Judul: Infektivitas dan efektivitas beberapa galur Rhizobium sp pada Calopogonium caeruleum Hemsl
Abstrak: Penelitian ini bertujuan untuk membandingkan infektivitas dan efektivitas delapan galur Rhizobium pada C. caeruleum pada perbedaan perlakuan pH media tumbuh, temperatur, dan konsentrasi Al dalam media tumbuh. Untuk mencapai tujuan penelitian dan memperhatikan kriteria infektivitas dan efektivitas, telah dilakukan empat percobaan yaitu (1) pengaruh pH larutan hara terhadap infektivitas dan efektivitas beberapa galur Rhizobium pada C. caeruleum, pembuatan kurva kerapatan populasi Rhizobium, PH media tumbuh dan (2) (3) pengaruh temperatur terhadap kerapatan populasi beberapa galur Rhizobium, dan media tumbuh terhadap kerapatan. (4) pengaruh konsentrasi Al dalam populasi beberapa galur Rhizobium. Percobaan pertama dilaksanakan selama 70 hari bertempat di rumah kaca menggunakan media pasir steril. Percobaan kedua, ketiga, dan keempat masing-masing dilaksanakan selama 9 hari di Laboratorium. Galur-galur Rhizobium yang digunakan diberi kode R1, R2, R3, R4, R5, R6, R7, dan R8. Taraf pH media tumbuh adalah 4.5 dan 6.0. Taraf temperatur adalah 28°C, 34°C, dan 40°C. Sedangkan taraf konsentrasi Al adalah 0, 20, 40 dan 80 uM. Pengamatan dilakukan terhadap morfologi sel dan koloni Rhizobium, rapat optik dan kerapatan populasi Rhizobium, perubahan PH media tumbuh, komponen pertumbuhan tanaman, komponen pembintilan, dan komponen penambatan N. Pengambilan contoh tanaman dilakukan pada 10, 25, 40, 55, dan 70 hari setelah inokulasi (HSI). Sebagai tolok ukur utama yang digunakan untuk infektivitas adalah banyak bintil akar dan untuk efektivitas adalah bobot N total daun. ...
Keyword: Rhizobium, Calopogonium caeruleum

Judul: Pengaruh Beberapa Media Pembawa terhadap Efektivitas Rhizobium japonicum
Abstrak: Percobaan ini dllaksanakan dengan tujuan untuk mengetahui pengaruh enaq media pemba\va terhadap efektivitas rhizobium japonicum, dan mencari liemung~inan meinbuat inokulant dari bahan yang murah dm mudah diperoleh apabila gambut tidak tersedia. Percobaan menggunakan Rancangan Acak Kelompok dengan tujuh perlakuan dalam tiga ulangan, masing-masing untuk periode simpan 2, 9 dan 16 minggu. Perlakuan-perlakuan tersebut adalah; (1) kontrol, (2) serbuk sabut kelapa (SAB), ( 3 ) gambut air taviar (GAT), (4) gambut pasang surut (GPS), (5) kompos merang padi (MER), 6) kompos lamtoro gung (LAM), dan (7) serbuk gergaji Albizzia falcata(ALB). Peubah yang diamati adalah bobot basah dan bobot kering bintil akar, bobot hasah dan bobot kering tajuk, bobot basah dan hobot kering akar pada saat tanaman berumur 42 hari; tinggi tanaman pads saat berbunga 50%; produksi biji kering tiap petair dan bobot 100 biji. Analisis data dilaikukan dengan Uji-F dan Uji Jarak Berganda Duncan.
Keyword: 

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