scholarly journals Studies on Matter Production in Wheat Plant : I. Diurnal changes in carbon dioxide exchange of wheat plant under field conditions

1973 ◽  
Vol 42 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Seikichi KOH ◽  
Atsuhiko KUMURA
Keyword(s):  
Carbon Dioxide ◽  
Wheat Plant ◽  
Field Conditions ◽  
Carbon Dioxide Exchange ◽  
Diurnal Changes ◽  
Matter Production

Photosynthesis of wheat under field conditions. II.* Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation. * Part I, Aust. J. Agric. Res., 1968, 19: 711.

A growth model for Trifolium subterraneum L. Swards

1978 ◽  
Vol 29 (1) ◽  
pp. 51 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Carbon Dioxide Exchange ◽  
Dry Matter Yield ◽  
Area Index ◽  
Crop Growth Rate ◽  
Matter Production ◽  
Final Yield

A simple deterministic model to simulate the time course of potential dry matter growth by subterranean clover swards in the field is described. Relationships used in the model were obtained mainly from experiments in temperature-controlled glasshouses and from measurements of rate of carbon dioxide exchange in an assimilation chamber. Canopy carbon dioxide exchange rates in the light and in the dark are calculated in the model from leaf area index, total dry matter, air temperature, irradiance and the crop growth rate of the sward. Photosynthates are distributed among different parts of plants according to empirical relationships. The model can estimate the potential dry matter growth of swards grown at different levels of irradiance and at different temperatures. Dry matter yield of a crop growing in the field without limitation of water and mineral nutrients can be predicted to within 20% for 100 days of growth. Potential dry matter yield of pure subterranean clover swards at Adelaide is predicted by the model to be strongly influenced by the time of cessation of growth. If the growth is terminated in the middle of October, an early start to growth as well as a high plant density will be advantageous for a high final yield. On the one hand, if the growing season extends until late November, there will be only a small effect of time of commencement of growth on final yield. The model suggests that leaf area index is an important determinant of dry matter production up to about 200 g m-2, and that increased maintenance respiration at a dry matter yield above about 600 g m-2 results in a decreased growth rate. The effects of variation in irradiance and temperature on dry matter production at different growth stages are assessed. It is concluded from use of the model that the effects of temperature on crop growth rate depend on the amount of dry matter present and on the level of solar radiation.

Alteration of size of wheat root systems and nitrogen fixation by associative nitrogen-fixing bacteria measured under field conditions

1988 ◽  
Vol 34 (6) ◽  
pp. 735-739 ◽  
Author(s):  
R. M. N. Kucey
Keyword(s):  
Plant Root ◽  
N Uptake ◽  
Wheat Plant ◽  
Root Systems ◽  
System Size ◽  
Wheat Root ◽  
Field Conditions ◽  
Total N ◽  
Matter Production ◽  
And Control

Spring wheat was inoculated with Azospirillum brasilense Cd or Bacillus C-11-25 under field conditions. Use of a 32P measuring technique showed that the root systems of Azospirillum-inoculated wheat occupied 54% of the soil volumes compared with uninoculated wheat plant root systems. Bacillus-inoculated wheat root systems were 82% of the size of uninoculated wheat root systems. Inoculated and control plants did not differ in dry matter production or in total N content. Inoculated plants received between 5 and 10% of the N contained in their tissues from associative N2 fixation as measured by 15N isotope dilution. Reduction of root system size in inoculated plants explains how the inoculated wheat plants in this study, and in previously reported studies, are able to absorb atmospheric N2 via associative N2 fixation without increasing total plant N uptake.

Corrigendum - Photosynthesis of wheat under field conditions. II. Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation.

Net carbon dioxide exchange of wheat, sorghum, and soybean

1975 ◽  
Vol 53 (4) ◽  
pp. 382-389 ◽  
Author(s):  
E. T. Kanemasu ◽  
C. K. Hiebsch
Keyword(s):  
Carbon Dioxide ◽  
Dry Matter ◽  
Growing Season ◽  
Dry Matter Production ◽  
Carbon Dioxide Exchange ◽  
Gas Analyzer ◽  
Light Saturation ◽  
Matter Production ◽  
Infrared Gas Analyzer ◽  
Effect Of Light

Canopy net carbon dioxide exchange (NCE) rates are needed to understand the effect of light on crop growth and development. NCE rates of sorghum, soybean, and wheat canopies were determined using field chambers and an infrared gas analyzer throughout a growing season. Whereas sorghum attained peak NCE rates early in season, soybean and wheat did not reach maximum rates until the late reproductive growth stage. Frequently during the season, NCE rates of sorghum were nearly four times those of soybeans and wheat. Solar radiation had a much greater affect on the NCE of sorghum than on that of soybeans. Apparent light saturation was observed in both soybeans and wheat. An expression for dry matter production of sorghum was derived using chamber data. The expression simulated the total dry matter production for sorghum in 1973, 1972, and 1970 within 20%.

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