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  • Articles  (73)
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  • Springer  (73)
  • 2020-2024
  • 1995-1999  (73)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (49)
  • Chemistry and Pharmacology  (24)
  • 1
    Electronic Resource
    Electronic Resource
    Temperature Effects on Soil Mineralization of Polylactic Acid Plastic in Laboratory Respirometers (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 101-108 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; respirometers ; soil degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A respirometric system was used to analyze the biodegradation of high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films in soil under laboratory conditions. The respirometric system consisted of air-conditioning pretraps, a soil reactor, and a carbon dioxide (CO2) posttrap. A 200-g homogeneous soil mixture of all-purpose potting soil : manure soil : sand [1 : 1 : 1 (w/w)] and 1.5 g of PLA plastic films in 1 × 1-cm2 squares was added to each bottle. The respirometers were placed in a 28, 40, or 55°C water bath for 182 days. Treatments (three replicates) included native corn starch (positive control), polyethylene (Glad Cling Wrap; negative control), and three PLA films: Ca-I (Cargill Dow Polymers LLC, monolayer), GII (Cargill Dow Polymers LLC, Generation II), and Ch-I (Chronopol; monolayer). The degree of polymer mineralization was indicated by the cumulative CO2 liberated from each respirometer. The initial average mineralization rate and total percentage mineralized of the PLA plastic films at 28, 40, and 55°C was 24.3, 41.5, and 76.9 mg/day with a 27, 45, and 70% carbon loss, respectively. No decrease in soil pH was observed after 182 days of mineralization. Hence, increase in soil temperature drastically enhanced the biodegradation of PLA plastic films in soil under laboratory conditions (P 〈 0.0001).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021812418325
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of temperature on performanceof LaNi4.76Sn0.24 metal hydride electrode’ (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1328-1332 
    Details
    ISSN: 1572-8838
    Keywords: metal hydride ; capacity ; temperature ; performance ; enthalpy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The effect of temperature on the performance of a LaNi4.76Sn0.24 metal hydride electrode was investigated in the temperature range of 0 to 50°C. The electrode showed a maximum discharge capacity at 25°C. The total resistance increases with a decrease of temperature from 50°C to 0°C. The apparent activation enthalpies at different states of charge were determined by evaluating the polarization resistance at different temperatures. It was found that the apparent activation enthalpy is an indicator of the relative reaction rate of the charge-transfer reaction and hydrogen absorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018460709968
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of Temperature and Relative Humidity on Polylactic Acid Plastic Degradation (1999)
    Springer
    Journal of polymers and the environment 7 (1999), S. 83-92 
    Details
    ISSN: 1572-8900
    Keywords: Polylactic acid ; temperature ; relative humidity ; degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three high molecular weight (120,000 to 200,000 g mol−1) polylactic acid (PLA) plastic films from Chronopol (Ch-I) and Cargill Dow Polymers (GII and Ca-I) were analyzed for their degradation under various temperature and relative humidity (RH) conditions. Two sets of plastic films, each containing 11 samples, were randomly hung in a temperature/humidity-controlled chamber by means of plastic-coated paper clips. The tested conditions were 28, 40, and 55°C at 50 and 100% RH, respectively, and 55°C at 10% RH. The three tested PLA films started to lose their tensile properties when their weight-average molecular weight (M w) was in the range of 50,000 to 75,000 g mol−1. The average degradation rate of Ch-I, GII, and Ca-I was 28,931, 27,361, and 63,025 M w/week, respectively. Hence, GII had a faster degradation rate than Ch-I and Ca-I under all tested conditions. The degradation rate of PLA plastics was enhanced by the increase in temperature and relative humidity. This trend was observed in all three PLA plastics (Ca-I, GII, and Ch-I). Of the three tested films, Ch-I was the first to lose its mechanical properties, whereas Ca-I demonstrated the slowest loss, with mechanical properties under all tested conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021808317416
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  • 4
    Electronic Resource
    Electronic Resource
    Electrochemical synthesis of cupric oxide powder Part II: Process conditions (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 81-85 
    Details
    ISSN: 1572-8838
    Keywords: cupric oxide ; powder ; current density ; temperature ; sodium sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Electrosynthesis of cupric oxide powder was carried out on a laboratory scale in an electrochemical cell under various experimental conditions. The electrolysis was appraised in terms of the particle size of the cupric oxide product and the anodic dissolution of the copper electrode. Using a previously determined pH value of 7.50, the other optimum electrolysis operating conditions established were a current density of 4000Am−2, temperature of 353K, and Na2SO4 concentration of 0.5m. The optimum values of current efficiency, cell voltage and specific energy consumption for the electrochemical synthesis of cupric oxide powder were determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003464914657
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  • 5
    Electronic Resource
    Electronic Resource
    Sulfate solubility algorithms for CaSO4–NaCl–H2O and Na2SO4–NaCl–H2O in chlor alkali brine at 25, 65, 75 and 85 ∘C (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 525-528 
    Details
    ISSN: 1572-8838
    Keywords: brine ; chlor-alkali cells ; solubility ; sulfate ions ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026405806916
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  • 6
    Electronic Resource
    Electronic Resource
    Excess volumes of binary mixtures of ethylbenzene with octanol, nonanol and dodecanol from 50 to 100°C and 0.1 to 7.5 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 153-170 
    Details
    ISSN: 1572-8927
    Keywords: Densities ; excess volume ; pressure ; temperature ; ethylbenzene ; octanol ; nonanol ; dodecanol ; order creation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The excess volume V E of binary mixtures of octanol, nonanol and dodecanol in ethylbenzene have been calculated from the densities measured with a vibrating tube densimeter at temperatures from 50 to 100 °C and at pressures from 0.1 to 7.5 MPa. The values of V E are positive for all the three mixtures in the complete temperature, pressure and mole fraction ranges studied. The maxima in V E is observed at 0.4 mole fraction of alkanol. The results are discussed in terms of specific interactions present in the binary mixtures. The second order thermodynamic quantities (∂V E /∂T)p,(∂V E /∂P)T and (∂V E /∂P)T which have been derived from the effect of temperature and pressure on V E , indicate an overall net creation of order in the binary mixtures of ethylbenzene with higher homologues of alkanols.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00972839
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  • 7
    Electronic Resource
    Electronic Resource
    Electrical conductances of aqueous sodium trifluoromethanesulfonate from 0 to 450°C and pressures to 250 MPa (1995)
    Springer
    Journal of solution chemistry 24 (1995), S. 753-769 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; sodium trifluoromethanesulfonate ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrical conductances of dilute (0.001 to 0.1 mol-kg−1) aqueous sodium trifluoromethanesulfonate (NaCF3SO3) solutions have been measured from 0 to 450°C and pressures to 250 MPa. The limiting molar conductance $$\Lambda _0 $$ increases with increasing temperature from 0 to 300°C and decreasing density from 0.8 to 0.3 g-cm−3. Above 300°C, $$\Lambda _0 $$ is nearly temperature independent, but increases linearly with decreasing density. The logarithm of the molal association constant of NaCF3SO3 calculated at temperatures from 372 to 450°C is represented as a function of temperature (Kelvin) and density of water (g-cm−3) by $$\log K_m = 0.888 - 330.4/T - (12.83 - 5349/T)\log \rho _w $$ The relative strengths of NaCF3SO3 and NaCl are similar within the accuracy of the current measurements over the limited range of temperature and pressure that could be investigated here.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01131043
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  • 8
    Electronic Resource
    Electronic Resource
    Low ambient temperature decreases cadmium accumulation in the liver and kidneys of the bank vole (Clethrionomys glareolus) (1996)
    Springer
    BioMetals 9 (1996), S. 363-369 
    Details
    ISSN: 1572-8773
    Keywords: cadmium ; copper ; iron ; photoperiod ; temperature ; zinc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The importance of photoperiod and ambient temperature on the accumulation of cadmium in the liver and kidneys of bank voles was determined in the present study. Males and females, aged 1 month, were given 3.0 μg Cd ml−1 drinking water and divided into four groups according to photoperiod (16 h light/8 h dark and 8 h light/16 h dark) and ambient temperature (20 or 5°C); liver and kidneys were removed for cadmium as well as copper, iron and zinc analyses at the end of 6 weeks. Bank voles exposed to 5°C in both photoperiods consumed approximately 30% less water containing cadmium than those kept at 20°C. However, the total accumulation of cadmium in the liver and kidneys of males and females exposed to the low temperatures was 4.3–4.8 and 2.2–3.3 times less than that in animals maintained at room temperature in the long and short photoperiod, respectively. Simultaneously, the low temperature brought about an increase in the copper concentrations in the liver (12–43%) and kidneys (47–78%), giving rise to an inverse correlation between the cadmium accumulation and the tissue copper concentration. In contrast to cadmium and copper, the concentrations of iron and zinc were affected primarily by photoperiod. These findings indicate that ambient temperature is an important determinant of cadmium retention in the bank vole. It appears that low temperature decreases tissue cadmium accumulation not only by reducing cadmium intake but also through changes in copper metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140605
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  • 9
    Electronic Resource
    Electronic Resource
    Voltammetric Analysis of Iodide and Diffusion Coefficients Between 25 and 85°C (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 373-393 
    Details
    ISSN: 1572-8927
    Keywords: Iodide ; voltammetry ; diffusion coefficients ; temperature ; Stokes–Einstein equation ; solvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The oxidation wave of iodide in 0.075 mol-L−1 H2SO4 was analyzed at 25, 40, 55, 70, and 85°C. The reversibility of the I2/I− system was checked using logarithmic transforms, half-wave potentials, and by studying I −1 = f(ω−1/2). The limiting currents obtained enabled us to determine the diffusion coefficient of I− using Newman's equation. These experimental results were compared with Nernst's limiting values. The Stokes–Einstein equation is not verified. Hydration numbers for I− at different temperatures were established. An empirical equation is proposed to predict the evolution of diffusion coefficients in a sulfuric acid medium with temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022679716395
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  • 10
    Electronic Resource
    Electronic Resource
    Ion association of dilute aqueous sodium hydroxide solutions to 600°C and 300 MPa by conductance measurements (1996)
    Springer
    Journal of solution chemistry 25 (1996), S. 711-729 
    Details
    ISSN: 1572-8927
    Keywords: Conductivity ; aqueous ; sodium hydroxide ; ion association ; temperature ; pressure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The limiting molar conductances Λ0 and ion association constants of dilute aqueous NaOH solutions (〈0.01 mol-kg−1) were determined by electrical conductance measurements at temperatures from 100 to 600°C and pressures up to 300 MPa. The limiting molar conductances of NaOH(aq) were found to increase with increasing temperature up to 300°C and with decreasing water density ρw. At temperatures ≥400°C, and densities between 0.6 to 0.8 g-cm−3, Λ0 is nearly temperature-independent but increases linearly with decreasing density, and then decreases at densities 〈0.6 g-cm−3. This phenomenon is largely due to the breakdown of the hydrogen-bonded, structure of water. The molal association constants K Am for NaOH( aq ) increase with increasing temperature and decreasing density. The logarithm of the molal association constant can be represented as a function of temperature (Kelvin) and the logarithm of the density of water by $$\begin{gathered} log K_{Am} = 2.477 - 951.53/T - (9.307 \hfill \\ - 3482.8/T)log \rho _{w } (25 - 600^\circ C) \hfill \\ \end{gathered} $$ which includes selected data taken from the literature, or by $$\begin{gathered} log K_{Am} = 1.648 - 370.31/T - (13.215 \hfill \\ - 6300.5/T)log \rho _{w } (400 - 600^\circ C) \hfill \\ \end{gathered} $$ which is based solely on results from the present study over this temperature range (and to 300 MPa) where the measurements are most precise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00973780
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  • 11
    Electronic Resource
    Electronic Resource
    Phosphorus supplying capacity of heavily fertilized soils II. Dry matter yield of successive crops and phosphorus uptake at different temperatures (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 123-134 
    Details
    ISSN: 1573-0867
    Keywords: heavily fertilized soils ; P supplying capacity ; P uptake ; residual P ; soil test methods ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nine heavily fertilized soils were collected from southern and central Norway. A greenhouse experiment in the phytotron was conducted to evaluate the P supplying capacities of these soils at different temperatures (9, 12 and 18 °C). The crops were grown in succession and the sequence was oat, rye grass (cut twice), oat, rape and oat. Effect of temperature on dry matter (DM) yield and P uptake was more marked up to the fourth crop but the effect varied among crops. The DM yields of oat and rape increased with increasing temperature but the opposite was the case with rye grass. The yield differences among soils at 12 °C were highly significant (p 〈 0.01) in contrast to 9 and 18 °C. The amount of P taken up by plants in these soils was highest at 18. °C. The P supplying capacity was highest in the soils with higher content of organic P. Generally, the soils of very fine and coarse texture classes failed to supply enough P to crops to avoid P deficiency in the successive crops. Soil P test (P-NH4-lactate) values in most of the soils increased with increasing temperatures. The highest temperature effect was seen in the Særheim sand soil. Soil P test extractants P-AL, Bray-1 and Colwell-P were used to determine P in the soil after each harvest and the soil P test values were compared with P uptake by crops. Only the P-AL extractant was significantly correlated to cumulative P removal (CPR) by plants in most of the soils. Regression equation was calculated for each soil. The value of removed P per harvest (RPH) varied from 10.33 to 20.87 mg P kg−1 soil. Phosphorus drawdown slope was determined for each soil and the number of consecutive harvests necessary to reduce the P-AL value to a normal level (110 mg P kg−1 soil) was calculated. The drawdown slope varied widely (1.257–2.801) and this reflected the P buffer capacity and the number of crops required to lower the soil test P value to a normal level. The highest drawdown slope was found in the soils with higher P supplying capacities. The Bray-1 extractant was significantly correlated in the soils with higher buffer capacity but the Colwell-P method did not show significant correlation in any of the soils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01991544
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  • 12
    Electronic Resource
    Electronic Resource
    Effects of temperature on nutrient release from slow-release fertilizers (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 179-187 
    Details
    ISSN: 1573-0867
    Keywords: electrical conductivity ; leaching ; nitrogen ; pH ; phosphorus ; potassium ; release pattern ; slow-release fertilizers ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We studied the effect of temperature on the release of N, P, and K from slow-release fertilizers (SRF). The study was conducted in micro-lysimeters filled with moist peat medium. Increasing the temperature from 4 to 12°C slightly increased N release from three different slow-release N (SRN) carriers with different particle sizes and coating thicknesses. At 21°C the rate of release was significantly different than the other two temperatures. Urea formaldehyde (UF), sulphur coated urea (SCU) and coated calcium nitrate (CCN), incubated in sphagnum moss peat, released between 3 and 20% of the applied N in six weeks. For eight synthetic and organic NPK carriers, the release pattern was similar to UF and SCU. However, the leaching losses of N from the NPK fertilizers were up to twenty times more than for the SRN products. Except for Osmocote® and Duna, which released 30–40% of the applied N as mineral-N within six weeks, all other slow-release and slowly mineralized NPK carriers acted like readily water-soluble compound NPK. Temperature did not affect the nutrient release from NPK fertilizers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00420552
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  • 13
    Electronic Resource
    Electronic Resource
    Nitrous oxide (N2O) emissions from soils in warm climates (1995)
    Springer
    Nutrient cycling in agroecosystems 42 (1995), S. 159-163 
    Details
    ISSN: 1573-0867
    Keywords: nitrous oxide ; tropical soils ; agriculture ; N availability ; temperature ; soil water content
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract N2O emission rates seem to be higher from soils in warm climates than from soils in temperate climates. Warm and moist conditions promote microbial processes that generate N2O. Clearance of tropical forests enhances N2O formation, but emission measurements from other agricultural operations in the tropics are few. Limiting fertilizer application to recommended rates applied at appropriate times and avoiding fallow land wherever practical serves to limit N2O emissions. More specific advice for agriculture in warm climates requires further studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750510
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  • 14
    Electronic Resource
    Electronic Resource
    Powdered elemental sulphur: oxidation rate, temperature dependence and modelling (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 19-28 
    Details
    ISSN: 1573-0867
    Keywords: elemental sulphur ; model ; oxidation rate ; particle size distribution ; soil ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Finely-powdered elemental sulphur is a useful source of fertilizer S, being readily oxidizable in soil to plant-available sulphate yet possessing some slow release characteristics. Two mesh sizes were evaluated using four soils from northeast Scotland. Particle size analysis found that the 120 and 300 mesh S samples had specific surface areas of 1300 and 1940 cm2 g−1, respectively, with most of the surface area in particles of 10 – 20 µm diameter. The S oxidation rate was similar in all four soils but was greater for the 300 mesh than for the 120 mesh S: mean values of 51% and 18% were oxidized over 7 weeks at 14 °C, respectively. The time course of oxidation followed a sigmoidal pattern with a pronounced lag which was modelled using the logistic equation. Maximum specific oxidation rates were 11–28 µg S cm−2 day−2 for the 300 mesh S at 14 °C. These were significantly slower at 7 °C and the temperature response was calculated as a Q10 of 4.0. A model of seasonal S oxidation was developed using a cosine function for the annual temperature, the Arrhenius equation to relate S oxidation rate to temperature and a generalization of the logistic equation to describe the time course of S oxidation. Simulations showed that the 300 mesh S would be useful for spring S applications in east Scotland and if applied in autumn could supply S during the autumn and again in the spring. The 120 mesh S would be less effective in autumn but more resistant to winter leaching. The 120 mesh S applied to the warmer soils of southwest England would behave the same as 300 mesh S applied in east Scotland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01985715
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  • 15
    Electronic Resource
    Electronic Resource
    Comparative studies on some analytical methods (1997)
    Springer
    Journal of thermal analysis and calorimetry 49 (1997), S. 857-862 
    Details
    ISSN: 1572-8943
    Keywords: analytical methods ; kinetics ; powder milk ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This work present comparative results on powder milk storage quality, obtained from analytical methods. Protein content was determined conventional (Kjeldahl) and colorimetric with biuret reagent at 540 nm and integral quality by thermogravimetric and biological methods. A method was developed for the protein separation of powder milk. Powder milk was submitted to degradation processes at 45, 60 and 80°C for 20 days. The results indicated that protein content values were inconsistent if determinations by Kjeldahl and colorimetric methods and biological tests were compared. There is evidence of thermal decomposition of powder milk as detected by biological and thermogravimetric methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996770
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  • 16
    Electronic Resource
    Electronic Resource
    Thermodynamics of Polyvinylacetate from 0 to 350 K (1998)
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 731-740 
    Details
    ISSN: 1572-8943
    Keywords: enthalpy ; entropy ; Gibbs energy ; heat capacity ; limiting polymerization temperature ; polyvinylacetate ; temperature ; thermodynamics of polymerization ; vinyl acetate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The temperature dependence of the heat capacity of vinyl acetate in the range 13 to 330 K and of polyvinylacetate between 4.9 and 330 K was determined by adiabatic vacuum calorimetry with an error of about 0.2%. Temperatures and enthalpies of physical transitions were measured. From the data obtained, the thermodynamic characteristics of melting of vinyl acetate and parameters of glass transition and glassy state of the monomer and polymer were calculated. The thermodynamic functions Ho(T)-Ho(0), So(T), Go(T)-Ho(0) were estimated for both materials from 0 to 350 K. The results of calculation and the literature value of enthalpy of bulk polymerization of vinyl acetate at T=350 K were used for the estimation of the thermodynamic parameters of its polymerization process ΔHpol o, ΔSpol o, ΔGpol oin the interval 0 to 350 K. A ceiling limiting temperature of polymerization Tceil owas evaluated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010179517532
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  • 17
    Electronic Resource
    Electronic Resource
    Characterization of a twin-torch transferred dc arc (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 309-331 
    Details
    ISSN: 1572-8986
    Keywords: Transferred arc ; voltage-current characteristic ; inhomogeneous plasma ; optical emission spectroscopy ; electron density ; temperature ; spatial distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The results of a twin-torch transferred de arc .study are presented. The arc system consists of two torches of opposite polarity, and a coupling zone of plasma jets located between them. The torch configuration increases the system reliability and efficiency during material plasma processing. The results of the study present data for the voltage-current characteristics, general behavior of the twin-torch arc, and spatial distribution of the plasma parameters. The plasma parameters have been measured using optical emission spectroscopy for a 200 A (20 k W) do arc, at atmospheric pressure, with argon and nitrogen introduced as plasma forming gases into the anode and the cathode units, respectively. The measurement technique used has allowed the determination of local electron density and temperature values in an inhomogeneous plasma volume having no axial sysmmetry. The data obtained illustrate the novel features of the twin-torch transfrred do arc for its applications in plasma processing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01459701
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  • 18
    Electronic Resource
    Electronic Resource
    Hydrogen/argon plasma jet with methane addition (1995)
    Springer
    Plasma chemistry and plasma processing 15 (1995), S. 333-351 
    Details
    ISSN: 1572-8986
    Keywords: Hydrogen/argon plasma ; methane ; do arc jet ; atmospheric pressure ; optical emission spectroscopy ; temperature ; density ; spatial distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Spatial distributions of plasma parameters are presented for a H2/Ar plasma jet with addition of methane. The plasma has been generated at atmospheric pressure by a 200 A (20 kW) nontransferred do arc. Optical emission spectroscopy has been used for the measurements assuming the plasma jet to be optically thin and to have an axial symmetry. Local spectral ernissivity values have been evaluated using a routine Abel inversion procedure. Half- width and emissivity of Hβ spectral line have been measured to determine the electron density and temperature of the plasma. The densities of excited C, CH radicals have been evaluated from the absolute emissivities of relevant molecular emission bands measured in limited spectral intervals in the visible spectrum. The emissivity ratios have been used to fund rotational and vibrational temperatures. The results supply information on methane decomposition and the behavior of molecular radicals in close-to-thermal plasma jets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01459702
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  • 19
    Electronic Resource
    Electronic Resource
    The effect of condensation on sporulation ofHelminthosporium solani on potato tubers infected with silver scurf and held in simulated store conditions (1997)
    Springer
    Potato research 40 (1997), S. 169-180 
    Details
    ISSN: 1871-4528
    Keywords: skin resistance ; temperature ; Solanum tuberosum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Chambers were designed to simulate environmental conditions present in commercial potato stores and were used to introduce condensation to tubers infected with silver scurf (Helminthosporium solani). The electrical resistance measured across the skin of tubers from the top of the chambers was consistently lower than that from the bottom of the chamber, and this was reflected in an increased number ofH. solani spores produced by the top tubers. An increase in the length of the condensation period resulted in the skin resistance remaining lower for a longer period and also resulted in higher number of spores. Tubers held at relatively high ambient temperatures (15 °C) required a shorter period of condensation to cause an increase in spore count. This investigation highlighted the need for close monitoring of store environments so that condensation events can be quickly identified and the tubers dried.
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    URL: http://dx.doi.org/10.1007/BF02358243
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    The effect of some environmental factors on potato tuber numbers (1997)
    Springer
    Potato research 40 (1997), S. 297-306 
    Details
    ISSN: 1871-4528
    Keywords: light ; temperature ; stolon growth medium ; below ground nodes ; Solanum tuberosum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Five experiments studied the effects of shading, temperature and stolon growth medium on stolon and tuber formation. The lowest numbers of stolons and tubers were produced at the higher and lower nodes. Numbers of primary stolons and tubers were relatively stable across nodes and treatments and variation in total numbers was largely due to changes in numbers of lateral and branch stolons. In the field, 70% shading reduced numbers of stolons and tubers by reducing lateral and branch stolons, while in hydroponics, 45% shading and temperatures at initiation had no effect on tuber numbers. In both environments later planting tended to reduce numbers of stolons and tubers. There were large effects of the physical environment, with compost producing three times as many tubers as dry vermiculite. The potential number of tubers may be determined by the number of stolons and the environmental conditions affecting stolon formation and development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02358011
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    Shoot development and flowering in potato (Solanum tuberosum L.) (1996)
    Springer
    Potato research 39 (1996), S. 581-607 
    Details
    ISSN: 1871-4528
    Keywords: assimilate partitioning ; flower primordia survival ; flower production ; photoperiod ; stem production ; temperature ; time to flower primordia initiation ; tuber initiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The shoot system of potato is a configuration of stems with terminal inflorescences. In this review, shoot development is quantified in terms of stem production, while stem development is quantified in terms of leaf and flower primordia production per stem, which are functions of the rates and the durations of primordia initiation. The effect of the position of the stem in the shoot system on number of leaves and flowers per stem is also evaluated. Flowering of individual stems is described by the ‘time to flower primordia initiation’ (expressed in number of leaves produced) and ‘flower production’ (a function of the number and the development of flower primordia). At warmer temperatures and longer daylengths the number of leaves and flower primordia per stem, and the number of stems per shoot increase by prolonging stem production and primordia development. Temperature and photoperiod also affect flower primordia survival by altering assimilate production and partitioning. The photothermal response of the number of leaves per stem is small compared to the response of stem production; at higher temperatures, flower primordia survival becomes the principal factor determining flower production. The similarity of the signals leading to flower primordia initiation and tuberization, and the relation between shoot and tuber growth are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02358477
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    High temperature conjugation of proteins with carbohydrates (1998)
    Springer
    Glycoconjugate journal 15 (1998), S. 131-138 
    Details
    ISSN: 1573-4986
    Keywords: protein ; conjugate ; carbohydrate ; lyophilization ; vaccine ; temperature ; heating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new procedure was used to conjugate lactose and dextran with BSA without using coupling or activating reagents. The method is simple, rapid and cheap. Reducing sugars covalently bind to proteins when lyophilized together and briefly heated to a high temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007067513242
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    Effects of Temperature on Growth and Efficiency of Yolk Utilisation in Eggs and Pre-feeding Larval Stages of Atlantic Salmon (1999)
    Springer
    Aquaculture international 7 (1999), S. 81-87 
    Details
    ISSN: 1573-143X
    Keywords: alevin ; Atlantic salmon (Salmo salar) ; development ; egg ; temperature ; thermal tolerance ; yolk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Three embryonic stages of Atlantic salmon (Salmo salar L.) were subjected to eight constant incubation temperatures (4, 7, 10, 12, 14, 16, 19 and 22 °C) exceeding the range usually experienced in natural conditions. A change in thermal tolerance during the embryonic and larval development was registered: pre-hatching stages showed an upper thermal limit at about 16 °C, while hatched larvae survived until 22 °C. Temperature significantly affects developmental rate, resulting in a faster development and, consequently, lower yolk weight percentage at higher temperatures. We found positive relationships between incubation temperature and body size (length and weight) in the less developed stages, in which some yolk remained, but size decreased at increasing temperatures when yolk was completely exhausted.
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    URL: http://dx.doi.org/10.1023/A:1009214804949
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    Growth and Chemical Composition of Spirulina Maxima and Spirulina Platensis Biomass at Different Temperatures (1999)
    Springer
    Aquaculture international 7 (1999), S. 261-275 
    Details
    ISSN: 1573-143X
    Keywords: cyanobacteria ; microalgae ; Spirulina ; Spirulina composition ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The influence of temperature on growth and biomass composition of two species of Spirulina, S. maxima and S. platensis used for food was studied. A 4L fermenter with temperature and agitation control was used to cultivate both species. Under continuous light, maximum cell production of 2.4 g l−1 was verified for both cultures studied at temperatures above 25 °C: S. maxima (30 °C and 35 °C) and S. platensis (25 °C and 30 °C). An accentuated lag phase was observed for all cultures at lower temperatures (15–20 °C), and a maximum biomass production of 1.5 g l−1 was achieved. It was also observed that an increase of temperature caused a marked decrease in protein content, while carbohydrate synthesis was stimulated. The concentration of γ-linolenic acid varied from 11–16% for S. maxima and from 12–14% for S. platensis, at the optimum growth temperatures. Greater culture volumes were also studied in order to compare the performance of glass and plastic containers. At optimum growth temperature, S. maxima produced the same cell growth and similar final biomass composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009233230706
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    Interactive effects of elevated carbon dioxide and growth temperature on photosynthesis in cotton leaves (1998)
    Springer
    Plant growth regulation 26 (1998), S. 33-40 
    Details
    ISSN: 1573-5087
    Keywords: carbohydrates ; elevated CO2 ; Gossypium hirsutum L. ; interaction ; photosynthesis ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Cotton (Gossypium hirsutum L., cv DPL 5415) plants were grown in naturally lit environment chambers at day/night temperature regimes of 26/18 (T-26/18), 31/23 (T-31/23) and 36/28 °C (T-36/28) and CO2 concentrations of 350 (C-350), 450 (C-450) and 700 μL L-1 (C-700). Net photosynthesis rates, stomatal conductance, transpiration, RuBP carboxylase activity and the foliar contents of starch and sucrose were measured during different growth stages. Net CO2 assimilation rates increased with increasing CO2 and temperature regimes. The enhancement of photosynthesis was from 24 μmol CO2 m-2 s-1 (with C-350 and T-26/18) to 41 μmol m-2 s-1 (with C-700 and T-36/28). Stomatal conductance decreased with increasing CO2 while it increased up to T-31/23 and then declined. The interactive effects of CO2 and temperature resulted in a 30% decrease in transpiration. Although the leaves grown in elevated CO2 had high starch and sucrose concentrations, their content decreased with increasing temperature. Increasing temperature from T-26/18 to 36/28 increased RuBP carboxylase activity in the order of 121, 172 and 190 μmol mg-1 chl h-1 at C-350, C-450 and C-700 respectively. Our data suggest that leaf photosynthesis in cotton benefited more from CO_2 enrichment at warm temperatures than at low growth temperature regimes.
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    URL: http://dx.doi.org/10.1023/A:1006035517185
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    Effects of radiation, especially ultraviolet B, on conidial germination and mycelial growth of grape powdery mildew (1996)
    Springer
    European journal of plant pathology 102 (1996), S. 441-449 
    Details
    ISSN: 1573-8469
    Keywords: monocyclic process ; epidemiology ; UV B ; temperature ; Uncinula necator ; Vitis vinifera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Conidia ofUncinula necator inoculated on vine leaf disks were exposed to different irradiation conditions during various combinations of irradiation periods. In controlled experiments at constant leaf temperature spore germination and mycelial growth were negatively affected by the UV B doses, irrespective of the exposition duration. In semi-controlled condition experiments, conidia were exposed to shaded, sunny and sunny without UV B radiation conditions. Shaded conditions were always more favourable to spore germination and mycelial growth than sunny conditions. Under two different ranges of temperature (20–24 and 26–31 °C for shaded conditions), the effect of radiation on germination and mycelial growth differed. Thus, the effect of radiation on spore germination and mycelial growth seems to be affected by temperature. In general, radiation effects increased as the number of exposition periods increased, indicating that both spore germination and mycelial growth were reduced, but not totally stopped by the different exposures. Germination was most affected by exposures applied just after inoculation, whereas mycelial growth was most affected by exposures applied one day after inoculation. These results indicate that radiation is an important factor to consider for a better understanding of the relationships between climate and grape powdery mildew epidemics.
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    URL: http://dx.doi.org/10.1007/BF01877138
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    Factors affecting germination of oospores of Peronospora viciae f.sp. pisi in vitro (1997)
    Springer
    European journal of plant pathology 103 (1997), S. 573-580 
    Details
    ISSN: 1573-8469
    Keywords: Pisum sativum ; host plant exudates ; light ; temperature ; infection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of host plant exudates, light and temperature on germination of oospores of Peronospora viciae f.sp. pisi in vitro were investigated. Seed and root exudates did not increase percentage germination, whereas light inhibited germination. The first germ tubes appeared after 4, 7, and 14 days of incubation at 15, 10 and 5 °C, respectively. The eventual level of germination was highest and had similar values at 5 and 10 °C. At 20 °C germination was poor and at 25 °C no germination was observed. Oospores placed on membrane filters were incubated on soil. When oospores were retrieved from the membrane filters after six days and placed in water at 10 °C, they germinated within 2 days. On soil significantly less oospores germinated than in water. Germinability of oospores stored in the dark at 5 or 20 °C at 30 or 76% RH was studied over a two-year period. Germinability generally increased over time, but fluctuations were observed indicating the occurrence of secondary dormancy. Time courses of germinability were generally similar for oospores stored at several temperatures and humidities. No effect of light on time course of germinability was found when oospores were exposed to alternating light-dark periods or stored in continuous dark for 140 days. Percentage germination observed in a germination assay was correlated with percentage infection determined in a bioassay.
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    URL: http://dx.doi.org/10.1023/A:1008607100742
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    Effects of Temperature on Infection in Capsicum sp. and Nicotiana benthamiana by Impatiens Necrotic Spot Tospovirus (1999)
    Springer
    European journal of plant pathology 105 (1999), S. 509-512 
    Details
    ISSN: 1573-8469
    Keywords: tospovirus ; resistance ; Capsicum sp. ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Infection by two isolates of impatiens necrotic spot tospovirus (INSV) under temperature regimes of 25/18°C (day/night) or 33°C (continuous) was studied in Capsicum annuum (systemically susceptible to tomato spotted wilt tospovirus, TSWV), C. chinense PI 152225 and PI 159236 (reacting hypersensitively to TSWV) and Nicotiana benthamiana (systemically susceptible to both tospoviruses). At 25/18°C infection was systemic in all hosts tested. At 33°C infection in N. benthamiana was systemic whereas in C. annuum and C. chinense it was restricted to the inoculated leaves. The result differed from that reported for TSWV, where high temperature made plants more susceptible, or caused no difference. Exchanging temperature regimes 6 h to 4 days after inoculation did not affect the final results one month later, with plants being only locally infected at 33°C continuous regime, or systemically infected at 25/18°C alternate regime. The two INSV isolates were biologically and serologically stable for 5 passages in N. benthamiana held continuously at 33°C.
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    URL: http://dx.doi.org/10.1023/A:1008742516820
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    Integrated Pharmacokinetic–Pharmacodynamic Model for Acetaminophen, Ibuprofen, and Placebo Antipyresis in Children (1998)
    Springer
    Journal of pharmacokinetics and pharmacodynamics 26 (1998), S. 559-579 
    Details
    ISSN: 1573-8744
    Keywords: acetaminophen ; age ; antipyretic ; fever ; ibuprofen ; pediatrics ; pharmacokinetics ; pharmacodynamics ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A descriptive profile for antipyretic drug action has been documented for children. However, a linked pharmacokinetic–pharmacodynamic (PK/PD) model is central to the understanding of antipyretic drug action in febrile children. This was examined for previously reported data from 178 febrile children who received a single oral dose of acetaminophen (APAP) (12.5 mg/kg), ibuprofen (IBU) (5 or 10 mg/kg), or placebo. Rectal temperatures and plasma levels (μg/ml) of APAP and IBU were measured for up to 12 hr after drug administration. Nonlinear regression analyses were applied to these measurements and yielded simultaneous solutions of an integrated one-compartment PK, link, and SigmoidEmax effect model in 102/153 febrile children given APAP or IBU. The PK parameters (tlag ,ka , β,T1 / 2β ,AUC0–∞ ,Vd/F,andClp/F) were not different than those reported previously, except the APAPka was significantly lower. The link component yieldedkeo s of 0.58±0.06 (X±SE), 0.70±0.11 and 0.57 ± 0.11 hr -1 for APAP, IBU05, and IBU10, respectively: the SigmoidEmax component yieldedEC50 s (μg/ml) and sigmoidicity (γ) of 4.63±0.39 and 3.98±0.42 for APAP, 11.33±1.35 and 3.97±0.58 for IBU05 and 12.83±1.89 and 4.27±0.63 for IBU10. On visual inspection of the efficacy–time profiles of the febrile children, a number of them had an apparent linear function (slope; Δ°C/hr) and/or a sinusoidal cyclic function “confounding” standard approaches to PD analysis. Thus, the temperature profiles of 91/102 children given APAP or IBU required the addition of a slope (Δ°C/hr) and/or a sinusoidal cyclic function to the SigmoidEmax component to fit the data satisfactorily. All 22 children given a placebo also required a slope and/or a cyclic function in their PD model. The residual Δ°Cs (observed-predicted) of the placebo group were not significantly different from 0. Thus, no placebo antipyretic effect was observed. Dose dependency of IBUAUC0–∞ was confirmed; doubling the dose from 5 to 10 mg/kg increased theAUC0→∞ by only 1.5-fold. The confounding effect of initial temperature (Tempi ) on antipyretic efficacy in all treatment groups except placebo was also confirmed to expose nonlinear pharmacodynamics. A significant (p=0.03) contribution ofTempi (but not age) on the value of the slope function was found. There was no consistent effect of age orTempi , on the cyclic component of the integrated model of antipyresis. In addition, a multiple linear relationship of age andTempi was observed with a large number of the PK, link, and PD variables in those who received IBU. Dose, age, andTempi interacted with β in a significant multiple linear relationship withAUC0–∞ . The effects of IBU dose, age, andTempi are pervasive and cascade down the chain of events leading to the PD response. The etiology of pyresis may create the slope function, the magnitude of which may be partially due to the underlying disease. In some cases, the cyclic function may be explained by temperature regulation. Regardless of their cause, both confound analysis of drug action and make the simple, unmodified SigmoidEMax effect model less than satisfactory for interpretation of antipyretic drug effects. The influence of Tempi on the magnitude of antipyretic drug response is also a finding with major impact on PD investigations of antipyretic medications. In children receiving IBU, dose and age are also confounders, in addition toTempi . A multiplicity of covariables must be taken into account when developing appropriate dosing regimens for these antipyretics in febrile children.
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    URL: http://dx.doi.org/10.1023/A:1023225217108
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    Micellization of triblock copoly(ethyleneoxide/tetrahydrofuran/ethylene oxide) (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 467-473 
    Details
    ISSN: 1435-1536
    Keywords: Key words Block copolymers ; micelle ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The association behaviour of triblock copoly(ethylene oxide/tetrahydrofuran/ethylene oxide), in particular E100T27E100, in aqueous solutions has been investigated by means of static and dynamic light scattering, nuclear magnetic reso-nance (NMR) and surface tension techniques. On raising the polymer concentration at room temperature, the copolymer aggregates to form micelles with an aggregation number of about 105 (R G, mic≈15 nm and R H, mic≈13 nm, as revealed by light scattering and FT-PGSE NMR measurements, respectively). The micelles are kinetically quite stable, the micellar lifetime is shown to be more than 1 h. The residence time of a single unimer in a micelle is more than 140 ms. The apparent radius of gyration R G, mic is fairly independent of concentration, but large effects are observed on varying the temperature. Raising the temperature initially results in an increase of the apparent micellar size, followed by a maximum at an intermediate temperature (≈45 °C). At higher temperatures a contraction of the micelles is observed. The shape of the micelles also appear to vary in this temperature interval. The interactions responsible for these phenomena are discussed in terms of, e.g., the temperature-dependent solubility of the alkylene oxide segments in water and polydispersity effects.
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    PGSE-NMR studies of solvent diffusion in poly(N-isopropylacrylamide) colloidal microgels (1995)
    Springer
    Colloid & polymer science 273 (1995), S. 405-411 
    Details
    ISSN: 1435-1536
    Keywords: NMR diffusion ; solvent diffusion ; hydrogels ; microgels ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The solvent self-diffusion coefficient has been studied in thermoshrinking poly(N-isopropyl acrylamide) microgel dispersions by the pulsed-gradient spin-echo PGSE-NMR technique, as a function of temperature and mass fraction. After suitable corrections for the temperature, the H2O/D2O ratio and the relative volume fractions, all the self-diffusion data obtained over a temperature range of approximately 40 °C and mass fraction (2–12 % wt/wt) could be superimposed with the volume fraction as the universal factor. The observed reduction in the solvent self-diffusion coefficient with volume fraction was greater than that predicted by simple obstruction theory. After correction for-, and the subsequent removal of the obstruction effect, the diffusion of the solvent through the core of the particle is elucidated. As found for other polymer-solvent systems, there were no specific binding effects. The diffusion of the solvent in these dispersions over such temperature and mass fraction ranges could be rationalised assuming a constant solvent self-diffusion coefficient in the core of the particles.
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    The phenology of fine root growth in a maple-dominated ecosystem: relationships with some soil properties (1998)
    Springer
    Plant and soil 201 (1998), S. 59-69 
    Details
    ISSN: 1573-5036
    Keywords: maple ; moisture ; phenology ; root growth ; soil fertility ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A two-year study was undertaken in a maple-dominated watershed of southern Québec, Canada, to examine relationships between trends in fine root growth, stem diameter growth, soil moisture, soil temperature, mineralized-N and extractable-P. Until September, soil temperature was consistently higher in 1995 than in 1994. Apart from the first sampling in mid-May, soil moisture was higher in 1994 than in 1995. In 1994, most fine roots were produced before leaf expansion, whereas in 1995, fine root production peaked in July. Annual fine root production was estimated to be 2.7 times higher in 1994 than in 1995. Stem growth was strongly associated with the seasonal and annual variation in soil temperature. Root and diameter growth were asynchronous in 1994 but not in 1995. Fine root production was associated with two groups of variables: a soil fertility (mineralized-N and extractable-P) group and a physical soil environment (moisture and temperature) group. Our results are consistent with the negative effect of high soil-N fertility on fine root production but are inconclusive as to the positive effect of high soil-P fertility. Soil conditions that are detrimental to root growth such as high N availability and anaerobiosis could modify the normal dynamics of fine root growth.
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    Floral initiation in field-grown forage peas is delayed to a greater extent by short photoperiods, than in other types of European varieties (1999)
    Springer
    Euphytica 109 (1999), S. 201-211 
    Details
    ISSN: 1573-5060
    Keywords: Pisum sativum L. ; frost resistance ; floral initiation ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Frost is one of the main climatic stresses which has to be overcome by a winter pea crop. Some forage lines show a delayed floral initiation, which helps them to escape the main winter freezing periods, as a higher susceptibility to frost is observed after floral initiation commences. Frost tolerant forage peas have been used in all winter pea breeding programs in France and our main purpose was to evaluate to what extent those lines and the current winter varieties are variable for the date of floral initiation in field conditions. A field experiment was carried out during two years at the INRA experimental station of Mons (northern France). Different genotypes (9 in 1995–1996 and 12 in 1996–1997) were sown at approximately monthly intervals between September and June to provide a range of photothermal conditions. The date of floral initiation was determined by destructive sampling. We observed variability for the date of floral initiation among the different genotypes and sowing dates. Our data particularly highlighted the different reactions to photoperiod. Three varieties had no detectable reaction. Six varieties exhibited a quantitative response, with varied intensities. Lastly, the three forage varieties showed a qualitative, high response to photoperiod, which indicated the presence of the Hr allele, already described in Pisum.
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    Effect of water availability pattern on yield of pearl millet in semi-arid tropical environments (1996)
    Springer
    Euphytica 89 (1996), S. 165-173 
    Details
    ISSN: 1573-5060
    Keywords: drought ; flowering ; grain yield ; pearl millet ; Pennisetum glaucum ; temperature ; water satisfaction index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Throughout much of the semi-arid tropics, fluctuations in grain yield can largely be attributed to differences in timing and intensity of drought stress. Since seasonal rainfall in these environments is often poorly related to grain yield, the aim of this paper was to establish a relationship between water availability and grain yield for pearl millet (Pennisetum glaucum (L.) R. Br.), grown across 24 semi-arid tropical environments in India. We used a simple soil water budget to calculate a water satisfaction index (WSI) throughout the season. The cumulative WSI at maturity explained 76% of the variance in grain yield. This was three times as much as explained by actual rainfall, because WSI accounted for differences in water losses and pan evaporation. A classification of environments into four groups of water availability patterns explained 75% of the environmental sum of squares for grain yield. For a subset of 13 environments, environmental differences in grain number could also be explained by water availability patterns, whereas differences in grain mass were related to both water availability and temperature. Our results indicate that cumulative WSI, which is an integrated measure of plant-available water, can provide an adequate estimation of the environmental potential for yield in environments where grain yield is mainly limited by variable availability of water.
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    URL: http://dx.doi.org/10.1007/BF00034602
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    Effect of water availability and temperature on the genotype-by-environment interaction of pearl millet in semi-arid tropical environments (1996)
    Springer
    Euphytica 89 (1996), S. 175-183 
    Details
    ISSN: 1573-5060
    Keywords: escape ; genotype-by-environment interaction ; pearl millet ; Pennisetum glaucum ; soil water availability, stress ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Grain yields in drought-affected environments are often characterized by large genotype-by-environment (GE) interactions, caused by a highly variable timing and intensity of stress occurrence. The aim of our study was to assess the effectiveness of simple meteorological environmental descriptions in providing an understanding of the environmental contribution to the GE interaction of pearl millet (Pennisetum glaucum (L.) R. Br.) in the semi-arid tropics. The experiment comprised fourteen genotypes, grown across 24 environments in India. Data on water availability throughout the season and maximum temperatures during grain filling were used to describe the environments. Escape from drought and heat stress were the major factors determining the GE interaction. Both the timing and intensity of stress occurrence were important. Knowledge of the environmental causes of the GE interaction may facilitate the identification of adaptive plant traits, and may also enable a more rational choice of test locations for breeding programs.
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    Adaptive properties of Picea abies progenies are influenced by environmental signals during sexual reproduction (1996)
    Springer
    Euphytica 92 (1996), S. 67-71 
    Details
    ISSN: 1573-5060
    Keywords: seed orchard ; phenology ; frost hardiness ; environmental preconditioning ; temperature ; photoperiod ; Norway spruce ; Picea abies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Several independent tests have shown that climate and weather during sexual reproduction influence the adaptive properties of the Picea abies progenies. This phenomenon is expressed in seed orchards established by moving parent trees, propagated as grafts, from north to south, from high to low elevation, or from outdoor to indoor greenhouse conditions. The progenies exhibit delayed flushing in the spring, later growth cessation of leader shoots in the summer, delayed bud-set, higher frequency of lammas shoots and delayed development of frost hardiness in the autumn compared to progenies reproduced in the colder native environment. The altered performance is persistent. We have found no effect on progenies of photoperiod and temperature treatments given to the males during meiosis and pollen production. However, when crosses were made in early spring (March), inside a heated greenhouse (short day, high temperature), the progenies are less frost hardy during cold acclimation than progenies from identical crosses performed in late spring (May; long day high temperature) in the greenhouse. The most hardy offspring were from crosses performed under outdoor conditions in May (long day, low temperature). These results indicate that some stages in reproduction, such as female meiosis, pollen tube growth, syngamy and early embryo development, are sensitive to temperature and/or photoperiod which then alter the phenotypic performance of the offspring. The most likely explanation is the existence of a regulatory mechanism affecting the expression of genes controlling adaptive traits. If this is true, it must have implications for the genetic interpretation of provenance differences in Norway spruce.
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    URL: http://dx.doi.org/10.1007/BF00022830
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    Breeding plans in case of global warming (1996)
    Springer
    Euphytica 92 (1996), S. 235-239 
    Details
    ISSN: 1573-5060
    Keywords: acclimatization ; adaptation ; annual rhythm ; diversity ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Many cultivated crop plants of temperate and cool temperate zones have during their domestication been transferred far from their original habitats and been distributed over a wide range of climates. In general crop plants seem to possess potential to climatic adaptation. Processes in the past have taken hundreds or thousands of years and over large number of generations. The concern on the velocity of the expected global warming and of subsequent changes in other factors justifies planning of breeding for global warming. Perennial plants, forest trees in particular are more at the focal point than annual plants. Most agricultural annuals may be replaced any year with another cultivar or species better adapted to contemporary circumstances. Trees need tens of years to reach commercial dimensions or fructiferous age. Capriciousness is the main problem of climate change. Large variation of temperature, precipitation among years actually masks the gradual change of average values. The amplitude of variation among years exceeds the predicted average change. Thus, plasticity of individuals besides within population variation in adaptive traits is a corner stone of breeding plans. From the ecological point of view two factors are significant: 1. mild winters may interfere dormancy release and frost tolerance, and also alter host-parasite relationships. 2. The timing of thermal seasons will change in relation to photoperiod. This phenomenon is most prominent in the far north, where the relative warming is largest and the photoperiodic pattern steepest. Even though perennial plants display potential of acclimatization, selection and breeding are eligible measures to improve productivity. As long as the magnitude and velocity of the global warming remain uncertain, it is impossible to set specified aims to breeding. The only reasonable method is to run parallelly several lines with differing patterns of adaptive traits. Multiple population breeding system (MPBS) seems to be tailored to this purpose.
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    URL: http://dx.doi.org/10.1007/BF00022850
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    Mineralisation of nitrogen from an incorporated catch crop at low temperatures: experiment and simulation (1997)
    Springer
    Plant and soil 188 (1997), S. 211-219 
    Details
    ISSN: 1573-5036
    Keywords: catch crop ; mineralisation ; nitrogen ; simulation model ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The release of nitrogen from incorporated catch crop material in winter is strongly influenced by soil temperatures. A laboratory experiment was carried out to investigate this influence in the range of 1-15 °C. Samples of sandy soil or a mixture of sandy soil with rye shoots were incubated at 1-5-10-15 °C, and samples of sandy soil with rye roots were incubated at 5-10-15 °C. Concentrations of Nmin (NH4 +-N and NO3 --N) were measured after 0-1-2-4-7-10 weeks for the sandy soil and the sandy soil:rye shoot mixture, and after 0-2-7-10 weeks for the sandy soil:rye root mixture. At 1 °C, 20% of total organic N in the crop material had been mineralised after ten weeks, indicating that mineralisation at low temperatures is not negligible. Maximum mineralisation occurred at 15 °C; after ten weeks, it was 39% of total applied organic nitrogen from shoot and 35% from root material. The time course of mineralisation was calculated using an exponential decay function. It was found that the influence of temperature in the range 1-15 °C could be described by the Arrhenius equation, stating a linear increase of ln(k) with T-1, k being the relative mineralisation rate in day-1 and T the temperature (°C). A simulation model was developed in which decomposition, mineralisation and nitrification were modelled as one step processes, following first order kinetics. The relative decomposition rate was influenced by soil temperature and soil moisture content, and the mineralisation of N was calculated from the decomposition of C, the C to N ratio of the catch crop material and the C to N ratio of the microbial biomass. The model was validated first with the results of the experiment. The model was further validated with the results of an independent field experiment, with temperatures fluctuating between 3 and 20 °C. The simulated time course of mineralisation differed significantly from the experimental values, due to an underestimation of the mineralisation during the first weeks of incubation.
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    URL: http://dx.doi.org/10.1023/A:1004255102840
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    Root and shoot elongation of rhizotron-grown seedlings of Eucalyptus nitens and Eucalyptus globulus in relation to temperature (1998)
    Springer
    Plant and soil 206 (1998), S. 37-46 
    Details
    ISSN: 1573-5036
    Keywords: Eucalyptus globulus ; Eucalyptus nitens ; root apical diameter ; root elongation ; shoot elongation ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Information on the growth response of a crop plant in relation to temperature can be helpful in selecting genotypes to suit local environments, scheduling favourable time of planting and forecasting growth and yield. To determine the effects of varying temperature on root and shoot elongation of eucalypt seedlings, elongation rates of roots and shoots were measured in rhizotrons for two species (Eucalyptus nitens (Deane and Maiden) Maiden, and Eucalyptus globulus Labill.) at a temperature range of 5–23 °C. Within this range of temperatures, elongation rates of roots and shoots of both species increased with an increase in temperature. Roots of E. globulus were more sensitive and shoots less sensitive to temperature than those of E. nitens. However, the threshold temperature corresponding with zero elongation rate predicted from the regression of elongation rate against temperature was similar for the roots (∼5 °C) and shoots (∼0 °C) of both species. Hysteresis did not appear to have a significant influence on root or shoot elongation of both species during warming compared with cooling. Results are discussed highlighting the importance of the interaction between development and growth of plant components.
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    URL: http://dx.doi.org/10.1023/A:1004337121719
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  • 40
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    Morphology and tissue quality of seedling root systems of Pinus taeda and Pinus ponderosa as affected by varying CO2, temperature, and nitrogen (1997)
    Springer
    Plant and soil 195 (1997), S. 107-119 
    Details
    ISSN: 1573-5036
    Keywords: carbohydrates ; carbon dioxide ; nitrogen ; nutrients ; roots ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Rising atmospheric carbon dioxide, nitrogen deposition and warmer temperatures may alter the quantity and quality of plant-derived organic matter available to soil biota, potentially altering rates of belowground herbivory and decomposition. Our objective was to simulate future growth conditions for an early successional (loblolly) and late successional (ponderosa) species of pine to determine if the physical and chemical properties of the root systems would change. Seedlings were grown for 160 days in greenhouses at the Duke University Phytotron at 35 or 70 Pa CO2 partial pressure, ambient or ambient + 5 °C temperature, and 1 or 5 mMNH4O3. Roots from harvested seedlings were analyzed for changes in surface area, specific root length, mass, total nonstructural carbohydrates (TNC), and concentrations of macro-nutrients. Surface area increased in both species under elevated CO2, due primarily to increases in root length, and this response was greatest (+138%) in loblolly pine at high temperature. Specific root length decreased in loblolly pine at elevated CO2 but increases in mass more than compensated for this, resulting in net increases in total length. TNC was unaffected and nutrient concentrations decreased only slightly at elevated CO2, possibly from anatomical changes to the root tissues. We conclude that future growth conditions will enhance soil exploration by some species of pine, but root carbohydrate levels and nutrient concentrations will not be greatly affected, leaving rates of root herbivory and decomposition unaltered.
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    URL: http://dx.doi.org/10.1023/A:1004291430748
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    Ammonium and nitrate uptake by Eucalyptus nitens: effects of pH and temperature (1999)
    Springer
    Plant and soil 214 (1999), S. 133-140 
    Details
    ISSN: 1573-5036
    Keywords: ammonium ; eucalyptus ; nitrate ; pH ; root uptake ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ammonium and nitrate uptake by roots of Eucalyptus nitens was characterised with respect to pH and temperature. Uptake of ammonium and nitrate was measured as depletion from solutions by roots of intact 11 week old solution-cultured seedlings. Uptake rates of ammonium were consistently higher than those of nitrate in all experiments. Uptake rates for ammonium were 200% higher at pH 4 than at pH 6, but for nitrate were unchanged. Uptake rates of ammonium and nitrate were both reduced to a similar extent (70%) with a decrease in temperature from 20 °C to 10 °C. For ammonium uptake, there was rapid (〈24 hr) adaptation to a reduction in root temperature. The apparent preference shown here for ammonium over nitrate could be indicative of E. nitens growing in cold, acidic forest soils where ammonium is commonly more available than nitrate. These results suggest that N uptake rates of E. nitens may be maximised under a wide variety of conditions if N is supplied predominantly in the ammonium form.
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    URL: http://dx.doi.org/10.1023/A:1004740204876
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    The response of soil microorganisms and roots to elevated CO2 and temperature in a terrestrial model ecosystem (1998)
    Springer
    Plant and soil 202 (1998), S. 251-262 
    Details
    ISSN: 1573-5036
    Keywords: climate change ; Ecotron ; microbial biomass ; microbial community structure ; soil enzymes ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract We investigate the response of soil microorganisms to atmospheric CO2 and temperature change within model terrestrial ecosystems in the Ecotron. The model communities consisted of four plant species (Cardamine hirsuta, Poa annua, Senecio vulgaris, Spergula arvensis), four herbivorous insect species (two aphids, a leaf-miner, and a whitefly) and their parasitoids, snails, earthworms, woodlice, soil-dwelling Collembola (springtails), nematodes and soil microorganisms (bacteria, fungi, mycorrhizae and Protista). In two successive experiments, the effects of elevated temperature (ambient plus 2 °C) at both ambient and elevated CO2 conditions (ambient plus 200 ppm) were investigated. A 40:60 sand:Surrey loam mixture with relatively low nutrient levels was used. Each experiment ran for 9 months and soil microbial biomass (Cmic and Nmic), soil microbial community (fungal and bacterial phospholipid fatty acids), basal respiration, and enzymes involved in the carbon cycling (xylanase, trehalase) were measured at depths of 0–2, 0–10 and 10–20 cm. In addition, root biomass and tissue C:N ratio were determined to provide information on the amount and quality of substrates for microbial growth. Elevated temperature under both ambient and elevated CO2 did not show consistent treatment effects. Elevation of air temperature at ambient CO2 induced an increase in Cmic of the 0–10 cm layer, while at elevated CO2 total phospholipid fatty acids (PLFA) increased after the third generation. The metabolic quotient qCO2 decreased at elevated temperature in the ambient CO2 run. Xylanase and trehalase showed no changes in both runs. Root biomass and C:N ratio were not influenced by elevated temperature in ambient CO2. In elevated CO2, however, elevated temperature reduced root biomass in the 0–10 cm and 30–40 cm layers and increased N content of roots in the deeper layers. The different response of root biomass and C:N ratio to elevated temperature may be caused by differences in the dynamics of root decomposition and/or in allocation patterns to coarse or fine roots (i.e. storage vs. resource capture functions). Overall, our data suggests that in soils of low nutrient availability, the effects of climate change on the soil microbial community and processes are likely to be minimal and largely unpredicatable.
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    URL: http://dx.doi.org/10.1023/A:1004309623256
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    Effect of temperature on rice growth in nutrient solution and in acid sulphate soils from Vietnam (1995)
    Springer
    Plant and soil 177 (1995), S. 73-83 
    Details
    ISSN: 1573-5036
    Keywords: acid sulphate soils ; iron ; Oryza sativa L. ; phosphorus ; temperature ; Vietnam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Climatic and soil factors are limiting rice growth in many countries. In Vietnam, a steep gradient of temperature is observed from the North to the South, and acid sulphate soils are frequently devoted to rice production. We have therefore attempted to understand how temperature affects rice growth in these problem soils, by comparison with rice grown in nutrient solution. Two varieties of rice, IR64 and X2, were cultivated in phytotrons at 19/21°C and 28/32°C (day/night) for 56 days, after 3 weeks preculture in optimal conditions. Two soils from the Mekong Delta were tested. Parallel with the growing experiments, these two soils were incubated in order to monitor redox potential (E h ), pH, soluble Al and Fe, soluble, and available P. Tillering retardation at 20°C compared to 30°C was similar in nutrient solutions and in soils. The effect of temperature on increasing plant biomass was more marked in solutions than in soils. The P concentrations in roots and shoots were higher at 20°C than at 30°C, to such an extent that detrimental effect was suspected in plants grown in solution at the lowest temperature. The translocation of Fe from roots to shoots was stimulated upon rising temperature, both in solutions and in soils. This led to plant death on the most acid soil at 30°C. Indeed, the accumulation of Fe in plants grown on soils was enhanced by the release of Fe2+ due to reduction of Fe(III)-oxihydroxides. Severe reducing conditions were created at 30°C: redox potential (E h ) dropped rapidly down to about 0 V. At 20°C, E h did not drop below about 0.2 V, which is a value well in the range of Fe(III)/Fe(II) buffering. Parallel to E h drop, pH increased up to about 6–6.5 at 30°C, which prevented plants from Al toxicity, even in the most acid soil. Phosphate behavior was obviously related to Fe-dynamics: more reducing conditions at 30°C have resulted in enhancement of available P, especially in the most acid soil.
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    URL: http://dx.doi.org/10.1007/BF00010339
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    Temperature effects on C- and N-mineralization from vegetable crop residues (1996)
    Springer
    Plant and soil 181 (1996), S. 25-30 
    Details
    ISSN: 1573-5036
    Keywords: C-mineralization ; crop residues ; incubation ; N-mineralization ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Net N-mineralization and nitrification from soil organic matter and from vegetable crop residues (leaf-blades of cauliflower and stems of red cabbage) were measured at 4 temperatures during aerobic incubation in the laboratory. C-mineralization from leaf-blades of cauliflower was monitored at 3 different temperatures. N-mineralization from soil organic matter was best described by zero order kinetics N(t)=kt whereas N- and C-mineralization from the crop residues were described by single first order kinetics. Stems of red cabbage mineralized much more slowly than leaf-blades of cauliflower. S-shaped functions were fitted to the relationship between the rate constants of both C and N-mineralization and temperature. The rate parameter κ of the S-shaped function reflects the temperature dependence of the mineralization rate k. The parameter κ for N-mineralization of the stem material (κ=5.36) was significantly higher than for the leaf-blades (κ=3.38), indicating that there is a strong interaction between temperature and resistance to degradation in the soil. N-mineralization from soil organic matter was least sensitive to temperature (κ=2.63). Temperature dependence of nitrification was not significantly different from mineralization over the temperature range considered. Rate constants for C-mineralization of cauliflower leaf-blades were higher than for N-mineralization, but the temperature dependence of the rate constants was not significantly different for both processes.
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    URL: http://dx.doi.org/10.1007/BF00011288
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    Temperature-induced alteration to root longevity in Lolium perenne (1997)
    Springer
    Plant and soil 190 (1997), S. 87-90 
    Details
    ISSN: 1573-5036
    Keywords: minirhizotron ; root longevity ; root mortality ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The production and mortality of roots is an important factor determining nutrient and carbon fluxes in terrestrial ecosystems. However, the effect of temperature on the longevity of roots is not understood. In this study the impact of changes in temperature on the longevity of Lolium perenne roots was determined. Plants were grown at 15 °C, 21 °C and 27 °C and their roots observed using a minirhizotron system. Major effects of temperature were measured with large reductions in root longevity occurring at higher temperatures. The implications of these data are discussed.
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    URL: http://dx.doi.org/10.1023/A:1004298804353
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    Predominance of ecophysiological controls on soil CO2 flux in a Minnesota grassland (1998)
    Springer
    Plant and soil 207 (1998), S. 77-86 
    Details
    ISSN: 1573-5036
    Keywords: Cedar Creek ; Minnesota ; light ; root respiration ; Scizachyrium scorparium ; soil CO2 flux ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ecosystem studies often study soil CO2 flux as a function of environmental factors, such as temperature, that affect respiration rates by changing the rate of utilization of carbon substrates. These studies tend not to include factors, such as photosynthesis, that affect the supply of carbon substrates to roots and root-associated processes. We examined the role of decreased carbohydrate source on soil CO2 flux and root respiration in an annually-burned grassland through manipulations of light intensity and removal of above ground biomass. We also quantified the contribution of root respiration to soil CO2 flux by measuring the respiration rates of excised roots. Two days of shading caused a 40% reduction in soil CO2 flux, while clipping was associated with a 19% reduction in soil CO2 flux. Both reductions were independent of soil and air temperature at the time of measurement. The relative decrease in soil CO2 flux observed in the clipping experiment was similar in magnitude to an observed decrease in root respiration per gram of root, linking decreased root activity and soil CO2 flux. From these experiments, we conclude that variation in factors that affect carbon availability to roots can be important determinants of soil CO2 flux and should be included explicitly in studies that measure or model soil CO2 flux.
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    URL: http://dx.doi.org/10.1023/A:1004417419288
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    Phenotypic variation for saturated fatty acid content in soybean (1996)
    Springer
    Euphytica 91 (1996), S. 289-295 
    Details
    ISSN: 1573-5060
    Keywords: breeding ; genotype x environment interaction ; palmitic ; stearic ; temperature ; Glycine max ; soybean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Concern over high saturates in human diets has prompted the development of soybean [Glycine max (L.) Merr.] lines producing oil with reduced saturated fatty acid concentration. To better understand those factors that influence phenotypic expression for palmitic and stearic acid content in soybean, thirty soybean lines random for saturated fatty acid content were grown in eight field environments contrasting for mean temperature during seed-filling. Palmitic and stearic acid content varied significantly (P〈0.01) both among genotypes and across environments, while genotype x environment interactions were reflected in changes in line variance and ranking for both traits. Therefore selection of a superior genotype for saturated fatty acid composition may not correlate well from one environment to another. In general, early-maturing lines were less sensitive than later-maturing lines in their response to changes in mean daily temperature for palmitic concentration. However, factors in addition to temperature appeared to influence genotype response for stearic acid content. It appears that genetic systems conditioning palmitic and stearic acids are independent, and that separate breeding strategies need be adopted to make simultaneous improvement for these two oil traits. In summary, development of soybean lines with low or high saturated fatty acid content may be accomplished through evaluation and selection in a few environments contrasting for temperature.
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    URL: http://dx.doi.org/10.1007/BF00033090
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    Abscisic acid, temperature and salinity interactions on growth and some mineral elements in Carthamus plants (1996)
    Springer
    Plant growth regulation 20 (1996), S. 225-236 
    Details
    ISSN: 1573-5087
    Keywords: abscisic acid ; Carthamus tinctorius ; safflower ; salinity ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth and contents of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), phosphorus (P) and sulphur (S) in shoot and root tissues of Carthamus tinctorius plants were measured at combinations of four nutrient solution osmotic potentials (Ψs=0, -0.3, -0.6 and -0.9 MPa) induced by NaCl and CaCl treatments, three constant temperatures (T) ranging from 15 to 35°C and four abscisic acid (ABA) concentrations (0,10,50 and 100 mg L−1). Unstressed and stressed plants grown in optimal temperature conditions (25°C) maintained higher growth rates (dry mass production) than plants grown under low and high temperatures (15 and 35°C respectively). Shoot and root growth (dry mass production) were largely inhibited by salinity but the magnitude of growth inhibition was temperature dependent. Safflower plants respond to salinity stress by increases in Ca, Cl and to a lesser extent Na in their shoots and roots and by a decrease in the ratio of fresh to dry weight. The ratio of K/Na was decreased progressively on salinization. With stressed plants, ABA application reduced the toxicity of salt treatment, improved K uptake under salinity, effectively increased K/Na ratio and helped the plants to avoid Na toxicity and sometimes enhanced growth. The effect of ABA on the growth was more pronounced at optimum temperature (25°C). The association between the internal mineral element concentrations was largely affected by ABA application and temperature change but a wide fluctuation in response was noticed. The effects of single factors (Ψs, T and ABA) on the growth and mineral contents were statistically significant. Also, bifactorial (Ψs× T, Ψs × ABA and T × ABA) and three factorial (Ψs × T × ABA) interactions significantly affected the parameters. Further statistical treatment of the data (coefficient of determination η2) led to four important findings: (1) Salinity (Ψs) was dominant in affecting Ca and Cl contents in both shoot and root as well as root Na content. (2) Temperature (T) had a dominant effect on growth, shoot K, Mg, P, S and root P, and S contents (3) The share of Ψs × T × ABA interaction was dominant for root Na and Mg contents. (4) The single factors and their interactions had a dual role in their subsidiary effects.
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    Heat damage in boxed white spruce (Picea glauca [Moench.] Voss) seedlings: Its pre-planting detection and effect on field performance (1995)
    Springer
    New forests 9 (1995), S. 237-259 
    Details
    ISSN: 1573-5095
    Keywords: damage detection ; electrolyte leakage ; heat damage ; root growth potential ; shipping ; storage ; temperature ; white spruce
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This study investigated the effects of holding 1+0 PSB313a white spruce (Picea glauca (Moench.) Voss) seedlings in storage boxes at air temperatures of 5, 10, 20, 30 and 40°C for 12, 24, 48, 72 and 96 h before planting. The ability to detect physiological damage to seedlings as a result of such treatment, before planting, was also examined. After one growing season, no needle damage or mortality 〉8% was found for temperature treatments up to 20°C for 4 days. At 30°C and above, seedling damage and mortality increased, while bud flush, shoot height, stem diameter and shoot dry weight decreased with increasing temperature and duration of treatment. Seedling mortality in the field was 100% after the 40°C treatment exposure for 72 h or longer. Pre-planting needle electrolyte leakage was indicative of visible needle damage 14 days after planting, whereas stem electrolyte leakage and root growth potential were more closely related to end of season plantation mortality. Despite the lack of damage observed at 20°C or below, preplanting exposure of white spruce seedlings to temperatures above 5°C, during transportation and field storage, is not recommended.
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    Effects of light, temperature, gibberellin (GA3) and their interaction on coleoptile and leaf elongation of tall, semi-dwarf and dwarf wheat (1996)
    Springer
    Plant growth regulation 18 (1996), S. 239-247 
    Details
    ISSN: 1573-5087
    Keywords: gibberellin ; leaf elongation ; light intensity ; Rht alleles ; temperature ; Triticum aestivum L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Near-isogenic wheat lines differing in height-reducing (Rht) alleles, in each of two cultivars, were used to investigate the effects of light intensity and of their interaction with temperature and GA3 application, on the elongation of the coleoptile and the first seedling leaf. Darkness caused a conspicuous increase in the lengths of the coleoptile and of the sheath and lamina of the first leaf, in GA3 treated and untreated seedlings of all genotypes grown at 11 and 25°C. The genotype effects and the effects of light intensity and GA3 application on leaf length were ascribed entirely to their effects on the rate of leaf elongation since the duration of leaf elongation was not affected by these factors. Temperature elevation from 11 to 25°C caused a 55% shortening of the duration of leaf elongation and a concomitant increase in elongation rate, which diminished with increased genotypic dwarfness. Accordingly, temperature elevation resulted in a significant reduction in leaf-length of the light-grown dwarf genotypes and the dark-grown dwarf and semi-dwarf genotypes. It is suggested that this temperature × light × genotype interaction effect is due to environmental dependent upper limits of elongation rate set by the Rht alleles.
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    URL: http://dx.doi.org/10.1007/BF00024388
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    Effects of artificial environmental conditions on anatomical and physiological ripening of Pinus sylvestris L. seeds (1995)
    Springer
    New forests 9 (1995), S. 205-224 
    Details
    ISSN: 1573-5095
    Keywords: Cone moisture content ; germination ; scots pine ; temperature ; X-ray
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To determine suitable conditions for artificial ripening of Scots pine seeds, cones collected on seven occasions between August 6 and November 26, 1990, in northern Sweden, were subjected to artificial ripening at different temperatures (+5°−+15°C) and cone moisture contents for 3–9 weeks. Complete physiological ripening and improved seed vigour were attained after artificial ripening if collection occurred no earlier than the beginning of September. The highest germination percentage after artificial ripening, ca 90%, was achieved for seeds collected after the anatomical ripening in nature had ceased and was at least as high as for seeds ripened in nature. Temperature did not influence ripening, whereas a low cone moisture content impaired ripening of those seeds collected earliest. The germination percentage was not influenced by 2–6 months of cone storage subsequent to artificial ripening, but seed vigour was impaired. Anatomical ripening during artificial ripening was very limited.
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    URL: http://dx.doi.org/10.1007/BF00035488
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    In situ forcing of pollen maturation in Jack pine and Japanese larch male cones (1995)
    Springer
    New forests 9 (1995), S. 261-272 
    Details
    ISSN: 1573-5095
    Keywords: accelerated growth ; bagging ; degree-days ; forcing ; humidity rate ; Jack pine ; Japanese larch ; Larix leptolepis ; male cones ; Pinus banksiana ; pollen ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Paper bags equipped with a polyethylene window were placed on branchlets 6 and 9 weeks before the time of pollen dispersal of Japanese larch and Jack pine, respectively. This technique produced a localized greenhouse effect around the branchlets, accelerating male cone development. For Jack pine trees, buds in bags with the window oriented upward had the shortest maturation time. In fact, it was possible to collect these pollen cones about 11 days before the unbagged control without decreasing the production of pollen. The mean germination rate of the pollen from the bags with the window pointed upward, however, was significantly lower than the control, by about 15%. Buds in bags with the window oriented downward had an accelerated development of about 9 days (compared to the control) but did not experience a decrease in pollen production or quality. This same technique caused the abortion of male cones of the Japanese larch trees. Thermal probes in the bags enabled us to follow the progression of temperature inside and outside the bags during the development of the male cone in each species. They revealed that the bags increased mean temperature, daily temperature range, and degree-day accumulation, and that this effect was most pronounced for Jack pine, when the polyethylene window was oriented upward.
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    URL: http://dx.doi.org/10.1007/BF00035491
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    Hysteresis in the temperature response of carbon dioxide and methane production in peat soils (1998)
    Springer
    Biogeochemistry 43 (1998), S. 253-272 
    Details
    ISSN: 1573-515X
    Keywords: carbon dioxide ; hysteresis ; methane ; peat ; temperature ; wetlands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The ability to predict the effects of climate change on trace gas fluxes requires a knowledge of microbial temperature responses. However, the response of a microbial community to temperature in a given substrate may be complicated by its thermal history. To examine the effect of sequentially changing temperature on methane and carbon dioxide production in different peat types, we incubated anaerobic peat samples from 3 types of northern peatlands, a bog, a sedge fen and a cedar swamp, in both rising and falling temperature regimes. Graphic and statistical comparisons of the different temperature regimes suggest hysteresis in microbial response to temperature, although the absolute rates at any given temperature often did not differ. Where regressions for temperature response (Arrhenius plots) were significant, they generally differed between temperature regimes. The greatest differences among treatments occurred during the first half of the 40-d incubation. Increases in carbon dioxide production were similar across all peat types, but methanogenesis varied widely: methane production was uniformly low in the bog peat but increased sharply with temperature in the other two peat types. The complicating effect of history or chronology on substrate responses to environmental stimuli may restrain our ability to model the responses of complex systems to changing conditions.
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    URL: http://dx.doi.org/10.1023/A:1006097808262
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    Effects of air pollutant-temperature interactions on mineral-N dynamics and cation leaching in reciplicate forest soil transplantation experiments (1997)
    Springer
    Biogeochemistry 39 (1997), S. 295-326 
    Details
    ISSN: 1573-515X
    Keywords: acidification ; aluminium ; Arrhenius’ law ; calcium ; cation leaching ; climate ; ion equilibrium ; forest soil ; N-cycle ; N-deposition ; nitrification ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Increased emissions of nitrogen compounds have led to atmosphericdeposition to forest soils exceeding critical loads of N overlarge parts of Europe. To determine whether the chemistry offorest soils responds to changes in throughfall chemistry, intactsoil columns were reciprocally transplanted between sites, withdifferent physical conditions, across a gradient of N and Sdeposition in Europe. The transfer of a single soil to the various sites affected itsnet nitrification. This was not simply due to the nitrificationof different levels of N deposition but was explained bydifferences in physical climates which influenced mineralizationrates. Variation in the amount of net nitrification between soiltypes at a specific site were explained largely by soil pH. Within a site all soil types showed similar trends in netnitrification over time. Seasonal changes in net nitrificationcorresponds to oscillations in temperature but variable time lagshad to be introduced to explain the relationships. WithArrhenius‘ law it was possible to approximate gross nitrificationas a function of temperature. Gross nitrification equalled netnitrification after adaptation of the microbial community oftransplanted soils to the new conditions. Time lags, andunderestimates of gross nitrification in autumn, were assumed tobe the result of increased NH 4 + availability due either tochanges in the relative rates of gross and net N transformationsor to altered soil fauna-microbial interactions combined withimproved moisture conditions. Losses of NO 3 - were associated with Ca2+and Mg2+ in non-acidified soil types and with losses ofAl3+ in the acidified soils. For single soils the ionequilibrium equation of Gaines-Thomas provided a useful approximationof Al3+ concentrations in the soil solution as a functionof the concentration of Ca2+. The between site deviationsfrom this predicted equilibrium, which existed for single soils, couldbe explained by differences in throughfall chemistry which affectedthe total ionic strength of the soil solution. The approach of reciprocally transferring soil columnshighlighted the importance of throughfall chemistry, interactingwith the effect of changes in physical climate on forest soilacidification through internal proton production, in determiningsoil solution chemistry. A framework outlining the etiology offorest die-back induced by nitrogen saturation is proposed.
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    URL: http://dx.doi.org/10.1023/A:1005814929879
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
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    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m- 2 yr-1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m-2 yr-1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
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    URL: http://dx.doi.org/10.1023/A:1006061814731
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    Feed Intake and Growth of Juvenile Silver Trevally at the Southern Limit of Their Distribution (1999)
    Springer
    Aquaculture international 7 (1999), S. 357-360 
    Details
    ISSN: 1573-143X
    Keywords: feed intake ; growth ; silver trevally (Pseudocaranx dentex) ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009296531292
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    Effect of source and nest size of N fertilizers and temperature on nitrification in a coarse textured, alkaline soil (1999)
    Springer
    Nutrient cycling in agroecosystems 54 (1999), S. 199-207 
    Details
    ISSN: 1573-0867
    Keywords: ammonium chloride ; ammonium sulphate ; nest placement ; nitrification ; temperature ; urea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Nitrification occurring in an alkaline sandy loam soil fertilized with urea, ammonium sulphate (AS) and ammonium chloride (AC) was studied in the laboratory at 20°C and 40°C for 30 days. Nitrogen fertilizers were applied as nest of sizes 0.2, 0.5, 1.0 and 2.0 g. Unfertilized control and soil mixed with 50 mg N kg-1 were also included as treatments. Nitrification in all the fertilizer treatments decreased markedly with increasing nest size. At 20°C, differences among the three N sources were not significant at 5 days after incubation but marked differences appeared thereafter. All the N was nitrified by 30 days in case of fertilizers mixed into the soil. In nest placement, nitrification ranged from 30.1 to 75.5%, 28.3 to 74.6% and 35.3 to 88.7% for urea, AC and AS, respectively. When equal amounts of fertilizers were placed in a nest, nitrification occurred at a slower rate with urea than with AC and AS. Rates of nitrification were significantly higher at 40°C than at 20°C. At 20 days, nitrification from different nest sizes ranged from 8.4 to 64.9% and from 24.9 to 87.0% at 20°C and 40°C, respectively. The difference in nitrification at two temperatures were more pronounced at higher nest sizes than at smaller nest sizes. While nitrification with the three N sources decreased linearly with increase in N concentration (nest size) in soil at 40°C, it showed a quadratic relationship at 20°C. At equal N concentration, the highest rate of nitrification occurred with urea and the lowest with AC. At the same rate of applied N (50–2000 mg kg-1), AC and AS increased electrical conductivity of soil by 1.3–9 times that of urea. Apparent mineral N recovery of applied N decreased with the increase in nest size.
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    URL: http://dx.doi.org/10.1023/A:1009741031827
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    Temperature effect on shear induced transition in surfactant solution (1997)
    Springer
    Colloid & polymer science 105 (1997), S. 322-325 
    Details
    ISSN: 1435-1536
    Keywords: Rheology ; surfactant solutions ; micelles ; phase transition ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Aqueous solutions of cationic surfactant with binding counterions exhibit a transition under shear. In this paper the steady shear properties of semidilute aqueous micellar solutions (cetylpyridinium chloride and sodium salicylate in brine) are presented as a function of concentration and temperature. The shear thinning behavior of this system could be described by the Carreau model at low shear rate and by a power law at higher shear rate. The temperature dependence of the zero shear viscosity follows an Arrhenius relationship. The critical shear rate at which the viscosity departs from its zero shear value is found to increase with temperature indicating the influence of this parameter on transition.
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    URL: http://dx.doi.org/10.1007/BF01188972
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    Responsiveness of Amaranthus retroflexus seeds to ethephon, 1-aminocyclopropane 1-carboxylic acid and gibberellic acid in relation to temperature and dormancy (1996)
    Springer
    Plant growth regulation 20 (1996), S. 259-265 
    Details
    ISSN: 1573-5087
    Keywords: ACC ; Amaranthus retroflexus ; dormancy ; ethephon ; ethylene ; germination ; gibberellic acid ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Dormant Amaranthus retroflexus seeds do not germinate in the dark at temperatures below 35°C. Fully dormant seeds germinate only at 35–40°C whereas non-dormant ones germinate within a wider range of temperatures (15 to 40°C). Germination of non-dormant seeds requires at least 10% oxygen, but the sensitivity of seeds to oxygen deprivation increases with increasing depth of dormancy. 10−6 to 10−4 M ethephon, 10−3 M 1-aminocyclopropane 1-carboxylic acid (ACC) and 10−3 M gibberellic acid (GA3) break this dormancy. In the presence of 10−3 M GA3 dormant seeds are able to germinate in the same range of temperatures as non-dormant seeds. The stimulatory effect of GA3 is less dependent on temperature than that of ethephon, while ACC stimulates germination only at relatively high temperatures (25–30°C). The results obtained are discussed in relation to the possible involvement of endogenous ethylene in the regulation of germination of A. retroflexus seeds.
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    URL: http://dx.doi.org/10.1007/BF00043316
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    Relationships between position on the parent plant and germination characteristics of seeds of parsley (Petroselinium crispum Nym.) (1996)
    Springer
    Plant growth regulation 18 (1996), S. 175-181 
    Details
    ISSN: 1573-5087
    Keywords: Germination ; gibberellin A4/7 ; light ; parsley ; Petroselinium crispum ; seeds ; temperature ; umbel position
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The percentage germination of seeds of parsley cv. Imperial Curled was higher in the light than in the dark, the high temperature limits for germination being 30 and 28°C for light and dark respectively. At the higher temperatures, the germination rate was slower in the dark. At 30°C, treatment with a gibberellin A4/7 mixture at 2 × 10−4 M partially alleviated the inhibiting effect of darkness on the germination percentage. Pre-incubation of parsley seeds at 35°C in the dark for 30 h increased the rate, but decreased the percentage, of germination of seeds incubated at 15°C in the light. Germination and seedling emergence studies were made on seed harvested from four different umbel positions. Although heavier seeds were produced from primary umbels than from other umbel orders, they were less viable as measured by seedling emergence in the glasshouse. The rate of emergence was decreased with increasing umbel order i.e. with later seed development: this was reflected in subsequent seedling weights, with seedlings from quarternary umbel seeds being about half the weight of those from primary umbel seeds. The upper temperature limit for dark germination was only slightly affected by umbel order, with quarternary umbel seeds being the most thermo-inhibited.
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    URL: http://dx.doi.org/10.1007/BF00024379
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    Ice nucleation in fruit juice from different varieties of sea buckthorn Hippophaë rhamnoides L. (1998)
    Springer
    Euphytica 102 (1998), S. 117-124 
    Details
    ISSN: 1573-5060
    Keywords: sea buckthorn ; climate ; freezing ; germination ; ice nucleators ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The main aim of the investigation was to study the effects of climate on the ice nucleation temperatures of fruit juice from sea buckthorn, Hippophaë rhamnoides L. This could provide information on possible adaptive values of ice nucleators in the fruits. It was also an aim to provide information on ice nucleation of fruit juice from different varieties of sea buckthorn. This was done to find suitable varieties for agricultural production of ice nucleator containing fruit juice. Such food grade ice nucleators can be used in the processing of food stuffs particularly where large ice crystals are desired. The ice nucleation temperatures were low in juice from unripe fruits in the summer, and peaked at − 6 °C in the autumn. There were no significant differences in nucleation temperatures in juice from fruits grown along a climatic gradient along the Trondheimsfjord. Juice from varieties originating from different parts of the world, but grown at the same fields, showed different mean nucleation temperatures, ranging from − 15.1 °C in a Swiss wild type of subsp. fluviatilis to − 6.1 °C in a Swedish wild type of subsp. rhamnoides. Varieties with very potent nucleators (− 2 °C to − 3 °C) were found, but these nucleators were present in low concentrations. Varieties with high concentration of nucleators within a small temperature range (− 6 °C to − 7 °C) were also found. No correlation between geographic origin and nucleation temperatures was found. Depending on conditions, freezing the fruits had either no, or a negative effect on the germination success. Since no adaptive benefit to the sea buckthorn could be demonstrated, the nucleating ability of the fruit juice is probably incidental.
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    URL: http://dx.doi.org/10.1023/A:1018336413479
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    Inheritance of temperature sensitivity of the photoperiod response in common bean (Phaseolus vulgaris L.) (1996)
    Springer
    Euphytica 91 (1996), S. 5-8 
    Details
    ISSN: 1573-5060
    Keywords: adaptation ; common bean ; flowering ; photoperiod ; temperature ; Phaseolus vulgaris
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Photoperiod response of flowering in common bean (Phaseolus vulgaris L.) is thought to be controlled by the genes Ppd and Hr. However, cultivars also vary in the degree that cooler temperatures reduces their sensitivity to photoperiod. To examine the inheritance of this temperature sensitivity, crosses of cvs. Gordo x de Celaya and Flor de Mayo × Rojo 70 were evaluated at two sites differing in mean temperature and using 12.5-h natural photoperiod or 18-h artificially extended photoperiod. Under 18-h photoperiod at the warmer site, Palmira, no plants of the parents or of the F2 populations flowered, confirming that the parents were sensitive to photoperiod. Under 12.5-h photoperiod at the cooler site, Popayan, the parents for each cross flowered at similar dates and no segregation for days to flower was observed. However, under 18-h photoperiod, de Celaya and Rojo 70 and the F1 populations did not flower within 100 days after planting, while the F2 and F3 populations showed segregation that was consistent with single gene inheritance, late flowering being dominant. Late flowering at Popayan under 18-h photoperiod indicates a lack of temperature sensitivity, so temperature insensitivity of the photoperiod response was dominant to sensitivity. The name Tip, for “temperature insensitivity of photoperiod response”, is proposed for this gene, with the recessive form of this gene conditioning earlier flowering at cooler temperatures with long daylengths. It is recognized that the observed segregation patterns could represent the effect of multiple alleles at the Ppd or Hr loci, and studies are proposed to test this possibility with molecular markers and recombinant inbred lines.
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    URL: http://dx.doi.org/10.1007/BF00035270
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    Carbon use in root respiration as affected by elevated atmospheric O2 (1995)
    Springer
    Plant and soil 187 (1995), S. 251-263 
    Details
    ISSN: 1573-5036
    Keywords: carbon budget ; CO2 ; global change ; nutrient status ; root respiration ; root weight ratio ; temperature ; water stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The use of fossil fuel is predicted to cause an increase of the atmospheric CO2 concentration, which will affect the global pattern of temperature and precipitation. It is therefore essential to incorporate effects of temperature and water supply on the carbon requirement for root respiration of plants to predict effects of elevated [CO2] on the carbon budget of natural and managed systems. There is insufficient information to support the contentention that an increase in the concentration of CO2 in the atmosphere will enhance the CO2 concentration in the soil to an extent that is likely to affect root respiration. Moreover, there is no convincing evidence for a direct effect of elevated atmospheric [CO2] on the rate of root respiration per unit root mass or the fraction of carbon required for root respiration. However, there are likely to be indirect effects of elevated [CO2] on the carbon requirement of plants in natural systems. Firstly, it is very likely that the carbon requirement of root respiration relative to that fixed in photosynthesis will increase when elevated [CO2] induces a decrease in nutrient status of the plants. Although earlier papers have emphasized that elevated [CO2] favours investment of biomass in roots relative to that in leaves, these are in fact indirect effects. The increase in root weight ratio is due to the more rapid depletion of nutrients in the root environment as a consequence of enhanced growth. This will decrease the specific rate of root respiration, but increase the carbon requirement as a fraction of the carbon fixed in photosynthesis. It is likely that these effects will be minor in systems where the nutrient supply is very high, e.g. in many managed arable systems, and increase with decreasing soil fertility, i.e. in many natural systems. Secondly, a decrease in rainfall in some parts of the world may cause a shortage in water supply which favours the carbon partitioning to roots. Water stress is likely to reduce rates of root respiration per unit root mass, but enhance the fraction of total assimilates required for root respiration, due to greater allocation of biomass to roots. Increased temperatures are unlikely to affect the specific rate of root respiration in all species. Broadly generalized, the effect of temperature on biomass allocation is that the relative investment of biomass in roots is lowest at a certain optimum temperature and increases at both higher and lower temperatures. The root respiration of some species acclimates to growth temperature, so that the effect of global temperature rise is entirely accounted for by the effect of temperature on biomass allocation. The specific rate of root respiration of other species will increase with global warming. In response to global warming the carbon requirement of roots is likely to decrease in temperate regions, when temperatures are suboptimal for the roots' capacity to acquire water. Here global warming will induce a smaller biomass allocation to the roots. Conversely, the carbon requirements are more likely to increase in mediterranean environments, where temperatures are often supraoptimal and a rise in temperature will induce greater allocation of biomass to the roots.
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    Effect of heat shock during grain filling on protein composition and technological quality of wheats (1998)
    Springer
    Euphytica 100 (1998), S. 147-154 
    Details
    ISSN: 1573-5060
    Keywords: wheat quality ; temperature ; heat shock ; polymeric protein ; nitrogen application ; breadmaking quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In southern Europe, the Mediterranean climate offers a unique opportunity for the production of high quality wheats, which are lacking in the European Economic Union. It is also responsible for the remarkable variability in both wheat yield and quality from year to year and from location to location. In this paper, the effects (in recent years) of the Mediterranean climate in Italy on grain yield and quality of bread and durum wheats are summarised with particular regard to high temperatures. Nitrogen fertilisation rate and timing were investigated in five cultivars grown at six sites. The impact of high temperature was evaluated in open field and pot experiments by imposing different temperature regimes during grain filling. Viscoelastic properties were evaluated with the Chopin alveograph for field experiments and with a Promylograph T3 apparatus for pot experiments. Protein composition was evaluated by SE-HPLC (size exclusion high performance liquid chromatrography). Agronomic trials indicated that high quality wheats can be obtained in a wide range of growing conditions. Viscoelastic properties were significantly affected by the temperature treatments. Short episodes of daily maximum temperatures above 35 °C caused a 'weakening' in both durum and bread wheat. High temperatures seemed to affect mainly the composition of the polymeric fraction (soluble/insoluble polymers) without influencing their synthesis.
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    URL: http://dx.doi.org/10.1023/A:1018353300618
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    Intrinsic earliness and basic development rate assessed for their response to temperature in wheat (1995)
    Springer
    Euphytica 83 (1995), S. 175-183 
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    ISSN: 1573-5060
    Keywords: basic development rate ; earliness ; intrinsic earliness ; flowering ; phenology ; temperature ; thermal time ; Triticum aestivum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The related concepts of basic vegetative period, intrinsic earliness and basic development rate in wheat are examined. These concepts have the common assumption that, if plants are vernalised fully and then grown at long daylength in order to remove any responses to vernalisation and photoperiod, the calendar or thermal time then taken to anthesis will be a characteristic of a genotype that will be heritable. Thus, regardless of temperature, early genotypes will always be earlier than late genotypes (providing there are no vernalisation and photoperiod responses). Using four genotypes, exposed to 50 days of vernalisation, and then grown at 18 h photoperiod under six temperature regimes ranging between 10 and 25°C, it is shown that; (1) no genotype had an absolute basic period as, depending on temperature, durations to anthesis for any one genotype varied by more than 50 days; (2) no genotype had an absolute value for intrinsic earliness (to anthesis), ranging for any genotype by more than 300°Cd depending on temperature; (3) basic development rate was not a single value for a genotype but varied with stage of development; (4) some genotypes changed their ranking for earliness depending on the temperature regime; and (5) genotypes were differentially sensitive to temperature for the subphases prior to anthesis. We conclude that the earliness descriptors should not be considered as static genotypic characteristics but as the result of the interaction between the genotype and temperature. Thus, the apparent earliness trait is likely to be related to temperature sensitivity.
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    A stability analysis of time to flowering as a screen for responsiveness to temperature and photoperiod in cowpea (Vigna unguiculata) (1996)
    Springer
    Euphytica 88 (1996), S. 77-84 
    Details
    ISSN: 1573-5060
    Keywords: cowpea ; flowering ; photoperiod ; stability analysis ; temperature ; Vigna unguiculata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Twenty-one genotypes of cowpea (Vigna unguiculata), comprising landraces and varieties, were grown in 22 photothermal environments in Nigeria and Niger, West Africa, and a stability analysis of days from sowing to flowering (f) was carried out. Cowpeas are rarely insensitive to photoperiod; they are typically quantitative shortday plants wherein f is delayed when photoperiod (P) is longer than the critical photoperiod (P c ). Therefore, in order to quantify genotypic variation in temperature sensitivity, genotype f was regressed against the mean trial f in circumstances where P〈P c (i.e. approximately ≤ 13 hd-1) and mean temperature (T) was between 19° and 28° C. Correspondingly, in order to assess genotypic variation in photoperiod sensitivity, trials where T was near optimal (25°–28° C) but where P ranged from 10–14.5 hd-1 were used. These stability analyses detected no significant differences (P〉0.05) between genotypes 9n temperature sensitivity but revealed significant differences (P〈0.001) in photoperiod sensitivity. Regression coefficients from the stability analysis were strongly correlated (r=0.94, 19df) with a photoperiod sensitivity constant, c′, determined from a photothermal flowering model. A stability analysis of f from field trials can therefore identify and quantify genotypic variation in response to temperature and photoperiod in cowpea.
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    Phenological adaptation to cropping environment. From evaluation descriptors of times to flowering to the genetic characterisation of flowering responses to photoperiod and temperature (1996)
    Springer
    Euphytica 92 (1996), S. 281-286 
    Details
    ISSN: 1573-5060
    Keywords: adaptation ; flowering ; photoperiod ; temperature ; germplasm ; characterisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Descriptor lists for the major cereals and grain legumes include information on the duration from sowing to flowering. This is because the first step towards maximizing crop yield by agronomic management or plant breeding is to ensure that the phenology of the crop is well matched to the resources and constraints of the production environment. In this context, durations from sowing to flowering are of critical importance if crops sown on the appropriate date and at the appropriate density are to have the potential to yield well in a given environment. In most annual crops, the timing of phenological events is modulated primarily by responsiveness to photoperiod and temperature with large differences in sensitivity among genotypes. Irrespective of the crop, many advantages accrue from analyses of these photothermal responses not in terms of the evaluation descriptor ‘time from sowing to flowering (f)’ but in terms of the ‘rate of progress towards flowering (1/f)’. A computer program RoDMoD has been developed to convert evaluation descriptors for times of flowering to characterisation descriptors of the flowering response of a genotype to photoperiod and temperature. The program and the associated phenological model were developed from research undertaken in controlled environments and then validated in the field over wide ranges of locations and seasons. These advances should contribute to the development of cultivars phenologically well adapted to their target environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00022856
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    Effect of pre-incubation humidity and temperature treatment on the in vitro germination of avocado pollen grains (1997)
    Springer
    Euphytica 94 (1997), S. 247-251 
    Details
    ISSN: 1573-5060
    Keywords: Persea americana ; avocado humidity ; Greece ; pollen grain germination ; temperature ; fruit-set
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Optimum in vitro germination of pollen grain of the avocado cultivars Fuerte, Nabal, Ettinger, Bacon and Zutano occurred at 25 °C. However, there were significant differences between cultivars in percentage germination and relative humidity (RH) requirements for optimum pollen grain growth. The most sensitive cultivar to relative humidity was Fuerte, in which the germination of pollen grain rose from 11.4%, at 40% RH, to about 50%, after one hour at 100% RH. The germination% of Nabal pollen grain was already high at 40% RH and was not increased by higher relative humidity. Increased relative humidity also helped to sustain the viability of avocado pollen. At 30 °C and 5% RH the pollen grains of Fuerte quickly lost its ability to germinate, at 40% RH for 1 hour, germination was reduced spectacularly compared to pollen kept in saturated with moisture environment where it was not affected the first 24 hours. The effects of temperature and relative humidity on fruit-set and yield of avocado are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002917915386
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  • 69
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    Modeling the temperature response of nitrification (1996)
    Springer
    Biogeochemistry 35 (1996), S. 433-445 
    Details
    ISSN: 1573-515X
    Keywords: ammonium oxidation ; growth rate ; maintenance energy ; modeling ; nitrification ; soil nitrate ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract To model nitrification rates in soils, it is necessary to have equations that accurately describe the effect of environmental variables on nitrification rates. A variety of equations have been used previously to describe the effect of temperature on rates of microbial processes. It is not clear which of these best describes the influence of temperature on nitrification rates in soil. I compared five equations for describing the effects of temperature on nitrification in two soils with very different temperature optima from a California oak woodland-annual grassland. The most appropriate equation depended on the range of temperatures being evaluated. A generalized Poisson density function best described temperature effects on nitrification rates in both soils over the range of 5 to 50 °C; however, the Arrhenius equation best described temperature effects over the narrower range of soil temperatures that normally occurs in the ecosystem (5 to 28 °C). Temperature optima for nitrification in most of the soils were greater than even the highest soil temperatures recorded at the sites. A model accounting for increased maintenance energy requirements at higher temperatures demonstrates how net energy production, rather than the gross energy production from nitrification, is maximized during adaptation by nitrifier populations to soil temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02183035
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  • 70
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    Methane emissions from wet grasslands on peat soil in a nature preserve (1999)
    Springer
    Biogeochemistry 44 (1999), S. 205-220 
    Details
    ISSN: 1573-515X
    Keywords: grassland ; ground water level ; methane ; peat ; temperature ; wetland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The area of wet grasslands on peat soil in the Netherlands is slowly increasing at the expense of drained, agriculturally used grasslands. This study aimed (i) to assess the contribution of wet grasslands on peat soil to methane (CH4) emissions, and (ii) to explain differences among sites and between years in order to improve our understanding of controlling factors. For these purposes, a field study was conducted in the period 1994–1996 in the nature preserve “Nieuwkoopse Plassen”, which is a former peat mining and agricultural area. Net CH4 emissions were measured weekly to monthly with vented closed flux chambers at three representative sites, and at ditches near these sites. Three-years average of CH4 emissions was 7.9 g CH4 m−2 yr−1 for Drie Berken Zudde, 13.3 for Koole, and 20.4 for Brampjesgat. Ditches near the sites emitted 4.2–22.5 g CH4 m−2 yr−1. The time-course of CH4 emissions for all experimental sites and years was fit with a multiple linear regression model with ground water level and soil temperature as independent variables. Lowering or raising the ground water level by 5 cm could decrease or increase CH4 emissions by 30–50%. Therefore, ground water level management of these grasslands should be done with care.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00992979
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  • 71
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    Factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on oilseed rape (Brassica napus) (1996)
    Springer
    European journal of plant pathology 102 (1996), S. 545-553 
    Details
    ISSN: 1573-8469
    Keywords: epidemiology ; inoculum concentration ; leaf age ; temperature ; wetness period
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Experiments to investigate the factors affecting the incubation period of dark leaf and pod spot (Alternaria brassicae) on leaves and pods of oilseed rape (Brassica napus) were done in controlled environment (constant temperatures) and glasshouse conditions (fluctuating temperatures). The length of the incubation period of dark leaf and pod spot decreased as infection and incubation temperatures increased from 6 to 20 °C. The incubation period decreased as wetness period increased from 2 to 12 h, as inoculum concentration increased from 80 to 2 × 103 spores ml−1 and as leaf age increased from 4 to 10 days. Asymptotes of leaf age and inoculum concentration, above which the length of the incubation period did not decrease, were 10 days and 2 × 103 spores ml−1, respectively. The shortest and longest incubation periods were 1 and 11 days. The mechanism by which the infection conditions influenced the incubation period of dark leaf and pod spot on oilseed rape seemed to be linked to lesion density. Usually, the length of the incubation period decreased greatly with increasing lesion density.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01877021
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  • 72
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    The influence of temperature, photoperiod and plant type on the predation rate of Macrolophus pygmaeus on Myzus persicae (1999)
    Springer
    BioControl 44 (1999), S. 281-289 
    Details
    ISSN: 1573-8248
    Keywords: Macrolophus pygmaeus ; photoperiod ; predation rate ; temperature ; predator
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of temperature and photoperiod on the rate of predation of nymphs and adults of the predator Macrolophus pygmaeus was studied using Myzus persicae prey feeding on egg-plant and pepper plants. The experiments were conducted at three photoperiods (16L:8D, 12L:12D and 8L:16D), three temperatures (20, 25 and 30 °C), and at 65% r.h. The rate of predation increased with temperature. Predation rate was affected by photoperiod on pepper but not on egg-plant. Females and fifth instar nymphs were the most voracious stages followed by third and fourth instar nymphs and males. First and second instar nymphs consumed far fewer aphids. Predation rate was higher on leaves of pepper than egg-plant, especially at 30 °C. Variation in the efficacy of this predator is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009959325331
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  • 73
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    Competitive ability of the antagonists Ulocladium atrum and Gliocladium roseum at temperatures favourable for Botrytis spp. development (1999)
    Springer
    BioControl 44 (1999), S. 329-346 
    Details
    ISSN: 1573-8248
    Keywords: biological control ; Botrytis aclada ; Botrytis cinerea ; cyclamen ; ecological adaptation ; hydrangea ; lily ; onion ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ulocladium atrum and Gliocladium roseum are fungal antagonists capable of suppressing sporulation of Botrytis spp. on dead plant parts. The effect of temperature (3 to 36 °C) on antagonist conidial germination and mycelial growth was assessed on agar. In addition conidial germination of U. atrum was measured on dead lily leaves. The optimum temperature of both antagonists for both conidial germination and mycelial growth was between 27 and 30 °C. U. atrum was less affected by lower temperatures than G. roseum. At optimum temperature, 50% of conidia of U. atrum and G. roseum germinated within 2.6 and 10.0 hrs, respectively. At low sub-optimal temperatures (6 °C), 50% of conidia germinated within 18 and 96 hours, respectively. In bioassays on dead onion leaves, U. atrum suppressed sporulation of B. cinerea and B. aclada at all temperatures tested (6 to 24 °C) by more than 85%. On dead cyclamen leaves, G. roseum was more efficient than U. atrum at 21 and 24 °C but, in contrast to U. atrum, showed no antagonistic activity at temperatures below 21 °C. On dead hydrangea leaves, U. atrum significantly reduced sporulation of B. cinerea at temperatures as low as 3 and 1 °C. Under Dutch growing conditions, the mean air temperature during leaf wetness periods in onion and lily fields was 15 °C with temperatures only occasionally above 20 °C. In greenhouse crops of cyclamen, the mean temperature during high humidity periods was 17 °C. It is therefore concluded that U. atrum is better adapted than G. roseum to temperatures which occur in the field, in greenhouse crops such as cyclamen, or during cold storage of plant stocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009907311624
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