Judul: Uji Viabilitas Formulasi Bakteri A6 sebagai Agens Hayati dan Aplikasinya pada Tanaman Padi
Abstrak: Invasive disease caused by microbial pathogens are one of the problem that could decrease the productivity of rice production in Indonesia. A6 formulation consisted of Bacillus cereus II.14, B. firmus E.65, and Pseudomonas aeruginosa C.32b has tested to inhibit the growth of Pyricularia oryzae (in vivo) and Rhizoctonia solani (in vitro). This research was aimed to observe the stability of A6 formulation as a potential biological agents through viability test of bacterial cell using talcum powder during 3 months of storage in room temperature. The results showed that the viability of A6 formulation was stable up to 3 months of storage. Result of the antagonism test showed that A6 formulation is significantly inhibit the growth of R. solani by 41.67%. The in vivo test of A6 formulation after two months of storage also showed the potential inhibition for the growth of pathogenic P. oryzae, R. solani, and Xanthomonas oryzae by 59.20%, 69.44%, and 48.78%, respectively.
Keyword: X. oryzae, R. solani, P. oryzae, cell viability, biological agents

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.
Keyword: 

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