Judul: Fungi Mikoriza Arbuskula dan Keberadaan Inangnya Dapat Memperbaiki Pertumbuhan Kedelai Organik
Abstrak: Soybean (Glycine max (L) Merrill) is one of the food crops as a source of vegetable protein. The purpose of this research was to determine the effect of rates of arbuscular mycorrhizal fungi (AMF) and the existence of sorghum, as an AMF host, on the growth and production of organic soybean. AMF was applied to each planting hole of soybean based on four different rates of 0, 1, 2, 2.5 g AMF hole-1. The existence of sorghum plant on the soybean plots, consisted of the presence and absence of sorghum in the plot. Both treatments were combined in nested design. Rates of AMF, in general, affected the growth and some yield components of soybean. Maximum growth was achieved at the rate of 2.08 g AMF hole-1. Soybean production was expected to increase in rate of more than 2.5 g AMF hole-1. Soybean productivity based on AMF rates were not significantly different, they were 1.35, 1.08, 1.04, and 1.15 ton ha-1 for 0, 1, 2, 2.5 g AMF ha-1, respectively. Without sorghum, soybean productivity was higher than that with the presence of sorghum, they were 1.25 and 1.05 ton ha-1, respectively. Improper placement of sorghum in the plot might have resulted in competition with soybean
Keyword: Sorghum bicolor, root infection, Glomus, Gigaspora, Acaulospora

Judul: Aplikasi Sembilan Produk Fungi Mikoriza Arbuskula Pada Tanaman Sorgum Varietas Samurai 1
Abstrak: Fungi Mikoriza Arbuskula merupakan simbiosis mutualisme antara fungi dan sistem perakaran tanaman tingkat tinggi untuk meningkatkan penyerapan unsur hara dalam tanah dan mengefisienkan pemakaian pupuk kimia. Penelitian ini bertujuan untuk menguji aplikasi sembilan produk fungi mikoriza arbuskula terhadap pertumbuhan dan produksi biomassa tanaman sorgum (Sorghum bicolor (L.) Moench) varietas samurai 1. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan 10 perlakuan dan 10 ulangan. Perlakuan kontrol menggunakan 100% dosis pupuk NPK dan perlakuan P1-P9 menggunakan 50% dosis pupuk NPK+20 gram produk fungi mikoriza arbuskula. Parameter yang diamati berupa: tinggi tanaman, diameter batang, jumlah daun, luasan daun, panjang malai, berat segar, berat kering, dan rasio daun dan batang. Data yang diperoleh dianalisis menggunakan Analisys Of Variance (ANOVA) dengan uji lanjut Duncan pada taraf uji 95%. Hasil penelitian menunjukkan bahwa mikoriza produk 6 dan produk 7 mampu menyamai perlakuan kontrol pada setiap parameter, sedangkan pada berat kering malai menunjukkan hasil yang lebih tinggi (p<0.05). Pemberian 20 gram produk mikoriza P6 ataupun P7 mampu menggantikan 50% dosis pupuk NPK yang digunakan Kata kunci: biomassa, pertumbuhan, produk FMA, pupuk NPK, tanaman sorgum., Arbuscular mycorrhizal fungi are a mutualism symbiosis between fungi and the root system of higher plants to increase the absorption of nutrients in the soil and make efficient use of chemical fertilizers. This study aimed to examine the application of nine products of arbuscular mycorrhizal fungi to the growth and biomass production of sorghum (Sorghum bicolor (L.) Moench) variety samurai 1. This study used a completely randomized design (CRD) with 10 treatments and 10 replications. Control treatment used 100% dose of NPK fertilizer and treatment P1- P9 used 50% dose of NPK fertilizer + 20 gram arbuscular mycorrhizal fungi product. Parameters observed were: plant height, stem diameter, number of leaves, leaf area, panicle length, fresh weight, dry weight, and leaf to stem ratio. The data obtained were analyzed using Analysis of Variance (ANOVA) with Duncan's further test at the 95% test level. The results showed that mycorrhizae product 6 and product 7 were able to match the control treatment on each parameter, while the dry weight of panicles showed significantly higher results (p<0.05). Giving 20 grams of P6 or P7 mycorrhizal products can replace 50% of the dose of NPK fertilizer used.
Keyword: Biomassa, Pertumbuhan, Produk FMA, Pupuk NPK, tanaman sorgum

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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