Judul: Pengaruh Kombinasi Kotoran Sapi, Pupuk Daun Silika, dan Pestisida terhadap Pertumbuhan dan Produksi Jagung (Zea mays) serta sifat Kimia Latosol, Dramaga
Abstrak: Maize is one of the agricultural crops that has similiar carbohydrate content with rice. The addition of foliar silica fertilizer is potential to prevent soil and water stress, pest attack, and to increase disease resistence as well as the growth and production of maize. This study was aimed to determine the effect of cow-dung manure, NPK fertilizer, foliar silica fertilizer and pesticides combinations on maize (Zea mays) growth and production and also on soil chemical properties of Latosol, Dramaga. The research was designed with randomized block design (RBD) with nine treatments and three replications. Treatment combinations was consisted of T0 (control), T1 (NPK), T2 (NPK + Foliar silica fertilizer), T3 (NPK + Pesticides), T4 (NPK + Foliar silica fertilizer + ½ Pesticides), T5 (Cow-dung manure + ½ NPK), T6 (Cow-dung manure + NPK + ½ Foliar silica fertilizer), T7 (Cow-dung manure + ½ NPK + pesticides), and T8 (Cow-dung manure + ½ NPK + Foliar silica fertilizers + ½ Pesticides). The results showed that generally cow-dung manure + ½ NPK (T5-T8) treatments indicated higher effect in promoting growth, nutrients uptake and corn cob production compared to treatments of NPK (T1-T4). The combination of NPK fertilizer, cowdung manure, foliar silica fertilizer and pesticides did not show significant effect statistically on soil total N, available P, and available Si. The exchangable potassium of soil tended to be higher in NPK combination (T1-T4) than cow-dung manure + ½ NPK combination (T5-T8). However, soil C-organic content in cowdung manure + ½ NPK combination (T5-T8) was higher than that in the NPK combination (T1-T4).
Keyword: Bogor Agricultural University (IPB), foliar silica fertilizer, cow-dung manure, maize

Judul: Pengaruh Pemberian Takaran Pupuk Amonium Sulfat terhadap Pertumbuhan, Produksi, Kadar dan Serapan Hara Tanaman Jagung (Zea mays L.) Pada Latosol Dramaga, Bogor
Abstrak: Maize (Zea mays L.) is one of food commodities and alternative forage that has been cultivated in Indonesia for a long time. The potential for post-harvest processing and food diversification encourage further development of maize cultivation. The aim of this study was to determine the effective doses of nitrogen fertilizer (ZA) application for growth, production, plant nutrients concentration and nutrient uptake of maize. The study was conducted in an experiment field using a Randomized Block Design, with eight treatments that were unfertilizer plot (Control), ZA-Standard, Urea-Standard and ZA-Tests in different doses of awarding (0.25 ZA, 0.50 ZA, 1.00 ZA, 1.50 ZA, 2.00 ZA). Each treatment was performed in three replications. Results showed that the highest growth of plant, maize production, N plant concentration and N uptake were achieved in treatment of 1.00 ZA, although it was not statistically different compared with the other treatments, except Control (unfertilizer plot) and 0.25 ZA treatment. The highest percentage of RAE (Relative Agronomic Effectiveness) was achieved by 1.00 ZA treatment, and its RAE value was increased up to 35.03% than ZA Standard.
Keyword: Bogor Agricultural University (IPB), production, plant nutrients concetration, maize, growth, ammonium sulfate

Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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