Judul: The Effectiveness of Combination between Promoting Growth Bacteria, Bradyrlzizobiu11l and Nutrition Sources in Affecting of Soybean Vegetative and Reproductive Growth
Abstrak: In intensive agriculture, continuous application of anorganic fertilizer can decrease soil fertility. The purpose of this research was to evaluate : (1) the effectiveness of combination between Bradyrhizobium and PGPR in influencing nutrient uptake, vegetative growth and yield of soybean in the field, and (2) the effect of biofertilizer in liquid form and solid form in combination with various nutrition sources on growth and production. The experiment was carried out using randomized block design with 3 factors. The first factor was Bradyrhizobium application with 2 levels i.e. without Bradyrhizobium (RO), and with Bradyrhizobium (Rl). The second factor was PGPR application with 3 levels i.e. without PGPR (PO), PGPR in liquid form (PI), and PGPR in solid fonn (P2). The third factor was nutrition sources application with 4 levels i.e. without nutrition sources (NO), with 100% recommendation dosage of NPK fertilizer (Nl), 100% recommendation dosage of compost (N2), and 50% dosage of NPK fertilizer + 50% dosage of compost (N3). Every unit had 3 replications, so that the total experiment were 72 units. The result showed that the application between Bradyrlzizobium in combination with PGPR improved nutrition uptake, plant growth and grain yield of soybean. The higher increase of total macro and micro nutrition uptake was recorded from the combined treatment between Bradyrhizobium and solid PGPR (RIP2) which an increase by about 66,20%, and 41,40%, followed by combination between Bradyrhizobium and liquid PGPR (RIPl) by 39,17% and 16,20% as compared to the control. The combination RIP2 increased number of branches, plant dry weight, root dry weight, number of nodule, dry weight of nodule, number of pod, and seed dry weight/plant by approximately 31,33%, 50,87%, 48,17%, 207,68%, 185.66%, 78,7%, 83,69%, respectively compared to the control. The best treatment was resulted by RIP2N2, the combination between Bradyrhizobium, solid PGPR and compost 100% dosage. This treatment had the significant in increasing the number of branches, fresh weight, plant dry weight and root dry weight by 101,64%, 159,30%, 118,42%, 115,36% respectively. This treatment also caused the improvement of number of pod, and seed dry weight/plant by 163,64% and 174,73%. These result showed that the biofertilizer produced from PGPR have synergical effect with Bradyrhizobium to improve nutrient absorption, growth and yield of soybean.
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Judul: he Effectiveness of Methylobacterium spp Isolate to Increase Production of Soybean (Glycine max L.).
Abstrak: Methylobacterium spp is one of bacteria that produces phytohormon which have potency to stimulate seed germination and plant growth to increase plant production. The aim of the research was to evaluate effectiveness of Methylobacterium spp and rates of fertilizer to increase soybean yield in field production. The research consisted of two experiments : (1) The effect of Methylobacterium spp application technique and rates of fertilizers on the soybean growth and production, (2) Effectiveness of Methylobacterium spp application technique to soybean yield in field production. The experiments were conducted in July 2012 to March 2013. The first experiment used Split Plot Design. The main plot was Methylobacterium spp application technique consisted of without Methylobacterium spp, seed soaking and spraying Methylobacterium spp at 15 and 30 days after planting (DAP), seed soaking and spraying Methylobacterium spp at 15 DAP and soaking seeds with Methylobacterium spp. The subplot was the rates of fertilizer N, P and K consisted of 0, 25, 50, 75 and 100% recommended rate of fertilizer (Rate of recommendation : 50 kg N ha-1, 100 kg P2O5 ha-1 dan 100 kg K2O ha-1). The second experiment used randomize complete block design. The experiment used two cultivation technologies are Methylobacterium spp and farmers. Methylobacterium spp cultivation technology used the best result of the experiment 1, seed soaking and spraying Methylobacterium spp at 15 DAP and 75% recommended rate of fertilizer. The farmers technology used 100% recommended rate of fertilizer. The results showed that seed soaking and spraying Methylobacterium spp at 15 DAP and 15+30 DAP significantly increased the age and total of flowering, total of pod , total of seed and weight of seed than without isolate application. The rate of fertilizer 50, 75 and 100% gives the same response at height of plant 56 DAP, total branches per plant and weight of seed per plant but significantly increase than without application. The seed soaking and spraying Methylobacterium spp technology and rate of fertilizer 75% significantly increased total production and seed vigour of soybean compared with the farmers technology.
Keyword: bacteria, cultivation technology, rates of fertilizer N, P and K

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.