Studies on the productivity of tropical pasture plants. IV.* Separation of photosynthetic and respiratory components of net assimilation rate by growth analysis and gas exchange techniques under natural lighting

1974 ◽  
Vol 25 (3) ◽  
pp. 415 ◽  
Author(s):  
MR Heslehurst ◽  
GL Wilson
Keyword(s):  
Growth Analysis ◽  
Short Wave ◽  
Net Assimilation Rate ◽  
Wave Radiation ◽  
Carbon Dioxide Exchange ◽  
Assimilation Rate ◽  
Natural Lighting ◽  
Lighting Conditions ◽  
Analysis Technique ◽  
Net Assimilation

The growth analysis technique for the separation of photosynthetic and respiratory components of net assimilation rate used in previous controlled environment studies of early vegetative growth was extended to natural lighting conditions. The use of short-wave radiation rather than days in the light as the quantification of photosynthetic opportunity in the regression analysis improved the accuracy of estimation of photosynthesis and respiration. In one experiment, concurrently with the growth analysis procedure, carbon dioxide exchange measurements were made on one grass and one legume. There was good agreement between the two methods in the estimates obtained. The data support conclusions from previous experiments concerning the superior growth rate of grasses. Species rankings were similar in both sets of experiments. ____________________ *Part III, Aust. J. Agric. Res., 22: 865 (1971).

Effects of Pseudopeziza leaf spot disease on growth and yield in lucerne

1977 ◽  
Vol 28 (6) ◽  
pp. 1029 ◽  
Author(s):  
WC Morgan ◽  
DG Parbery
Keyword(s):  
Growth Analysis ◽  
Experimental Period ◽  
Field Trials ◽  
Net Assimilation Rate ◽  
Growth And Yield ◽  
Leaf Spot Disease ◽  
Assimilation Rate ◽  
Long Term Effect ◽  
Rate Of Increase ◽  
Net Assimilation

Growth analysis of lucerne plants infected with Pseudopeziza medicaginis compared with growth analysis of healthy plants showed that, while infection caused a general decrease in relative growth rate and leaf area ratio and affected the relative proportions of leaf, stem and root, there was no overall change in the growth pattern during the experimental period (7 weeks). In addition to retarding the net assimilation rate in leaves and roots, infection did slow down the rate of increase of net assimilation rate in leaves as well as its rate of decrease in roots. Infection delayed and possibly reduced flowering. Glasshouse, phytotron and field trials showed that infection with P. medicaginis can reduce dry matter production in lucerne by over 40%. It was shown that, in the absence of fresh infections, the influence of a single period of infection can have a considerable long-term effect.

SEEDLING GROWTH OF CRESTED WHEATGRASS AND RUSSIAN WILD RYEGRASS

1970 ◽  
Vol 50 (5) ◽  
pp. 559-563
Author(s):  
S. SMOLIAK ◽  
A. JOHNSTON ◽  
D. B. WILSON
Keyword(s):  
Seedling Growth ◽  
Dry Matter ◽  
Photosynthetic Efficiency ◽  
Growth Analysis ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Crested Wheatgrass ◽  
Agropyron Desertorum ◽  
Net Assimilation

Seedlings of crested wheatgrass, Agropyron desertorum (Fisch.) Schult., cultivar Summit, and Russian wild ryegrass, Elymus junceus Fisch., cultivar Sawki, were grown in the greenhouse for 7 weeks. Each week 20 plants were destructively harvested for growth analysis. Leaf and tiller numbers and leaf lengths were recorded for an additional 10 plants of each species. Mean net assimilation rate of crested wheatgrass was significantly higher (P < 0.01) than that of Russian wild ryegrass, apparently indicating greater photosynthetic efficiency in the former. In 7 weeks, crested wheatgrass seedlings produced nearly twice as much total dry matter as Russian wild ryegrass seedlings.

scholarly journals RESPONS OF GROWTH ANALYSIS PARAMTERS OF SOME COTTON CULTIVARS TO INTEGRATED WEED MANAGEMENT

2016 ◽  
Vol 47 (1) ◽  
Author(s):  
Al-Chalabi & Hammood
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Growth Analysis ◽  
Crop Growth ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Relative Growth ◽  
Crop Growth Rate ◽  
Crop Density ◽  
Net Assimilation

A field experiment was conducted at the experimental field, Department of Field Crop - College of  Agriculture Abu-Ghraib- University of Baghdad, during summer season at 2012 and 2013, to determine the response of  growth analysis parameters in some cotton cultivars to Integrated Weed Management. A randomized complete block design (RCBD) arranged according to split-plot was used with three replicates, included six weed control treatments as Main-plots where as Sub-plots included eight cotton cultivars. The results showed various to response of  growth analysis parameters to weed control treatments , the treatment of weedfree with normal crop density of 106667 plant.h-1 and high crop density of 200000 plant.h-1 during 70 -90 days after sowing achieved highest crop growth rate of 10.80 , 9.87 g.m-2.day-1 at first season respectively and 9.81, 9.35 g.m-2.day-1 at second season respectively, and highest net assimilation rate of 1.668 , 1.208 mg.cm-2.day-1 at first season respectively, and 1.504 , 1.004 mg.cm-2. day-1 at second season respectively, highest relative growth rate of  50.48 , 48.52 mg.g-1. day-1 at first season respectively, and 38.49 , 37.78 mg.g-1.day-1 at second  season respectively , Has cultivar in first season and Marsomi-1 cultivar in second season achieved  highest crop growth rate of 9.62 , 9.03 g.m-2.day-1 respectively, highest net assimilation rate of 1.399 ,1.188 mg.cm-2.day-1 respectively, Abu-Ghraib5 cultivar achieved highest relative growth rate of  57.19 , 44.66 mg.g-1.day-1 at both season respectively. The treatment of half rate of trifluraline 1.2 L.h-1 applied with high crop density with Has cultivar achieved  highest crop growth rate of  9.29 g.m-2.day-1 at first season, and with Marsomi-1 cultivar of  9.92 g.m-2. day-1 at second season, and highest net assimilation rate with Has cultivar of 1.163 , 1.040 mg.cm-2. day-1  at both season respectively, highest relative growth rate with Cocker 310 cultivar of  36.17 , 39.14 mg.g-1.day-1  at both season respectively, this results confirmed the integrated among cultivars, herbicides, and high crop density to improve this characters .

scholarly journals Functional growth analysis of diploid potato cultivars (Solanum phureja Juz. et Buk.)

2020 ◽  
Vol 14 (3) ◽  
pp. 402-415
Author(s):  
Tatiana María Saldaña-Villota ◽  
José Miguel Cotes-Torres
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Growth Analysis ◽  
Potato Cultivars ◽  
Net Assimilation Rate ◽  
Diploid Potato ◽  
Assimilation Rate ◽  
Degree Days ◽  
Net Assimilation ◽  
Accumulated Degree Days

Plant growth analysis has been widely used to study factors that influence plant growth. This analysis uses a set of quantitative methods that describe and analyze the growth of plants and their organs. It uses data from direct measurements (weight, area, volume) and quantifies and analyzes growth using indexes based on models defined by mathematical functions. This study conducted a functional growth analysis of diploid potato cultivars in Colombia. The functional growth analysis of diploid potato cultivars was carried out over three consecutive growing seasons in Medellín, Colombia. A randomized block design was used with two levels of fertilization and five repetitions. The first factor corresponded to the three potato cultivars, and the second factor was two fertilization levels: 260 and 778 kg of fertilizer per hectare. Samples were taken weekly, and each sample was an entire plant per experiment unit. The dry weight of each organ and the leaf area were measured. These measurements were used to calculate the relative growth rate, leaf area ratio, net assimilation rate, and specific leaf area. The development time was evaluated in accumulated degree-days with threshold temperatures of 2 and 29°C. The three cultivars recorded their highest net assimilation rate at 1,252 accumulated degree days (ADD), with values of 0.0002565, 0.0002021, and 0.0001778 g cm-2 ADD-1 in the ‘Latina’, ‘Guaneña’, and ‘Colombia’ cultivars, respectively. The Latina cultivar stood out in several physiological characteristics, including the fastest developing cultivar. ‘Latina’ also had the highest total dry mass accumulated in the cycle (271.05 g) and accumulated dry matter in tubers (237 g).

Effects of Temperature and CO2Concentration on the Growth of Cotton (Gossypium hirsutum), Spurred Anoda (Anoda cristata), and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 751-757 ◽  
Author(s):  
David T. Patterson ◽  
Maxine T. Highsmith ◽  
Elizabeth P. Flint
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Short Term ◽  
Leaf Weight ◽  
Matter Production ◽  
Total Plant ◽  
Net Assimilation ◽  
Total Dry Weight

Cotton, spurred anoda, and velvetleaf were grown in controlled-environment chambers at day/night temperatures of 32/23 or 26/17 C and CO2concentrations of 350 or 700 ppm. After 5 weeks, CO2enrichment to 700 ppm increased dry matter accumulation by 38, 26, and 29% in cotton, spurred anoda, and velvetleaf, respectively, at 26/17 C and by 61, 41, and 29% at 32/23 C. Increases in leaf weight accounted for over 80% of the increase in total plant weight in cotton and spurred anoda in both temperature regimes. Leaf area was not increased by CO2enrichment. The observed increases in dry matter production with CO2enrichment were caused by increased net assimilation rate. In a second experiment, plants were grown at 350 ppm CO2and 29/23 C day/night for 17 days before exposure to 700 ppm CO2at 26/17 C for 1 week. Short-term exposure to high CO2significantly increased net assimilation rate, dry matter production, total dry weight, leaf dry weight, and specific leaf weight in comparison with plants maintained at 350 ppm CO2at 26/17 C. Increases in leaf weight in response to short-term CO2enrichment accounted for 100, 87, and 68% of the observed increase in total plant dry weight of cotton, spurred anoda, and velvetleaf, respectively. Comparisons among the species showed that CO2enrichment decreased the weed/crop ratio for total dry weight, possibly indicating a potential competitive advantage for cotton under elevated CO2, even at suboptimum temperatures.

Varietal differences in growth characteristics in sugar cane

1987 ◽  
Vol 108 (1) ◽  
pp. 245-247 ◽  
Author(s):  
S. Singh ◽  
P. N. Gururaja Rao
Keyword(s):  
Growth Rate ◽  
Sugar Cane ◽  
Growth Characteristics ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Area Index ◽  
Relative Growth ◽  
Varietal Differences ◽  
Net Assimilation ◽  
High Yielding Varieties

In sugar cane, investigations made earlier (Singh & Gururaja Rao, 1985) have shown that high-yielding varieties have higher net assimilation rate than low-yielding types. Similarly, differences in progeny means for relative growth rate and net assimilation rate have been reported by George (1965). In other crops also, varietal differences in leaf area index and net assimilation rate have been reported (Watson, 1947). It appears that in this crop, limited attempts have been made to study all the growth characteristics. This paper describes the differences in most of the growth characteristics in six sugar-cane varieties.

scholarly journals Wplyw stopnia krzewienia się roślin na akumulacje biomasy organicznej u niektórych odmian zwyczajnej pszenicy ozimej [Influence of tillering degree on the accumulation of dry matter of some winter wheat varieties]

2015 ◽  
Vol 28 (2) ◽  
pp. 155-175
Author(s):  
Witold Drezner
Keyword(s):  
Winter Wheat ◽  
Dry Matter ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Wheat Varieties ◽  
H Index ◽  
Net Assimilation ◽  
Winter Wheat Varieties

The correlation between the net assimilation rate and the degree of plant tillering are investigated for several varieties of simple winter wheat. The net assimilation rate (E, NAR, An) of the studied varieties for different degrees of tillering, individual shoots and individual plants is described according to the units mg/cm<sup>2</sup> • 24 h. Index of efficiency of assimilation surface (F, LAR, I<sub>S</sub>) is determined in units cm<sup>2</sup>/mg. The tillering ability of vegetative shoots in plaints is a very important factor which increases the total assimilate stirfaice value and the assimilation effectivity of the plant's biomass.

Studies on the productivity of tropical pasture plants. V.* Effect of shading on growth, photosynthesis and respiration in two grasses and two legumes

1974 ◽  
Vol 25 (3) ◽  
pp. 425 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson ◽  
MR Heslehurst
Keyword(s):  
Radiant Energy ◽  
Net Assimilation Rate ◽  
Assimilation Rate ◽  
Pasture Production ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Analysis Techniques ◽  
Net Assimilation ◽  
Photosynthesis And Respiration ◽  
Pasture Plants

Two grasses and two legumes were grown at three illuminances: one grass and one legume in a growth cabinet (100, 50 and 34% relative illuminance) and one of each in a glasshouse (100, 30 and 10% relative illuminance). The response to shading was investigated by using classical growth analysis techniques, and the photosynthesis-respiration balance obtained by Watson and Hayashi's method. Shading caused a reduction in the proportion of root and a corresponding increase in the proportion of leaf, and an increase in the shoot/root ratio in all species except green panic. The relative growth rates of grasses (which were only clearly superior at the highest illuminance) were affected more by shading than were those of legumes, and the greater shading effect resulted from a greater decrease in net assimilation rate, and to a lesser extent, from a smaller compensatory increase in leaf area ratio in the grasses than in the legumes. The greater sensitivity of net assimilation rate of grasses to shading arose from a stronger dependence of the photosynthetic rate on illuminance. The significance of these findings for pasture production is discussed. Both tiller and runner production were dependent upon the total amount of radiant energy received by the plant, and in the growth cabinet, at least, were independent of its intensity, duration and sequence. ______________________ *Part IV, Aust. J. Agric. Res., 25: 415 (1974).

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