Judul: Performance of Compression Sprayer for Weed Control at Various Pressures and Concentrations of Herbicide Solutions
Abstrak: Salah satu metode pengendalian gulma secara kimiawi yaitu dengan mengaplikasikan herbisida menggunakan sprayer. Tujuan penelitian ini adalah menganalisis kinerja compression sprayer untuk pengendalian gulma pada berbagai tekanan dan konsentrasi larutan herbisida. Perlakuan menggunakan tekanan 200 kPa, 300 kPa, dan 400 kPa. Parameter di laboratorium yaitu lebar penyemprotan efektif sebesar 0.56 m, 0.64 m, 0.72 m, debit penyemprotan efektif sebesar 0.451 liter/menit, 0.5 liter/menit, 0.586 liter/menit, kerapatan droplet sebesar 42.56 droplet/cm², 64.8 droplet/cm², 75.2 droplet/cm², dan diameter droplet sebesar 298.54 µm, 276.39 µm, 252.31 µm. Parameter di lapangan yaitu debit aplikasi herbisida, kapasitas penyemprotan, biaya aplikasi herbisida, dan efektivitas pengendalian gulma. Perubahan tekanan dari 200 kPa, 300 kPa, dan 400 kPa dengan konsentrasi larutan herbisida 10% menghasilkan debit aplikasi herbisida sebesar 0.0567 liter/menit, 0.068 liter/menit, 0.0833 liter/menit, kapasitas penyemprotan sebesar 28.35 liter/ha, 34 liter/ha, 41.65 liter/ha, biaya aplikasi herbisida sebesar Rp78 864.58/ha, Rp113 498.17/ha, Rp170 386.33/ha, dan efektivitas pengendalian gulma sebesar 72.31%, 80.35%, 91.77%. Semakin kecil diameter droplet dan semakin besar kapasitas penyemprotan yang dihasilkan maka semakin mudah droplet masuk ke stomata gulma serta semakin tinggi konsentrasi larutan herbisida yang diaplikasikan ke gulma maka menghasilkan efektivitas pengendalian gulma yang semakin besar., One method of chemical weed control is applying herbicides using a sprayer. The purpose of this study was to analyze the performance of a compression sprayer for weed control at various pressures and concentrations of herbicide solution. The treatment uses a pressure of 200 kPa, 300 kPa, and 400 kPa. Testing parameters were carried out in the laboratory and in the field. Measurements in the laboratory are effective spraying width with a value of 0.56 m, 0.64 m, 0.72 m, effective spraying rate of 0.451 liters/minute, 0.5 liters/minute, 0.586 liters/minute, droplet density of 42.56 droplets/cm², 64.8 droplets/cm², 75.2 droplets/cm², and droplet diameter of 298.54 µm, 276.39 µm, 252.31 µm. Measurements in the field are herbicide application rate, spraying capacity, herbicide application cost, and weed control effectiveness. Changes in pressure from 200 kPa, 300 kPa, and 400 kPa with 10% concentration herbicide solution resulted in a herbicide application discharge of 0.0567 liters/minute, 0.068 liters/minute, 0.0833 liters/minute, a spraying capacity of 28.35 liters/ha, 34 liters/ha, 41.65 liters/ha, the cost of herbicide application was Rp78 864.58/ha, Rp113 498.17/ha, Rp170 386.33/ha, and the effectiveness of weed control was 72.31%, 80.35%, 91.77%. The smaller droplet diameter and the greater resulting spraying capacity, the easier for the droplets to enter the weed stomata and the higher concentration of the herbicide applied to the weed, the effectiveness of weed control greater.
Keyword: compression sprayer, droplet, herbicide, pressure, weed control effectiveness

Judul: Performance of Motorized Carrying Sprayer for Weed Control at Various Concentrations of Herbicide Solutions and Liquid Pressure
Abstrak: Knapsack power sprayer memiliki keunggulan yaitu besar tekanan bisa diatur dengan mengubah bukaan throttle, sehingga dapat ditentukan besar tekanan cairan, ukuran butiran semprot (droplet) dan kerapatan droplet sesuai dengan konsentrasi larutan herbisida yang digunakan. Tujuan penelitian ini adalah untuk menentukan kinerja herbiciding gulma lahan kering pada berbagai konsentrasi larutan herbisida dan tekanan cairan menggunakan knapsack power sprayer. Hasil uji kinerja knapsack power sprayer di laboratorium untuk nosel kerucut diperoleh tekanan yang paling optimum dengan bukaan throttle 50% (P3) sebesar 25 kgf/cm2. Sedangkan 4 parameter utama pada bukaan throttle 50% (P3) antara lain diameter droplet, kerapatan droplet , lebar penyemprotan efektif dan debit penyemprotan masing-masing sebesar 221.67 µm; 275.64 droplet/cm2, 0.96 m, dan 6.27 liter/menit. Hasil kinerja pengendalian gulma di lapangan yang paling optimum dengan konsentrasi larutan herbisida 3,5% (C3) untuk nosel kerucut yaitu diperoleh efektivitas terbesar adalah 81.67% dengan kapasitas keluaran sebesar 46.01 liter/ha serta biaya larutan aplikasi herbisida sebesar Rp 8 695.97 per jam. Sedangkan hasil uji kinerja knapsack power sprayer di laboratorium untuk nosel kipas diperoleh tekanan yang paling optimum dengan bukaan throttle minimum (P1) sebesar 10 kgf/cm2. Sedangkan 4 parameter utama pada bukaan throttle minimum (P1) antara lain diameter droplet, kerapatan droplet, lebar penyemprotan efektif dan debit penyemprotan masing-masing sebesar 198,67 µm; 214.93 droplet/cm2, 1,12 m, dan 3,08 liter/menit. Hasil kinerja pengendalian gulma di lapangan yang paling optimum pada konsentrasi larutan herbisida 1,5% (C1) untuk nosel kipas yaitu diperoleh efektivitas terbesar 82.43%; dengan kapasitas keluaran sebesar 5.36 liter/ha serta biaya larutan aplikasi herbisida sebesar Rp 1 181.25 per jam., Knapsack power sprayer has the advantage that it can be adjusted by changing the throttle opening, so that the liquid pressure, droplet size and droplet density can be determined according to the concentration of the herbicide solution used. The purpose of this study was to determine the performance of dryland weed herbicides at various concentrations of herbicide solutions and liquid pressure using a knapsack power sprayer. The results of the knapsack power sprayer performance test in the laboratory for the cone nozzle obtained the most optimal pressure with a throttle opening of 50% (P3) of 25 kgf / cm2. Meanwhile, the 4 main parameters at the 50% throttle opening (P3) include droplet diameter, droplet density, effective spraying width and spraying discharge of 221.67 µm; 275.64 droplets / cm2, 0.96 m, and 6.27 liters / minute. The most optimal field control results with a concentration of 3.5% herbicide solution (C3) for the most effective cone nozzle is 81.67% with an output capacity of 46.01 liters / ha and the cost of herbicide application solution is IDR 8 695.97 per hour . While the results of the knapsack power sprayer performance test in the laboratory for the fan nozzle, the optimal pressure is obtained with a minimum throttle opening (P1) of 10 kgf / cm2. Meanwhile, the 4 main parameters for the minimum throttle opening (P1) are droplet diameter, droplet density, effective spraying width and spraying discharge of 198.67 µm respectively; 214.93 droplets / cm2, 1.12 m, and 3.08 liters / minute. The most optimal field control results were at a concentration
Keyword: weeds, knapsack power sprayer, herbicide solution concentration, pressure

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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