In a long-term continuous maize experiment set up in 1959, the functional method of growth analysis was applied to investigate the effect of various levels of farmyard manure and mineral fertilisation on the growth of maize (Zea mays L.) and on the dynamics of the growth parameters over a 3-year period (2005–2007). The experiment involved two nutrient levels (based on the active agent equivalence principle): Level l: the NPK equivalent of 35 t ha−1 farmyard manure (FYM), applied in the form of FYM, FYM + mineral fertiliser or mineral fertiliser; Level 2: the NPK equivalent of 70 t ha−1 farmyard manure (FYM), applied in the form of FYM, FYM + mineral fertiliser or mineral fertiliser. The computerised growth analysis program elaborated by Hunt and Parsons (1974) was used to describe the effect of FYM and mineral fertiliser and to evaluate the results. This program fits functions to calculate the absolute growth rate (AGR), the relative growth rate (RGR), the net assimilation rate (NAR) and the leaf area ratio (LAR).The Hunt-Parsons program fitted a third-degree function to the dynamics of total dry matter production and second- or third-degree functions to that of the leaf area growth. The highest mean values of AGR were obtained in treatments with the higher level of mineral fertiliser alone or mineral fertiliser + FYM when the weather was favourable (2.05–2.31 g plant−1 day−1), and in treatments with the lower quantity of mineral fertiliser alone or mineral fertiliser + FYM in the case of dry weather (1.73–1.74 g plant−1 day−1). In 2005 and 2006 the absolute growth rate gave a good characterisation of the various fertiliser effects, which exhibited high values with significant differences, while in 2007 lower AGR values were obtained and no fertiliser effects were observed. In the dry year (2007) the maximum values of NAR and LAR were higher in all the treatments than in the wetter years (except at the lower rate of mineral fertiliser alone). In the case of NAR, the results obtained with the functional method of growth analysis, based on function fitting, were easier to interpret than those obtained using the classical method.It was concluded from the results that in long-term experiments the use of the functional method of growth analysis gave a more precise evaluation of the effects of fertiliser treatments and the year on the growth of maize in the vegetative growth stage and on the mean and maximum values of growth parameters.
A simulation study of a PGNAA measuring arrangement with a252Cf neutron source for the characterization of cement raw materials was carried out using the MCNP code to investigate the effect on the system response of varying the bulk density and the water contentvw of samples of fixed dry composition. The source is placed at the centre of a lead cylinder of extemal radiusRPb. This cylinder is enclosed in a coaxial cylinder of polyethylene moderator of extermal radiusRin. The sample material is confined to the space between an outer cylindrical surface of radiusRout and the moderator cylinder. The first series of simulation runs was carried out for different sets of values ofRin,Rout and , and constantvw. The system specific responseS (count rate per wt%) shows a broad maximum aroundTM=Rin-RPb=4 cm andTS=Rout-Rin=8.5 cm and a dependence on that is almost linear in the region of the maximum. In a second series of runs the dependence ofS onvw was studied for a geometry corresponding to a real experiment described elsewhere and for a geometry for which the density saturation effect is already apparent. It is shown that when the sensitivity of the system is optimized both andvw must be used as calibration parameters while in the low-sensitivity design regionvw can be used as the only calibration parameter.
Molecular orbital calculations (EHT, IEHT, IEHT + Madelung correction) have been applied to a series of tin halides. A calculation procedure is described to derive the charge density of the electrons at the nucleus (0). The dependence of the isomer shift on covalency effects is demonstrated. The influence of the outer charge of the molecules on the isomer shift is shown. The relative change of nuclear charge radius R/R is calculated for tin.
Authors:T. Eriksen, H. Christensen, and E. Bjergbakke
The hydrogen production in -irradiated (dose rate 0.73 Gy·s–1), compacted, water-saturated bentonite (=2.12 g·cm–3) has been determined experimentally, using a gas-chromatographic technique. Hydrogen concentration in the clay pore water and hydrogen diffusion out of the irradiated bentonite have been calculated using a homogeneous reaction model. The calculated hydrogen transport out of the bentonite depends on the Fe2+ and HCO
concentration in the pore water. Agreement between experimental and calculated results can be obtained if it is assumed that a 20 m layer of water is formed between, the clay and the -source.
Molecular orbital calculations have been performed to obtain the electron density and electric field gradient at the iron nucleus of tetracarbonylethene iron Fe(CO)4(C2H4) produced by UV-irradiation of pentacarbonyliron cocondensed homogeneously with ethene in a low temperature matrix, so as to estimate the Mössbauer parameters of the species. Mössbauer isomer shifts and electron densities at iron nuclei (O) of Fe(CO)n (n=5,4,3,2) as well as Fe(CO)4(C2H4) are discussed: they have fairly good linear relationship to give –0.27 mm/s/aO–3. An isomer of Fe(CO)4(C2H4) produced via thermal reactions of Fe(CO)4 with ethene in a stratified matrix is discussed by comparing the calculated and observed Mössbauer parameters.
Authors:S. Zehtab-salmasi, A. Javanshir, R. Omidbaigi, H. Alyari, and K. Ghassemi-golezani
Field and greenhouse experiments were carried out in order to determine the effects of water supply and sowing date on the performance and essential oil production of anise (Pimpinella anisum L.). The results indicated that mean leaf area (LA), specific leaf area (SLA), relative growth rate (RGR), relative water content (RWC), grain yield and essential oil decreased, while the root/shoot ratio and the oil percentage of the seeds increased when the available soil water decreased to below 80% in the greenhouse. It was concluded that for higher grain and essential oil production, anise must be sown early in the spring (April 4 to 16) in Tabriz. Water deficit during stem elongation and umbel appearance reduced anise growth, grain yield and oil production. Seeds harvested at the waxy stage had higher oil content than those harvested at earlier or later stages.
The use of growth analysis and growth parameters could make an important contribution to improving the utilisation of N fertiliser by maize hybrids. In 2001 and 2002 the effect of four N fertiliser rates (0, 80, 160, 240 kg ha
) on the growth and productivity of three maize hybrids with different vegetation periods was studied in a long-term experiment involving continuous maize, representing a stress environment, set up in Martonvásár on chernozem soil with forest residues almost 50 years ago. Each year eight samples were taken at 14-day intervals for the destructive method of growth analysis. N fertiliser was found to have a significant effect on the growth parameters of individual plants (RGR, NAR, LAR) in both the vegetative and generative stages of growth, up to N rates of 80 and 160 kg ha
, respectively. The value of RGR increased until the N
treatment and that of NAR until N
, while LAR declined significantly in response to N fertilisation. RLGR was enhanced by N fertiliser up to a rate of N
, and all the N treatments reduced the extent of leaf withering. Among the growth parameters of the canopy, the values of CGR and HI rose significantly up to N
and that of LAI
up to N
. The cumulative values of LAD and BMD were highest in the N
treatment. All the growth parameters increased as the vegetation period of the hybrids lengthened, and all reflected the year effect. Compared to the highest N rate, N stress of 29–38% was calculated for the control treatment. On average, N fertilisation resulted in a 6–27% relative decline in LAI after flowering.
Chang ( 2010b ) to define patent share of a company in its most important technological field (PS MIT ) as its patent counts in its most important technological field divided by the total patent counts owned by the company. Relative growth rate (RGR
Using the classical and functional methods of growth analysis, the effect of mineral N fertiliser (0, 80, 160 and 240 kg ha
) on the dynamics of growth and growth parameters was studied in 2001 and 2002 in a two-factorial, long-term experiment set up in a split-plot design on three maize hybrids with different genotypes, Mv 272 (FAO 280), Mv 355 (FAO 390) and Maraton (FAO 450). The following growth parameters were calculated to characterise the effect of N fertiliser: the absolute growth rate (AGR, ALGR), the relative growth rate (RGR), the leaf area index (LAI), the net assimilation rate (NAR) and the harvest index (HI).Similar tendencies were found for the yield response of maize and the values of the growth parameters as a function of N fertilisation. Based on the results of principal component analysis, multiple regression analysis and discriminant analysis, the parameters AGR, LAI
, ALGR and HI were found to have a decisive influence on the grain yield of maize. It could be concluded from the results that growth parameters can be used to predict the N fertiliser responses of maize in early growth stages.
Authors:A. Zebarjadi, H. Ghasempour, and Z. Soheilikhah
The aim of the work was to evaluate the callus induction response and in vitro drought tolerance of eight genotypes of safflower. The experiment was laid out as a completely randomized design in a factorial arrangement with three replications. To evaluate the drought tolerance of the genotypes, growing calli were exposed to drought stress after two subcultures by adding different concentrations of mannitol to the culture medium for one month. Under stress conditions, the genotypes were compared in terms of proline content, cell viability, relative growth rate, ion content (Na+ and K+), relative water content and index of tolerance. Drought affected all the measured biochemical and physiological factors and there were significant differences between the tested genotypes. The proline content increased in drought-stressed calli, and mannitol, as a stress agent, stimulated the synthesis of proline in all the genotypes, especially at the highest concentration (505 mM), whereas the ion contents, cell viability, RWC, RGR and index of tolerance exhibited a significant decrease. This suggested that these biochemical and physiological traits could be used to predict the drought tolerance of safflower genotypes. The results indicated that the cultivars Isfahan and LRV-51-51 were more drought-tolerant under in vitro conditions than the other genotypes.