Judul: Kajian Agrometeorologi Tanaman Bawang Merah di Kabupaten Grobogan pada Berbagai Perlakuan Jarak Tanam
Abstrak: Kondisi cuaca dan iklim serta teknik budidaya merupakan faktor yang memengaruhi produktivitas tanaman bawang merah. Penelitian ini bertujuan mengetahui pengaruh jarak tanam dengan sistem tegel (TG) dan jajar legowo (JL) terhadap produktivitas bawang merah, menentukan jarak tanam optimal dengan menggunakan model simulasi, dan mengetahui teknik budidaya bawang merah berkaitan dengan karakteristik agrometeorologi di Kabupaten Grobogan. Penelitian lapang dilaksanakan di Desa Simo, Kabupaten Grobogan. Penelitian menggunakan perlakuan lima jarak tanam yaitu TG1 (14 cm x 14 cm), TG2 (16 cm x 16 cm), TG3 (18 cm x 18 cm), JL1 (16 cm x 14 cm), dan JL2 (16 cm x 18 cm), penyusunan model simulasi menggunakan masukan data cuaca dan tanaman hasil pengamatan lapang, serta menggunakan wawancara dan kuesioner untuk mengetahui teknik budidaya petani bawang merah di Kabupaten Grobogan. Hasil kajian menunjukkan perlakuan TG2 menjadi jarak tanam paling optimal dibandingkan jarak tanam lainnya ditinjau dari produktivitas, efisiensi penggunaan radiasi matahari (RUE), serta risiko serangan penyakit tanaman. Model simulasi dapat menggambarkan fase perkembangan, hari panen, indeks luas daun, dan produktivitas dengan akurasi mencapai 97,94%. Petani di Grobogan telah mengembangkan beberapa teknik budidaya dan kearifan lokal dalam merespons kondisi cuaca untuk meningkatan produktivitas bawang merah di musim hujan maupun musim kemarau., Weather and climate conditions, as well as cultivation techniques, influence the productivity of shallot plants. This research aims to determine the effect of planting distance under tegel (TG) and jajar legowo (JL) systems on shallot productivity, to determine optimal planting distance using a simulation model, and to determine shallot cultivation techniques related to agrometeorological characteristics in the Grobogan Regency. Field research was carried out in Simo Village, Grobogan Regency. The research used five plant spacing treatments, namely TG1 (14 cm x 14 cm), TG2 (16 cm x 16 cm), TG3 (18 cm x 18 cm), JL1 (16 cm x 14 cm), and JL2 (16 cm x 18 cm), preparing a simulation model using input of weather data and plants from field observations, as well as using interviews and questionnaires to determine the cultivation techniques of shallot farmers in the Grobogan Regency. The study results show that TG2 treatment is the most optimal planting distance compared to other planting distances in terms of productivity, radiation use efficiency (RUE), and the risk of plant disease infestation. The simulation model can describe development phases, harvest days, leaf area index, and productivity with an accuracy of 97.94%. Farmers in Grobogan have developed several cultivation techniques and local wisdom in responding to weather conditions to increase shallot productivity in the rainy and dry seasons.
Keyword: cultivation techniques, growth, plant simulation models, plant spacing, shallot plants

Judul: Plant Spacing Modelling Analysis Towards Shallot Productivity (Field Study: Brebes Regency)
Abstrak: Kondisi cuaca dan penggunaan sumber daya mempengaruhi produktivitas bawang merah. Analisis ini mengkaji hubungan antara pertumbuhan bawang merah dengan kondisi iklim sekitar untuk mengoptimalkan produktivitas dengan menggunakan perlakuan jarak tanam. Penelitian ini bertujuan untuk mengetahui pengaruh jarak tanam terhadap produktivitas bawang merah dalam respon kondisi cuaca harian yang dapat dimodelkan menggunakan model simulasi untuk menentukan jarak tanam yang optimal. Penelitian lapang dilakukan di Desa Karangbale, Brebes, Jawa Tengah, yang merupakan salah satu sentra produksi bawang merah. Model simulasi dapat menggambarkan proses pertumbuhan bawang merah dengan uji t berpasangan dengan p value lebih besar dari 0,05 untuk semua variabel pertumbuhan seperti hari panen, produktivitas, dan LAI pada semua perlakuan. Hasil analisis menunjukkan jarak tanam JT3TG (16x16 cm) lebih optimal dibandingkan dengan JT1TG (14x14 cm), JT2TG (18x18 cm), JT1JL (14x16 cm), dan JT2JL (14x18 cm) ditinjau dari produktivitas, efisiensi penerimaan radiasi, dan serangan hama dan penyakit tanaman, Weather conditions and resource use affect shallot productivity. This analysis examines the relation between the growth of shallot plants and the surrounding climatic conditions to optimize productivity using plant spacing treatment. This study aims to determine the effect of spacing on shallot productivity in response to daily weather conditions which can be modelled using a simulation model to determine optimal planting space. Field research was conducted in Karangbale Village, Brebes, Central Java, which is one of the shallot production centres. The simulation model can predict the shallot growth process with paired t-test with p-value greater than 0.05 for all growth variables such as harvest days, productivity, and LAI in all treatments. The results of the analysis showed that JT3TG (16x16 cm) was more optimal spacing rather than JT1TG (14x14 cm), JT2TG (18x18 cm), JT1JL (16x14 cm), and JT2JL (16x18 cm) in terms of productivity, radiation reception efficiency, and the lowest pests and crop diseases infestation.
Keyword: crop model simulation, growth, plant spacing, productivity, radiation use efficiency

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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