Judul: Effect of Variety and Spacing Patterns on Growth and Production of Corn (Zea mays L.)
Abstrak: Jagung merupakan salah satu komoditas yang sangat penting di Indonesia. Produksi jagung di Indonesia belum dapat memenuhi kebutuhan nasional. Peningkatan produktivitas dapat dilakukan salah satunya dengan pengaturan jarak tanam dan pemilihan varietas yang tepat. Penelitian ini bertujuan untuk mengetahui pengaruh varietas dan pola jarak tanam yang berbeda serta interaksinya terhadap pertumbuhan dan produksi jagung. Perlakuan yang digunakan yaitu varietas yang terdiri dari varietas jagung hibrida Poneer 27 dan varietas jagung bersari bebas Bisma, dan jarak tanam yaitu jarak tanam jajar legowo sistem double row dan jarak tanam persegi yang masing-masing terdiri dari 2 taraf. Rancangan percobaan yang digunakan yaitu split-plot dengan rancangan lingkungan RKLT, yang diulang sebanyak 3 kali. Varietas jagung Pioneer 27 menunjukkan nilai rata-rata komponen hasil, hasil biji kering ubinan, dan produktivitas yang lebih tinggi (6,12 ton ha-1) dari Bisma (4,62 ton ha-1). Perlakuan jarak tanam tidak berpengaruh nyata terhadap peubah pertumbuah vegetatif tanaman, namun jarak tanam 80 cm × 25 cm menghasilkan bobot tongkol tanpa klobot dan bobot 1000 butir tertinggi. Rata-rata produktivitas dari semua jarak tanam adalah 5,37 ton ha-1., Corn is one of the most important commodities in Indonesia. Corn production in Indonesia has not been able to meet national needs. One of the ways to increase productivity is by setting the spacing and selecting the right varieties. This study aims to determine the effect of different varieties and spacing patterns and their interactions on maize growth and production. The treatments used were varieties consisting of Poneer 27 hybrid corn varieties and Bisma-free pollinated corn varieties, and the spacings were row spacing with double row system and square spacing, each consisting of 2 levels. The experimental design used was a split-plot with an RKLT environmental design, which was repeated 3 times. The Pioneer 27 maize variety showed a higher average yield component, dry grain yield, and productivity (6,12 ton ha-1) than Bisma (4,62 ton ha-1). Spacing treatment had no significant effect on plant vegetative growth variables, but 80 cm × 25 cm spacing resulted in the highest cob weight without cob and 1000 grain weight. The Pioneer 27 maize variety has a higher dry grain yield per tile and productivity than Bisma. The average productivity of all spacings is 5.37 tons ha-1.
Keyword: plant density, maize varieties, vegetative growth, yield components

Judul: The Effect of Urea Fertilization and Varieties on Maize (Zea mays L.) Plants in Terms of Biomass and Seed Production
Abstrak: Jagung merupakan tanaman pangan yang mempunyai peran strategis dalam pembangunan pertanian dan perekonomian nasional. Produktivitas jagung sangat ditentukan oleh mutu genetik varietas yang ditanam dan pemupukan yang tepat. Kegiatan penelitian ini bertujuan mengetahui pengaruh pemupukan berbagai dosis pupuk urea terhadap dua varietas jagung yang ditanam melalui produksi biomassa dan biji. Penelitian dilakukan pada Januari hingga Mei 2023 di Kebun Percobaan Leuwikopo Departemen Agronomi dan Hortikultura, Institut Pertanian Bogor, Dramaga, Bogor, Jawa Barat. Penelitian dilaksanakan menggunakan rancangan petak terbagi dalam rancangan kelompok lengkap teracak dengan tiga kali ulangan. Perlakuan terdiri dari 2 faktor yaitu varietas dan dosis pupuk urea. Varietas sebagai petak utama dan dosis pupuk urea sebagai anak petak. Dua varietas jagung, BISI 18 (hibrida) dan Bisma (komposit) ditanam dan dipupuk dengan dosis urea 0, 175, 350, dan 525 kg ha-1 . Peningkatan dosis urea hingga 525 kg ha-1 secara linier meningkatkan total bobot kering, bobot tongkol dengan kelobot, bobot tongkol tanpa kelobot, diameter tongkol, bobot biji per tongkol, dan bobot biji per plot. Tinggi tanaman, jumlah daun, diameter batang, panjang tongkol, dan nilai SPAD menunjukkan respon kuadratik dengan dosis urea optimum masing-masing 461,25, 435, 350, 435 dan 518 kg ha-1 . Dosis urea 439,25 kg ha-1 merupakan dosis optimum untuk mencapai produktivitas tinggi pada kedua varietas tersebut., Maize is a food crop that has a strategic role in the development of agriculture and the national economy. Maize productivity is largely determined by the genetic quality of the varieties planted and proper fertilization. This research activity aims to determine the effect of fertilizing various doses of urea fertilizer on two varieties of corn grown through the production of biomass and seeds. The research was conducted from January to May 2023 at the Leuwikopo Experimental Garden, Department of Agronomy and Horticulture, IPB University, Dramaga, Bogor, West Java. The research used a split-plot design in a completely randomized group design with three replications. The treatment consisted of 2 factors, variety and dose of urea fertilizer. The variety is the main plot and the dosage of urea fertilizer is the sub-plot. Two maize varieties, BISI-18 (hybrid) and Bisma (composite) were grown and fertilized with urea doses of 0, 175, 350, and 525 kg ha-1 . The increasing urea dose up to 525 kg ha-1 linearly increased the total dry weight, ear weight with husks, ear weight without husk, ear diameter, seed weight per ear, and weight of seed per plot. Plant height, number of leaves, stem diameter, cob length, and SPAD values showed a quadratic response with optimum urea doses of 461.25, 435, 350, 435, and 518 kg ha-1 , respectively. The urea dose of 439.25 kg ha-1 is the optimum dose to achieve high productivity for both varieties.
Keyword: ear weight, ear diameter, optimum dose, productivity, total dry weight

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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