untuk varietas Opal F1 dan Oktan F1. Rancangan yang digunakan dalam masing-masing percobaan adalah Rancangan Kelompok Lengkap Teracak (RKLT) dengan 4 perlakuan dan 3 ulangan sehingga terdapat 12 satuan percobaan. Adapun taraf perlakuan adalah dosis pupuk anorganik yang meliputi pupuk urea, SP-36, dan KCl, yaitu 0; 50; 100; dan 150% dari dosis rekomendasi untuk mengetahui dosis pupuk optimum N, P, dan K pada tanaman paria. Berdasarkan rekomendasi dari PT. East West Seed Indonesia, pemupukan untuk paria per tanaman adalah 25 g urea, 24 g SP-36 dan 14 g KCl. Hasil penelitian menunjukkan bahwa pemberian pupuk tunggal N, P, dan K meningkatkan karakter pertumbuhan dan produksi tanaman paria varietas Opal F1 dan Oktan F1. Hubungan antara dosis pupuk dan bobot buah per tanaman masih linier. Produksi buah paria Opal F1 per tanaman tertinggi adalah 469,90 g dengan 100% dosis pupuk rekomendasi sedangkan produksi buah paria Oktan F1 per tanaman tertinggi adalah 473,82 dengan 150% dosis pupuk rekomendasi. Berdasarkan uji t, didapatkan perbedaan yang nyata pada peubah bobot dan panjang per buah paria Opal F1 dan Oktan F1., Bitter gourd (Momordica charantia L.) is a member of Curcubitaceae family and classified as a herbaceous annual, vine, and is known to have a bitter taste. Bitter gourd contains phytochemical compounds that are beneficial for human’s health such as triterpenoids, flavonoids, phenolic compounds, alkaloids, and saponins. There are several varieties of bitter gourd that have been cultivated in Indonesia, including varieties from PT. East West Seed Indonesia (Ewindo), for example Opal F1 and Oktan F1 varieties. The determination of the optimum dose for both varieties need to be tested for the achievement of optimal growth and production. Therefore, this research was carried out at the IPB Cikarawang Experimental Station, Dramaga, Bogor starting from January to April 2023. This study consisted of 2 separate sets of experiments, namely for Opal F1 and Oktan F1 varieties using a one-factor Randomized Complete Block Design (RCBD), namely single fertilizer dose of N, P, and K with various doses 0, 50, 100, 150% of recommendation rate. The recommendation rate of fertilizer follows PT. East West Seed Indonesia 25 g urea, 24 g SP-36, and 14 g KCl. The results showed that the application of single fertilizers N, P, and K increased the growth and production character of bitter gourd plants of Opal F1 and Oktan F1 varieties. The relationship between fertilizer dose and fruit weight per plant is still linear. The highest
Keyword: Curcubitaceae, hara daun, Momordica charantia L., pigmen buah

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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