Judul: Frekuensi Kunjungan Elaeidobius kamerunicus Faust. pada Bunga Betina dan Efektivitasnya terhadap Pembentukan Buah Kelapa Sawit
Abstrak: Elaeidobius kamerunicus (Coleoptera: Curculionidae) is the most effective pollinator of oil palm. This research aimed to study visiting frequency of E. kamerunicus on female flowers and its effectiveness to oil palm’s fruit set. Fix sample method was used to observe visiting frequency of E. kamerunicus. Observations were conducted in 10 minutes in the morning (09:00-10:00 am), afternoon (13:00-14:00 pm), and evening (16:00-17:00 pm). The environmental parameters were measured to know its effect to visiting frequency the weevil. The weevil mostly visited the flower in the morning (109 weevils/10 minutes), decreased at afternoon (26 weevils/10 minutes), and in the evening (13 weevils/10 minutes). The average visiting frequency of weevil to the female flowers was 50 individuals/10 minutes. Pollen load of the male weevil was 1440 pollen, while the female loaded about 635 pollen. The pollen viability on male and female body of the weevil were 8.65% and 7.90%, respectively. The average of oil palm’s fruit set in Sukamaju Plantation was 77.87%. The visiting frequency of weevil to the female flowers was positively related to the oil palm’s fruit set.
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Judul: Frekuensi Kunjungan Kumbang Penyerbuk Elaeidobius kamerunicus pada Bunga Betina Tanaman Kelapa Sawit di Perkebunan PTPN VIII Cimulang, Bogor
Abstrak: Elaeidobius kamerunicus had known as weevil pollinator which had important role in oil palm pollination. Application of the weevil can increase of oil production and fruit set. Visiting frequency of E. kamerunicus determine to pollination of palm oil. This study aimed to know visiting frequency of E. kamerunicus on oil palm’s female flowers age six years. Visiting frequency of E. kamerunicus was observed by fixed sample method in 4x10 minutes using three time blocks, which is in the morning (09.00-10.00 am), afternoon (01.00-02.00 pm), and evening (04.00-05.00 pm). Observations were conducted in 10 days on 10 different trees. Environment parameters which were temperature, humidity, wind speed, and light intensity were measured. A result showed that the highest weevil visitation frequent (130 weevils/10 minutes) to female flowers occurred in the morning. Visiting frequency in afternoon (28 weevils/10 minutes) and in evening (31 weevil/10 minutes) were lower than in the morning. The weevil’s visiting frequency related significantly to temperature and humidity.
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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