scholarly journals Effect of artificial shading on growth and morphogenesis of rauvolfia serpentina benth. Ex. Kurz and r. Tetraphylla L.

1970 ◽  
Vol 18 ◽  
pp. 21-26
Author(s):  
MP Trivedi ◽  
Rachna Kumari
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Weight Ratio ◽  
Dry Weight ◽  
Rauvolfia Serpentina ◽  
Light Regimes ◽  
Light Intensities ◽  
Partial Shade ◽  
Net Assimilation ◽  
Artificial Shading

Context: Plants behaviour is greatly influenced by light intensity, quality and photoperiods. Rauvolfia serpentina Benth. ex. Kurz and R. tetraphylla L. grow well during April to September with longer daylength and maximum light intensity. Growth of both the species continues during rest months with slow rate. From their overall performance in their normal habitat R. serpentina seems to appear that it can tolerate some shading as against R. tetraphylla.   Objective: To study the growth behaviour of R. serpentina and R. tetraphylla under three different light intensities i.e. full open sun, partial shade and shade in a glasshouse.   Materials and Methods: Experiments were done on three light regimes measured with the help of luxmeter, i.e. full light under natural condition with 100% light under netted cloth cover with 90% and diffused light under muslin cloth with 70% Seedlings were raised in earthenware pots. The harvesting was started after 2 weeks after transference of the plants to their appropriate light intensities. The performance of species was judged with respect to mean dry weight accumulation, leaf area increase, relative growth rate, leaf area ratio, specific leaf area, leaf weight ratio, net assimilation rate and α.   Results: In both species dry weight and leaf area increased steadily in successive harvests but R. serpentina and R. tetraphylla appear to behave differently in their response to different light regimes. R. serpentina grows well in partial shade and full light as against R. tetraphylla which does well in full light than in partial shade. R. serpentina always maintained an edge over R. tetraphylla.   Conclusion: Both species showed the value of α more than one in most regimes. It means that they are morphogenetically well balanced and are ready for flowering. Keywords: Artificial shading; Growth; Morphogenesis; Rauvolfia serpentine; R. tetraphylla. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8770 JBS 2010; 18(0): 21-26

scholarly journals Effects of temperature and light intensity on growth of fodder beet (Beta vulgaris L. var. crassa Mansf.)

1970 ◽  
Vol 36 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Sebahattin Albayrak ◽  
Necdet Çamas
Keyword(s):  
Light Intensity ◽  
Plant Growth ◽  
Leaf Area ◽  
Growth Parameters ◽  
Growth Models ◽  
Weight Ratio ◽  
Dry Weight ◽  
Root Weight ◽  
Leaf Weight ◽  
Net Assimilation

Changes in plant growth viz. leaf area, leaf weight ratio, root weight ratio, dry leaf weight, dry root weight, total plant dry weight, specific leaf area, leaf thickness, leaf area ratio, net assimilation rate and relative growth rate due to the effects of environmental conditions such as temperature and light intensity were described by plant growth models. All equations produced for growth parameters were affected by light intensity and temperature. From multi-regression analysis, close relationships were found between actual and predicted growth parameters. The regression coefficients (r²) of the equations for growth parameters varied from 0.95 to 0.99 for cultivar Ecdogelb and 0.83 to 0.99 for cultivar Ecdorot, respectively.  

AN ANALYSIS OF DRY MATTER PRODUCTION OF DOUGLAS-FIR SEEDLINGS IN RELATION TO TEMPERATURE AND LIGHT INTENSITY

1967 ◽  
Vol 45 (11) ◽  
pp. 2063-2072 ◽  
Author(s):  
Holger Brix
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Dry Matter ◽  
Douglas Fir ◽  
Dry Matter Production ◽  
Dry Matter Distribution ◽  
Pronounced Increase ◽  
Light Intensities ◽  
Matter Production ◽  
Net Assimilation

Seedlings of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were grown in growth chambers under all combinations of three temperatures (13, 18, and 24 °C) and three light intensities (450, 1000, and 1800 ft-c). Dry matter production of leaves, stem, and roots was determined at 65 and 100 days after germination. The leaf area produced per unit of leaf dry weight and the dry matter distribution to the plant organs was measured. Net assimilation rates between the ages of 65 and 100 days were calculated. Rates of photosynthesis per unit of leaf were determined at different light intensities and temperatures, and rates of respiration of plant top and of roots were found for different temperatures.Increasing light intensity affected dry matter production in two opposing ways: (i) it increased the rate of photosynthesis per unit leaf area, and (ii) it decreased the leaf area added per unit of dry matter produced. A pronounced increase in growth with increase in temperature from 13 to 18 °C was a result of a temperature influence on production of leaf area rather than the effect of photosynthesis per unit of leaf. Net assimilation rates decreased with increase in temperature at all light intensities.

scholarly journals Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 843-846 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yoshiaki Kitaya ◽  
Saki Hayashi
Keyword(s):  
Leaf Area ◽  
Growth Parameters ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Unit Leaf Area ◽  
Cucumber Seedlings ◽  
Unit Leaf ◽  
Net Assimilation ◽  
Normal Light

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.

Étude de la plasticité phénotypique chez le Chrysanthemum leucanthemum. I. Croissance, allocation de la biomasse et reproduction

1988 ◽  
Vol 66 (11) ◽  
pp. 2285-2298 ◽  
Author(s):  
Céline Boutin ◽  
Pierre Morisset
Keyword(s):  
Phenotypic Plasticity ◽  
Light Intensity ◽  
Leaf Area ◽  
Weight Ratio ◽  
Total Weight ◽  
Root Weight ◽  
Intensity Level ◽  
Nutrient Levels ◽  
Light Intensities ◽  
Chrysanthemum Leucanthemum

Phenotypic plasticity was experimentally studied in plants sampled from two tetraploid populations of ox-eye daisy, Chrysanthemum leucanthemum L. Plants were cloned and ramets were grown in an outdoor garden, in two independent experiments aimed at measuring the effects of light intensity (three treatments) and nutrient level (three treatments). When plants of the same genotype were grown under different light intensities, phenotypic plasticity was high for the following characteristics: total biomass, root weight to total weight ratio, leaf area, leaf area to total weight or specific leaf weight ratio, stem height, branching, number of heads, and time of flowering and fruiting. Genotypes grown under the three nutrient levels showed less plasticity, especially for leaf-related features. Biomass allocation patterns were also measured. Generally, lower light intensities resulted in an increase of allocation to leaves and a corresponding decrease of allocation to roots. On the other hand, lower nutrient levels caused an increase of allocation to roots accompanied by a decrease of allocation to heads, but had little effects on allocation to leaf material. The effective reproductive effort (percentage of biomass allocated to mature achenes) was higher under the lowest light intensity level, but did not change significantly with nutrient levels. The results are discussed in relation to the specificity of plastic responses with respect to the nature of environmental stresses. The prolific production of heads that remained immature at the onset of cold autumn temperatures is interpreted as a nonadaptative tactic in C. leucanthemum.

Effects of different concentrations of atmospheric CO2on growth and yield components of wheat

1981 ◽  
Vol 97 (2) ◽  
pp. 335-339 ◽  
Author(s):  
N. Sionit ◽  
B. R. Strain ◽  
H. Hellmers
Keyword(s):  
Leaf Area ◽  
Yield Components ◽  
Ecological Impact ◽  
Weight Ratio ◽  
Co2 Enrichment ◽  
Dry Weight ◽  
Plant Size ◽  
Growth And Yield ◽  
Root Shoot Ratio ◽  
Net Assimilation

SummaryGrowth and yield components of a semi-dwarf spring wheat (Triticum aestivumL., cv. GWO 1809) were determined under three different atmospheric CO2a concentrations (350, 675 and 1000 μ1/1) in controlled environment chambers of the Duke University Phytotron. CO2 enrichment enhanced tiller and head emergence and increased the number of head-producing tillers and the total dry weight of the plants. Total leaf area, stem height and root/shoot ratio of the plants were greater at high CO2concentrations than at low. Net assimilation rate (NAR) increased with increasing CO2concentration and decreased with plant size. There was little effect of CO2enrichment on leaf weight ratio (LWR) and leaf area ratio (LAR) and no significant effect on specific leaf area (SLA). The weight and number of seeds were significantly higher with increasing CO2concentration. The results of this study provide evidence that important changes in plant growth and development may occur during the next century if global CO2enrichment continues. Some of these changes would have important ecological impact in natural and managed ecosystems in the future.

Leaf Expansion Limits Dry Matter Accumulation of Salt-Stressed Maize

1994 ◽  
Vol 21 (5) ◽  
pp. 663 ◽  
Author(s):  
GR Cramer ◽  
GJ Alberico ◽  
C Schmidt
Keyword(s):  
Salt Tolerance ◽  
Leaf Area ◽  
Carbon Allocation ◽  
Weight Ratio ◽  
Dry Weight ◽  
Leaf Expansion ◽  
Dry Matter Accumulation ◽  
Relative Growth ◽  
Nacl Salinity ◽  
Net Assimilation

Two maize (Zea mays L.) hybrids, differing in their salt tolerance (percentage of control on a dry weight basis) and ability to accumulate Na+ in the shoot, were treated with 80 mol m-3 NaCl salinity or 80 mol m-3 NaCl plus 8.75 mol m-3 CaCl2. Multiple harvests were performed and the interactions of salinity with time were examined with growth analysis. Relative growth rate (RGR) and leaf area ratio (LAR) were significantly reduced by NaCl salinity, but net assimilation rate (NAR) was unaffected. Supplemental Ca2+ improved RGR by maintaining LAR closer to control values. LAR was inhibited in the early stages of salt stress, but was not limiting growth relative to controls in later stages. Salinity also reduced the specific leaf area and leaf weight ratio, which indicates that leaf expansion and carbon allocation were altered. Differences in salt tolerance between the hybrids were small, but significant throughout the lifecycle of the plants. These differences were associated with differences in leaf elongation rates and LAR within the first 9 days of salinity.

scholarly journals A method to improve leaf succulence quantification

1999 ◽  
Vol 42 (1) ◽  
Author(s):  
André Mantovani
Keyword(s):  
Leaf Area ◽  
Weight Ratio ◽  
Volume Ratio ◽  
Dry Weight ◽  
Fresh Weight ◽  
Ecological Implications ◽  
Leaf Succulence ◽  
Sun Leaves

Leaf succulence has important physiological and ecological implications. Currently it is quantified by Delf's index (fresh weight/leaf area) and fresh weight/ dry weight ratio. Both indeces are reconsidered and a new index is proposed. Shade and sun leaves from terrestrial, hemiepiphytic and epiphytic aroids were studied. Delf's formula, which does not consider dry weight, overestimated leaf succulence. As fresh weight / dry weight ratio (fw / dw) does not consider leaf area, plants with the same fw / dw ratio were more than five times different in area. The last case was only possible with a decrease in surface / volume ratio and a increase of mesophyll thickness, components not measured by fw / dw ratio. The new index proposed here, which takes into consideration dry weight and leaf area, showed a high correlation to mesophyll thickness.

scholarly journals Leaf Characteristics and Yield Performance of Mungbean (Vigna radiata L.) Varieties under Different Levels of Shading

2018 ◽  
Vol 15 (2) ◽  
pp. 40-51
Author(s):  
M A Hossain ◽  
M A Hasan ◽  
S Sikder ◽  
A K M M B Chowdhury
Keyword(s):  
Light Intensity ◽  
Grain Yield ◽  
Vigna Radiata ◽  
Dry Weight ◽  
Light Levels ◽  
Spongy Layer ◽  
Partial Shade ◽  
Shade Condition ◽  
Reduced Light ◽  
Leaf Dry Weight

An experiment was carried out to evaluate the leaf characteristics and yield performances of mungbean (Vigna radiata L.) under different light levels at the Crop Physiology and Ecology Research Field of Hajee Mohammad Danesh Science and Technology University, Dinajpur during March to June 2016. The experiment was laid out in a split plot design with three replications. Three light levels (L100 - 100 % light intensity, L75- 75 % light intensity and L50- 50% light intensity) were assigned in the main plots and four varieties (BARl Mung-6, BINA Mung-8, BINA Mung-5 and BU Mug-4) were assigned in subplots. Mosquito nets of different pore size were used for maintaining 75 and 50 percent light intensity. Leaf area was increased due to reduced light levels in all mugbean varieties but the increment was significant in BINA Mung-5 and BINA Mung-8 only at 75% light intensity at 40 days after sowing and only in BARI Mung-6 with L50 and BU Mug-4 with L75 and L50at 50 days after sowing. Due to reduced light levels, leaf dry weight was affected more in BINA Mung-5 and BU Mug- 4 than BARI Mung-6 and BINA Mung-8. Leaf thickness was reduced under shade in all the mungbean varieties, except in BU Mug-4 at 75% light intensity, and the reduction in leaf thickness was mainly due to the reduction in thickness of spongy layer. The palisade layer thickness was influenced insignificantly but spongy layer thickness was increased in BINA Mung-5 at 100% light intensity. The grain yields (t ha-1) of BARI Mung-6 and BINA Mung-8 remained stable under partial shade condition but the grain yield of BINA Mung-5 and BU Mug-4 was reduced drastically under partial shade condition. Higher leaf dry weight, number of pods plant-1, seeds pod-1, and heavier grains in BARI Mung-6 and BINA Mung-8 contributed to the higher grain yield plant-1 under partial shade condition than in BINA Mung-5 and BU Mug-4.The Agriculturists 2017; 15(2) 40-51

Phenyl indole-3-thiolobutyrate increases growth of transplanted 1-0 red oak

1988 ◽  
Vol 18 (1) ◽  
pp. 131-134
Author(s):  
Daniel K. Struve ◽  
W. Timothy Rhodus
Keyword(s):  
Leaf Area ◽  
Butyric Acid ◽  
Dry Weight ◽  
Area Ratio ◽  
Leaf Area Ratio ◽  
Red Oak ◽  
Relative Growth ◽  
Auxin Treatment ◽  
Net Assimilation

The basal 1 cm of taproot of dormant bareroot 1-0 red oak (Quercusrubra L.) seedlings were given a 3-s dip in 20, 40, or 80 mM concentrations of indole-3-butyric acid (IBA), phenyl indole-3-thiolobutyrate (P-ITB), or equal parts IBA and P-ITB at 20 or 40 mM concentrations. Sixty control seedlings were dipped in 95% ethanol, while 30 seedlings were used for each auxin treatment. Seedlings were potted on May 12, 1986, and grown outdoors. At the end of the 104-day study period, all concentrations of IBA and P-ITB significantly increased number of roots regenerated (from 5.3 with 20 mM IBA to 11.9 for 80 mM IBA) compared with control seedlings. However, P-ITB-treated seedlings produced significantly more leaves (20–24) and leaf area (320–472 cm2), and up to 10 g more dry weight than IBA and non-auxin-treated seedlings. P-ITB treated seedlings had higher relative growth and net assimilation rates and lower leaf area ratio than IBA-treated or control seedlings. Seedlings treated with 20 mM of equal parts IBA and P-ITB were similar to P-ITB-treated seedlings while seedlings treated with the 40 mM IBA and P-ITB combination were similar to IBA-treated seedlings.

scholarly journals Fitness Cost of Imazamox Resistance in Wild Poinsettia (Euphorbia heterophylla L.)

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Weight ◽  
Area Ratio ◽  
Fitness Cost ◽  
Seed Plant ◽  
Growth Indices ◽  
Relative Growth ◽  
Net Assimilation

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.

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