Judul: The influence of some nutritional conditions on nodulation of and nitrogen fixation by peanut plants
Abstrak: The objective of this work was to investigate the effects of nitrogen, phosphorus, calcium and magnesium on the growth and nitrogen fixation process in peanut plants under greenhouse conditions. The results of a series of preliminary experiments conducted to determine satisfactory growing conditions in terms of rooting medium and nutrient solution are reported. Efforts were made to determine a satisfactory ratio between quartz gravel and oyster shells for the rooting medium. Studies were also conducted to determine the stage of growth required for the development of adequate nodules. The effects of the addition of phosphorus and different forms of calcium along with the influence of magnesium on peanut growth and nodulation were studied. The effect of time of application of nitrogen on growth and nodulation also was studied as well as the influence of pH. It was found that the plants could probably be harvested between six and ten weeks of age. The best pH seemed to be about 5.8. Satisfactory levels of phosphorus, calcium and magnesium were determined. Oyster shells worked well as part of the substrate. It might have been better to have supplied the calcium in a form other than oyster shells because of the nutrients other than calcium found in the shells. An experiment was conducted using N isotopic nitrogen as a tracer to determine the effect of nitrogen on total growth, nodulation and nitrogen fixation by peanut plants. Low levels of nitrogen aided nodulation. not inhibit nodulation completely. Very high levels did Results of this experiment indicate that the addition of some nitrogen to some field grown peanut plants may be beneficial and profitable.
Keyword: Nitrogen, Phosphorus, Grown peanut plants

Judul: Pengaruh aplikasi pupuk organik dan pupuk anorganik terhadap pertumbuhan, produksi serta mutu benih kacang tanah (Arachis hypogaea L.)
Abstrak: The research was carried out at the Seed Science and Technology Laboratory, Soil Science Laboratory, Laboratory of Biology and Laboratory of Plant Ecology IPB Darmaga, Bogor from March to July 2006. The aim of the research was to study the effect of organic and inorganic fertilizers on growth, yield and seed quality of peanut (Arachis hypogaea L.). A single factor experiment with 9 treatments was arranged in a Randomized Block Design with 3 replications. The treatments consist of : recommended dosage of inorganic fertilizer (20 kg/ha Urea, 45 kg/ha TSP, 50 kg/ha KCI) = PI, Goat manure (5 ton/ha) = P2, combination of Goat manure (5 ton/ha) and inorganic fertilizer (20 kg/ha Urea, 45 kg/ha TSP and 50 kg/ha KCI) = P3, Rhizobium inoculant (40 g/2000 m2) = P4, combination of Rhizobium inoculant and inorganic fertilizer (10 kg/ha Urea, 22.5 kg/ha TSP and 25 kg/ha KCI) = P5, Biocompos (5 ton/ha) = P6, combination of Rhizobium inoculant (40 g/2000 m2) and Biocompos (5 ton/ha) = P7, MTM (200 g/ha) = P8, combination of MTM (200 g/ha) and inorganic fertilizer (20 kg/ha Urea, 22.5 kg/ha TSP and 25 kg/ha KCI) = P9. Results of the experiment showed that application of organic fertilizer and its combination with inorganic fertilizer could produce high seed yield similar to the recommended dosage of inorganic fertilizer, 17.30 -22.03 g /plant. However application of Rhizobium inoculant or Biocompos alone produced lower seed yield, 12.27 - 13.57 g /plant, than the recommended inorganic fertilization. MTM was the best treatment producing the highest seed yield and better performance where 4 of plant growth variables including branch number, leave width, dry and fresh weight of nodule significantly higher than those of the recommended inorganic fertilization. For seed viability and vigor as seed quality variables, there was no significant difference among the treatments.
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