Judul: Kajian Tablet Aktinomiset Endofit terhadap Pengendalian Penyakit Hawar Daun Bakteri dan Peningkatan Pertumbuhan Tanaman Padi
Abstrak: Bacterial leaf blight (BLB) is an important disease in rice plants that cause production to decrease. Endophytic actinomycetes has been known to have an important role in enhancing rice plant’s growth. This research aimed to assess the capability of endophytic actinomycetes based product in controlling BLB disease, to improve rice plant’s growth, and to identify bacteria causing the BLB disease. Selected endophytic actinomycetes (AB131, AB131-2, and PS4-16) biomass were produced using modified molasses-soybeans medium and formulated into tablet. Biological product application was done by seed coating and soaking the roots of seedlings. Identification of bacteria causing the BLB disease was done using API iii 20 NE kit. Application of endophytic actinomycetes tablet at 200 g ha-1 in the field was able to increase plant height by 4% higher than control. Endophytic actinomycetes tablet could reduced BLB disease severity up to 74%. Based on morphological and biochemical characters, bacteria causing BLB disease which was isolated from the affected leaves in the field was indicated as Sphingomonas paucimobilis. Result of Koch's postulates test showed that S. paucimobilis produced similar symptoms with BLB disease in rice plant.
Keyword: bacterial leaf blight, biological product, endophytic actinomycetes, rice, Sphingomonas paucimobilis

Judul: Studi Keefektifan Formulasi Spora Bacillus Subtilis Sebagai Agens Pengendali Hayati Penyakit Hawar Daun Bakteri dan Hawar Pelepah Serta Pemicu Pertumbuhan Pada tTanaman Padi:
Abstrak: In controlling rice diseases, most farmers still rely on chemical pesticide as the solution. However, because of high cost and negative effects of chemical pesticide, biocontrol is one of alternative solutions. Bacillus subtilis is a model of biocontrol agents to control many plant diseases, because its ability to produce antimicrobial and plant growth promoting substances. This research aimed to examine the effectiveness of Indonesian isolate of B. subtilis spore formulation through seed treatment and foliar spray with different frequencies and concentrations to control bacterial leaf blight (Xanthomonas oryzae pv. oryzae) and sheath blight (Rhizoctonia solani) diseases of rice. The influence of the formulation application to plant growth and other microbes was evaluated. The experiment was conducted in greenhouse and field with factorial experimental design. Seed treatment, concentration and frequency of application and its interaction effectively suppressed bacterial leaf blight and sheath blight diseases, increased plant growth and reduced yield loss. The concentration at 2% is recommended for applying the formulation. The interval of application at 1 and 2 week showed equal effect to disease suppression and increased yield. Application of B. subtilis spore formulation increased yield of Ciherang, Cisantana, and Sintanur as much as 26,3%, 18,5%, and 15,4% respectively. Application of the formulation gave no significant effect to microbe diversity in the field.
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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. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular