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: Pemberian kombinasi jerami, pupuk daun silika, dan insektisida terhadap pertumbuhan dan produksi padi, serta sifat kimia Latosol Situ Gede, Dramaga, Bogor
Abstrak: Rice is the major carbohydrate source for Indonesian. Rice demand as staple food increase continuously, so it an effort to increase rice production is needed. The objectives of this research was to examine the application of straw, foliar silica fertilizer, insecticide, and their combinations on growth, yield, and nutrient uptake of rice plant, also soil chemical properties of Latosol Situ Gede, Dramaga, Bogor. This research used randomized block design (RBD) with nine treatment combinations and three replications, namely T0 (Control), T1 (NPK), T2 (NPK + Foliar Silica Fertilizer), T3 (NPK + Insecticide), T4 (NPK + Foliar Silica Fertilizer + ½ Insecticide), T5 (½ NPK + Straw), T6 (½ NPK + Straw + Foliar Silica Fertilizer), T7 (½ NPK + Straw + Insecticide), and T8 (½ NPK + Straw + Foliar Silica Fertilizer + ½ Insecticide). The results showed that the treatment of inorganic fertilizer and rice straw material combined with foliar silica fertilizer and or pesticide showed significantly higher effect compared with Control (unfertilized plot or no pesticide plot, T0), but among the treatments did not indicate significant difference. Generally, the effect of NPK treatments (T1-T4) on the number of filled rice grains per panicle, the weight of rice grains, N, P, K, Si uptake of rice plant, soil organic C, exchangeable potassium, and soil available Si were not significant difference with the treatments of 1/2NPK+rice straw (T5-T8). This showed that the application of rice straw could substitute 50% of inorganic fertilizer (NPK). Total- N, available-Si, and K uptake tended to be higher in the treatments of compared with the treatments of NPK.
Keyword: Bogor Agricultural University (IPB), yield., straw, foliar silica fertilizer, rice plant, insecticide

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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