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Jagadeesh Mosali Kefyalew Desta Roger K. Teal Kyle W. Freeman Kent L. Martin Jason W. Lawles 《Journal of plant nutrition》2013,36(12):2147-2163
ABSTRACT One would expect foliar applied phosphorus (P) to have higher use efficiencies than when applied to the soil, but limited information is available concerning this. Experiments were conducted in 2002, 2003, and 2004 to determine the effect of foliar applications of P on winter wheat grain yields, P uptake, and use efficiency. Twelve treatments containing varying foliar P rates (0, 1, 2, and 4 kg ha? 1 in 2002 and 2003 and additional 8, 12, 16, and 20 kg ha? 1 in 2004) with and without pre-plant rates of 30 kg ha? 1 were evaluated. Foliar applications of P at Feekes 7 generally increased grain yields and P uptake versus no foliar P. Use efficiency was higher when P was applied at Feekes 10.54. Results from this study suggested that low rates of foliar applied P might correct mid-season P deficiency in winter wheat, and that might result in higher P use efficiencies. 相似文献
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Xi Li Kiwamu Ishikura Chunying Wang Jagadeesh Yeluripati Ryusuke Hatano 《Soil Science and Plant Nutrition》2013,59(1):116-132
Hierarchical Bayesian (HB) methods are useful tools for modeling multifaceted, nonlinear phenomena such as those encountered in ecology, and have been increasingly applied in environmental sciences, e.g., to estimate soil gas flux from different soil textures or sites. We have developed a model of soil carbon dioxide (CO2) flux based on soil temperature (T, 5 cm depth) and water-filled pore space (WFPS, 5 cm depth) using HB theory. The HB model was calibrated using a dataset of CO2 flux measured from bare soils belonging to four texture classes in 14 upland field sites in a watershed in central Hokkaido, Japan, in the nonsnow-cover season from 2003 to 2011. The numerical software HYDRUS-1D was used to simulate daily WFPS, and the estimated values were significantly correlated with the measured WFPS (R2 = 0.68, P < 0.001). Compared to a nonhierarchical Bayesian model (Bayesian pooled model), the CO2 predictions with the HB model more accurately represented texture-specific observations. The simulation–observation fit of the CO2 flux model was R2 = 0.64 (P < 0.001). More than 90% of the observed daily data were within the 95% confidence interval. The HB model exhibited high uncertainty for high CO2 flux values. The HB model calibration revealed differing sensitivity of CO2 flux to T and WFPS in different soil texture classes. CO2 flux increased with an increase in T, and it increased to a lesser degree with a finer texture, possibly because the clay and silt facilitated soil aggregation, thus reducing temperature fluctuations. WFPS values between 0.48 and 0.64 resulted in optimal conditions for CO2 flux. The minimum WFPS value increased with an increase in clay content (P < 0.05). Although only a small number of soil types were studied in only one season in this study, the HB model may provide a method for predicting how the effects of soil temperature and moisture on CO2 flux change with texture, and soil texture could be regarded as an upscaling factor in future research on regional extrapolation. 相似文献
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Cereal rye (Secale cereale L.) is an important forage crop in the USA for stocker cattle (Bos sp.) production, thus making forage yield an important breeding objective for the crop. However, little information is known about the repeatability for forage yield in this crop. The objectives of this research were to: (i) estimate variance components for forage yield from long‐term variety trials, (ii) estimate the repeatability for forage yield and (iii) relate this to breeding strategies for increased forage yield in rye. Trials were conducted over 14 years where 97 USA open‐pollinated varieties (OPVs) were evaluated. Repeatability ranged from 0.57 to 0.86 when the data were analysed by year for the 3 years with significant genotype main effects. Possible explanations for the lack of significant genotype main effects are discussed. Practical implications of these findings indicate that the development of improved cultivars with greater forage yield will require improved methods of selection based on family performance rather than the current methods based primarily on single plant visual selection. 相似文献
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Raghu Patil Junjappa Srividya Narayanamurthy Desai Panchali Roy Nagalakshmi Narasimhaswamy Juliet Roshini Mohan Raj Murali Durgaiah Aradhana Vipra Udaya Ravi Bhat Smitha Komarla Satyanarayana Nandini Shankara SuneelKumar Muragesh Basingi Jagadeesh Janardhan Bhat Sukumar Hariharan Bharathi Sriram Sriram Padmanabhan 《Veterinary research communications》2013,37(3):217-228
In this study, we demonstrate the antibacterial activity of P128 on Staphylococcus isolates responsible for canine pyoderma. Eighty seven swabs were collected from dogs suffering from pyoderma and subjected to antibiotic sensitivity test and 46 Staphylococcus strains were isolated and characterized. In-vitro antimicrobial susceptibility testing with P128 was done by Minimum Inhibitory Concentration (MIC) method as per CLSI guidelines. All the Staphylococci isolated from the dogs with pyoderma, although showed resistance to various antibiotics tested, were lysed by P128. Clinical efficacy of P128 was examined in 17 dogs with pyoderma by application of the P128 hydrogel twice daily for 8 days and the results indicated complete healing of all the lesions of all the dogs under treatment. Under the conditions of this study, P128 was found to be a potent convenient proteinaceous drug for the treatment of staphylococcal pyoderma in dogs. 相似文献
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Jagadeesh B. Yeluripati Marcel van Oijen A. Neftel W.J. Parton 《Soil biology & biochemistry》2009,41(12):2579-321
The most widely applied soil carbon models partition the soil organic carbon into two or more kinetically defined conceptual pools. The initial distribution of soil organic matter between these pools influences the simulations. Like many other soil organic carbon models, the DAYCENT model is initialised by assuming equilibrium at the beginning of the simulation. However, as we show here, the initial distribution of soil organic matter between the different pools has an appreciable influence on simulations, and the appropriate distribution is dependent on the climate and management at the site before the onset of a simulated experiment. If the soil is not in equilibrium, the only way to initialise the model is to simulate the pre-experimental period of the site. Most often, the site history, in terms of land use and land management is often poorly defined at site level, and entirely unknown at regional level. Our objective was to identify a method that can be applied to initialise a model when the soil is not in equilibrium and historic data are not available, and which quantifies the uncertainty associated with initial soil carbon distribution. We demonstrate a method that uses Bayesian calibration by means of the Accept-Reject algorithm, and use this method to calibrate the initial distribution of soil organic carbon pools against observed soil respiration measurements. It was shown that, even in short-term simulations, model initialisation can have a major influence on the simulated results. The Bayesian calibration method quantified and reduced the uncertainties in initial carbon distribution. 相似文献
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S.L. Jagadeesh B.S. Reddy N. Basavaraj G.S.K. Swamy Kirankumar Gorbal Laxminarayan Hegde G.S.V. Raghavan S.T. Kajjidoni 《Scientia Horticulturae》2007
Ninety-five jackfruit types selected from Western Ghats of India, which is the centre of origin for the species, were analyzed using Mahalanobis D2 technique to determine the degree of divergence present among the selections. The studies revealed that majority of selections (91), irrespective of their ecogeographic area, were grouped in one cluster and the remaining 4 types were solitary with one selection in each cluster. Inter cluster distance was maximum between clusters D and E (525.8) and minimum inter cluster divergence was observed between clusters B and C (106.1). Cluster means for all economically important characters were not found to be highest in any one cluster indicating the vast diversity on account of indigenous and cross-pollinated nature of the crop. The maximum relative contribution to the total divergence was by number of seeds per fruit and TSS:Acid ratio indicating the ample amount of variability in these traits and hence the selection process for crop improvement in jackfruit should deem these characters. 相似文献
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M. van Oijen D.R. CameronK. Butterbach-Bahl N. Farahbakhshazad P.-E. JanssonR. Kiese K.-H. RahnC. Werner J.B. Yeluripati 《Agricultural and Forest Meteorology》2011,151(12):1609-1621
Four different parameter-rich process-based models of forest biogeochemistry were analysed in a Bayesian framework consisting of three operations: (1) Model calibration, (2) Model comparison, (3) Analysis of model-data mismatch.Data were available for four output variables common to the models: soil water content and emissions of N2O, NO and CO2. All datasets consisted of time series of daily measurements. Monthly averages and quantiles of the annual frequency distributions of daily emission rates were calculated for comparison with equivalent model outputs. This use of the data at model-appropriate temporal scale, together with the choice of heavy-tailed likelihood functions that accounted for data uncertainty through random and systematic errors, helped prevent asymptotic collapse of the parameter distributions in the calibration.Model behaviour and how it was affected by calibration was analysed by quantifying the normalised RMSE and r2 for the different output variables, and by decomposition of the MSE into contributions from bias, phase shift and variance error. The simplest model, BASFOR, seemed to underestimate the temporal variance of nitrogenous emissions even after calibration. The model of intermediate complexity, DAYCENT, simulated the time series well but with large phase shift. COUP and MoBiLE-DNDC were able to remove most bias through calibration.The Bayesian framework was shown to be effective in improving the parameterisation of the models, quantifying the uncertainties in parameters and outputs, and evaluating the different models. The analysis showed that there remain patterns in the data - in particular infrequent events of very high nitrogenous emission rate - that are unexplained by any of the selected forest models and that this is unlikely to be due to incorrect model parameterisation. 相似文献