Judul: Keefektifan Agens Antagonis dalam Pengendalian Rebah Kecambah Cabai Merah
Abstrak: One of the major problems during cultivating of chilli is antrachnose disease. The cause of chili anthracnose can various as Colletotrichum acutatum, C. gloeosporoides, and Gloeosporium piperatum. Pathogens can cause seed decay, damping off, and anthracnose fruit rot. The objective of experiment is to evaluate the effectiveness of several antagonist agents in controlling damping off disease. The identification results show that the cause of anthracnose which can be isolated from the seeds and chilies are Gloeosporium piperatum. Antagonist agent Trichoderma harzianum (TH1), Gliocladium fimbriatum (G84), Bacillus subtilis (B12), and Pseudomonas fluorescens (P1) can inhibited the growth of pathogen colonies in vitro as 100%, 100%, 95.43%, and 39.83%. In the in vivo test is known that isolates TH1, G84, B12, and P1 is very effective (100%) in the controlling of chili damping off. Both of single treatment or combination treatment antagonist agents were not different significantly to control the damping off disease. The fourth of antagonist agents are very potential in controlling the damping off disease of red pepper germination
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Judul: Keefektifan Kombinasi Plant Growth Promoting Rhizobacteria dan Unsur Mikro dalam Pengendalian Penyakit Antraknosa pada Cabai Merah
Abstrak: Anthracnose is an important disease on chili pepper caused by Colletotrichum sp.. The pathogen can attack from early stage of fruit until harvesting. The losses due to this disease ranging from 40-80%, and even up to 100%. Plant Growth Promoting Rhizobacteria (PGPR) is a group of bacteria which growth and colonize arround roots area (rhizosphere), that has some beneficial effects in plant, such as growth promoting and as biological control agent. The purpose of this research was to determine the effectiveness of PGPR consisting of Pseudomonas fluorescens and Bacillus polymixa, combined with micronutrients MnSO4 0.05%, ZnSO4 0.05%, MnSO4 0.05%+ ZnSO4 0.05%, and commercial fertilizer Growmore 10-55-10, to suppress anthracnose disease on chili pepper. This experiment used a Randomized Block Design (RBD) with 6 treatments and 3 blocks. Variables measured were seed germination, plant height, number of leaves, and the severity of anthracnose disease. The results showed that the treatments with PGPR and or combined with micronutrients could not suppress the disease severity comparing with conventional control measure. Combining with micronutrients (MnSO4) increased the PGPR capability on plant growth promoting effects.
Keyword: Bogor Agricultural University (IPB), Plant Growth Promoting Rhizobacteria., micronutrients, chili, Anthracnose

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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