Observations on Rhizoctonia Disease Expression in Sandhill Potatoes and Effect of Temperature on Fungal Growth Rate.

1979 ◽  
Vol 8 (2) ◽  
pp. 14 ◽  
Author(s):  
EJ Cother
Keyword(s):  
Growth Rate ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Disease Expression ◽  
Rhizoctonia Disease

Review and synthesis of experimental data on organic matter decomposition with respect to the effect of temperature, moisture, and acidity

1998 ◽  
Vol 6 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Charlotta Walse ◽  
Björn Berg ◽  
Harald Sverdrup
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Organic Matter ◽  
Soil Moisture ◽  
Mass Loss ◽  
Growth Rates ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Decomposition Model ◽  
Bacteria And Fungi

A review and synthesis of experimental decomposition data was performed with the objective of finding parameter values for a decomposition model. Experimental data were retrieved from the literature and included data on mass loss rates, nitrogen mineralization rates, carbon dioxide evolution rates, and growth rates of bacteria and fungi. Environmental variables included in the synthesis were air temperature, soil moisture, and soil acidity (concentration of H+ and Al3+ in soil solution). The variables were assumed to act as separate, multiplicative rate regulating factors on soil microbial processes. The model outline includes four organic matter pools: (i) easily decomposable compounds, (ii) holocellulose, (iii) lignin, and (iv) resistant compounds. It was assumed that the decomposition of the easily decomposable substances can be modeled as the growth rate of bacteria, while the decomposition of lignin and resistant compounds can be modeled as the growth rate of fungi. The decomposition of the substances included in the holocellulose pool was assumed to follow an intermediate function. Results show that enough data are available for the parameterization of a model of the suggested type. The effect of temperature on decomposition rate seems to increase with decreasing nutrient concentration of the substrate. Decomposition rates increase with relative soil moisture saturation. Bacterial growth rates are generally more sensitive to low pH than fungal growth rates. Decomposition of mixed organic material is inhibited in an intermediate fashion. The combined impact of H+ and Al3+ on the growth rates of bacteria and fungi can be modeled with an ion-exchange expression, preferably the Vanselow expression. It was concluded that some additional experiments would be needed for further model development purposes. Such experiments should be set up as mass loss experiments and last for a minimum of 2 weeks.Key words: decomposition, model, acidification, aluminum, pH.

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.

Low temperature effects on the growth of evening primrose (Oenothera spp.) rosettes

2004 ◽  
Vol 52 (1) ◽  
pp. 19-28
Author(s):  
A. F. Fieldsend
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Relative Rate ◽  
Field Trials ◽  
Effect Of Temperature ◽  
Relative Growth ◽  
Evening Primrose ◽  
Intermittent Exposure ◽  
Environment Experiment

In field crops of evening primrose (Oenothera spp.) the post-winter growth of rosettes is slow to re-start. The effect of temperature on the growth of rosettes was assessed in a controlled environment experiment. Relative growth rate was positively correlated with temperature, but in apparent contrast to the results from field trials, the rosettes grew at constant temperatures as low as 6.5ºC. However, following transfer to warmer temperatures an increase in relative growth rate did not occur until 7-10 days later, whilst a change to a cooler environment caused an immediate reduction in relative growth rate. Thus, it seems likely that growth is inhibited by intermittent exposure to temperatures of 0°C or below. Partitioning of biomass between root and shoot was independent of temperature, but at 6.5ºC the relative rate of leaf area increase was very low. Consequently, the specific leaf area was lower in rosettes growing at lower temperatures.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

scholarly journals Development of Algae Guard Façade Paint with Statistical Modeling under Natural Phenomena

2018 ◽  
Author(s):  
Sheraz Ahmed Qureshi ◽  
Amir Shafeeq ◽  
Aamir Ijaz ◽  
Muhammad Moeen Butt
Keyword(s):  
Growth Rate ◽  
Paint Film ◽  
Effect Of Temperature ◽  
Natural Phenomena ◽  
Linear Effect ◽  
Positive Unit ◽  
Algae Growth ◽  
Temperature Variable ◽  
Explained Variation ◽  
The Individual

Algaecides are chemicals that cause serious health problems. Conventional paints contain algaecides to improve the algae resistance on the paint film. Present research has suggested an environmental friendly paint formulation that focuses on developing algae resistance without having algaecides. In this research, Algae growth on newly developed paint is modeled by incorporating dirt resistance of paint and natural phenomena including humidity, temperature and time respectively. The fitted Model revealed explained variation of 59.65% in the average algae growth, of which, Dirt Resistance, Humidity and temperature and some of their interactions play significant role in this variation. Model suggests that the proposed newly developed paint without algaecides is more resilient to algae growth and significantly decreased the average algae growth rate by 0.53% as compared to conventional paints. Keeping the effect of all other factors constant, if dirt resistance of paint (Dc value) increases by one percent, average algae growth decreases by 12.98%; when temperature increases by 1oC, average algae growth decreases by 22.4%; a positive unit change in the joint linear effect dirt resistance, temperature and humidity caused a decrease in average algae growth by 0.0031%. It was also observed that the individual effect of humidity variable was inversely related with average algae growth. However the combination of humidity and temperature, humidity and dirt resistance, humidity and time, and the quadratic effect of humidity were found to increase the average algae growth rate. The cubic effect of temperature variable by one degree centigrade resulted in decrease of average algae growth by 0.000907%.

scholarly journals Studies in the geotropism of the pteridophyta V—Some effects of temperature on growth and geotropism in Asplenium bulbiferium

1935 ◽  
Vol 116 (800) ◽  
pp. 479-493 ◽  
Keyword(s):  
Growth Rate ◽  
Effect Of Temperature ◽  
Horizontal Position ◽  
Present Position ◽  
Minimum Period ◽  
Plant Life ◽  
Latent Time ◽  
Presentation Time ◽  
Effects Of Temperature ◽  
The Given

Although temperature and gravity both influence plant life, and although both factors have been studied for many decades, there is surprisingly little literature decades, there is surprisingly little literature dealing with the relation between the two; and none, so far as I can discover, on the effect in any Pteridophyte. Navez (1929) who criticized the work of some investigators on the effect of temperature on the geotropism of a few seedlings, sums up the present position in his remark that the conclusions of workers are very different and often in opposition. The present paper gives the results of 1100 experiments carried out mainly between the years 1922 and 1927, and though it is realized that much remains to be done on the question, it is believed that the results which have been obtained are of some value. For general methods, reference may be made to previous “Studies” in this series. Geotropic sensitivity, as measured by presentation time at different stages in development of the frond, was fully worked out by Waight (1923) for 20°C, and is adopted here as a standard of reference. The growth rate recorded in the tables is that for the particular frond under investigation, or is the average of the fronds examined during the day of the experiment. Nearly all the experiments included in the tables were conducted during the months of April-October, as I have since been able to show that there is an annual rhythm in geotropic irritability. A decrease in sensitivity occurs in winter, and hence experiments performed in November-March are not strictly comparable with those carried out in the summer. The following abbreviations are used:- P.S. = period of stimulation. P.T. = presentation time, i. e ., the minimum period of stimulation in a horizontal position, which, under the given conditions, will cause a movement of approximately 5° in about 80% of the fronds. L.T. = latent time (Prankerd, 1925) in hours. N = “normal time,” i. e ., the P.T. For different stages of the frond at 20°C (see Waight, 1923).

The Effect of Temperature on the Growth and Respiration of Fish Embryos (Salmo Fario)

1932 ◽  
Vol 9 (3) ◽  
pp. 271-276
Author(s):  
A. H. WOOD
Keyword(s):  
Growth Rate ◽  
Oxygen Consumption ◽  
Relative Intensity ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Effect Of Temperature ◽  
Total Oxygen ◽  
Average Efficiency ◽  
Complete Development ◽  
Time Required

1. The rate of respiration (as expressed in c.c. O2 per gram embryo per hour) of the embryos of Salmo fario remains constant at any given temperature until the embryo has reached its maximum growth-rate, after this point it declines. It is suggested that the rate of respiration may be proportional to the amount of available yolk. 2. When incubated at 7° C. the time required to complete development after hatching was 58 days and the total oxygen consumed by an average embryo during this period was 20·31 c.c. (N.T.P.). At 12° the time required for the completion of development was reduced to 27 days, but the oxygen consumption remained practically unchanged at 20·71 c.c. At 3° C. the time required for development was 108 days and the oxygen consumption was 26·96 c.c. per embryo. 3. At 7 and 12° C. the efficiency of development was found to be identical with the value given by Gray for 11·5° C., viz. 63 per cent.; at 3°C. the average efficiency over the period considered was only 54 per cent. 4. It is suggested that, between the limits of temperature to which a trout egg is normally exposed, the effect of temperature on respiration is neither greater nor less than its effect on the growth-rate; possibly both processes are dependent on the same controlling factor. Above and below this range of temperature, the relative intensity of the respiratory processes (to those of growth) is increased, and a smaller embryo is the final result of incubation.

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