Judul: The Agronomic Performance of Ratoon and  Modified Ratoon Salibu in the Multi Canopy Rice Cultivation System
Abstrak: Penggunaan teknologi multikanopi dengan sistem sisip dan modifikasi teknik ratun yang disebut “salibu” dalam budidaya padi diharapkan dapat memberikan manfaat berupa peningkatan potensi hasil melalui luas panen vertikal dan intensitas panen. Tujuan dari penelitian ini adalah mempelajari performa pertumbuhan, fisiologi, dan hasil dari tanaman padi yang telah diratun pada sistem budidaya multikanopi dan menetapkan kombinasi varietas yang memiliki performa terbaik. Multikanopi dilakukan dengan penanaman varietas pendek (Inpari 32, Inpari 33, dan Inpari 43) secara kombinasi dengan varietas tinggi (IPB 3S, IPB 9G, dan Batang Piaman). Varietas pendek dipindah tanam dengan jarak tanam 4:1 dengan jarak 30 cm dan 15 cm. Varietas tinggi dipindah tanam di antara baris tanaman pendek. Setelah panen tanaman induk, ratun salibu konvensional dan ratun modifikasi salibu diamati pertumbuhan dan produksinya. Penampilan multikanopi menunjukkan hasil yang lebih tinggi jika dibandingkan dengan monovarietas. Teknik ratun modifikasi salibu lebih baik dari ratun konvensional pada seluruh sifat morfologi, fisiologis, serta bobot hasil gabah. Memanfaatkan padi yang lebih tinggi sebagai tanaman sisip untuk multikanopi yang dikombinasikan dengan ratun salibu yang dimodifikasi dapat direkomendasikan untuk mendapatkan keuntungan dari peningkatan intensitas panen sebagai strategi pemanfaatan lahan., The use of multicanopy technology with an insert system and modification of the ratoon technique called "salibu" in rice cultivation is expected to provide benefits in the form of increased yield potential through vertical harvest area and harvest intensity. This research aimed to study the growth performance, physiology, and yield of ratooned rice plants in a multi-canopy cultivation system and determine the combination of varieties that had the best performance. Multi-canopy was carried out by planting short varieties (Inpari 32, Inpari 33, and Inpari 43) in combination with tall varieties (IPB 3S, IPB 9G, and Batang Piaman). Short varieties were transplanted with a spacing of 4:1 with a distance of 30 cm and 15 cm. Tall varieties are transplanted between rows of short plants. After harvesting the mother plants, the conventional and modified crusader rats were observed for growth and production. Multi-canopy performances showed higher yields when compared to monovarieties. The modified cruciferous rattan technique was better than conventional ratoons in all morphological, physiological properties, and grain yield weight. Utilizing taller paddy as a multicanopy insert crop in combination with modified crucian carp can be recommended to benefit from increased crop intensity as a land use strategy.
Keyword: combination of varieties, land use, parent crop, ratoon productivity

Judul: Increasing Rice (Oryza sativa L.) Productivity through Multi-canopy Cultivation System at KP BB Padi, Sukamandi
Abstrak: Sistem budi daya multi-kanopi merupakan salah ide baru yang dikembangkan untuk peningkatan produktivitas dengan memanfaatkan ruang tumbuh vertikal. Penanaman lebih dari satu varietas yang memiliki tinggi berbeda dalam satu lahan, sehingga terbentuk kanopi bertingkat. Tujuan penelitian untuk mengetahui komponen yang mempengaruhi peningkatan produktivitas padi. Percobaan dilakukan di Kebun Percobaan BB Padi, Subang, Jawa Barat. Rancangan yang digunakan adalah RKLT faktorial dua faktor, yaitu sistem budi daya dan varietas. Sistem budi daya ada tiga yaitu monovarietas, multi-kanopi sisip 1 dan multi-kanopi sisip 2. Varietas yang digunakan adalah Inpari 32, Inpari 33 dan IPB 9G sebagai tanaman sisip. Hasil penelitian menunjukkan bahwa terdapat interaksi antara perlakuan pada tinggi tanaman 6 MST dan jumlah malai per rumpun. Penerapan sistem budi daya multi-kanopi berpotensi untuk meningkatkan produktivitas padi. Produktivitas yang didekati dengan proyeksi hasil menunjukkan bahwa peningkatan produktivitas tertinggi pada perlakuan varietas Inpari 32 dengan sistem budi daya multi-kanopi sisip 1 yaitu sebesar 19,36%., The multi-canopy cultivation system is one of the new ideas developed for increasing productivity by utilizing vertical growing space. Planting more than one variety of different heights in one field, so a multi-tiered canopy is formed. The purpose of the study is to determine the components that affect the increase in rice productivity. The experiment was conducted at the BB Padi Experimental Garden, Subang, West Java. The design used is a two-factorial RKLT, namely the cultivation system and variety. There are three cultivation systems, namely monovarietas, multi-canopy insert 1 and multi-canopy insert 2. The varieties used are Inpari 32, Inpari 33, and IPB 9G as insert plants. The results showed that there was an interaction between the treatment of plant height of 6 MST and the number of panicles per clump. The application of multi-canopy cultivation stem has the potential to increase rice productivity. Productivity approached with potential results showed that the highest increase in productivity in the Inpari 32 variety treatment with a multi-canopy insert 1 cultivation system was 19.36%.
Keyword: insert, multi-canopy, vertical

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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