Judul: Agronomic Performance and Yield Potential of 30 Maize Hybrids under Biotic Stress Conditions
Abstrak: Jagung adalah komoditas yang memiliki nilai ekonomis dengan permintaan meningkat setiap tahunnya sehingga perlu dilakukan peningkatan potensi hasil. Banyak faktor yang mempengaruhi potensi hasil jagung sehingga perlu dilakukan pengujian terhadap calon varietas baru. Penelitian ini bertujuan mengevaluasi keragaan agronomi dan potensi hasil 30 hibrida jagung. Penelitian dilaksanakan di Grujukan, Puger Kulon, Jember mulai dari bulan September 2020 hingga Januari 2021. Rancangan percobaan yang digunakan yaitu rancangan kelompok lengkap teracak dengan tiga ulangan. Terdapat 32 genotipe yang diuji yaitu 30 genotipe berasal dari persilangan antara galur IPB dengan galur koleksi Balitsereal dan dua varietas pembanding (BISI 2 dan NK6172). Hasil penelitian menunjukkan bahwa terdapat keragaman antar genotipe pada karakter daya tumbuh, umur berbunga jantan, tinggi tanaman, tinggi tongkol utama, diameter batang, diameter tongkol, jumlah baris biji, jumlah biji dalam baris, bobot tongkol, bobot biji per tongkol, bobot seribu biji, kadar air, dan rendemen hasil. Genotipe juga berpengaruh nyata terhadap ketahanan terhadap serangan ulat dan bulai. Terdapat sepuluh genotipe uji yang memiliki potensi hasil setara dengan kedua varietas pembanding, dan yang terbaik diantaranya yaitu P13xNei., Maize is a commodity having a high economic value with increasing demand over years, and therefore it is necessary to increase its production. Several factors affected maize yield, so it is important to evaluate the prospective of new varieties. This research aimed to evaluate the agronomic performance and yield potential of 30 maize hybrids. The research was conducted at Grujukan, Puger Kulon, Jember from September 2020 to January 2021. The experimental design was a randomized complete block design with three replications. Thirty two maize hybrids, consisting of 30 hybrids of IPB lines x ICERI lines, and two commercial hybrid varieties as checks (BISI 2 and NK6172), were evaluated. The results indicated variations among genotypes for character of growth percentage, days to anthesis, plant height, main ear height, stem diameter, ear diameter, number of grain rows per ear, number of grain in rows, ear weight, grain weight per ear, 1000 grain weight, grain moisture, and yield percentage. In addition, the genotype also had significant effects on fall armyworm and downy mildew resistance. Ten test hybrids had a comparable yield potential with the two check varieties, and the best among which was P13xNei.
Keyword: hybrid evaluation, maize breeding

Judul: Identification of Morpho-Agronomic Characteristics of 48 Inbred Lines of Maize (Zea mays L.)
Abstrak: Pengembangan jagung sangat prospektif karena nilai multigunanya. Pemuliaan jagung merakit varietas hibrida merupakan upaya penting. Keragaman genetik dalam populasi jagung diperlukan untuk menyeleksi calon tetua hibrida. Penelitian ini bertujuan mempelajari keragaman karakter morfologi dan agronomi serta mengidentifikasi galur jagung yang potensial sebagai tetua hibrida. Penelitian dilakukan di Kebun Percobaan Leuwikopo, Dramaga, Bogor, pada September 2023 hingga Januari 2024 menggunakan rancangan kelompok lengkap teracak augmented. Varietas pembanding meliputi BISI-18, JHG02, P21, P27, NK Perkasa, dan NK Sumo dengan enam ulangan, serta 48 genotipe yang diuji. Hasil penelitian menunjukkan genotipe jagung berpengaruh nyata pada hampir semua karakter kecuali anthesis silking interval. Perbedaan nilai tengah ditemukan pada sebagian besar karakter agronomi dan komponen hasil. Keragaman morfologi juga terlihat pada intensitas antosianin pada malai, rambut, dan akar penyangga, serta mengombaknya tepi helaian daun. Seleksi dapat dilakukan pada hampir seluruh karakter kuantitatif karena memiliki nilai heritabilitas arti luas yang tergolong tinggi. Terdapat tiga klaster utama berdasarkan fenotipe. Genotipe dalam klaster 1 seperti L15, NEI, M8, M9, L41s, P13, dan L42 berpotensi dikembangkan sebagai tetua hibrida. Korelasi kuat antara karakter agronomi dan komponen hasil belum ditemukan, korelasi didapati pada beberapa karakter seperti umur berbunga jantan dan betina, tinggi tanaman dan tinggi tongkol serta antar karakter lainnya., The development of corn commodities is promising due to its multifunctional value. Corn breeding to develop hybrid varieties is an important effort. Genetic diversity in corn populations is needed as a source for hybrid breeding. This study aimed to elucidate genetic diversity based on morphological and agronomic characteristics of 48 inbred lines and identify potential lines. The research was conducted from September 2023 to January 2024 at Leuwikopo Experimental Station, Dramaga, Bogor, West Java. The experiment used an augmented randomized complete block design with six replications for the checks. Forty-eight inbred lines were evaluated along with six check varieties BISI-18, JHG02, P21, P27, NK Perkasa, and NK Sumo. The results showed that genotypes significantly influenced all observed traits except the anthesis silking interval. Differences in mean values were found in most agronomic traits and yield components. Morphological diversity was also observed in the intensity of anthocyanin on the tassels, silks, and brace roots, as well as the leaf edge pattern. Selection can be performed on almost all quantitative traits due to their high broad-sense heritability values. There are three main clusters based on phenotype. Genotypes in cluster 1 such as L15, NEI, M8, M9, L41s, P13, and L42 tended to be potential as hybrids’ parents due to their good per-se morpho-agronomic traits. There is no strong correlation between agronomic traits and yield, but correlations were observed among some traits such as male and female flowering time, plant height and ear height, as well as among other traits.
Keyword: karakterisasi, keragaman genetik, heatmap, characterization, genetic variation

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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