Growth kinetics of Marquis wheat. VII. Dependence on photoperiod and light compensation point in vegetative phase

1977 ◽  
Vol 55 (6) ◽  
pp. 639-643 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
Plant Growth ◽  
Growth Kinetics ◽  
Radiant Energy ◽  
Dry Weight ◽  
Compensation Point ◽  
Rate Coefficients ◽  
Vegetative Phase ◽  
Light Compensation Point ◽  
Light Intensities

The maximum rate coefficients for the vegetative phase of growth in dry weight of shoots and roots were independent of the photoperiod in plants grown at six different light intensities of 12- or24-h duration at 20 °C. The strict dependence of plant growth on only the total daily incident radiant energy was proved by the superposition of hyperbolic plots of growth coefficients obtained for five different photoperiods and for the different light intensities. Root growth was very sensitive to photoperiod at moderate light intensity. Growth kinetics changed from first to zero order in plant dry weight at a 12-h photoperiod with a light intensity of 150 ft-c (3750 ergs cm−2 s−1) depending on pretreatment. The light compensation point of plant growth occurred at16 × 107 ergs cm−2 day−1; that for shoots was lower, and that for roots was higher.

scholarly journals THE EFFECTS OF LIGHT INTENSITY AND FERTILIZER RATE ON THE ACCLIMATIZATION POTENTIAL OF CHAMAEDOREA ELEGANS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 583b-583 ◽  
Author(s):  
Trinidad Reyes ◽  
Terril A. Nell ◽  
Charles A. Conover ◽  
James E. Barrett
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Carbohydrate Content ◽  
Compensation Point ◽  
Plant Performance ◽  
Fertilizer Rate ◽  
Light Compensation Point ◽  
Light Intensities ◽  
Chamaedorea Elegans ◽  
Fertilizer Rates

Effects of three light intensities (564, 306 and 162 μmol m-2 s-1) and three fertilizer rates (220, 440 and 880 mg/15 cm pot, weekly) were evaluated on acclimatization potential of Chamaedorea elegans. Treatments were applied during four months under greenhouse conditions after which plants were placed indoors (20 μmol m-2 s-1, 21±2C and 50% RH) for two months. Light compensation point (LCP) was significantly reduced by decreasing light intensity and increasing fertilizer rates. Leaf and root fresh and dry weights increased with irradiance while shoots were not affected. Chlorophyll a levels were higher in plants grown under the lowest light intensity. Carbohydrate content is being analyzed and anatomical examination of leaves studied. Plant performance indoors will be discussed. These studies demonstrate that Chamaedorea, a monocot, acclimatizes similarly to dicots.

Growth kinetics of Marquis wheat. I. Light dependence

1972 ◽  
Vol 50 (1) ◽  
pp. 89-99 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
Growth Kinetics ◽  
Complex Form ◽  
Dry Weight ◽  
High Light Intensity ◽  
High Light ◽  
Rate Coefficients ◽  
Primary Analysis ◽  
Growth Coefficient ◽  
Root Dry Weight

As early growth is exponential it was measured as the pseudo-first-order rate coefficient, k1′. The growth coefficient is independent of the method of measurement, so different values derived from different measurements such as dry weight, fresh weight, chlorophyll content, and area reflected somewhat different aspects of growth in a given organ. At low light intensity k1′ was highest for lamina dry weight and lowest for root dry weight, and at high light intensity, highest and lowest k1′.were obtained for "stem" dry weight and lamina area, respectively. The differences in rate coefficients between organs were less than 10% of their values at high light intensity. The rectangular hyperbolic fit of the dependence of k1′ on light intensity was used to compute a maximum value (kmL) independent of light intensity. A kmL of 0.34 per day was obtained for plants of Marquis wheat grown at 25 °C with Hoagland's solution in Went's medium under controlled environment, and the highest value, 0.37, was achieved by dry weight of "stems." A complex form parameter was also computed, and it included a function of the efficiency of light use for growth, which was highest for leaf area and lowest for root dry weight. Measurements on complete morphological entities such as whole organs are best interpreted. Growth kinetics and its relationship to "growth analysis" were discussed in distinct favor of the former approach. The growth coefficient as the relative growth rate has been abused and that term should be dropped. The prospects of kinetic or primary analysis as the standard quantitative method are great, as initially envisaged by V. H. Blackman half a century ago.

EAR LENGTH AND SPIKELET NUMBER OF WHEAT GROWN AT DIFFERENT TEMPERATURES AND LIGHT INTENSITIES

1965 ◽  
Vol 43 (3) ◽  
pp. 345-353 ◽  
Author(s):  
D. J. C. Friend
Keyword(s):  
Light Intensity ◽  
Low Temperatures ◽  
Dry Weight ◽  
High Light ◽  
Morphological Development ◽  
Spikelet Number ◽  
Light Intensities ◽  
Different Temperatures ◽  
Total Plant ◽  
Effects Of Temperature

The number of spikelets on the differentiating inflorescence and the ear at anthesis was highest at high light intensities and at low temperatures. The length of the developing inflorescence and the ear, the height of the main stem, and the total plant dry weight at the time of anthesis were also greatest under these conditions.These results are related to differential effects of temperature and light intensity on the rates and duration of apical elongation, morphological development of the ear, and spikelet formation.

scholarly journals The growth of three varieties of black pepper (Piper nigrum) under different light intensities related to indigenous hormones role

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
Issukindarsyah Issukindarsyah ◽  
Endang Sulistyaningsih ◽  
Didik Indradewa ◽  
Eka Tarwaca Susila Putra
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Plant Growth ◽  
Leaf Area ◽  
Surface Area ◽  
Dry Weight ◽  
Root Surface ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Root Surface Area

Abstract. Issukindarsyah, Sulistyaningsih E, Indradewa D, Putra ETS. 2020. The growth of three varieties of black pepper (Piper nigrum) under different light intensities related to indigenous hormones role. Biodiversitas 21: 1778-1785. Low light intensity causes the alteration of plant biochemical and morphological as the mechanism of adaptation. The experiment used split-plot design with three replications. The main plots were three light intensity levels, i.e. 100%, 75%, and 50% radiation; while subplots were three varieties namely Nyelungkup, Petaling 1 and Petaling 2. This research was conducted to figure out the effect of shadings on hormones and the growth of three varieties of black pepper (Piper nigrum L.). The results showed that in initial vegetative growth, varieties of Nyelungkup and Petaling 1 had higher growth of both ortotroph and plagiotroph branches, leaf number, leaf area, length of root, root surface area, plant dry weight, nett assimilation rate, and plant growth rate than the variety of Petaling 2. The light intensity of 50% and 75% increased the auxin and gibberellin contents of the leaf but they did not affect the zeatin. The maximum gibberellin and auxin contents of leaf were recorded at 75% light intensity. The 50% and 75% light intensity raised the length, diameter, and internode of ortotroph branch; number, length, and internode of plagiotroph branch; leaf number; leaf area; leaf area ratio; length of root; root surface area; plant growth rate and plant dry weight related to indigenous hormones role.

Photosynthetic apparatus in Selaginella. I. Morphology and photosynthesis under different light and temperature regimes

1970 ◽  
Vol 48 (10) ◽  
pp. 1843-1852 ◽  
Author(s):  
Richard Jagels
Keyword(s):  
Light Intensity ◽  
Photosynthetic Apparatus ◽  
Dry Weight ◽  
Photosynthetic Rates ◽  
Sterile Culture ◽  
Light Levels ◽  
Light Intensities ◽  
Temperature Regimes ◽  
Normal Green ◽  
Branching Patterns

Several hydrophytic and umbrophilic species of Selaginella were grown in sterile culture and scrutinized for morphological and photosynthetic variability under light intensities between 0 and 500 ft-c and temperatures of 9° and 22 °C. Bleaching was induced by raising light intensity; and for a particular light intensity was enhanced by lowering temperature. Regreening could be achieved by reversing conditions. Branching patterns, leaf symmetry, and orientation of leaves to axis were also light dependent. Light levels which produced normal green plants for S. uncinata initiated only half-saturation photosynthetic rates. Photosaturating light intensities, if applied for several weeks, induced bleaching. Based on fresh or dry weight bleaching plants had lower photosynthetic rates than green plant's; but based on chlorophyll content the photosynthetic rates of green and bleaching plants were the same.

Growth kinetics of Marquis wheat. IV. Temperature dependence

1973 ◽  
Vol 51 (4) ◽  
pp. 729-736 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Light Intensity ◽  
Plant Growth ◽  
Net Photosynthesis ◽  
Absolute Maximum ◽  
Temperature Optimum ◽  
Differential Growth ◽  
Low Light ◽  
Growth Coefficient ◽  
Light Intensities ◽  
Kinetics Of

Earlier described data from this laboratory were subjected to primary growth analysis. The plants had been grown in constant conditions of light intensity (200 to 2500 ft-c) and temperature (10° to 30 °C) at five different settings each. Multiple temperature optima were revealed and interpreted. The computed maximum plant growth coefficient was highest in value at 25 °C (plant kmL = 0.44 day−1) and secondarily so at 15 °C, but at the experimental light intensities the plant growth coefficient was maximal at 15 °C. The higher temperature optimum was characteristic of roots and "stems" (stem plus leaf sheaths) whose growth coefficients displayed a prominent peak at 25 °C (root kmL ~ 0.8 day−1, "stem" kmL = 0.4 day−1). This optimum was shifted downward with decreasing light intensity until temperature insensitivity was attained at low light intensity. The low-temperature optimum at 15 °C was principally displayed by leaf blades (lamina kmL = 0.47 day−1) whose computed maximum growth coefficient also showed a secondary maximum at 25°, but the 15 °C peak was the only one evident at low light intensities. It was tentatively concluded that the 25 °C temperature optimum was that of net translocation, and that the 15 °C temperature optimum was that of net photosynthesis in which photosynthesis was primarily balanced by photorespiration in wheat. The differential growth of the organs represented their relative sink strengths for attracting growth substrate, as dependent on light intensity and temperature. The availability of photosynthate was considered to be the dominating factor in the kinetics of growth free from inorganic limitations. When there was very little photosynthate the tissues benefited from translocation on a "first come first serve" basis. The high values of kmL pushed the absolute maximum plant growth coefficient, kM, of Marquis wheat toward 0.5 or 50% per day, and the basis of the advantage over previous approximations must be elucidated by further experiments. The computed relative efficiency of the use of photosynthate for growth was temperature dependent, but its value at optimum temperature was similar to previous estimates.

Growth kinetics of Marquis wheat. II. Carbon dioxide dependence

1972 ◽  
Vol 50 (4) ◽  
pp. 883-889 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Carbon Dioxide Concentration ◽  
Dry Weight ◽  
Maximum Growth ◽  
Carbon Dioxide Enrichment ◽  
Low Light ◽  
Growth Coefficient ◽  
Light Intensities ◽  
Wide Range

Marquis wheat was grown in growth rooms with four different concentrations of carbon dioxide and four to seven different intensities of light in a 16-h photoperiod at 25 °C. Growth was expressed quantitatively as the pseudo-first-order rate coefficient. Carbon dioxide stimulated growth, but the effect was greater the lower the light intensity in opposition to the known effect on photosynthesis. Carbon dioxide and light, in effect, did not influence the "rate" of growth of wheat additively but, rather, mutually compensated over a wide range. The growth coefficient of the roots was a little less than that of the shoots at all carbon dioxide concentrations and light intensities, probably owing to the cost of translocation. However, root growth benefited most from carbon dioxide enrichment at low light intensities. At intermediate light intensity there appeared to be a carbon dioxide concentration optimal for shoot growth. Carbon dioxide enrichment did not influence the maximum growth coefficient of Marquis wheat with respect to light intensity. The light-using efficiency of growth, calculated for vanishingly low light intensity at which it is maximal, was maximal for shoots at 1300 ppm CO2 but that for laminal area and root dry weight increased with CO2 to 2200 ppm at which the value for "leaves" was nearly fourfold that for roots. Unlike photosynthesis, the stimulation of growth by raised CO2 concentration was accomplished by increased efficiency of, and not capacity for, the net photosynthetic use of light.

scholarly journals Effects of Light Intensity and Paclobutrazol on Growth and Interior Performance of Pachira aquatica Aubl.

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1291-1295 ◽  
Author(s):  
Qiansheng Li ◽  
Min Deng ◽  
Jianjun Chen ◽  
Richard J. Henny
Keyword(s):  
Light Intensity ◽  
Growth Form ◽  
Foliar Application ◽  
Canopy Height ◽  
Internode Length ◽  
Compensation Point ◽  
Photon Flux ◽  
Plant Canopy ◽  
Light Compensation Point ◽  
Compact Growth

Pachira aquatica Aubl. has recently been introduced as an ornamental foliage plant and is widely used for interiorscaping. Its growth and use under low light conditions, however, have two problems: leaf abscission and accelerated internode elongation. This study was undertaken to determine if production light intensity and foliar application of paclobutrazol [β-(4-chlorophenyl)methyl-α-(1,1-dimethylethyl)-1H- 1,2,4- triazole-1-ethanol] improved plant growth and subsequent interior performance. Two-year-old P. aquatica trunks were planted in 15-cm diameter plastic pots using a peat-based medium and were grown in a shaded greenhouse under three daily maximum photosynthetic photon flux densities (PPFD) of 285, 350, and 550 μmol·m−2·s−1. Plant canopy heights, average widths, and internode lengths were recorded monthly over a 1-year production period. Two months after planting, the plant canopy was sprayed once with paclobutrazol solutions at concentrations of 0, 50, and 150 mg·L−1, ≈15 mL per plant. Before the plants were placed indoors under a PPFD of 18 μmol·m−2·s−1 for 6 months, net photosynthetic rates, quantum yield, and light saturation and compensation points were determined. Results showed that lowering production light levels did not significantly affect canopy height, width, or internode length but affected the photosynthetic light response curve and reduced the light compensation point. Foliar application of paclobutrazol reduced internode length, thereby resulting in plants with reduced canopy height and width and more compact growth form. Paclobutrazol application also reduced the light compensation point of plants grown under 550 μmol·m−2·s−1. Plants with the compact growth form did not grow substantially, dropped fewer leaflets, and thus maintained their aesthetic appearance after placement indoors for 6 months. These results indicated that the ornamental value and interior performance of P. aquatica plants can be significantly improved by producing them under a PPFD range between 285 and 350 μmol·m−2·s−1 and foliar spraying of paclobutrazol once at a concentration between 50 and 150 mg·L−1.

Photosynthesis and photorespiration rates at the CO2 compensation point

1970 ◽  
Vol 48 (6) ◽  
pp. 1271-1276 ◽  
Author(s):  
N. R. Bulley ◽  
E. B. Tregunna
Keyword(s):  
Light Intensity ◽  
Closed System ◽  
Specific Activity ◽  
High Specific Activity ◽  
Compensation Point ◽  
Gas Analyzer ◽  
Co2 Compensation Point ◽  
Light Intensities ◽  
Soybean Leaves

Attached soybean leaves in a closed system were fed high specific activity 14CO2 at four CO2 compensation points (30, 53, 110, 204 μl/l CO2) which were produced by different O2 concentrations (10, 21, 44, 80% O2). Rates of CO2 uptake and evolution were measured simultaneously using an infrared CO2 gas analyzer and a Geiger tube. The CO2 compensation point was proportional to O2 concentration but did not change for the two light intensities used. The rates of CO2 exchange at the compensation point did increase with light intensity. These rates of CO2 exchange also increased with the increasing CO2 concentration of the compensation point (for increasing O2 concentrations) but tended to saturate for compensation points greater than 110 μl/l CO2.

scholarly journals CULTURE CONDITIONS AND THE DEVELOPMENT OF THE PHOTOSYNTHETIC MECHANISM

1946 ◽  
Vol 29 (6) ◽  
pp. 429-440 ◽  
Author(s):  
Jack Myers ◽  
Keyword(s):  
Light Intensity ◽  
Maximum Rate ◽  
Cultured Cells ◽  
Dry Weight ◽  
High Rate ◽  
Light Limitation ◽  
Transitional Region ◽  
Rate Of Growth ◽  
Light Intensities ◽  
Rate Of Photosynthesis

1. Chlorella pyrenoidosa has been grown in a continuous-culture apparatus under various light intensities provided by incandescent lamps, other conditions of culture being maintained constant. Light intensity curves for cells immersed in the No. 11 Warburg buffer and in Knop's solution + 4.4 per cent CO2 at a saturating light intensity were determined as characteristics of the photosynthetic mechanism. These characteristics were referred to the centrifuged cell volume as an index of quantity of cellular material. 2. Cells grown at intensities in the range of about 35 f.-c. develop a capacity for a high rate of photosynthesis (c.mm. O2/hour/c.mm. cells). At culture intensities above or below this range the cells produced have a lower capacity for photosynthesis. A similar effect is observed for rate of photosynthesis per unit dry weight or rate per unit cell nitrogen. 3. The rate of photosynthesis per cell or rate per unit chlorophyll shows no maximum at any light intensity of culture but increases continuously throughout the range of light intensities studied. 4. Maximum rate of growth is attained at a light intensity of about 100 f.-c. The hypothesis is advanced that at culture intensities above that needed to give maximum rate of growth (100 f.-c.) a mechanism is developed which opposes the photosynthetic process and removes the photosynthetic products. 5. The low capacity for photosynthesis shown by cells grown at culture intensities below 35 f.-c. finds no immediate explanation. 6. The shape of the light intensity curve is markedly affected by the light intensity at which the cells have been cultured. Cells grown at lower intensities give light intensity curves approaching the Blackman type with a short transitional region between light limitation and light saturation.

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