803 research outputs found

    Evidence of Parent Cell Walls in the Woods of Three Coniferous Species

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    The occurrence of parent cell walls in normal wood of Cedrus deodara and compression wood of Araucaria cookii and Pinus halepensis was studied under the electron microscope. Only part of the parent cell wall traversing the intercellular space was visible in compression wood trachieds of A. cookii and P. halepensis while parent wall can be seen between two splitted radial rows of trachieds in the normal wood of C. deodara

    Effect of row spacing and cultivar on biomass yield and quality of Sorghum bicolor L. Moench

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    Ein zweijähriges Forschungsprojekt wurde durchgefĂĽhrt, um den Effekt verschiedener Reihenabstände auf den Biomasseertrag und die chemische Zusammensetzung verschiedener Sorghum-Sorten unter Feldbedingungen in Deutschland zu untersuchen. Es wurden drei Reihenweiten berĂĽcksichtigt (75 cm, 37,5 cm, Doppelreihen mit 75 cm zwischen und 10–15 cm innerhalb der Doppel­reihe). Diese Reihenweiten wurden im Jahr 2008 in Kombina­tion mit zwei Sorten (Goliath (S. bicolor Ă— S. bicolor), Bovital (S. bicolor Ă— S. sudanense)) und im Jahr 2009 mit fĂĽnf Sorten (Goliath, Bovital, Aron (S. bicolor), Rona 1 (S. bicolor) und Akklimat (S. sudanense)) untersucht. Im Jahr 2008 wurden signifikante LAI-Unterschiede 90 Tage nach Feldaufgang zwischen den getesteten Sorten beobachtet, wobei Bovital höhere LAI-Werte erreichte als Goliath. Von allen getesteten Sorten wurde der niedrigste LAI bei der Sorte Akklimat zu allen drei Terminen gemessen. Der niedrige Reihenabstand von 37,5 cm fĂĽhrte zu einer Erhöhung des LAI im Vergleich zu den anderen Reihenweiten. DarĂĽber hinaus wurde beobachtet, dass ein weiterer Reihenabstand in beiden Jahren eine signifikante Verringerung der Anzahl an Trieben/m2 verursachte. Der Biomasseertrag von Sorghum schwankte in beiden Experimenten von minimal 10,10 t TM/ha (cv. Akklimat 2009) bis maximal 19.72 t TM/ha (cv. Goliath 2008). Der Reihenabstand hatte im Jahr 2008 keinen Einfluss auf den Trockenmasseertrag, während im Jahr 2009 die Doppelreihe und 37,5 cm Reihenweite zu signifikant höheren Biomasse-Erträgen fĂĽhrten. Die Proteinkonzentration war im Jahr 2008 bei geringen Reihenabständen gleich, während deutlich niedrigere Werte fĂĽr 75 cm Reihenabstand festgestellt wurden. Im Jahr 2009 wurden dagegen bei der Reihenweite von 75 cm und bei der Doppelreihe signifikant höhere Proteinkonzentrationen beobachtet als bei einem Reihenabstand von 37,5 cm. Rona 1 erreichte mit 18,7% TM die höchsten Zucker-Konzentrationen aller getesteten Sorten. Unter den fĂĽnf getesteten Sorten zeigten Rona 1 und Aron niedrigere Konzentrationen an Neutral-Detergenzien-Faser (NDF), Säure-Detergenzien-Faser (ADF) und Säure-Detergenzien-Lignin (ADL).    Two years research was conducted to study comprehensively the effect of different row spacing on biomass yield and chemical composition of different sorghum cultivars under field conditions in Germany. Three row spacing (75 cm, 37.5 cm, double rows 75 cm apart with strip rows of 10–15 cm) and two cultivars (Goliath (S. bicolor Ă— S. bicolor), Bovital (S. bicolor Ă— S. sudanense)) were included in 2008, while the same row spacings and five cultivars (Goliath, Bovital, Aron (S. bicolor), Rona 1 (S. bicolor), Akklimat (S. sudanense)) were tested in 2009. In 2008 the leaf area index (LAI) difference between the tested cultivars was significant only after 90 days following germination when Bovital reached higher LAI than Goliath. Among all five tested cultivars in 2009 the lowest LAI was observed for Akklimat at all three measuring dates. The narrow row space of 37.5 cm led to increased LAI while the wider row spacing caused a significant decrease of the number of tillers/m2 in both years. Dry matter yield of sorghum ranged in both experimental years from min. 10.10 t DM/ha (cv. Akklimat 2009) to max. 19.72 t DM/ha (cv. Goliath 2008). Row spacing had no clear effect on the dry matter yield in 2008 whereas in 2009 double rows of 75 cm and narrow row spacing (37.5 cm) led to significantly higher biomass yield than wide row spacing of 75 cm. Effects of row spacing were inverse between years regarding crude protein concentration. Cv. Rona 1 accumulated highest values of sugar concentration (18.7%) and together with cv. Aron lowest values for neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) concentration compared with other cultivars.   &nbsp

    Effect of NaCl Salinity on Growth, Nodulation and Total Nitrogen Content in Sesbania Sesban

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    A pot experiment was conducted to determine the effect of salinity on growth nodulation and nitrogen content of Sesbania sesban. Fifteen days old S. sesban seedlings grown in sandy loam soil were irrigated with NaCl solution of 0.034 mol/L, 0.069 mol/L, 0.103 mol/L, 0.137 mol/L and 0.172 mol/L. The plants were harvested after 80 days. Fresh and dry weight of shoots and roots and root- shoot ratio decreased progressively with the increasing salinity levels. Root showed more inhibition than shoot. Nodules were observed on the roots of plants growing in all fi ve salinity levels but they showed morphological alterations in size and shape. The number and size of the nodules per plant and their fresh and dry weight decreased with increasing salinity levels. The percentage of tissue nitrogen also decreased progressively with the increasing salinity levels

    Influence of urea application on growth, yield and mineral uptake in two corn (Zea mays L.) cultivars

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    A pot experiment was conducted in a wire netting green house in order to assess the beneficial effect of urea on corn cultivars (C-20 and C-79) differing in yield production. Corn plants were grown in loam soil with alkaline in reaction. Application of varying urea levels did not change the physico-chemical properties of soil. Four weeks-old corn plants were subjected to varying levels of urea (0, 50, 100, 175 and 225 kg/ha urea) for 8 (mid-season harvest) and 15 weeks (final harvest). After which, plants growth, yield and mineral nutrient status of the two corn cultivars were assessed for both mid-season and final harvest. It was observed that cv. C-20 showed higher (P<0.1) growth and yield. Addition of varying levels of urea enhanced the growth and yield of both the corn cultivars. However, 175 kg urea /ha was found to be more effective (P<0.1) in enhancing growth and yield of both the cultivars. The rate of urea application at a rate of 175 kg/ha had greater beneficial effect on cv. C-20 due to improved mineral nutrient (N, P, K, Cu, Fe, Mn and Zn) status of the cultivar.Keywords: Corn cultivars, fertilizer treatment, urea, mineral nutrition, plant growt

    Vegetation zonation along the geological and geomorphological gradient at Eastern slope of Sulaiman range, Pakistan

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    The vegetation of gypsiferous strata of Sulaiman range (30°33/ N to 30°41/30// north latitude and 70°32/ E to 70°41/30// east longitude, annual rainfall more than 100 mm) was analyzed using ordination (DECORANA) and classificatory cluster analysis techniques. Four plant associations were recognized in the study area. The application of the classification to the ordination allowed an interpretation of vegetation distribution in terms of topography and redistribution of rainwater, the nature of soil, bed rock and geological strata. The pattern of plant communities along the first ordination axis suggested that beside the landscape, substrate plays an important role in determining the boundaries between the plant communities. The assessment of the floristic suggested that there were three classes of plants: first there are plants of alluvial sandy plains (psymophytes), secondly; those of permanent water courses (hydrophytes) and thirdly, there are plants that grow on rocky hard strata (xerophytes/lithophytes). The observed pattern in available soil calcium seems related to long term redistribution of water that occurs during rainfall events because soil calcium, magnesium and moisture content have similar distributions along the transect. High calcium content for rocky strata was due to its parent geological gypsiferous formation. Although the boundaries across the landscape were associated with down slope movement of water, soil particles and cations, it was difficult to assess the relative importance of these factors in comparison with landscape level. The vegetation patterns revealed are discussed in relation to environmental factors and problems of plant assemblage in vegetation of the area.Key words: Vegetation analysis, plant communities, Sulaiman range, Pakistan

    Effect of T-tail on the Aerodynamic Characteristics and Static Stability of an Aircraft – A Computational Analysis

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    It is the purpose of this paper to find out the effect of T-tail on Aerodynamic characteristics and static stability of an aircraft. A T-tail aircraft with a configuration of tail with the horizontal stabilizer placed above the vertical stabilizer. Typically, a tail configuration in T shape. T- tail configuration is proposed with a goal of enhancing stability and controllability during high angle of attack and low speeds. Data is presented from a series of XFLR5 analysis to qualify the aerodynamic effect of T-tail over a range of angle of attack from -150 to +150. Various graphs were obtained during this analysis which indicates that the T-tail configuration can perform better at low speeds

    Ultrastructural Studies on Root Nodules of Pithecellobium dulce (Roxb.) Benth. (Fabaceae)

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    Ultrastructural studies were conducted on Pithecellobium dulce (Roxb) Benth. root nodules collected from trees growing under natural conditions. Rhizobial infection on root surface of P. dulce started with curling of root hair. Both curled and straight root hairs were observed. The internal structure of a mature nodule showed an epidermis, cortex, vascular region and a bacteriod region. Vascular bundles were amphicribral. A distinct periderm consisted of sclereid tissue could be observed in the cortex outside the vascular tissue. The bacteroid region contained infected and un-infected (interstitial) cells intermingled with each other. Infected cells of developing nodules as well as of mature nodules were vacuolated. Infection threads were also observed in the bacteroid zone. The rhizobia were released from the infection thread into the host cytoplasm form rhizobial (unwalled) droplets. Rhizobia were also observed in the intercellular spaces between infected cells. Starch grains were observed in the interstitial cells

    Effects of Seawater Salinity on Seedling Growth Nodulation and Tissue Nitrogen in Acacia nilotica (L.) Delile

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    A pot experiment was conducted to determine the effect of sea water salinity on growth, nodulation and nitrogen content of Acacia nilotica (L.) Delile seedlings. Eight weeks old seedlings were irrigated with 40, 50, 60, 70 and 80% sea water for one month. After 12 weeks the plants were uprooted and the nodules were observed for their frequency, shapes and sizes. Nodules showed morphological alterations in size and shape in different salinity levels. The root-shoot ratio, nitrogen contents in the leaf, stem and root were analyzed. In general salt stress resulted in a decrease of plant growth, nodulation and percent tissue nitrogen in A. nilotica plants. Root-shoot ratio showed gradual increase with increasing sea water concentrations. Nitrogen contents decreased in leaf and stem, whereas it increased in roots. Nodules showed morphological alterations in size and shape with increasing salinity. A. nilotica accumulated NaCl in the xylem of the roots that may be considered as a preliminary salt tolerant mechanism adopted by the plant

    Bio-methane Production from Sorghum Elite Lines under the Climatic Conditions of Pakistan

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    Fossil foils are depleting dramatically to meet the ever blooming energy demands. Plant biomass is a best source of renewable energy which can be used for bio-fuel production in order to meet the energy demands. Therefore, this study was conducted for two consecutive years 2016 and 2017 to screen out best lines of sorghum for biomass yield, chemical composition and bio-methane yield. The results revealed that tested lines had differential responses for biomass yield, biomass quality and methane yield. Line 5018, performed remarkably and produced maximum leaf area index (LAI), leaf area duration (LAD) and crop growth rate (CGR) followed by L-6024 whereas the minimum LAI, LAD and CGR were recorded for L-5025. Maximum plant height, leaves per plant and dry matter yield ha-1 was observed in L-5018, whereas the minimum plant height leaves per plant and dry matter yield ha-1 was recorded in L-5025. Likewise, L-5018 also had maximum protein content, acid detergent fiber, neutral detergent fiber, lignin content and ash content whereas the L-1914 had the minimum values for these parameters amongst the tested li- nes. In addition, L-1914 produced maximum specific yield, however, L-5018 produced maximum methane yield ha-1 owing to higher dry matter yield ha-1. The results of this study suggested that L-5018 can be used to develop high biomass cultivars with good methane yield potential
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