Judul: Evaluasi daya hasil dan ketahanan tomat terhadap pecah buah di dataran rendah
Abstrak: Pecah buah adalah gangguan fisiologis yang umum terjadi pada budidaya tomat dataran rendah. Penelitian bertujuan untuk menguji daya hasil tomat generasi M7 di lapang serta identifikasi pecah buah. Penelitian ini dilakukan di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor pada bulan Januari hingga Mei 2020. Genotipe yang diuji terdiri atas 10 galur M7 dan 2 pembanding. Terdapat 5 galur yang tahan atau sangat tahan terhadap pecah buah dan potensi hasil sama dengan varietas pembanding, yaitu galur M7/495 Lombok 1/9-2-8 (L1), M7/495 Lombok 4/1-3-6 (L2), M7/990 Lombok 2/2-2-6 (L3), M7/495 STBGL/ 2-3-7 (S1), dan M7/990 Lombok 1/9-5-8 (L4). Galur yang memiliki produktivitas paling tinggi adalah galur M7/495 Kefamino 6/1-3-7 (Kf), namun rentan terhadap pecah buah. Galur M7/990 Lombok 1/9-5-8 (L4) memiliki bobot buah paling tinggi dan tahan terhadap pecah buah. Galur M7/495 Lombok 4/1-3-6 (L2) memiliki nilai Indeks pecah (IPB) buah sebesar 0,00%, sedangkan galur M7/495 GL 2-8-10 (G), M7/990 STBGL/1-9-4 (S2), M7/495 Kefamino 6/1-3-7 (Kf), M7/990 Kudamati/1-9-4 (Ku), dan M7/495 Kemir/4-7-4 (Km) rentan terhadap pecah buah dengan nilai nilai Indeks pecah buah (IPB) sebesar 18,89-39,36%., Fruit cracking is a common physiological disorder in lowland tomato cultivation. The aim of the study was to test the yield of M7 generation tomatoes in the field and to identify fruit cracking. This research was conducted at the Leuwikopo Experimental Garden of IPB, Dramaga, Bogor from January to May 2020. The tested genotypes consisted of 10 M7 lines and 2 comparisons. There are 5 lines that are resistant or very resistant to fruit cracking and the yield potential is the same as the comparison variety, namely M7/495 Lombok 1/9-2-8 (L1), M7/495 Lombok 4/1-3-6 (L2), M7/990 Lombok 2/2-2-6 (L3), M7/495 STBGL/ 2-3-7 (S1), and M7/990 Lombok 1/9-5-8 (L4). The line that had the highest productivity was the M7/495 Kefamino 6/1-3-7 (Kf) line, but it was susceptible to fruit cracking. The M7/990 Lombok 1/9-5-8 (L4) line had the highest fruit weight and was resistant to fruit cracking. The M7/495 Lombok 4/1-3-6 (L2) line had a fruit rupture index value of 0,00%, while the M7/495 GL 2-8-10 (G) line, M7/990 STBGL/1-9 -4 (S2), M7/495 Kefamino 6/1-3-7 (Kf), M7/990 Kudamati/1-9-4 (Ku), and M7/495 Kemir/4-7-4 (Km) vulnerable against fruit cracking with the value of the fruit cracking index of 18.89-39.36%.
Keyword: yield, genotype, fruit cracking

Judul: Yield Potential Evaluation of Tomato Mutant Genotypes for Assembling Tomatoes Tolerant to Cracking Fruit in the Lowlands
Abstrak: Pecah buah merupakan salah satu gangguan fisiologis yang terjadi pada tanaman tomat. Pecah buah dapat mengurangi hasil produksi dan berdampak nyata pada kerugian buah yang dapat dipasarkan. Penelitian ini bertujuan untuk menguji genotipe-genotipe mutan yang toleran pecah buah dan berproduksi tinggi. Penelitian ini dilaksanakan pada bulan Juli-November 2019 di Kebun Percobaan Leuwikopo IPB, Dramaga, Bogor, Jawa Barat. Percobaan dilakukan menggunakan Rancangan Acak Kelompok Lengkap (RAKL) dengan satu faktor yaitu perlakuan genotipe tomat mutan dengan 13 taraf. Penelitian dilakukan dengan tiga ulangan sehingga diperoleh 39 satuan percobaan. Hasil penelitian menunjukan bahwa perlakuan genotipe memberikan pengaruh nyata pada beberapa karakter seperti tinggi tanaman, diameter buah, panjang buah, bobot per buah, bobot buah per tanaman, dan produktivitas. Genotipe M5/990 Kudamati 1/9-4 memiliki nilai bobot per buah dan produktivitas per hektar tertinggi sebesar 934,7 g dan 29,91 ton ha-1 dan toleran terhadap pecah buah dengan kriteria tahan, Cracking fruit is one of the physiological disorders that occur in tomato plants. Cracking fruit can reduce production yields and have a significant impact on marketable fruit losses. This study aims to examine mutant genotypes that are tolerant of fruit breaking and high yielding. This research was conducted in July- November 2019 at the Leuwikopo Experimental Garden, IPB, Dramaga, Bogor, West Java. The experiment was conducted using a Completely Randomized Block Design (RAKL) with one factor, namely the treatment of mutant tomato genotypes with 13 levels. The study was conducted with three replications so that 39 experimental units were obtained. The results showed that the genotype treatment had a significant effect on several characters such as plant height, fruit diameter, fruit length, weight per fruit, fruit weight per plant, and productivity. Genotype M5/990 Kudamati 1/9-4 had the highest weight value per fruit and productivity per hectare of 934.7 g and 29.91 tons ha-1 and was tolerant of fruit breaking with the criteria of resistance.
Keyword: fruit  breaking, tomatoes, plant breeding, productivity

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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