Judul: Weevil Elaeidobius kamerunicus Faust Population in Oil Palm (Elaeis guineensis Jacq) at PTPN VIII Kebun Sukamaju, Cikidang, Sukabumi
Abstrak: High productivity of oil palm is affected bypollination. Elaeidobius kamerunicus is weevil pollinator that can increase fruit set of oil palm. Weevil population was influenced by natality, mortality, and migration. The objective of this research were to study weevil E. kamerunicus population and environmental factors on oil palm estate at Sukamaju, Cikidang, Sukabumi. Weevil population were observed by stratified random sampling method in male flowers were located at three blocks of the estate on Juny, August, and October 2010. Sex ratio of female and male weevil was counted. Relationship between environmental factors and weevil population were analyzed by Pearson correlation. The highest population of weevil occured in August.Weevil population at Sukamaju was lower than the minimum weevil population for optimum pollination. Sex ratio of female and male weevil during observation was 3:1. Rainfall has the highest effect to weevil population among parameters measured.
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Judul: Demography and Population of Elaeidobius kamerunicus Faust (Coleoptera:Curculionidae) as a Pollinator of Oil Palm (Elaeis guineensis Jacq) in PT. Agri Andalas Plantation, Bengkulu Province
Abstrak: Elaeidobius kamerunicus is an insect pollinator of oil palm. These weevil live and thrive in the male flowers of oil palm. The aims of the research were to study demography and population of E. kameunicus in male flower of oil palm. Demography study of the weevil were observed in the laboratory. One individual male and female of weevil were reared in the box, feeding by one spikelet of male flower. Observation of demographic study were conducted from 2nd day after rearing, until the weevil died. Populations of E. kamerunicus in oil palm plantations were measured by using a sampling method. We selected nine spikelet per bunch of male flower and counted the number of weevil per spikelet. The number of weevil per spikelet and number of spikelet per bunch were counted to determine the number of weevil per bunch. We counted the numbers of anthesis male flower per hectare to determine the number of weevil per hectare. Environmental parameters i.e temperature, humidity, light intensity, and rainfall were measured. The relationship between weevil population and environmental parameters were analyzed by Principal Component Analysis (PCA). Results showed that weevil E. kamerunicus tooks 14-17 days to grow from egg to imago. Statistics demography of the weevil were: generation time (T) was 19 days, gross reproduction rate (G) was 11 individuals, the net reproductive rate (Ro) was 5 individual and intrinsic growth rate (r) was 0.24. Population of the weevil on oil palm age 3 and 6 years were higher in January (41.102 individuals per hectare) and February (153.226 individuals per hectare). While, the lower population of the weevil were found in March (22.618 individuals per hectare) and April (98.693 individuals per hectare). In average, fruit set of oil palm age 3 and 6 years were 82,8% and 83,3%, respectively.
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Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix