Judul: Potensi bakterisida senyawa metabolit Penicillium spp. terhadap Ralstonia solanacearum penyebab penyakit layu bekteri pada cabai
Abstrak: Penelitian ini bertujuan untuk mengkaji secara in-vitro dan in-vivo potensi senyawa metabolit Penicillium spp. sebagai bakterisida Ralstonia solanacearum penyebab penyakit layu bakteri pada cabai. Penelitian dilaksanakan di Laboratorium Bakteriologi Tumbuhan Departemen Proteksi Tanaman Fakultas Pertanian Institut Pertanian Bogor mulai Februari hingga Mei 2009. Isolat yang digunakan antara lain Bacillus subtilis B-12, Pseudomonas fluorescens Pf P-24 dan Ralstonia solanacearum Rs-32 koleksi Laboratorium Bakteriologi Tumbuhan Departemen Proteksi Tanaman IPB, lima isolat Penicillium spp. (Penicillium brevicompactum, P. chrysogenum, P. hirsutum, P. italicum dan P. viridicatum) koleksi IPB culture collection, Departemen Biologi Fakultas MIPA IPB. Dari lima isolat tersebut, tiga diantaranya (P. chrysogenum, P. brevicompactum dan P. viridicatum) mampu menghambat pertumbuhan R. solanacearum. Pada uji dual culture yang paling efektif menghambat pertumbuhan R. solanacearum adalah senyawa metabolit dari P. brevicompactum dengan waktu inkubasi selama 3 minggu dan pada konsentrasi 1,5% senyawa metabolit tersebut paling efektif menekan populasi R. solanacearum pada media cair. Pada uji in-vivo, baik pada perlakuan dengan atau tanpa aplikasi senyawa metabolit P. brevicompactum, tanaman tidak menunjukkan gejala penyakit layu bakteri. Namun perendaman benih menggunakan senyawa metabolit tersebut mampu meningkatkan daya berkecambah benih dengan pertumbuhan tanaman yang lebih bagus.
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Judul: Potensi streptomyces sp. sebagai agens pengendali biologi ralstonia solanacearum penyebab penyakit layu pada tanaman cabai
Abstrak: Penelitian ini bertujuan untuk menapis isolat Streptomyces sp. Yang dapat digunakan sebagai agens pengendali biologi R. Solanacearum pada tanaman cabai dan menentukan formulasi Streptomyces sp. yang baik dalam mengendalikan R solanacearum. Metode yang digunakan cawan tuang dan cawan sebar. Sebanyak 13 isolat dari 21 isolat berhasil diremajakan diperoleh Streptomyces sp. PD 14-19 yang mempunyai daya hambat yang konstan terhadap R solanacearum pada biji in vitro. Kemampuan Streptomyces sp. PD 14-19 menghambat kejadian penyakit mengindikasikan bahwa isolat tersebut berpotensi sebagai agens pengendali biologi R solanacearum pada tanaman cabai.
Keyword: Streptomyces, Ralstonia solanacearum

Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite