Judul: Respon Pengisian Gabah pada Padi yang Mengalami Cekaman Suhu Tinggi
Abstrak: Global warming could imply negative impact on reducing productivity of rice. The aim of this research was to study grain filling response of rice using some rice varieties grown under high temperature stress. The research was conducted at the University Farm IPB, Babakan Sawah Baru, Dramaga, Bogor. Research was perfomed using split plot design with two factors: temperature (main plots) and varieties of IR64, Ciherang, Jatiluhur, and Way Apo Buru (subplot). The results showed that the increasing of average maximum temperature of 4.07°C form 35.44°C to 39.51°C gave the same response of grain filling on each variety. Moreover it was significantly different on the maximum height, full grain at primary tip, and the weight of 1 000 grains at secondary base. High temperature has tendency on the weight of full grain at secondary tip total full grain at primary tip.
Keyword: global warming, grain filling dispersion, grain weight

Judul: Keragaan Pertumbuhan dan Produksi Beberapa Varietas Padi pada Dua Kondisi Suhu yang Berbeda
Abstrak: The objective of the research was to get the information about rice growth performance and production rice at two different temperature conditions and to study the effects of high temperature stress on production of rice. An experiment was conducted at Experimental Field Cikabayan, University Farm, IPB, Bogor. Rice was planted at two conditions, at the optimum temperature (in the open ground) and at the high temperature (in the green house). The experiment was arranged in a randomized completely block design with three replications. The extremely high tempetature will increase sterility in grain. The results showed that there were significant differences among the varieties evaluated for all traits observed. The results also showed that time of heading, time of flowering and length of penicle were not affected by temperature conditions. The traits of number of productive tiller, time of heading, time of flowering, height at generative stage, the leaf greenness at generative stage, time of harvesting, number of filled grain, number of total grain, weight of filled grain, and weight of 1000 grain were affected by genotypes x temperature conditions. Based on this study, the varieties that could maintain their yield under high temperature conditions are Situ Patenggang, Mekongga, IR-64, Kalimutu, and IPB 6R. The varieties could be used as genetic material in breeding program.
Keyword: tropical conditions, rice, high temperature

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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