Judul: Pengendalian Gulma Padi Sawah dengan Herbisida Berbahan Aktif Bispyribac Sodium
Abstrak: One of the main problems on increasing rice production is weeds. The objective of this research was to determine the effectiveness of bispyribac sodium herbicide to control weed in paddy field. The experiment was conducted in Cibanteng village, Bogor regency, West Java from November 2012 to February 2013. The research was arranged at randomized block design with four replications which consisted of eight bispyribac sodium treatments i.e: 50 ml ha-1, 100 ml ha-1, 150 ml ha-1, 200 ml ha-1, 250 ml ha-1, 300 ml ha-1, manual weeding and no weeding. The result showed that the application of bispyribac sodium herbicide at a dose of 50 ml ha-1 to 300 ml ha-1 could control Ludwigia octovalvis, Echinocloa crus-galli, Fimbristylis miliacea, Eclipta prostata and Cynodon dactylon weed species. Bispyribac sodium application at all dosages only caused lightweihgt Phytotoxicity Syimptoms on rice plants
Keyword: weed, rice, dosage, bispyribac sodium herbicide

Judul: Dampak Aplikasi Herbisida Sodium Bispiribak pada (Bispyribac sodium) Tanaman Padi Sawah terhadap Residunya dalam Tanah dan Tanaman Padi (Jerami dan Beras)
Abstrak: Herbicides are agricultural chemicals used to control weeds or to inhibit plant growth normally. The use of chemicals is considered much more efficient, cheaper and faster because it saves labors. Weeds are wild plants that can be reduce the rice yield if not controlled effectively. The cost of weed control in rice plant reaches 50% of total production cost. This study purposed to analyze herbicide residue in soil, straw and yield (rice), and to analyze economic comparison of rice cultivation with and without the use of herbicides. Data are obtained from the result of research conducted in the rice planting field at Cijujung Village, Cibungbulang District, Bogor and at Agrochemical Materials Residue Laboratory, Agricultural Environment Research Center, Bogor. The result of this study shows that based on analysis of Bispyribac sodium herbicide residue in three samples, that are soil, straw and yield (rice), the highest herbicide concentration is found in straw sample. The Maximum Residue Limit of Bispyribac sodium herbicide is 2 ppm, the concentration of herbicide residue in rice samples are still below the Maximum Residue Limit and still within safe limit to consume. Based on the analysis of farming, comparative cost analysis for rice cultivation with Bispyribac sodium 0.5 l/ha treatment give more effective influence and more profitable for both energy and economically than rice cultivation with manual treatment.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology