Judul: Induksi pembungaan dan biologi bunga pada tanaman jahe putih besar (Zingiber officinale Rosc.)
Abstrak: Rhizome is usually used for propagation of large white ginger (Zingiber officinale Rosc). The major restriction of using rhizome as material for propagation is pests and diseases spread through rhizome, such as bacterial wilt, leaf pock, rhizome flea, and rhizome flies. True seed is considered as one of potential alternatives breakthrough to be developed. However, true seed production is hindered by limited flower production. Therefore this research was aimed at studying flower induction and flowering biology of large white ginger var. Cimanggu 1. The research consisted of two steps; first, flower induction with low media water content and use of paclobutrazol as two separate experiments and the second was observation on flowering biology. The experiments for flower induction was arranged in completely randomized block design with one factor, i.e. 1) controlling water content of the media at: 48-49, 45-46, 42-43, 39– 40, 36-37, and 33-34 %; and 2) using paclobutrazol as soil drench: 0, 20, 40, 60, 80, 100 ppm. Observation on flowering biology includes pollen viability and stigma receptivity. Result of experiment indicated that low media water content did not induce flowering, but 100 ppm paclobutrazol as soil drench produced more flowers at earlier stage. Pollen viability was highest at 45 min. after blooming (MAB) and declines sharply after 60 MAB. Stigma receptivity presumably occurred at the time when secretion was produced and the stigma tip was transparant, however the precise time is yet to be investigated further.
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Judul: Respon Pertumbuhan Jahe Putih Kecil (Zingiber officinale var. Amarum) terhadap Pemupukan pada Media Tanpa Tanah.
Abstrak: Small ginger cultivation still have an issue, it is Ralstonia solanacearum bacteria that causes quite large yield loss. The character of Ralstonia solanacearum is soil borne and can survive a long time in the soil, so that the study was conducted using media without soil which is a mixture of coconut coir dust (cocopeat) and rice husk. The research aims to determine the growth response of small white ginger in a mixture of coconut coir media (cocopeat) and rice husk media, with the intake of certain fertilizers. The experiment was conducted in Greenhouse of Balai Penelitian Tanaman Rempah dan Obat (Balittro), Bogor, West Java Cimanggu from September 2014 to February 2015. The study using a randomized Complete Block Design Group (RKLT) one factor with six treatments and four repetition. Treatment in the form of a complete fertilizer dose applications, among others; P0 (0 g / l) as a control, P1 (1 g / l), P2 (2 g / l), P3 (3 g / l), P4 (4 g / l), and P5 (5 g / l) , The results showed that the dosage of fertilizers affect plant height, number of leaves, leaf length, height and number of tillers but had no effect on stem diameter, whereas for production factor variable dosage of fertilizer affect root length, number of roots, rhizome weight, fresh weight biomass and the dry weight of biomass but did not affect the fresh weight and dry weight of root. Small white ginger can grow well in the mixture rice husk and coconut coir dust (cocopeat) media, a dose that produces the best rhizome weight is 3 g/l (P3).
Keyword: white small ginger, rice husk, cocopeat

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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