Judul: Effect of Soil P and K Content on the Growth and Yield of Tomato (Lycopersicon esculentum) in Garut Andisols.
Abstrak: Tomat merupakan komoditas hortikultura yang banyak dibudidayakan dan dimanfaatkan di Indonesia. Produktivitas tomat dapat ditingkatkan dengan pendekatan teknologi budidaya seperti menggunakan teknologi irigasi dan pemupukan yang presisi. Penelitian ini menggunakan rancangan kelompok lengkap teracak (RKLT) dengan satu faktor berupa taraf status hara P dan K (rendah, sedang, dan tinggi) menggunakan perangkat uji tanah kering (PUTK). Analisis taraf hara P dan K pada tanah Andisol menggunakan PUTK terhadap tanaman tomat dapat digunakan. Hasil pada penentuan taraf hara P berbeda nyata pada hasil bobot kering tajuk, bobot kering total, jumlah buah total, dan bobot buah total. Taraf hara P tinggi menunjukkan rataan hasil produktivitas yang paling tinggi yaitu 307,59 gram/tanaman. Hasil pada penentuan taraf hara K menunjukkan perbedaan sangat nyata pada jumlah buah total dan berbeda nyata pada bobot kering tajuk, bobot kering total, dan bobot buah total. Taraf hara K tinggi menunjukkan rataan hasil produktivitas yang paling tinggi dari semua perlakuan yaitu 320,17 gram/tanaman., Tomato is a horticultural commodity that is widely cultivated and used in Indonesia. Tomato productivity can be increased by using cultivation technology approaches such as using irrigation technology and precise fertilization. This study used a completely randomized block design (RKLT) with one factor of P and K nutrient status levels (low, medium, and high) from the results of Garut Andisol soil testing using a perangkat uji tanah kering (PUTK). Analysis of P and K nutrient levels in Andisol soil using PUTK for tomato plants can be used. The results for determining the levels of P nutrients were significantly different in the results of shoot dry weight, total dry weight, total fruit number, and total fruit weight. The high level of P nutrient indicates the highest average yield of productivity, that is 307.59 gram/plant. The results for determining the K nutrient levels showed highly significant differences in the total fruit number and significantly different in shoot dry weight, total dry weight, and total fruit weight. The high K nutrient level showed the highest average yield of all treatments, that is 320.17 grams/plant.
Keyword: PUTK, Taraf Hara, Generatif, Vegetatif

Judul: Uji Daya Hasil Tomat (Solanum lycopersicum L.) Koleksi PKHT IPB di Tajur
Abstrak: Tomat merupakan komoditas hortikultura yang bernilai ekonomi serta bermanfaat bagi kesehatan tubuh manusia. Konsumsi tomat meningkat seiring dengan peningkatan kesadaran masyarakat akan pola hidup sehat. Populasi tomat di dataran tinggi mulai terbatas akibat persaingan dengan komoditas pertanian lainnya. Oleh karena itu, diperlukan perluasan populasi tomat kedataran rendah. Namun, memiliki kendala yaitu kesesuaian iklim, produktivitas, kualitas buah, ketahanan terhadap hama dan penyakit, sehingga pemuliaan tanaman tomat adaptif dataran rendah perlu dilakukan. Penelitian ini bertujuan untuk menguji daya hasil genotipe tomat (Solanum lycopersicum L.) koleksi PKHT IPB di dataran rendah. Percobaan dilaksanakan di kebun percobaan Tajur PKHT IPB, pada bulan Januari hingga April tahun 2013. Percobaan menggunakan rancangan kelompok lengkap teracak, satu faktor dan tiga ulangan. Faktor tersebut adalah genotipe tomat yang terdiri dari genotipe IPBT3, IPBT8, IPBT30, IPBT33, IPBT34, IPBT43, IPBT53, IPBT57, IPBT60, IPBT64, IPBT78 serta tiga varietas komersil (Intan, Karina dan Ratna) sebagai pembanding. Hasil penelitian menunjukan bahwa genotipe berpengaruh nyata terhadap keseluruhan karakter uji kecuali diameter batang. Genotipe tomat yang memiliki daya hasil lebih baik dari varietas pembanding Intan dan Karina adalah IPBT57 dan IPBT64. Karakter panjang daun, umur berbunga dan bobot buah pertanaman berkorelasi positif terhadap produktivitas tanaman. Genotipe tomat yang diuji beradaptasi cukup baik dilokasi uji coba., Tomato is a horticultural commodity that has economic value and is beneficial for the health of the human body. Consumption of tomato is increasing along with increasing public awareness of healthy lifestyle. Tomato population in the highland is starting to be limited due to competition with other agricultural commodities. Therefore, expending the lowland tomato is a necessity. However, it has constraints that are climate suitability, productivity, fruit quality, resistance to pests and diseases, so that the breeding of lowland adaptive tomato plants needs to be done. The research aimed to obtain the yield information of tomato genotype collection of PKHT-IPB. The experiment was conducted at Tajur, Bogor from January till April 2013. The experiment used a randomized complete block design, single factor and three replications. The factor was genotype that consisted of IPBT3, IPBT30, IPBT33, IPBT34, IPBT43, IPBT53, IPBT57, IPBT60, IPBT64, IPBT78 genotypes, and three comercial varieties (Intan, Karina and Ratna) as controls. The results showed that the genotypes significantly affected the overall character except for the stem diameter character. Tomato genotypes that had a better yield ability than commercial varieties Intan dan Karina were IPBT57 and IPBT64. Character of leaf length, flowering age and fruit weight were positively correlated with plant productivity. The tomato genotypes tested adapted quite well in the trial locations.
Keyword: dataran rendah, genotipe, produktivitas

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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