Photosynthesis of wheat under field conditions. IV. The influence of density and leaf area index on the response to radiation

1971 ◽  
Vol 22 (1) ◽  
pp. 11 ◽  
Author(s):  
DW Puckridge ◽  
DA Ratkowsky
Keyword(s):  
Carbon Dioxide ◽  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Net Photosynthesis ◽  
Good Prediction ◽  
Area Index ◽  
Rectangular Hyperbola ◽  
Carbon Dioxide Uptake ◽  
Good Agreement

The photosynthesis of two cultivars of wheat at three densities of sowing was measured during the growing season of 1968. When the data were plotted as carbon dioxide uptake versus leaf area index (LAI) (leaf laminae and green stem) for a fixed value of solar radiation, it was found that all of the data could be fitted by a single curve, irrespective of variety, sowing density, or time of season when the measurements were made. Since the curve was of continuously decreasing slope, the carbon dioxide uptake per unit LAI was highest for the low values of LAI and was reduced with the increased light interception at high LAI. For a solar radiation of 0.6 cal/cm2/min the approximate maximum net photosynthesis was 4.5 g CO2/m2/hr for an LAI of 6. A mathematical model for photosynthesis was found to give good prediction of carbon dioxide uptake versus solar radiation for most of the period of measurement. For each plot, a rectangular hyperbola was fitted to the data. When the parameters of the model were subsequently plotted as a function of LAI, then within a given variety, it was found that lines of common slope but differing intercepts could be drawn through the points for different sowing densities. From these fitted lines together with the measured values of LAI and respiration, carbon dioxide uptake was then predicted as a function of solar radiation by employing the rectangular hyperbola model. Good agreement between predicted and measured values of photosynthesis was obtained.

Photosynthesis of wheat under field conditions. III. Seasonal trends in carbon dioxide uptake of crop communities

1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Weight ◽  
Field Conditions ◽  
Wheat Cultivars ◽  
Area Index ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.

Hyperspectral characteristics and leaf area index monitoring of rice (Oryza sativa L.) under carbon dioxide concentration enrichment

2021 ◽  
Vol 54 (3) ◽  
pp. 231-243
Author(s):  
Chao Liu ◽  
Zhenghua Hu ◽  
Rui Kong ◽  
Lingfei Yu ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oryza Sativa ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Oryza Sativa L ◽  
Carbon Dioxide Concentration ◽  
Area Index

scholarly journals The effect of light availability on leaf area index, biomass production and plant species composition of park grasslands in Warsaw  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 543-548 ◽  
Author(s):  
P. Dąbrowski ◽  
B. Pawluśkiewicz ◽  
Kalaji HM ◽  
Baczewska AH
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Light Availability ◽  
Vegetation Coverage ◽  
Light Conditions ◽  
Area Index ◽  
Sward Height ◽  
Poa Trivialis ◽  
Leaf Density

How light conditions affect development of park grasslands is a question that has not been satisfactory addressed. The aim of this study was therefore determination of the level to which unfavorable light conditions influence grassy parks area and relationships between parameters which determine state of turf grasses. Researches were conducted in two parks in Warsaw, in various light conditions and included measurement of: leaf density, sward height, leaf area index (LAI), and botanical composition of the communities. The leaf density of shaded areas did not exceed 70%. LAI value varied from 0.5 to 0.9-fold lower than in the areas in half-shade and in sun. The participation of basic lawn species at Skaryszewski Park was higher under shade, while at Łazienki Królewskie was higher in full-sunlight areas. The state of tested grassy areas in limited solar radiation does not satisfy the requirements of recreational and representational functions. The development processes of vegetation coverage were inhibited at the sites of lower solar radiation. LAI was influenced by both leaf coverage and sward height. Agrostis stolonifera and Poa trivialis may be recommended to create grass areas under limited solar radiation.

scholarly journals PERTUMBUHAN DAN PRODUKSI PAPRIKA PADA BERBAGAI INTENSITAS RADIASI SURYA DI DATARAN RENDAH, BATAM(GROWTH AND PRODUCTION OF SWEET PEPPER CULTIVATED UNDER DIFFERENT SOLAR RADIATION INTENSITY AT LOWLAND REGION OF BATAM)

Agromet ◽  
2005 ◽  
Vol 19 (2) ◽  
pp. 57
Author(s):  
Z. Noor ◽  
B.F. Simatupang ◽  
Yonny Koesmaryono
Keyword(s):  
New Zealand ◽  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Radiation Intensity ◽  
Ultra Violet ◽  
Sweet Pepper ◽  
Area Index ◽  
Hydroponic System ◽  
Solar Radiation Intensity

<p>An experiment has been conducted in Batam Island to study the response of sweet pepper which cultivated at lowland of 20 m asl, during November 2001 to May 2002. Five varieties have been used namely, Bangkok, Gold Flame, New Zealand, Spartacus and Tropica. Plants cultivated using hydroponic system under plastic house with ultra violet protection. The radiation of 100% (control) and it reduce of 25% and 50% used as treatment in order to determine the microclimate favourable for growing pepper in lowland. The results shown that reducing radiation intensity has influenced significantly on vegetatif growth, except leaf area index. The plants were grown under 100% and 25% radiation intensity performed taller with more branches compare to the plants under 50%. Variety of Spartacus has grew tallest than others. Stem diameter of control plants performed bigger than other plants, while reducing radiation intensity has no effect significantly to leaf area index. Experiment also revealed that reducing radiation intensity has significant effect on number and weight of peppers per plant, and thickness of flesh, compare to control. In general, Gold flame has produced best quality than others varieties although it has less number of fruits compare to Tropica.</p>

Photosynthesis in Artificial Communities of Wheat, Lucerne, and Subterranean Clover Plants

1967 ◽  
Vol 20 (3) ◽  
pp. 623 ◽  
Author(s):  
RW King ◽  
LT Evans
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dark Respiration ◽  
Subterranean Clover ◽  
Net Photosynthesis ◽  
Area Index ◽  
Light Intensities

The relation between leaf area index (L.A.I.) and rates of net photosynthesis at three light intensities, and of dark respiration, was examined throughout the course of growth of artificial communities of wheat and lucerne at 20�C, and of subterranean clover at 25� /20�C.

scholarly journals Conversion Efficiency of Photosynthetically Active Radiation for Soybean Cultivations in Spatial Arrangements

2019 ◽  
Vol 11 (9) ◽  
pp. 213
Author(s):  
Braulio Otomar Caron ◽  
Ana Paula Rockenbach ◽  
Denise Schmidt ◽  
Thaise Dieminger Engroff ◽  
Felipe Schwerz ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Conversion Efficiency ◽  
Photosynthetically Active Radiation ◽  
Area Index ◽  
Active Radiation ◽  
Soybean Cultivars ◽  
Growth Habits ◽  
Conversion Efficiencies

The objective of this paper was to assess the efficiency of photosynthetically active radiation (PAR) intercepted in dried phytomass of soybean cultivars of determinate and indeterminate growth habits in different spatial arrangements. All experiments were carried out during the 2013/2014 crop year, two soybean cultivars (BMX Ativa RR/determinate and BMX Turbo RR/indeterminate) in a spatial arrangements (45, crossed, 20, 20 &times; 40, 20 &times; 60, 20 &times; 80 cm). Starting from first emergence up to the point of maturation, 14 phytomass assessment were evaluated with seven days interval, in which one plant was sampled per repetition. Greater conversion efficiencies of solar radiation were obtained in paired arrangements. Paired arrangements, and 20 cm, lead to a greater leaf area index, and possibly a greater interception of the diffused radiation and an increase of conversion efficiency and the overall cultivation productivity of BMX Ativa RR and BMX Turbo RR.

scholarly journals Effect of Solar Radiation on Severity of Soybean Rust

2012 ◽  
Vol 102 (8) ◽  
pp. 794-803 ◽  
Author(s):  
Heather M. Young ◽  
Sheeja George ◽  
Dario F. Narváez ◽  
Pratibha Srivastava ◽  
Andrew C. Schuerger ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Epicuticular Wax ◽  
Soybean Rust ◽  
Disease Development ◽  
Area Index ◽  
Detached Leaf

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a damaging fungal disease of soybean (Glycine max). Although solar radiation can reduce SBR urediniospore survival, limited information is available on how solar radiation affects SBR progress within soybean canopies. Such information can aid in developing accurate SBR prediction models. To manipulate light penetration into soybean canopies, structures of shade cloth attenuating 30, 40, and 60% sunlight were constructed over soybean plots. In each plot, weekly evaluations of severity in lower, middle, and upper canopies, and daily temperature and relative humidity were recorded. Final plant height and leaf area index were also recorded for each plot. The correlation between amount of epicuticular wax and susceptibility of leaves in the lower, middle, and upper canopies was assessed with a detached leaf assay. Final disease severity was 46 to 150% greater in the lower canopy of all plots and in the middle canopy of 40 and 60% shaded plots. While daytime temperature within the canopy of nonshaded soybean was greater than shaded soybean by 2 to 3°C, temperatures recorded throughout typical evenings and mornings of the growing season in all treatments were within the range (10 to 28.5°C) for SBR development as was relative humidity. This indicates temperature and relative humidity were not limiting factors in this experiment. Epicuticular wax and disease severity in detached leaf assays from the upper canopy had significant negative correlation (P = 0.009, R = –0.84) regardless of shade treatment. In laboratory experiments, increasing simulated total solar radiation (UVA, UVB, and PAR) from 0.15 to 11.66 MJ m–2 increased mortality of urediniospores from 2 to 91%. Variability in disease development across canopy heights in early planted soybean may be attributed to the effects of solar radiation not only on urediniospore viability, but also on plant height, leaf area index, and epicuticular wax, which influence disease development of SBR. These results provide an understanding of the effect solar radiation has on the progression of SBR within the soybean canopy.

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