Judul: Kajian Resistensi Lima Varietas Sorgum terhadap Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae)
Abstrak: Sorgum merupakan serealia sumber karbohidrat yang dapat dijadikan sebagai substitusi beras. Di tempat penyimpanan, biji sorgum banyak mengalami masalah yang disebabkan oleh hama gudang, salah satunya Rhyzopertha dominica (F.). Kerusakan yang diakibatkan serangga hama gudang mencapai 30%. Tujuan dari penelitian ini adalah mengetahui resistensi lima varietas sorgum terhadap serangan R. dominica selama masa penyimpanan. Penelitian ini dilaksanakan di Laboratorium Entomologi SEAMEO-BIOTROP. Lima varietas sorgum yang diujikan yaitu Numbu, Lokal Bandung, Lokal Wonogiri, CTY-33, dan B-76. Uji resistensi dilakukan dengan menginfestasikan 40 imago R. dominica ke dalam stoples plastik bervolume 1000 ml yang berisi 100 gr biji sorgum selama 14 hari, kemudian seluruh imago dikeluarkan lagi, kemudian seluruh wadah diinkubasi selama 42 hari. Antara hari ke-42-80 seluruh imago F1 yang muncul dikeluarkan kembali dari biji sorgum dan dihitung. Tingkat resistensi biji sorgum didasarkan pada Indeks Kerentanan Dobie (IKD). Hasil penelitian menunjukan bahwa varietas CTY-33 relatif lebih resisten daripada varietas lainnya dengan nilai IKD 3.814, tingkat kekerasan biji sorgum diketahui sebagai faktor resistensi.
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Sorghum, Rhyzopertha dominica, Resistance, Dobie index of susceptibility

Judul: Kajian Resistensi Lima Varietas Sorgum terhadap Rhyzopertha dominica (F.) (Coeloptera: Bostrichidae).
Abstrak: Sorghum is a cereal crop source of carbohydrate that can be used as a substitute for rice. Sorghum seed storage facing many problems caused by stored product pest, one of them is Rhyzopertha dominica (F.). Damage to sorghum seed caused by insect pests reach 30%. The objective of this research was to evaluate the resistance of five sorghum varieties against R. dominica during storage. Research was conducted at Entomology Laboratory SEAMEO- BIOTROP. Bioassays were conducted by infesting 40 adults of R. dominica to 1000 ml plastic jar containing 100 g sorghum seed for 14 days and then taken out from the jars. All the jars, then incubated for 42 days. Five sorghum varieties tested were Numbu, local Bandung , Local Wonogiri, CTY-33, and B-76. Between day 42-80, all F1 adults came out from the seeds were counted. Resistance level then determined by Dobie Index of Susceptibility (DIS). Weight loss from each variety were also calculated. Research result showed that CTY-33 was the most resistant variety with DIS value of 3.814, seed hardness seemed to be the resistance factor.
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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