Judul: Population of Plant-hoppers and Spiders in Biointensive and Conventional Rice Croping
Abstrak: Padi merupakan salah satu tanaman serelia penting yang digunakan sebagai makanan pokok sebagian besar penduduk dunia. Padi tergolong dalam tanaman pangan berupa rumput berumpun dan memiliki kemampuan beradaptasi yang tinggi pada berbagai kondisi lingkungan. Penelitian bertujuan mengetahui perbandingan populasi hama wereng dan populasi laba-laba pada pertanaman padi biointensif dan konvensional di Kampung Darim, Kecamatan Terisi, Kabupaten Indramayu, Provinsi Jawa Barat. Metode penelitian yang digunakan adalah metode pengamatan langsung dilakukan dengan menetapkan titik pengamatan secara terpilih yang mewakili bagian tengah lahan sawah dengan ukuran 10 m x 10 m. Pada setiap lahan sawah ditentukan 100 grid pengamatan, grid pengamatan berukuran 1 m2. Data diolah dan dianalisis menggunakan aplikasi Microsoft excel 2013. Hasil penelitian menunjukkan bahwa populasi wereng lebih tinggi pada lahan pertanaman padi dengan perlakuan biointensif, populasi laba-laba lebih tinggi pada lahan pertanaman padi dengan perlakuan biointensif. Spesies yang ditemukan yaitu Araneus inustus, Neoscona theisi, Atypena adelina, Pardosa pseudoannulata, Tetragnathidae sp., Oxyopes javanus, dan Harmochirus sp. Dominasi spesies yang ditemukan yaitu Atypena adelina baik pada lahan dengan perlakuan biointensif maupun konvensional. Famili yang mendominasi pada pada lahan dengan perlakuan biointensif maupun konvensional adalah Famili Araneidae., Rice is one of the important cereal crops which is used as a staple food for most of the world's population. Rice is classified as a food crop in the form of clump grass and has high adaptability to various environmental conditions. This study aims to determine the comparison of planthopper populations and spider populations in biointensive and conventional rice plantations in Darim Village, Terisi District, Indramayu Regency, West Java Province. The research method used is a direct observation method carried out by determining selected observation points that represent the middle of the rice field with a size of 10 m x 10 m. In each rice field, 100 observation grids are determined, the observation grid is 1 m2 in size. The data was processed and analyzed using the Microsoft Excel 2013 application. The results showed that the planthopper population was higher on rice plantations with biointensive treatment, the spider population was higher on rice plantations with biointensive treatment. The species found were Araneus inustus, Neoscona theisi, Atypena adelina, Pardosa pseudoannulata, Tetragnathidae sp., Oxyopes javanus, and Harmochirus sp. The dominant species found was Atypena adelina both on land with biointensive and conventional treatment. The family that dominates on land with biointensive and conventional treatment is the Araneidae family.
Keyword: dominasi, keragaman, musuh alami

Judul: Population Abundance of Rice Pests and Predators in the Jajar Legowo and Conventional Planting System in Baregbeg Village, Lakbok District, Ciamis Regency
Abstrak: Padi (Oryza sativa L.) merupakan salah satu tanaman pangan penting di Indonesia. Hama menjadi salah satu faktor pembatas dalam peningkatan produksi padi. Penelitian ini bertujuan untuk memperoleh informasi kelimpahan populasi hama pada pertanaman padi dengan sistem tanam jajar legowo dan konvensional di Desa Baregbeg, Kecamatan Lakbok, Kabupaten Ciamis, Jawa Barat. Penentuan tanaman contoh dilakukan dengan metode sampling diagonal pada empat subpetak dalam setiap petak pengamatan. Populasi hama dan musuh alami diamati mulai umur tanaman 3 minggu setelah tanam (MST) sampai 12 MST dengan interval satu minggu. Hama yang ditemukan pada sistem tanam jajar legowo dan konvensional adalah wereng batang cokelat (Nilaparvata lugens), keong mas (Pomacea canaliculata) dan walang sangit (Leptocorisa oratorius). Sedangkan predator yang ditemukan pada kedua sistem tanam adalah laba-laba serigala (Pardosa pseudoannulata) (Lycosidae) dan kumbang jelajah (Paederus fuscipes) (Staphylinidae). Secara umum kelimpahan hama pada kedua sistem tanam relatif rendah, namun ada kecenderungan populasi hama pada sistem tanam jajar legowo lebih rendah dibandingkan konvensional., Rice (Oryza sativa L) is one of the main food crop commodities in Indonesia. Plant pests are limiting factor in increasing crop production. This study aimed to get information pests population in rice cultivation using the legowo and conventional planting system in Baregbeg Village, Lakbok District, Ciamis Regency, West Java. The determination of the sample plants was carried out using a diagonal sampling method with four subplots in each plot. Pests and natural enemy populations were observed from the age of 3 weeks after planting (WAP) to 12 WAP with one week intervals. Pests found in the jajar legowo and conventional cropping systems were the brown planthoppers (Nilaparvata lugens), the golden snail (Pomacea canaliculate) and the rice bug (Leptocorisa oratorius). While the predators found in both cropping systems were the wolf spiders Pardosa pseudoannulata (Lycosidae) and the rove beetles Paederus fuscipes (Staphylinidae). In the general, the abundance of pests population in both planting system was relatively low, but there was a tendency for the pest population in the jajar legowo planting system to be lower than conventional.
Keyword: hama, populasi, predator, sistem tanam jajar legowo

Judul: Pembuatan Film Tipis Cu2ZnSnS4 sebagai Lapisan Penyerap Cahaya pada Sel Surya Menggunakan Metode Elektrodeposisi
Abstrak: Thin film of Cu2ZnSnS4 (CZTS) is an alternative semiconductor used as light absorber layer on solar cell. CZTS can replace silicon that commonly used as commercial semiconductor. The advantage of using CZTS as absorber layer is due to the abundance of its chemical composer on earth, and its high value of absorption coefficient. The absorber layer was made by using electrodeposition method on ITO glass substrates. The films were deposited at room temperature using potentiostatic mode with a potential of –1.05 V for 30, 45, and 60 minutes. After that, the films were annealed at two different temperatures, 180 ºC and 500 °C, for 45 minutes in N2/H2S atmosphere. Based on X-ray diffraction analysis, the polycrystalline thin film obtained fall into kesterite crystal phase. This type of crystal was obtained when the CZTS was annealed at 500 °C in H2S/N2 atmosphere. The value of optical band gap energy for the CZTS thin film was 2.2 eV with the film thickness about 1.228–6.366 μm. The sample of CZTS with electrodeposition time of 45 minutes and annealing temperature of 500 °C showed the best result and in conformity with absorber layers criteria for solar cells.
Keyword: semiconductor, ITO glass, CZTS thin film, electrodeposition