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Yield Increases (yield + increase)
Selected AbstractsGrowth and Yield Response of Facultative Wheat to Winter Sowing, Freezing Sowing and Spring Sowing at Different Seeding RatesJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2006A. Ozturk Abstract Growth and yield of wheat are affected by environmental conditions and can be regulated by sowing time and seeding rate. In this study, three sowing times [winter sowing (first week of September), freezing sowing (last week of October) and spring sowing (last week of April)] at seven seeding rates (325, 375, 425, 475, 525, 575 and 625 seeds m,2) were investigated during the 2002,03 and 2003,04 seasons, in Erzurum (Turkey) dryland conditions, using Kirik facultative wheat. A split-plot design was used, with sowing times as main plots and seeding rates randomized as subplots. There was a significant year × sowing time interaction for grain yield and kernels per spike. Winter-sown wheat produced a significantly higher leaf area index, leaf area duration, spikes per square metre, kernel weight and grain yield than freezing- and spring-sown wheat. The optimum time of sowing was winter for the facultative cv. Kirik. Grain yields at freezing and spring sowing were low, which was largely the result of hastened crop development and high temperatures during and after anthesis. Increasing seeding rate up to 525 seeds m,2 increased the spikes per square metre at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as sowing time in maximizing grain yield. Changes in spikes per square metre were the major contributors to the grain-yield differences observed among sowing times and seeding rates. Yield increases from higher seeding rates were greater at freezing and spring sowing. We recommended that a seeding rate of 525 seeds m,2 be chosen for winter sowing, and 575 seeds m,2 for freezing and spring sowing. [source] Evaluation of an action threshold-based IPM wheat model in Rheinland (Germany) in 1999/2001,EPPO BULLETIN, Issue 3 2003M. Heger Under the specific agricultural and climatic conditions of Rheinland (DE), 48 field trials in three years demonstrated the practicability of the action threshold-based fungicide strategy of the IPM wheat model. The underlying data for action thresholds and dosage of fungicides applied are outlined. The cereal pathogens concerned, predominantly Mycosphaerella graminicola and Puccinia recondita, were controlled in the early stages of epidemic development using reduced rates of fungicides. The IPM wheat model gave a high efficacy of control, in terms of disease incidence and disease severity, under both low and high disease pressure conditions. The yield levels resulting from this effective reduction in diseases were nearly the same as those of the disease-free variant. Total yield increase varied between 15% and 30% with an overall average of around 20%, and resulted in monetary benefits of 50,100 EUR ha,1 in the years considered. [source] Agronomic factors affecting the yield and quality of forage maize in Ireland: effect of sowing date and plastic film treatmentGRASS & FORAGE SCIENCE, Issue 1 2002G. P. Keane The objectives of these studies were to examine the effects of sowing date and plastic film on the yield and quality of forage maize (Zea mays L.) in Ireland, a marginal maize-growing area. In 1989,95, comparisons were made of maize sown through clear plastic film (PP treatment), and maize sown in the conventional manner without plastic (NP treatment), in terms of dry-matter (DM) yield and quality (cob, grain and starch contents). The PP treatment significantly increased DM yields in five years, with a mean yield increase of 3·10 t ha,1. Whole-plant DM content increased (significant in four years) by a mean of 0·15; cob content increased (significant in five years) by a mean of 0·32; grain content increased (significant in all of the three years examined) by 0·75; and starch content increased from 236 to 318 g kg,1 DM (P < 0·01) in 1995 where the plastic film treatment was used. Organic matter digestibility values were similar for both treatments in 1995. Sowing date in the April-May period had no consistent effect on DM yields, but early sowings did increase cob (significant, except in 1994), grain (significant in one (1995) of the two years tested) and starch (P < 0·05) contents (only tested in 1995). Sowing on 11 April 1995 through perforated plastic gave lower yields than the NP treatment sown on the same date, due to severe frost damage in early May. [source] Shade darkening effect of polyorganosiloxane modified with amino and hydroxy groups on dyed polyester microfiber fabricJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2007Kongliang Xie Abstract The novel polyorganosiloxane material S-101 modified with amino and hydroxy groups is synthesized. Shade darkening effect of modified polyorganosiloxane on dyed polyester microfiber fabric is investigated by reflectance spectrum, color yield (K/S), and the color differences (,E). The colorimetric data of CIELAB is discussed. The results show that the novel material of silicone polymer modified with amino and hydroxy groups has excellent shade darkening effect on dyed polyester microfiber fabric. The rates of the color yield increase (I%) of all dyed fabric with four dyes (Disperse Yellow S-4RL, Red GS, Blue 2BLN, and Black SF-R) exceed 10%. The shapes of the reflectance spectra curves of the dyed fabrics before and after treated with S-101 are not noticeable change. The dyed fabrics with the polymer have not significant effect on the wash fastness and wet rubbing fastness. The low reflectance thin film on dyed fabrics is formed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 [source] Assessment of potential approaches to improve Eucalyptus globulus kraft pulping yieldJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2007A. S. Santiago Abstract The main goal of this work is to study the potential approaches to improve polysaccharides retention during Eucalyptus globulus kraft pulping. The addition of anthraquinone to kraft pulping leads to the highest pulp yield while the addition of urea promotes lower depolymerization of polysaccharides (higher pulp viscosity), but does not have a significant effect on yield. The early interruption of kraft cooking followed by oxygen delignification is a reliable approach to increase pulp yield, particularly when pulping is interrupted at the end of the faster and more selective kinetic regime (bulk phase). Yield loss during oxygen delignification is considerably lower than that incurred in the last phase of kraft pulping. Pulping with OH,/HS, charge profiling, carried out with liquor injection in three different phases leads to a yield increase. However, this increase results from a lower total alkali charge applied when profiling pulping is compared to standard pulping conditions, rather than to alkali profiling. Standard kraft pulping with different active alkali (AA) charges demonstrated that this operational variable is determinant for pulp yield and viscosity. Pulping experiences with lower AA (14%) resulted in a higher and almost constant pulp viscosity and in a higher pulp yield, assigned to improved retention of both cellulose and xylan. During the last stage of pulping, cellulose content decreases, this being mainly responsible for the decrease of pulp yield, while xylan content is almost constant, a feature attributed to the peculiar structure of this E. globulus's hemicellulose. Copyright © 2007 Society of Chemical Industry [source] Is plant performance limited by abundance of arbuscular mycorrhizal fungi?NEW PHYTOLOGIST, Issue 1 2005A meta-analysis of studies published between 198 Summary ,,We conducted meta-analyses of 290 published field and glasshouse trials to determine the effects of various agricultural practices on mycorrhizal colonization in nonsterile soils, and the consequence of those effects on yield, biomass, and phosphorus (P) concentration. ,,Mycorrhizal colonization was increased most by inoculation (29% increase), followed by shortened fallow (20%) and reduced soil disturbance (7%). The effect of crop rotation depended on whether the crop was mycorrhizal. Increased colonization resulted in a yield increase in the field of 23% across all management practices. ,,Biomass at harvest and shoot P concentration in early season were increased by inoculation (57 and 33%, respectively) and shortened fallow (55 and 24%). Reduced disturbance increased shoot P concentration by 27%, but biomass was not significantly affected. Biomass was significantly reduced in 2% of all trials in which there was a significant increase in colonization. ,,Irrespective of management practice, an increased mycorrhizal colonization was less likely to increase biomass if either soil P or indigenous inoculum potential was high. [source] LESSONS FROM THREE DECADES OF GREEN REVOLUTION IN THE PHILIPPINESTHE DEVELOPING ECONOMIES, Issue 2 2006Jonna P. ESTUDILLO O13; O33; O53 The purpose of the current paper is to assess the changing contributions of successive generations of modern varieties of rice (MV) to yield increase and stability and the changes in total factor productivity (TFP) in irrigated, rainfed, and upland ecosystems in the Philippines. We found that the yield increase in irrigated ecosystem has been by far the highest, which can be attributed to the diffusion of pest- and disease-resistant MV. The contribution of MV to yield increase in the rainfed ecosystem has been less significant, but much more compared with that of upland ecosystem. The rainfed and upland ecosystems have experienced an upward trend in yield, albeit slowly, because of the diffusion of improved traditional varieties and MV suitable to adverse production environments. The contribution of MV cum irrigation has accounted for approximately 50% of the growth of TFP in Central Luzon. [source] Water gas shift reaction via Pd-based membranesASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2009Silvano Tosti Abstract The water gas shift reaction has been studied in tubular Pd-based membranes: a thin walled dense tube and a composite Pd-ceramic tube have been considered. A computer code based on a finite element model has been developed for modelling the membrane reactor. The model accounts for the reaction kinetic, the hydrogen diffusion through the porous ceramic support and permeation through the PdAg membrane and for the partial pressure gradients of hydrogen generated at the permeate side of the membrane when a flow of purge gas is introduced. The code has been used to assess the influence of temperature, lumen pressure, presence of wall effects and sweep gas mode on the reaction conversion and hydrogen yield of the membrane reactors. At 200 kPa of lumen pressure and counter-current sweep mode, it was found that both reaction conversion and hydrogen yield increase with temperature: the dense and the composite membranes exhibit very close values of conversion (more than 99% at 400 °C) and hydrogen yield (96,97% at 400 °C). In co-current mode, the highest values of both reaction conversion and hydrogen yield have been assessed at 350 °C, while it was demonstrated that the beneficial effects of increasing the lumen pressure up to 400 kPa are maximum at 300 °C. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Elevated atmospheric CO2 effects on biomass production and soil carbon in conventional and conservation cropping systemsGLOBAL CHANGE BIOLOGY, Issue 4 2005Stephen A. Prior Abstract Increasing atmospheric CO2 concentration has led to concerns about potential effects on production agriculture as well as agriculture's role in sequestering C. In the fall of 1997, a study was initiated to compare the response of two crop management systems (conventional and conservation) to elevated CO2. The study used a split-plot design replicated three times with two management systems as main plots and two CO2 levels (ambient=375 ,L L,1 and elevated CO2=683 ,L L,1) as split-plots using open-top chambers on a Decatur silt loam (clayey, kaolinitic, thermic Rhodic Paleudults). The conventional system was a grain sorghum (Sorghum bicolor (L.) Moench.) and soybean (Glycine max (L.) Merr.) rotation with winter fallow and spring tillage practices. In the conservation system, sorghum and soybean were rotated and three cover crops were used (crimson clover (Trifolium incarnatum L.), sunn hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)) under no-tillage practices. The effect of management on soil C and biomass responses over two cropping cycles (4 years) were evaluated. In the conservation system, cover crop residue (clover, sunn hemp, and wheat) was increased by elevated CO2, but CO2 effects on weed residue were variable in the conventional system. Elevated CO2 had a greater effect on increasing soybean residue as compared with sorghum, and grain yield increases were greater for soybean followed by wheat and sorghum. Differences in sorghum and soybean residue production within the different management systems were small and variable. Cumulative residue inputs were increased by elevated CO2 and conservation management. Greater inputs resulted in a substantial increase in soil C concentration at the 0,5 cm depth increment in the conservation system under CO2 -enriched conditions. Smaller shifts in soil C were noted at greater depths (5,10 and 15,30 cm) because of management or CO2 level. Results suggest that with conservation management in an elevated CO2 environment, greater residue amounts could increase soil C storage as well as increase ground cover. [source] Evaluating Tripsacum -introgressed maize germplasm after infestation with western corn rootworms (Coleoptera: Chrysomelidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2009D. A. Prischmann Abstract Maize (Zea mays L.) is a valuable commodity throughout the world, but corn rootworms (Chrysomelidae: Diabrotica spp.) often cause economic damage and increase production costs. Current rootworm management strategies have limitations, and in order to create viable management alternatives, researchers have been developing novel maize lines using Eastern gamagrass (Tripsacum dactyloides L.) germplasm, a wild relative of maize that is resistant to rootworms. Ten maize Tripsacum -introgressed inbred lines derived from recurrent selection of crosses with gamagrass and teosinte (Zea diploperennis Iltis) recombinants and two public inbred lines were assessed for susceptibility to western corn rootworm (Diabrotica virgifera virgifera LeConte) and yield in a two-year field study. Two experimental maize inbred lines, SDG11 and SDG20, had mean root damage ratings that were significantly lower than the susceptible public line B73. Two other experimental maize inbred lines, SDG12 and SDG6, appeared tolerant to rootworm damage because they exhibited yield increases after rootworm infestation in both years. In the majority of cases, mean yield per plant of experimental maize lines used in yield analyses was equal to or exceeded that of the public inbred lines B73 and W64A. Our study indicates that there is potential to use Tripsacum -introgressed maize germplasm in breeding programs to enhance plant resistance and/or tolerance to corn rootworms, although further research on insect resistance and agronomic potential of this germplasm needs to be conducted in F1 hybrids. [source] Ex ante analysis of the benefits of transgenic drought tolerance research on cereal crops in low-income countriesAGRICULTURAL ECONOMICS, Issue 4 2009Genti Kostandini Drought tolerance; Transgenic; Research benefits; Intellectual property rights Abstract This article develops a framework to examine the ex ante benefits of transgenic research on drought in eight low-income countries, including the benefits to producers and consumers from farm income stabilization and the potential magnitude of private sector profits from intellectual property rights (IPRs). The framework employs country-specific agroecological,drought risk zones and considers both yield increases and yield variance reductions when estimating producer and consumer benefits from research. Benefits from yield variance reductions are shown to be an important component of aggregate drought research benefits, representing 40% of total benefits across the eight countries. Further, estimated annual benefits of US$178 million to the private sector suggest that significant incentives exist for participation in transgenic drought tolerance research. [source] Synthesis of liquid crystalline poly(1-pentyne)s and fabrication of polyacetylene,perovskite hybridsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2006Jianli Hua Abstract Poly(1-pentyne)s containing biphenyl and phthalimido pendant groups with different spacer lengths {P1(m); [HCC(CH2)3OBiphOCO(CH2)mN(CO)2C6H4]n, Biph4,4,biphenylyl; m = 7, 10} are synthesized in satisfactory yields by WCl6 -Ph4Sn catalyst in toluene at elevated temperatures. The structures and properties of the polymers are characterized and evaluated by IR, NMR, TGA, DSC, POM, and XRD analyses. Both of the polymers are thermally stable (Td , 300 °C) and exhibit nematicity at high temperatures. Their phthalimido groups are converted into amino groups by hydrolysis, which can, after acidification, complex with lead(II) bromide to furnish polyacetylene,perovskite hybrids in high yields. The organic components contribute good solubility to the hybrids, while the perovskite framework induces the polyacetylene chains to align within the inorganic sheets. The hybrids emit a strong UV light of 374 nm upon photoexcitation, whose quantum yield increases with an increase in the spacer length. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3538,3550, 2006 [source] Farmers' perceptions of soil erosion and its consequences in India's semiarid tropicsLAND DEGRADATION AND DEVELOPMENT, Issue 3 2005J. Kerr Abstract This paper investigates farmers' perceptions of soil erosion and how it affects crop yields, land values, and private conservation investments in India's semiarid tropics. It is based on three types of data: (1) a survey of farmers in three study villages; (2) a plot survey by a professional soil surveyor in the same villages; and (3) experimental and simulated data from nearby research stations with similar conditions. Farmers' perceptions of erosion are compared to the surveyor's using kappa, a statistical measure of interrater agreement. Perceived erosion,yield relationships are estimated econometrically and compared to experimental and simulated data. Effects on land values and conservation investments are estimated econometrically. Findings suggest that farmers are keenly aware of rill erosion but less aware of sheet erosion; kappa values ranging from 0 to 0·28 suggest low agreement with the soil surveyor. They anticipate annual yield losses of 5·8,11,per,cent due to rill erosion; these figures are reasonably consistent with those from nearby research stations. They anticipate yield increases of 3·8,14·5,per,cent due to installation of soil conservation bunds, largely because they can harvest soil from up the slope and capture organic matter. Perceived erosion has some effect on land values and soil conservation investments, but other factors such as irrigation and soil type have a much greater effect. These findings suggest that promoting soil conservation requires capitalizing on farmers' interest in short-term gains, such as from water and nutrient management. Copyright © 2005 John Wiley & Sons, Ltd. [source] Sustainable production of crops and pastures under drought in a Mediterranean environmentANNALS OF APPLIED BIOLOGY, Issue 2 2004NEIL C TURNER Summary Mediterranean environments are characterised by cool wet winters and hot dry summers. While native vegetation in Mediterranean-climatic zones usually comprises a mixture of perennial and annual plants, agricultural development in the Mediterranean-climatic region of Australia has led to the clearing of the perennial vegetation and its replacement with annual crops and pastures. In the Mediterranean environments of southern Australia this has led to secondary (dryland) salinisation. In order to slow land degradation, perennial trees and pasture species are being reintroduced to increase the productivity of the saline areas. The annual crops and pastures that form the backbone of dryland farming systems in the Mediterranean-climatic zone of Australia are grown during the cool wet winter months on incoming rainfall and mature during spring and early summer as temperatures and rates of evaporation rise and rainfall decreases. Thus, crop and pasture growth is usually curtailed by terminal drought. Where available, supplementary irrigation in spring can lead to significant increases in yield and water use efficiency. In order to sustain production of annual crops in Mediterranean environments, both agronomic and genetic options have been employed. An analysis of the yield increases of wheat in Mediterranean-climatic regions shows that there has generally been an increase in the yields over the past decades, albeit at a lower rate than in more temperate regions. Approximately half of this increase can be attributed to agronomic improvements and half to genetic improvements. The agronomic improvements that have been utilised to sustain the increased yields include earlier planting to more closely match crop growth to rainfall distribution, use of fertilisers to increase early growth, minimum tillage to enable earlier planting and increase plant transpiration at the expense of soil evaporation, rotations to reduce weed control and disease incidence, and use of herbicides, insecticides and fungicides to reduce losses from weeds, insects and disease. Genetic improvements include changing the phenological development to better match the rainfall, increased early vigour, deeper rooting, osmotic adjustment, increased transpiration efficiency and improved assimilate storage and remobilisation. Mediterranean environments that are subjected annually to terminal drought can be both environmentally and economically sustainable, but to maximise plant water use efficiency while maintaining crop productivity requires an understanding of the interaction between genotypes, environment and management. [source] Beyond semi-dwarf wheat yield increases: impacts on the Australian wheat industry of on-going spillovers from the International Maize and Wheat Improvement CenterAUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2007John P. Brennan Wheat genetic materials developed from research at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico for developing countries have provided spillover benefits to Australia. Varieties developed from those genetic materials have resulted in yield increases in Australia. While the initial impact came through the introduction of higher-yielding semi-dwarf wheat crops, those impacts have continued in the post-semidwarf period. CIMMYT's success in developing countries has also reduced the world price for wheat. While the lower prices affect returns in Australia, the increased yields in Australia from the CIMMYT spillovers from both the semi-dwarfs and the post-semidwarf phases have provided benefits to Australia averaging A$30 million per year. [source] Corn ethanol growth in the USA without adverse foreign land-use change: defining limits and devising policiesBIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 3 2010Paul W. Gallagher Abstract This study addresses the question: ,How does a 15 billion gallon per year renewable fuel standard (RFS) compare to the capacity of the US corn market to generate necessary input supplies for the ethanol industry?' The analysis accounts for adjustments in world corn and soybean markets, including corn technology improvements (yield increases) that allow substantial production growth on the existing corn area, and byproduct (DDG) replacement of displaced corn-feed demand. Our midpoint estimate suggests that increased production on foreign lands only accounts for a small fraction (6%) of the RFS demand expansion. Further, corn yield response to moderate price increases would likely offset much of the foreign production increase. US policies that could sever any remaining link between US ethanol expansion and environmentally sensitive regions of the world feed economy are discussed. Copyright © 2010 Society of Chemical Industry and John Wiley & Sons, Ltd [source] Radiolysis of Confined Water: Hydrogen Production at a High Dose RateCHEMPHYSCHEM, Issue 12 2005Sophie Le Caër Dr. Abstract The production of molecular hydrogen in the radiolysis of dried or hydrated nanoporous controlled-pore glasses (CPG) has been carefully studied using 10 MeV electron irraditation at high dose rate. In all cases, the H2 yield increases when the pore size decreases. Moreover, the yields measured in dried materials are two orders of magnitude smaller than those obtained in hydrated glasses. This proves that the part of the H2 coming from the surface of the material is negligible in the hydrated case. Thus, the measured yields correspond to those of nanoconfined water. Moreover, these yields are not modified by the presence of potassium bromide, which is a hydroxyl radical scavenger. This experimental observation shows that the back reaction between H2 and HO. does not take place in such confined environments. These porous materials have been characterized before and after irradiation by means of Fourier-transform infrared (FT-IR) spectroscopy, electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) techniques, which helps to understand the elementary processes taking place in this type of environment, especially the protective effect of water on the surface in the case of hydrated glasses. [source] Chemical-looping combustion process: Kinetics and mathematical modelingAICHE JOURNAL, Issue 4 2010Ion Iliuta Abstract Chemical Looping Combustion technology involves circulating a metal oxide between a fuel zone where methane reacts under anaerobic conditions to produce a concentrated stream of CO2 and water and an oxygen rich environment where the metal is reoxidized. Although the needs for electrical power generation drive the process to high temperatures, lower temperatures (600,800°C) are sufficient for industrial processes such as refineries. In this paper, we investigate the transient kinetics of NiO carriers in the temperature range of 600 to 900°C in both a fixed bed microreactor (WHSV = 2-4 g CH4/h/g oxygen carrier) and a fluid bed reactor (WHSV = 0.014-0.14 g CH4/h per g oxygen carrier). Complete methane conversion is achieved in the fluid bed for several minutes. In the microreactor, the methane conversion reaches a maximum after an initial induction period of less than 10 s. Both CO2 and H2O yields are highest during this induction period. As the oxygen is consumed, methane conversion drops and both CO and H2 yields increase, whereas the CO2 and H2O concentrations decrease. The kinetics parameter of the gas,solids reactions (reduction of NiO with CH4, H2, and CO) together with catalytic reactions (methane reforming, methanation, shift, and gasification) were estimated using experimental data obtained on the fixed bed microreactor. Then, the kinetic expressions were combined with a detailed hydrodynamic model to successfully simulate the comportment of the fluidized bed reactor. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source] | ||||||||||||||||||||||