Judul: Growth and Production of Sorghum Varieties of Samurai 1 Second Ratun by Treatment with Urea Fertilizer Dosage and Harvest Age
Abstrak: Sorgum merupakan tanaman serealia yang tumbuh di daerah tropis serta lahan marginal yang tahan terhadap kekeringan. Percobaan ini bertujuan mengevaluasi pertumbuhan dan produksi biomassa varietastanaman sorgum (Sorgum bicolor (L.) Monech) samurai 1 berasal dari turunan benih penjenis pada ratun kedua dengan dosis N dan umur panen. Penelitian ini menggunakan rancangan acak kelompok faktorial dengan 3 taraf urea, yaitu P1 (100 kg urea ha-1 ), P2 (200 kg urea ha-1 ), dan P3 (300 kg urea ha-1 ), dan 3 umur panen, yaitu T1 60 hari setelah panen (HSP), T2 65 HSP dan 70 HSP dengan 4 ulangan kelompok. Hasil penelitian menunjukkan bahwa tidak terdapat perbedaan nyata pada interaksi antar perlakuan terhadap pertumbuhan dan produksi sorgum. Hasil biomassa terbaik sebesar 63,80 ton ha-1 ditunjukkan oleh perlakuan 200 kg urea ha-1 dan 70 HSP. Kesimpulan dari penelitian ini adalah sorgum Samurai 1 yang dipupuk 200 kg urea ha-1dan dipanen pada umur 70 HSP menghasilkan pertumbuhan dan produksi biomassa tertinggi., Sorghum is a cereal plant that growsin the tropics and marginal landsthat are resistant to drought. This experiment was aimed to evaluate the growth and biomass production of the samurai 1 (Sorghum bicolor (L.) Monech) harvested at derivative time at second regrowing ratoon combined with N. This study used a factorial randomized design with 3 levels of urea, namely P1 (100 kg urea ha-1 ), P2 (200 kg urea ha-1 ), and P3 (300 kg urea ha-1 ), and 3 harvest if time, namely T1 60 days after harvest (DAH), T2 65 DAH and 70 DAH with 4 replicate groups. The results showed that there was no significant difference in the interaction between treatments on growth and production of sorghum. The best biomass yield of 63.80 tons ha-1 was indicated by the treatment of 200 kg urea ha-1 and 70 DAP. The conclusion of this study was that Samurai 1 sorghum fertilized with 200 kg urea ha1 and harvested at 70 DAP resulted in the highest growth and biomass production.
Keyword: Harvest age, production, sorghum, urea

Judul: Growth and Production of Sorghum Plant Varieties F1 Samurai 1 in the Ratun 1 With Urea Level and Harvesting Age
Abstrak: Penelitian ini bertujuan mengkaji pengaruh dosis pupuk N dan umur panenterhadap pertumbuhan dan produksi biomassa sorgum Samurai 1. Penelitian inimenggunakan rancangan acak kelompok pola faktorial terdiri dari 3 taraf dosis pupuk urea yaitu P1 (100 kg urea/ha), P2 (200 kg urea/ha), dan P3 (300 kg urea/ha), serta 3 taraf umur panen yaitu T1 (60 hari setelah panen (HSP)), T2 (65 HSP), T3 (70 HSP) dengan setiap kombinasi perlakuan diulang 4 kali sebagai kelompok. Hasil penelitian menunjukkan bahwa pengaruh interaksi dosis pupuk urea dan umur panen terlihat pada parameter jumlah daun, berat kering total, berat kering batang dan berat kering malai per hektar dengan nilai tertinggi diperoleh dari kombinasi perlakuan dosis pupuk urea 200 kg urea/ha dan umur panen 70 HSP. Perlakuan dosis pupuk urea sebagai faktor tunggal tidak berpengaruh nyata pada parameter yang diamati. Sementara itu umur panen sebagai faktor tunggal berpengaruh nyata terhadap tinggi tanaman dan kadar brix dengan nilai tertinggi ditunjukkan oleh perlakuan umur panen 70 HSP. Kesimpulan dari hasil penelitian ini adalah sorgum Samurai 1 yang dipupuk 200 kg urea/hadan dipanen pada umur 70 HSP menghasilkan pertumbuhan dan produksi biomassa tertinggi., This research aimed to evaluate the effect of N fertilizer application and harvesting age on growth and biomass production of sorghum Samurai 1. This study use factorial block randomized design composing of 3 dose levels of urea fertilizer, namely P1 (100kg urea/ha), P2 (200 kg urea/ha), and P3 (300 kg urea /ha)), and 3 harvesting age level, namely T1 60 day after harvest (DAH), T2 65 DAH and T3 70 DAH with 4 group replications. The results showed that interaction between treatments of urea fertilizer dosage and harvesting age influenced (P>0.05) leave numbers, total dry weight, stem dry weight and panicle dry with the greatest value obtained from combination of 200 kg urea/ha and harvesting age of 70 DAH. Treatments of urea fertilizer dosage as a single factor had no significant effects on the observed parameters. Meanwhile, harvesting age as a single factor had significant effects on plant height and brix levels with the highest value indicated by the harvesting age treatment of 70 DAH. It is concluded that application of 200 kg urea/ha on sorghum Samurai 1 harvested at 70 DAH revealed the highest biomass production.
Keyword: growth, harvesting age, production, sorghum, urea fertilizer dosage

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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