Judul: Pengaruh pemberian kompos batang pisang terhadap pertumbuhan semai Jabon (Anthocephalus cadamba Miq.)
Abstrak: Addition of compost could increase plant growth. Compost derived from banana stem could be added as admixture in nursery medium for growing jabon seedlings. This research studied the effect of addition of various composts on the growth of jabon (Anthocephalus cadamba Miq.) seedlings. The objectives of this study were: (1) to test the quality of compost produced from banana stem in improving the growth of jabon seedlings, and (2) to learn the effect of composts from banana stem and other composts existing in the market (Ofer, Cocopeat, Guano and Andam) on the growth of jabon seedlings. Growth media being used in this research were soil, sand and compost with proportion of 2:1:1(v/v/v). As control, soil and sand with proportion of 3:1 (v/v) were used. Experiment was in Completely Randomized Design (CRD) with 6 treatments. The treatments being given were control; and addition of Ofer, Guano, Andam, Cocopeat and Compost of banana stem. Each treatment was replicated 6 times and each replication consisted of 4 jabon seedlings. Variables being observed were seedling height, seedling diameter, total dry mass (biomass), shoot root ratio, media weight, media compactness and results of tissue analysis. Addition of compost increased height and diameter growth of jabon seedlings. Addition of banana stem compost and Ofer was the better treatment for increasing total dry weight (biomass) of jabon seedlings with percentage of increase of 177.3% and 77,3% as compared with control. Addition of compost could decrease the total weight of media. Compact media were found in control media; and media with addition of compost Ofer, banana stem and Andam. According to results of tissue analysis, jabon seedlings which were grown in banana stem compost could absorb N as much as 18 gr; P as much as 2.6 gr; and K as much as 15.8 gr, whereas with Ofer could absorp N as much as 14.4 gr, P as much as 1.5 gr, and K as much as 9.2 gr. Therefore, compost of banana stem was better as compared with composts which are circulated in market (Ofer, Guano, Cocopeat, and Andam) in increasing the growth of jabon seedlings. In its application, compost of banana stem and Ofer could be added to planting media so that growth of jabon seedling could be better.
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Judul: Pertumbuhan Semai Jabon (Anthocephalus cadamba Roxb Miq) Pada Media Pasca Penambangan Batubara Yang Diperkaya Fungi Mikoriza Arbuskula, Limbah Batubara dan Pupuk NPK
Abstrak: One of the problems created by coal mining activities is the progressive increase of critical land area size and environmental damage, which are among other things in the form of worsening physical, chemical and biological properties of soils which lead to decrease of soil fertility and disturbed plant growth. Growth and nutrient absorption by Jabon seedlings have been studied in terms of their respond toward application of Arbuscular Mycorrhizal Fungi (AMF), coal waste, and soil media being used after coal mining operation. The experiment was designed as factorial completely randomized design, comprising 3 treatment factors, namely, species of AMF inoculants (control, Glomus sp., and Gigaspora sp.), growth media (control, mixture of 15% south Kalimantan coal, and mixture of 15 % Jambi coal) and concentration of NPK fertilizer (control, 2 gram/polybag, and 4 gram/polybag) with 10 replications, so that in total, there were 270 experimental units. Results showed that interaction between AMF, growth media and fertilizer had significant effects on parameters of diameter increment, shoot biomass, root biomass, total dry weight, index of planting stock quality, and percent of AMF colonization. Parameter of height increment and number of Jabon seedling leaves were affected by interaction between AMF and fertilizer. Treatment combination of AMF inoculants, coal powder, and NPK fertilizer was able to increase the concentration and absorption of nutrients N, P and K. The three treatments combination showed positive correlation between increase in concentration of nutrients N, P and K; and shoot biomass of Jabon seedlings.
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Judul: Penghitungan Nilai Resistor Pengganti Menggunakan Nilai Eigen dan Vektor Eigen Ortonormal dari Matriks Laplace
Abstrak: Nilai resistor pengganti dapat dihitung dengan menggunakan nilai-nilai eigen dan vektor-vektor eigen ortonormal dari matriks Laplace yang diperoleh dari hubungan suatu gambar jaringan resistor dalam bentuk graf. Karena matriks Laplace adalah suatu matriks Hermite yang real dan simetrik, juga merupakan matriks semidefinit positif maka nilai-nilai eigen dari matriks Laplace adalah real taknegatif dan vektor-vektor eigennya adalah real yang saling ortogonal. Dalam tulisan karya ilmiah ini dibahas lima bentuk jaringan resistor (resistors network) yang hingga dalam bentuk graf : 1. Jaringan resistansi dua-simpul. 2. Jaringan satu dimensi dengan kondisi batas bebas. 3. Jaringan satu dimensi dengan kondisi batas periodik. 4. Jaringan dua dimensi dengan kondisi batas bebas. 5. Jaringan dua dimensi dengan kondisi batas silindrik.
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