Judul: Pengaruh aplikasi bakteri perakaran pemacu pertumbuhan tanaman pada tiga genotipe cabai (Capsicum annum L.) terhadap pertumbuhan tanaman serta kejadian penyakit penting cabai
Abstrak: In Indonesia, chilli was an important vegetable commodity refer to production area as well as it’s value, but production of chilli in Indonesia still very low. The low production was caused by a lack of proper cultivation techniques, seed quality, and pest and plant disease. Important disease that can decrease the production of chilli includes antrachnose disease, bacterial wilt, mosaic and mottle virus in chilli. The disease controlling effort that were recently developed and relatively safe for the environment, using Plant Growth-promoting Rhizobacteria (PGPR). The objective of this study was to determine the effect of PGPR usage, that were P. fluorescens PG01 isolates, B. polymixa BG25 and a mixture of both isolates (PG01 + BG25) against agronomic characters and incidence of important diseases in the three genotypes of chilli (IPB C5, C10 IPB, and Kopay) on the field. The experiment was performed from February until November, 2009 on farmer land were located on Desa Cibatok I, Kecamatan Cibungbulang, Kabupaten Bogor. The experiment was arranged in split plot design, were randomly treated with bacterial group as main plots and genotypes as subplots. Four levels main plots were PGPR treatments isolates PG01, BG25, PG01 + BG25, and without PGPR treatment as a comparison. The three subplots were C10 IPB, C5 IPB, and Kopay. In the experiment there were 12 treatment combinations, each treatment consisted of three replications, so there are 36 experimental units. Each experimental unit consisted of 20 plants, with a total 720 plants were tested. PGPR treatments significantly influenced the plant height and number of branches, but gave no significant effect on leaves number. The highest growth improvement on vegetative phase was occurred by the mixed bacterial treatment (PG01 + BG25). IPB C10, C5 genotypes and varieties of IPB Kopay have different agronomic characteristics measured on plant height, number of branches and number of leaves. PGPR treatment did not affect significantly to crop production and disease incidence (antraknosa, bacterial wilt, TMV, CMV, and ChiVMV). Antrachnose infections most commonly found in Kopay varieties, while the bacterial wilt infection occurs more frequently in genotypes IPB C5.
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Judul: Pengaruh Aplikasi Starter Solution Pada Tiga Genotipe Cabai (Capsicum Annuum L.) Terhadap Pertumbuhan Tanaman serta Kejadian Penyakit Penting Cabai
Abstrak: TRIYANI DUMARIA. Pengaruh Aplikasi Starter Solution pada Tiga Genotipe Cabai (Capsicum annuum L.) terhadap Pertumbuhan Tanaman serta Kejadian Penyakit Penting Cabai. Dibimbing oleh SRI HENDRASTUTI HIDAYAT dan MUHAMAD SYUKUR. Permasalahan budidaya tanaman cabai dapat terjadi mulai dari fase benih sampai fase pembentukan buah. Beberapa masalah penting yang dapat merugikan komoditas ini antara lain kualitas benih, gangguan hama dan penyakit tanaman, dan teknik budi daya yang kurang tepat. Untuk menanggulangi masalah penyakit tersebut di atas dapat dilakukan langkah-langkah pengendalian, misalnya dengan memperhatikan kesuburan tanah melalui aplikasi pupuk dan menggunakan beberapa genotipe cabai yang resisten. Salah satu metode pemupukan selain pupuk organik adalah aplikasi starter solution atau larutan pupuk pemula. Tujuan penelitian ini adalah mengamati karakter agronomi dan kejadian penyakit utama pada tiga genotipe tanaman cabai (Kopay, IPB C10, dan IPB C5) yang diberi perlakuan starter solution dengan konsentrasi yang berbeda (0 g/l, 15 g/l, dan 30 g/l). Dalam penelitian ini digunakan rancangan petak terbagi (split plot design) rancangan acak kelompok dengan starter solution sebagai petak utama dan genotipe cabai sebagai anak petak. Tiga taraf petak utama yaitu konsentrasi 0 g/l, 15 g/l, dan 30 g/l. Tiga taraf anak petak yaitu genotipe IPB C5 dan IPB C10, serta varietas Kopay. Terdapat sembilan kombinasi perlakuan, masing-masing perlakuan terdiri dari tiga kelompok, sehingga terdapat 27 satuan percobaan. Masing-masing satuan percobaan terdiri dari 20 tanaman, dengan jumlah keseluruhan adalah 540 tanaman uji. Konsentrasi starter solution selama enam minggu pengamatan tidak memberikan pengaruh yang nyata terhadap beberapa komponen fase vegetatif tanaman yang mencakup jumlah daun dan tinggi tanaman, tetapi berpengaruh nyata terhadap jumlah cabang dan waktu antesis. Walaupun demikian perlakuan starter solution dengan konsentrasi 15 g/l dan 30 g/l dapat meningkatkan komponen fase vegetatif tanaman. Dapat disimpulkan bahwa dua genotipe (IPB C5 dan IPB C10) dan satu varietas (Kopay) cabai yang digunakan memiliki karakter agronomi yang berbeda berdasarkan pengukuran jumlah daun, jumlah cabang, dan tinggi tanaman. Potensi produksi genotipe IPB C5 lebih tinggi dibandingkan genotipe IPB C10 dan varietas Kopay. Konsentrasi starter solution tidak memberikan pengaruh yang nyata terhadap kejadian penyakit. Perkembangan penyakit sangat ditentukan oleh genotipe cabai. Genotipe IPB C5 lebih banyak terinfeksi oleh Colletotrichum spp. dan Erwinia carotovora, sementara genotipe Kopay lebih banyak terinfeksi oleh CMV dan ChiVMV. Kejadian penyakit antraknosa, CMV dan TMV pada genotipe IPB C10 cenderung lebih rendah dibandingkan kedua genotipe yang lain.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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