Judul: Effectiveness of Arbuscular mycorrhiza fungi and natural phosphorus fertilizer utilization on growth, biomass and asiaticoside production of asiatic pennywort (Centella asiatica l. Urban) on Andosol.
Abstrak: Consumer demands for safe and healthy food require more advanced agricultural production that is free of chemical contaminant and heavy metals harmful for health. Arbuscular mycorrhiza fungi (AMF) as biological agent in several species of plants are now starting to get much attention. AMF are very important which is involved in various biogeochemical of nutrients in order to ensure plant fitness as well as terrestrial ecosystem stability. Currently, it is important to find the alternative materials that can be used as sources of phosphorus due to the need of lower cost, environmentaly friendly, and easily available. Rock phosphate and cow bone meal are some of the natural materials that can be used as a phosphorus sources alternative. Public interest increased to medicines derived from natural products including asiatic pennywort (Centella asiatica L. Urban), and required the availability of adequate of raw material supplies and quality. Cultivation of raw material to produce standardized of asiatic pennywort is not known completely, so its need research support. This dissertation is based on four experiments with the main objective was to find the role of AMF and its relation to the use of natural phosphorus fertilizer on growth, development, biomass, and asiaticoside production of asiatic pennywort. Results of the researches showed that many different types of AMF spores extracted from rhizosphere of asiatic pennywort. Symbiosis AMF with asiatic pennywort was quite compatible that is indicated by high to very high root colonization relatively, and the effectiveness to increase yield and nutrient uptake of N, P, K. Isolates mixture of AMF was more effective than single spores in increasing biomass of asiatic pennywort. Rock phosphate and cow bone meal are the source of natural P that are potential to substitute for synthetic fertilizers, especially on acid soils. Inoculation of AMF increased leaf dry weight, shoot dry weight, and total dry weight by 14.7, 17.1, and 18.0% respectively. Inoculation of AMF significantly increased the growth, nutrient uptake, biomass, and asiaticoside content of asiatic pennywort. Different inoculation timing of AMF did not significantly affect all the variables of growth, development, and plant biomass, but increased asiaticoside production. Timing of inoculation at seedling stage and transplanting resulted on the highest leaf dry weight, shoot dry weight, and total dry weight 4.88 g, 15.22, and 18.05 g plant-1 or increased 77.6, 70.1, and 88.2% respectively, than without AMF (control) plants. Rock phosphate and cown bone meal did not significantly affect growth, development, and plant biomass but provide positive effect on the high roots colonization of AMF 79.4 and 82.0% respectively, than control.
Keyword: 

Judul: Nutrient and asiaticocide biosynthesis diagnoses using plant tissues analyses to compose fertilizer recommendation and harvest system on asiatic pennywort (Centela asiatica).
Abstrak: Balanced and rational application of fertilizer can be achieved when the status and dynamics of the nutrients in the soil and in the plant’s requirements for the nutrients are taken into consideration for maximum production. This approach may be well-applied and profitable if the fertilizer recommendation is based on soil and plant tissue tests, but the result of plant tissues test is not worthly when there is no result of correlation and calibration. The disertation is composed based on the results of four experiments which aims are: 1) the exact leave tissue used for nutrients status NPK of asiatic pennywort diagnose, 2) the NPK status and NPK dosage of fertiilizer for maximum asiaticocide bioactive of asiatic pennywort, 3) the exact harvest system of asiatic pennywort for maximum production of asiaticocide bioactive, 4) to achieve the information of asiatic pennywort agriculture technique with maximum production of asiaticocide that fulfill the MMI condition (1.20 %) and 5) to know the range of NPK required for asiatic pennywort. The research was conducted at the research station Gunung Putri, Pacet, Cianjur district. The exact harvest of asiatic pennywort at high altitude for high production of aimplisia and asiaticocide bioactive are at 5 months of age. The exact leave for the diagnose of nutrient status in determining NPK fertilizer for asiatic pennywort is the firts (1st) leaf of 5 months for NPK analyses. The vegetative growth charactheristic that may be analysed, which is used as asiaticocide production type on the application of NPK fertilizer, are total amount of leaf, leaf’s length, leaf’s width, total amount of primary vine, and total amount of section. The best regression model between the NPK nutrient concentrations of leave samples and the relative results of asiatic pennyworth plant (dry weight of simplicia and asiaticocide weight) are quadratic. The critical level of NPK nutrients of asiatic pennywort leaves for dry weight production of simplicia are 2.97 % N , 0.23 % P, and 3.98 % K. The critical level of asiaticocide production are at 2.98 % N, 0.23 % P and 3.85 % K. Based on quadratic regression model, the NPK fertilizer dosages for the maximum production of dry weight simplicia are 2.57 g N/plant, 0.72 g P/plant and 2.69 g K/plant. The NPK concentrations of leaves samples are 4.33 N%, 0.32 P%, and 4.96 K%. The concentrations of NPK fertilizer of sample leaves are 3.58 % N, 0.39 % P and 4.84 % K. The system for harvesting frequency of ratoon of asiatic pennywort, applied every 5 months (R3) produce the highest fresh weight (28.88 t/ha), dry weight (18 t/ha) and asiaticocide weight (25.8 kg/ha) compared with the other harvests system. Best fertilizing recommendation based on quadratic regression pattern of calibration test results from N< P, and K, the standards achieved for N, P, and K leaf’s nutrient status were 3.58% N, 0.39% P, and 4.84% K. While the maximum dosage of multinutrient fertilizer being recommended for asiatic pennywort is (2.04 g N + 0.42 g P + 2.93 g K)/plant/season with ratoon harvest system interval of 5-month, it is hoped the
Keyword: 

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix