Judul: Keanekaragaman dan kelimpahan artropoda pada pertanaman bawang daun dan wortel yang ditanam secara monokultur dan tumpangsari
Abstrak: Green onion is a seasonal crop with ecological conditions that are frequently changed. This makes unstable condition between populations of pests and natural enemies (predators, parasitoids and pathogens). Brief observations in the field found that pest infestations on carrot fields were frequently low. Results of several studies indicated that carrot could attract parasitoids of insect pests. The objective of this research was to study the diversity and abundance of arthropods on green onion and carrot grown in monoculture and intercropping. Experiment with four treatments and four replications was set in randomized complete block design. The treatments were: P1) green onion grown in monoculture; P2) green onion sprayed with carrot leaf extract; P3) green onion and carrot grown in intercropping; and P4) carrot grown in monoculture. Observations of arthropods were conducted by setting pitfall traps and yellow sticky traps weekly. Collected arthropods were identified by using Introduction to The Study of Insects, Insects of Australia, and Hymenoptera of The World. Data were analyzed with Shanon- Wienner index, and analysis of variance by using Minitab 17. The result indicated that the culture system of green onion and carrot did not affect diversity of arthropods for the whole season. The arthropod community on green onion and carrot was dominated by Liriomyza spp. (Diptera: Agromyzidae), ants (Hymenoptera : Formicidae), and Collembola.
Keyword: Bogor Agricultural University (IPB), intercropping., green onion, diversity, carrot, Arthropods

Judul: Keanekaragaman dan Parasitisasi Parasitoid pada Pertanaman Sayuran di Bogor
Abstrak: In an agricultural area, agroecosystem could influence diversity and parasitism of parasitoids as natural enemies of insect pests. A survey to learn diversity and rate of parasitism of insect pests by parasitoids had been conducted in several agricultural fields with different criteria, such as farming practice (organic and convensional), species richness of vegetable crops (5-8 sp. and 9-15 sp.) and different crop ages (3, 4 and 5 months), in Bogor from August to October 2012. By making a 50 steps line transect for every field, eggs, larvae and pupa of insect pests were collected monthly, reared in laboratory and incidence of parasitism were calculated. The results showed that there were no significant differences on diversity and rate of parasitism based on three criterias used. However, based on the diversity of vegetable plant species around, the rate of parasitism in field with less plant species diversity (5-8 sp.) was higher than the field with more vegetable plant species diversity (9-15 sp.). These results might be caused by the limited number of samplings conducted and other potential factors such as surrounding habitat, seasonal fluctuation, and complex interactions between species in agroecosystem.
Keyword: 

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