Judul: Litterfall Production and Semi Aerobic Decomposition of Leaf Mahogany (Swietenia macrophylla King).
Abstrak: Mahogany (Swietenia macrophylla King) is one of the most valuable tropical tree in the world, due to their potential use in the development of artificial forest such as a forest city. Mahogany trees produced enough litter, however the litter was not used maximally. These litter can be used as a compost fertilizer after composting decomposition. This research aims were to assess the productivity of litter mahogany, to evaluate the effect of leaf size mahogany and addition of EM4. Mahogany litter productivity was measured using litter-trap method. Litter leaf fall was trapped by 1m x 1m sample plot. There were 24 sample plots placed under mahagony stands. The plot height was 50 cm above the soil surface. Semi aerobic decomposition was set up in bucket with nets. The cover of the bucket had 3 holes with a diameter of 2 mm for air ventilation and maintaining moisture. Temperature and pH were monitored weekly. The experiment was set up with two factors completely randomized design. The first factor was the size of litter with 3 different sizes i.e. 25-30 cm2 (P1), 7-10 cm2 (P2) and 0,7-1 cm2 (P3). The second factor was microbes (EM4) addition with 3 different volume i.e. 5 ml (K1), 10 ml (K2) and 20 ml (K3). The microbes (EM4) was prepared with 100 g of sugar in 1 liter water. Data were analyzed using the F test at the 95% confidence level. If there was significancy, then continued with DMRT. Enumeration of bacterial groups was conducted using 4 selective media i.e. MRSA media for Lactobacillus sp, SCA for Actinomycetes sp, sistrom’s media for photosynthetic bacteria, and PDA for yeast. Productivity of litterfall was determined from the average of collected litter. The reduction rate of semi aerobic litter decomposition were used to show the decomposition rate. Total concentration organic carbon, nitrogen, phosphate and potash were analised at the end of experiment. The results showed that the highest litter productivity of mahogany at sixteen weeks of composting periode, it was 89.24 g/m2/week in May-June (the dry season). The highest litter productivity was found in tree no 2 (with 33 cm in diameter, 20 m in height, and 5.5 m crown thickness). Total productivity was 1415 g/m2/week. The results showed that P3K2 treatment was the most efficient decomposition process, it was shown at seven week of composting periode. This treatment was combination of 0.7-1 cm2 litter size and addition of 10 ml EM4.
Keyword: Litterfall production of mahogony, semi aerobic decomposition

Judul: Seed Viability of Mahogany (Swietenia macrophylla King.) at Different Temperatures and Storage Time
Abstrak: Swietenia macrophylla atau mahoni berdaun lebar adalah jenis eksotik dari Amerika Tengah dan Selatan. Pohon ini memiliki berbagai manfaat dan kegunaan. Penyimpanan benih masih menjadi permasalahan yang utama, karena dapat menurunkan viabilitas benih. Daya simpan benih dipengaruhi oleh kondisi benih dan kondisi lingkungan. Oleh karena itu, penelitian ini bertujuan menguji pengaruh suhu dengan masa simpan terhadap viabilitas benih mahoni serta menghitung Indeks Mutu Bibit (IMB). Percobaan dilakukan menggunakan Rancangan Acak Kelompok (RAK) faktorial dengan 2 faktor. Faktor pertama terdiri atas empat taraf perlakuan suhu yaitu suhu ruang (24 °C), 4 °C, 0 °C, dan -20 °C. Faktor kedua yaitu perlakuan masa penyimpanan yang terdiri atas 4 taraf yaitu 1 sampai 4 minggu, dengan interval 1 minggu. Hasil penelitian menunjukkan bahwa interaksi suhu dan masa simpan memengaruhi jumlah daun, jumlah akar primer dan sekunder, nisbah tajuk akar, dan bobot basah total bibit mahoni. Benih mahoni yang disimpan pada suhu kamar selama 1 minggu menghasilkan viabilitas benih terbesar, dengan benih mahoni yang disimpan pada suhu ruang selama 1 minggu menghasilkan viabilitas benih tertinggi sebesar 80%, IMB dengan nilai 0,03 ̶ 0,04., Swietenia macrophylla or big-leaf mahogany is an exotic species from Central and South America. This tree has various benefits, so it’s used as an industrial plantation forest and afforestation in Indonesia. However, seed storage of mahogany is a major problem in cultivation, because it can reduce seed viability. The storability of seeds is influenced by seed and environmental conditions. Therefore, this study aimed to examine the effect of temperatureand storage time on the viability of S. macrophylla seeds and to calculate the Seedling Quality Index (SQI). The experiment was carried out using a factorial Randomized Block Design (RBD) with 2 factors. The first factor has consisted of four levels of temperature treatment, namely room temperature (24 °C), 4 °C, 0 °C, and -20 °C. The second factor was the storage period treatment which consisted of 4 levels, namely 1 up to 4 weeks, with 1-week intervals. The results showed that the interaction between temperature and storage time affected the number of leaves, primary and secondary roots, root/shoot ratio, and total wet weight of S. macrophylla seedlings. Mahogany seeds that were stored at room temperature for 1 weekresulted in the highest seed viability, with SQI of 0,.03 - 0,.04.
Keyword: Bobot basah, indeks mutu bibit, mahoni berdaun lebar, viabilitas

Judul: Kriteria Osilasi Untuk Pertidaksamaan Diferensial Taklinear Orde Dua
Abstrak: dimana pertidaksamaan dibatasi pada suatu selang [T,oo) dengan T?:O, aCt) kontinu pada selang [0,00) dan j(u) mempunyai turunan pertarna yang kontinu pada selang (-00,00) dengan uj(u) >0 untuk u;"O. Dengan menggunakan Asumsi A dan Asurnsi B, diperoleh beberapa teorerna ten tang kriteria osilasi untuk pertidaksamaan diferensial taklinear orde dua.
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