Judul: Nematode Community in Carrot Cultivation Land and Its Relationship with Soil Microbial Population
Abstrak: Nematoda merupakan hama pengurang hasil bagi sebagian besar tanaman agronomi termasuk wortel (Daucus carota). Informasi mengenai keanekaragaman dan kepadatan populasi nematoda pada lahan wortel dengan membedakan kondisi kesehatan tanamannya belum banyak dilaporkan. Penelitian ini bertujuan mengidentifikasi komunitas nematoda tanah dan melihat korelasinya dengan populasi mikrob tanah. Sampel tanah diambil dari empat lahan pertanaman wortel yang di dalamnya terdapat tanaman yang sehat dan bergejala sakit. Identifikasi nematoda dilakukan dengan melihat ciri morfologinya. Hasil penelitian menunjukkan terdapat 30 genus nematoda pada lahan pertanaman wortel yang dikelompokkan ke dalam lima grup tropik. Kelimpahan nematoda per grup tropik di setiap lokasi berbeda nyata (P < 0,05), namun tidak berbeda nyata antar kondisi kesehatan tanaman. Berdasarkan indeks keragaman Shannon-Wiener, keanekaragaman nematoda di empat lahan pertanaman wortel masuk dalam kategori sedang (1 < H’ < 3). Nilai MI, PPI, dan SI berbeda nyata antar lokasi, namun tidak berbeda nyata antar kondisi kesehatan tanaman. Populasi bakteri tanah di empat lokasi dan dua kondisi tanaman tidak berbeda nyata (P > 0,05). Komunitas nematoda tanah memiliki korelasi yang lemah terhadap populasi mikrob tanah (nilai korelasi <0,5).
Keyword: diversity index, maturity index, plant health, soil food web

Judul: Identifikasi Nematoda Parasit Utama pada Wortel (Daucus carota L.) di Kabupaten Cianjur
Abstrak: Plant-parasitic nematodes are one of the casual pathogen of decreasing carrots production. This research was aimed to identify plant-parasitic nematodes that associated with carrots in Cianjur District. The infected tubers, carrot roots, and 100 ml soil sampels were taken from the infested field. Nematodes were extracted from soil and root samples by flotation-centrifugation and mist chamber techniques. Parasitic nematodes were identified based on their morphological characters. In addition, Meloidogyne sp. were characterized by the female perineal pattern. Six genera of plant-parasitic nematodes, that were Meloidogyne, Helicotylenchus, Pratylenchus, Rotylenchulus, Criconemoides, and Xiphinema were detected associated with carrot. Three species of Meloidogyne, that were M. incognita, M. arenaria, and M. javanica were identified.
Keyword: Bogor Agricultural University (IPB), perineal pattern, morphological characters

Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4