Judul: Perkembangan Kolonisasi Ektomikoriza dan Pertumbuhan  Semi Dipterocarpaceae dengan Pemberian Asam Oksalat dan  Asam Humat serta Inokulasi Ektomikoriza
Abstrak: Dipterocarpaceae merupakan salah satu jenis tanaman penting di Indonesia. Namun, kesinambungan produksinya belum dapat dicapai karena kesulitan pengadaan bibit. Hal ini disebabkan 0leh musim buah yang tidak teratur dm sifat bijinya yang recalcitrant. Kesul itan ini mendorong dilakukannya berbagai upaya untuk meningkatkan kualitas bibit, antara lain dengan aplikasi ektomikoriza dan asam organik.
Keyword: 

Judul: Respon pertumbuhan stek shorea salanica BL. terhadap pemberian asam humat dan inokulasi cendawan ektomikoriza
Abstrak: Pohon-pohon Dipterocarpaceae merupakan komponen utama hutan hujan tropika basah dan oleh karenanya hutan tersebut sering disebut hutan Dipterocarp. Kesulitan penyimpanan biji dan masa panen yang sering terganggu oleh keadaan lingkungan menyebabkan ketersediaan bibit seringkali tidak sesuai dengan kebutuhan. Pohon-pohon jenis Dipterocarpaceae memiliki hubungan yang erat dengan fungi ektomikoriza. Berdasarkan penelitian Santoso (1988), inokulasi fungi ektomikoriza pada anakan Dipterocarpaceae dapat meningkatkan penyerapan unsur hara makro dan mikro yang menyebabkan peningkatan pertumbuhan anakan Dipterocarpaceae. Menurut Senn (1990) asam humat mempunyai beberapa fungsi antara lain memperbaiki struktur tanah, memperbaiki aerasi dan daya ikat kation, mengaktifkan mikroba, mempengaruhi cara bekerjanya enzim, meningkatkan pertumbuhan akar, dan mencegah klorosis. Penelitian ini bertujuan untuk mengetahui respon pertumbuhan stek Shorea selanica terhadap pemberian asam humat dan inokulasi cendawan ektomikoriza dari jenis Scleroderma columnare. Dari penelitian ini diharapkan pemberian asam humat dapat meningkatkan asosiasi pertumbuhan cendawan dan akar sehingga tanaman mampu menyerap unsur hara yang ada di dalam tanah secara optimal yang dapat meningkatkan pertumbuhan stek Shorea selanica, selain itu diharapkan pula agar bibit yang dihasilkan mampu beradaptasi dengan baik di lapangan dan sudah mengandung mikoriza. Penelitian ini dilaksanakan di Lab. Bioteknologi Kehutanan dan Lingkungan-Pusat Penelitian Bioteknologi IPB, Lab. Silvikultur SEAMEO-BIOTROP, serta Balai Penelitian Tanah dan Agroklimat (Balittanak)-Bogor. Bahan-bahan yang digunakan meliputi zeolit, stek Shorea selanica, asam humat (Humega ™ 6%), spora Scleroderma columnare, Hiponex merah, insektisida, larutan Twin 80, dan aquades. Sedangkan alat-alat yang digunakan adalah bak plastik, polybag dan kantong plastik putih kapasitas 1 kg, alat tulis, alat ukur, alat hitung, timbangan analitik dan elektrik, karung, oven, kamera, stirrer, suntikan, mikroskop binokuler dan mikroskop compound, alat penyiram, gelas ukur, pipet, botol film, gelas preparat, cawan petri, paranet, gunting dan program SAS...
Keyword: 

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
Keyword: