Judul: Growth and Productivity of Red Okra [Abelmoschus esculentus (L. Moench)] with Pruning at Two Planting Distances
Abstrak: Okra [Abelmoschus esculentus (L. Moench)] merupakan tanaman sayuran setahun yang buahnya memiliki khasiat obat. Tujuan penelitian ini adalah mempelajari pengaruh pemangkasan dan jarak tanam serta interaksinya terhadap pertumbuhan vegetatif dan produktivitas buah okra muda. Percobaan dilaksanakan di Kebun Percobaan Leuwikopo IPB pada bulan Januari hingga Mei 2019. Percobaan ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan dua faktor yaitu pemangkasan dan jarak tanam. Tiga pemangkasan yang digunakan yaitu: kontrol (tidak dipangkas), wiwil (pemangkasan tunas lateral), dan topping (pemangkasan tunas apikal). Jarak tanam terdiri atas 60 cm x 20 cm dan 60 cm x 40 cm. Pewiwilan dan topping dilaksanakan pada 2-3 minggu setelah pindah tanam (MSP), topping dilaksanakan pada tinggi 15-20 cm pada daun ke-5 dari bawah. Hasil penelitian menunjukkan pertumbuhan cabang lebih dipengaruhi oleh pemangkasan, sedangkan persentase hidup cabang dipengaruhi oleh interaksi antara dua perlakuan. Nilai peubah fase generatif terendah diperoleh pada pemangkasan wiwil. Produksi per tanaman okra belum dipengaruhi oleh pemangkasan namun oleh jarak tanam yaitu produktivitas tertinggi terdapat pada jarak tanam 60 cm x 20 cm., Okra [Abelmoschus esculentus (L. Moench)] is an annual vegetable plant which fruit has medicinal properties. The purpose of this experiment was to study the effect of pruning and planting distance as well as their interactions on vegetative growth and productivity of young okra fruit. This research was conducted at Leuwikopo experimental station, IPB University, Bogor, from January to May 2019. This experiment used a Randomized Complete Block Design (RCBD) with two factors namely pruning and planting distance. Three pruning were control (no pruning), lateral bud pruning (wiwil), and topping (apical bud pruning). Planting distance consisted of 60 cm x 20 cm and 60 cm x 40 cm. Both lateral shoot pruning and topping was carried out at 2-3 week after transplanting (WAT), topping was pruned at 15-20 cm height on the 5th leaf from the bottom. The results showed that branch growth was more influenced by pruning, while the percentage of living branches was influenced by the interaction of both treatment factors. The lowest generative value was obtained from lateral shoot pruning. Production of okra plant was not affected by pruning but by planting distance namely the highest productivity was found at 60 cm x 20 cm.
Keyword: buah muda, cabang, topping, tunas lateral, Zahira

Judul: Frequency of Organic Fertilization Determines the Growth and Yield of Okra (Abelmoschus esculentus L. Moench.).
Abstrak: Tanaman okra populer di negara Asia karena memiliki banyak manfaat dari mulai daun muda, batang, kuncup bunga, polong muda sampai biji dari buah okra. Sebagai sayuran fungsional, produk pertanian memiliki nilai tambah jika dibudidayakan secara organik. Okra yang dibudidayakan secara organik memerlukan panduan pemupukan karena pembentukan bunga dan buah okra tidak berlangsung serentak. Panduan yang sudah tersedia untuk pemupukan tanaman okra, yaitu dilakukannya pemupukan anorganik secara bertahap. Pengujian pemupukan okra menggunakan pupuk kandang kambing susulan tidak memperbaiki pertumbuhan dan produksi buah okra. Oleh karena itu perbaikan teknik aplikasi pupuk kandang ayam dengan pengaturan frekuensi pemupukan diharapkan dapat menghasilkan teknologi budidaya okra yang lebih baik. Penelitian ini dilaksanakan pada September - Desember 2022 di kebun percobaan organik IPB di Cikarawang, Bogor. Penelitian ini menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan satu faktor yaitu frekuensi pemupukan yang terdiri dari tanpa pemupukan, satu, dua, dan tiga kali pemupukan dengan dosis tunggal 18 ton pupuk kandang ayam ha-1. Hasil penelitian menunjukkan bahwa pemberian pupuk kandang ayam sebanyak 18 ton ha-1 yang diberikan secara sekaligus (2 minggu sebelum tanam) meningkatkan secara cepat karakter morfologi dan fisiologi tanaman okra di awal pertumbuhan. Pemberian pupuk secara bertahap yaitu 2 minggu sebelum tanaman dan 4 minggu setelah tanam meningkatkan tinggi tanaman 11 MSP, jumlah daun 11 MSP, kadar K daun, jumlah polong, bobot polong dan paling baik dalam meningkatkan produktivitas polong muda tanaman okra., The okra plant is popular in Asian countries because it has many benefits, from young leaves, stems, flower buds, young pods to seeds from okra fruit. As functional vegetables, agricultural products have added value if they are cultivated organically. Organically cultivated okra requires fertilization guidance because the formation of okra flowers and fruit does not take place simultaneously. Guidelines that are already available for fertilizing okra plants, namely carrying out inorganic fertilizers in several stages. Testing of okra fertilization using goat manure did not improve the growth and fruit production of okra. Therefore, improving the chicken manure application technique by adjusting the frequency of fertilization is expected to produce better okra cultivation technology. This research was conducted in September - December 2022 at the IPB organic experimental field in Cikarawang, Bogor. This study used a Randomized Completely Block Design (RCBD) with one factor, namely the frequency of fertilization which consisted of no fertilization, one, two and three times of fertilizing with a single dose of 18 tons chicken manure ha-1. The results showed that the application of chicken manure as much as 18 tons ha-1 which was given at once (2 weeks before planting) rapidly increased the morphological and physiological characters of okra plants at the beginning of growth. Gradual application of fertilizer i.e. 2 weeks before planting and 4 weeks after planting increased plant height by 11 WAP, number of leaves by 11 WAP, leaf K content, number of pods, pod weight and was the best in increasing the productivity of young pods of okra plants
Keyword: hara daun, okra hijau, pemupukan bertahap, polong muda, hara daun, okra hijau, pemupukan bertahap, polong muda

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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