Judul: Effectiveness of Bioherbicide Based on Purple Nutsedge  Bulb Granule Formulation with Various Shapes and Sizes to Control Weeds in  Shallots (Allium cepa L.)
Abstrak: Bawang merah merupakan komoditas hortikultura yang memiliki potensi unggul dan tingkat konsumsinya tinggi di Indonesia. Peningkatan produksi bawang merah secara nasional masih banyak kendala yaitu kehadiran organisme pengganggu tanaman, cuaca, kelembaban, dan kondisi umbi. Bioherbisida dapat menjadi solusi yang ramah lingkungan. Penelitian bertujuan menguji keefektifan bioherbisida berbahan umbi teki (Cyperus rotundus L.) formulasi butiran berbagai bentuk dan ukuran terhadap pertumbuhan gulma dan pengaruhnya pada budi daya bawang merah. Percobaan disusun dengan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT). Perlakuan pada penelitian ini berupa kontrol, penyiangan manual, bioherbisida butiran bulat sangat kecil, bioherbisida butiran bulat kecil, bioherbisida butiran bulat sedang, bioherbisida butiran bulat besar, bioherbisida butiran tabung sangat kecil, bioherbisida butiran tabung kecil, bioherbisida butiran tabung sedang, bioherbisida butiran tabung besar, mulsa plastik hitam perak, dan herbisida oksifluorfen 240 g L-1 . Analisis pendugaan pengaruh dari perlakuan bioherbisida dengan uji F pada taraf nyata a = 5% dan uji lanjut dengan Duncan’s Multiple Range Test (DMRT) pada taraf 5%. Hasil penelitian menunjukkan bahwa semua perlakuan bioherbisida berbasis umbi teki secara efektif mampu menekan pertumbuhan gulma hingga 30 HST. Berdasarkan keefektifannya dalam menekan pertumbuhan gulma dan pengaruh terhadap produksi umbi bawang merah, perlakuan bioherbisida yang terbaik adalah bioherbisida tabung tabung sedang., Shallots are horticultural commodity with superior potential and high consumption levels in Indonesia. National shallot production faces several challenges including the presence of plant pests, weather conditions, humidity, and bulb conditions. Bioherbicides can be an environmentally friendly solution. This research aims to test the effectiveness of bioherbicides based on purple nutsedge (Cyperus rotundus L.) bulb granule formulations of various shapes and sizes on weed growth and their impact on shallot cultivation. The experiment was designed using a Complete Randomized Group Design (RKLT). Treatments in this study included control, manual weeding, very small round granule bioherbicide, small round granule bioherbicide, medium round granule bioherbicide, large round granule bioherbicide, very small tube granule bioherbicide, small tube granule bioherbicide, medium tube granule bioherbicide, large tube granule bioherbicide, black silver plastic mulch, and oxyfluorfen herbicide 240 g L -1 . The influence estimation analysis of bioherbicide treatments was conducted using an F-test at a significance level of a = 5% and further tested using Duncan’s Multiple Range Test (DMRT) at a 5% level. The results showed that all bioherbicide treatments based on purple nutsedge were effective in suppressing weed growth up to 30 days after treatment. Based on their effectiveness in suppressing weed growth and their influence on shallot bulb production, the best bioherbicide treatments is the medium tube granule bioherbicide.
Keyword: Alelopati, Bawang merah varietas SS Sakato, Formulasi butiran, Herbisida pra-tumbuh, Pertanian berkelanjutan

Judul: The Effectiveness of Various Mixed Formulations of Leaf Extracts from Tetracera indica L. Merr and Tubers of Cyperus rotundus L. as Bioherbicides in Controlling Weeds in Shallot Cultivation
Abstrak: Salah satu cara untuk mengendalikan gulma pada tanaman bawang merah adalah menggunakan herbisida sintetik, namun penggunaan herbisida secara berlebihan tidak ramah terhadap lingkungan. Senyawa yang terkandung dalam T. indica dan C. rotundus berpotensi sebagai bioherbisida. Penelitian bertujuan mendapatkan formulasi campuran T. indica L. Merr. dan umbi teki C. rotundus L. yang efektif untuk mengendalikan gulma pada pertanaman bawang merah. Percobaan disusun dalam Rancangan Kelompok Lengkap Teracak (RKLT) faktor tunggal dengan delapan perlakuan dan empat ulangan. Perlakuan yang diuji yaitu : tanpa penyiangan (P0), formulasi tepung C. rotundus dosis 22,5 kg ha-1 + T. indica dosis 45 kg ha-1 (P1), formulasi pelet C. rotundus dosis 22,5 kg ha-1 + T. indica dosis 45 kg ha-1 (P2), formulasi maserat air C. rotundus dosis 22,5 kg ha-1 + T. indica dosis 45 kg ha-1 (P3), formulasi maserat metanol C. rotundus dosis 22,5 kg ha-1 + T. indica dosis 45 kg ha-1 (P4), formulasi maserat metanol C. rotundus dosis 45 kg ha-1 (P5), formulasi maserat metanol T. Indica dosis 45 kg ha-1 (P6), dan penyiangan manual (P7). Satuan percobaan berupa bedengan berukuran 5 m × 1 m. Hasil penelitian menunjukkan bahwa aplikasi formulasi pelet, maserat metanol dosis campuran, maserat C. rotundus, dan maserat T. indica efektif dalam menekan pertumbuhan gulma spesies R. exaltata saat 4-6 MSA, namun tidak efektif dalam menekan pertumbuhan gulma D. ciliaris, A. sessilis, C. rotundus dan C. dactylon. Formulasi campuran bioherbisida yang efektif adalah formulasi pelet dan formulasi maserat metanol. Formulasi pelet C. rotundus + T. indica dosis 22,5 kg ha-1 + 45 kg ha-1 dapat menekan gulma total dari 57,26% hingga 64,09% sedangkan formulasi maserat metanol C. rotundus + T. indica dosis 22,5 kg ha-1 + 45 kg ha-1 dari 48,21% hingga 56,29%. Perlakuan berbagai formulasi bioherbisida tidak mempengaruhi pertumbuhan tinggi tanaman, jumlah daun, dan jumlah umbi serta hasil panen bawang merah., One way to control weeds in shallot plants is by using synthetic herbicides, but excessive use of herbicides is not environmentally friendly. Compounds contained in T. indica and C. rotundus can be used as bioherbicides. The research aimed to obtain a mixture formulation of T. indica L. Merr. and C. rotundus L. tubers were effective in controlling weeds in shallot cultivation. The experiment was arranged in a Completely Randomized Design (CRD) with a single factor comprising eight treatments and four replications. The treatments tested were: without weeding (P0), C. rotundus flour formulation at a dosage of 22.5 kg ha-1 + T. indica dosage of 45 kg ha-1 (P1), C. rotundus pellet formulation at a dosage of 22.5 kg ha-1 + T. indica dosage of 45 kg ha-1 (P2), C. rotundus water macerate formulation at a dosage of 22.5 kg ha-1 + T. indica dosage of 45 kg ha-1 (P3), C. rotundus methanol macerate formulation at a dosage of 22.5 kg ha-1 + T. indica dosage of 45 kg ha-1 (P4), C. rotundus methanol macerate formulation at a dosage of 45 kg ha-1 (P5), T. indica methanol macerate formulation at a dosage of 45 kg ha-1 (P6), and manual weeding (P7). The experimental unit consisted of beds measuring 5 m
Keyword: Allelophaty, Allium ascalonicum, dose, pre-emergence, vegetation analysis

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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