Judul: Beberapa aspek penularan bakteri layu (pseudomonas solanacearum E. F. Smith) melalui umbi kentang dan kemungkinan penanggulannya
Abstrak: Deteksi jumlah bibit kentang yang terinfeksi bakteri layu dilakukan dengan cara mengisolasi patogen dari sampel bibit yang diambil dari beberapa sentra produksi kentang di Jawa Barat, Jawa Tengah, dan Jawa Timur. Dari hasil penelitian diketahui bahwa intensitas serangan Bakteri layu pada pertanaman kentang tercatat sebesar 17, 3 persen (kisaran 15,56 _sampai 16,75 persen) dan jumlah bibit yang terinfeksi patogen tersebut berkisar dari 5,58 sampai 6,68 persen. Umbi bibit ini merupakan sumber utama inokulum bakteri layu pada daerah yang belum terinfeksi. Semakin tinggi persentase bibit sakit semakin banyak bagian pertanaman kentang yang terkena serangan bakteri layu. Deteksi bakteri layu dari bibit kentang dilakukan dengan melihat gejala dalam umbi bibit, isolasit bioasai dan inkubasi bibit. Cara-cara ini sangat efektif untuk mendeteksi bakteri layu pada umbi bibit. Hasil deteksi tertinggi sampai terendah berturut-turut diperoleh dengan cara isolasi (38,44 - 51,55 persen), melihat gejala dalam umbi bibit (17,78 persen), bioasai (12,22 persen), dan inkubasi bibit (3,37 persen).
Keyword: Field crops;, Incubation tubers;, Bioassay;, Bakterisida;, Bogor Agricultural University;

Judul: Pengujian ketahanan beberapa varietas kentang (Solanum tuberosum L.) terhadap penyakit layu bakteri
Abstrak: Tujuan penelitian ini adalah untuk mengetahui tingkat ketahanan beberapa varietas kentang terhadap serangan Pseudomonas solanacearum dan melihat hubungan antara gejala layu yang tampak pada tanaman dengan persentase umbi terinfeksi. Varietas kentang yang diuji adalah Kennebec, DTO 28, Granola, Nooksack, Norchip, Russet Burbank, Astarte, Eba, Atlantic, MS 42.3 serta Desiree. Percobaan dilakukan di dalam rumah plastik di Subbalithor Cipanas dan inokulasi dilakukan dengan cara pelukaan akar. Tingkat ketahanan tanaman kentang dibagi ke dalam empat kelompok berdasarkan nilai intensitas serangan pada pengamatan terakhir. Jika intensitas serangan O -20 % digolongkan tahan, 21 -40 % digolongkan agak tahan, 41 -60 % digolongkan agak rentan dan 61 -100 % digolong­kan rentan. Dari 11 varietas yang diuji terdapat empat varietas kentang yang tahan yaitu Nooksack, Granola, Astarte dan DTO 28, empat varietas yang agak tahan yaitu MS 42.3, Eba, Atlantic dan Norchip, dua varietas agak rentan yaitu Russet Burbank dan Kennebec serta satu varietas yang ren­tan yaitu Desiree. Intensitas serangan berkorelasi positif dengan per­sentase umbi terinfeksi maupun persentase kehilangan hasil.
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Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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