The effect of gibberellic acid on apparent photosynthesis and dark respiration of simulated swards of Pennisetum clandestinum Hochst

1972 ◽  
Vol 23 (2) ◽  
pp. 205 ◽  
Author(s):  
DC Lester ◽  
OG Carter ◽  
FM Kelleher ◽  
DR Laing
Keyword(s):  
Gibberellic Acid ◽  
Respiration Rate ◽  
Dry Matter ◽  
Dark Respiration ◽  
Dry Weight ◽  
Temperature Cycle ◽  
Dark Respiration Rate ◽  
Area Index ◽  
Pennisetum Clandestinum ◽  
Stimulation Of

Gibberellic acid (GA3 at 40 g/ha equivalent was applied to simulated swards of Pennisetum clandestinum (kikuyu grass) at the fourth leaf stage in a glasshouse held at a 25°C maximum and 15° minimum diurnal temperature cycle. Continuous 24-hr recordings of apparent photosynthesis and dark respiration in relation to normal variation in solar radiation were made on the whole swards by using an open chamber system monitored by infrared gas analysis. No effect was noted until 9 days from spraying, by which time the GA3 application stimulated the apparent photosynthetic rate of the sward and reduced the dark respiration rate. These effects became greater with time. The stimulation of apparent photosynthesis increased as the level of radiation increased. At 21 days from spraying, while large increases in apparent photosynthesis and reductions in dark respiration rate were being recorded, a botanical separation of the swards was made. GA3 increased the total dry weight (tops plus roots) of the sward and the dry matter above soil level. The latter effect was due to a greater amount of stem dry matter in the GA3-treated sward. GA3 reduced the dry weight of senescent leaf blade and leaf sheath tissue. GA3 had no effect on leaf area index. Area per leaf was increased, but GA3 stimulated apical dominance reduced the number of leaves per sq metre of sward. It is postulated that stimulation of apparent photosynthesis by GA3 is related to leaf age and a change in canopy structure through an improvement in leaf dispersion.

Responses of Subterranean Clover Communities to Temperature. II. Effects of Temperature on Dark Respiration Rate

1977 ◽  
Vol 4 (1) ◽  
pp. 159 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury
Keyword(s):  
Respiration Rate ◽  
Growth Temperature ◽  
Dry Matter ◽  
Dark Respiration ◽  
Subterranean Clover ◽  
Growth Equation ◽  
Dry Matter Accumulation ◽  
Measured Temperature ◽  
Dark Respiration Rate ◽  
High Respiration Rate

The rates of dark respiration of subterranean clover communities, grown at 12, 16, 20 and 24°C in naturally lit temperature-controlled glasshouses, were measured several times during growth. The dark respiration rate, measured at growth temperature, increased linearly with increase in plant dry matter for each temperature and it increased approximately linearly with increase in temperature at a given dry matter. A low crop growth rate shown by communities with dry matter greater than 300 g m-2 at a temperature of 24°C was largely accounted for by a high respiration rate. The temperature coefficient of dark respiration (Q10) was inversely related to growth temperature. Dark respiration rate at 28°C was lower for communities grown at 24°C than for communities grown at 12 or 16°C when the comparison was made at the same dry matter. Calculated dark respiration rate from shoot dry matter, growth temperature and current measured temperature was close to the measured rate, indicating the dark respiration rate of subterranean clover communities to be largely accounted for by these factors. Use of an integrated form of a growth equation and allowing for dark efflux shows, on a 12 hour day, the rate of dry matter accumulation at 24°C to be the same as that at 12°C.

Dark respiration of leaves and traps of terrestrial carnivorous plants: are there greater energetic costs in traps?

2010 ◽  
Vol 5 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Lubomír Adamec
Keyword(s):  
Plant Species ◽  
Respiration Rate ◽  
Dark Respiration ◽  
Dry Weight ◽  
Carnivorous Plant ◽  
Carnivorous Plants ◽  
Clear Relationship ◽  
Leaf Lamina ◽  
Dark Respiration Rate ◽  
Energetic Costs

AbstractIn this study, O2-based dark respiration rate (RD) in leaf and trap cuttings was compared in 9 terrestrial carnivorous plant species of 5 genera to decide whether traps represent a greater energetic (maintanence) cost than leaves or photosynthetic parts of traps. RD values of cut strips of traps or leaves of terrestrial carnivorous plants submerged in water ranged between 2.2 and 8.4 nmol g−1 s−1 (per unit dry weight) in pitcher traps of the genera Sarracenia, Nepenthes, and Cephalotus, while between 7.2 and 25 nmol g−1 DW s−1 in fly-paper or snapping traps or leaves of Dionaea and Drosera. No clear relationship between RD values of traps (or pitcher walls) and leaves (or pitcher wings or petioles) was found. However, RD values of separated Drosera prolifera tentacles exceeded those of leaf lamina 7.3 times.

scholarly journals Effect of Organic Manures on Growth, Rhizome Yield and Quality Attributes of Turmeric (Curcuma longa L.)

2012 ◽  
Vol 10 (1) ◽  
pp. 16-22 ◽  
Author(s):  
M. Z. U. Kamal ◽  
M. N. Yousuf
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Curcuma Longa ◽  
Dry Weight ◽  
Fresh Weight ◽  
Area Index ◽  
Yield Attributes ◽  
Organic Manures ◽  
Neem Cake ◽  
Yield And Quality

The investigation was carried out to evaluate the effect of different organic manures on turmeric with reference to vegetative growth, biomass production, rhizome yield and its attributes of turmeric (Curcuma longa L.). Turmeric showed better response to the application of organic manures. Plant with neem cake application had the taller plant (79.30 cm), maximum number of tillers per plant (5.40), leaf number (5.40), leaf area (44.09) leaf area index (0.429), fresh weight of halum ( 190.05g), fresh weight of root (49.13 g), fresh weight of rhizome per plant (256.21 g) and dry weight of halum (15.21g), dry weight of root (7.32 g), dry weight of rhizome per plant (40.35 g), total dry matter yield (6.85 t ha-1) than those received other types of manures. Moreover, yield attributes such as number of mother rhizomes per plant-1 (1.75), more number of primary rhizomes per plant-1 (5.19), secondary rhizomes per plant-1 (18.03) and tertiary rhizomes per plant (7.69) were also highly accelerated by neem cake application. Similarly, the same treatment expressed the best in terms of size of mother rhizome (7.69 cm), primary rhizome (21.86 cm) and secondary rhizomes (7.05 cm).All these parameters in cumulative contributed to  produce the highest estimated fresh rhizomes yield & cured rhizomes yield (29.48 t ha-1, 5.59 t ha-1 respectively). The highest curing percentage (20.28) was observed in T3 treatment having mustard cake@ 2.0 t/ha. Thus, organic manure like neem cake was best fitted natural fertilizer for turmeric cultivation.DOI: http://dx.doi.org/10.3329/agric.v10i1.11060The Agriculturists 2012; 10(1): 16-22

Dark respiration rate of transgenic tomato plants expressing FeSOD1 gene under chloride and sulfate salinity

2014 ◽  
Vol 40 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Ye. N. Baranova ◽  
E. N. Akanov ◽  
A. A. Gulevich ◽  
L. V. Kurenina ◽  
S. A. Danilova ◽  
...  
Keyword(s):  
Respiration Rate ◽  
Dark Respiration ◽  
Transgenic Tomato ◽  
Dark Respiration Rate ◽  
Tomato Plants ◽  
Transgenic Tomato Plants

scholarly journals Effect of Planting Date and Gibberellic Acid on the Growth and Yield of Garlic

2010 ◽  
pp. 132-140 ◽  
Author(s):  
MA Islam ◽  
MH Reza ◽  
SMAHM Kamal ◽  
MA Wazed ◽  
KM Islam
Keyword(s):  
Gibberellic Acid ◽  
Plant Height ◽  
Dry Matter ◽  
Dry Weight ◽  
Planting Date ◽  
Growth And Yield ◽  
Planting Time ◽  
Local Cultivar ◽  
Number Of Leaves ◽  
Bulb Yield

An experiment was conducted with a local cultivar of garlic to study the effects of planting date and gibberellic acid on the growth and yield of garlic at the field laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during November 2001 to April 2002. Early planting influenced the plant height, leaf number, bulb diameter and total dry matter. With the delay in planting time starting from November 7, the yield was chronologically reduced in later plantings. Significantly the highest bulb yield (2.67 t/ha) was recorded when planting was done on November 7 and lowest yield (0.92 t/ha) was obtained from December 22 planted crop. Bulb yield was higher in control plants than those of GA3 treated plants. The interaction effects of planting date and different concentrations of GA3 differed significantly in respect of plant height, number of leaves, bulb diameter and dry weight of roots, leaves and bulbs and yield of garlic.

scholarly journals Comparison of the Photosynthetic Capacity of Phragmites australis in Five Habitats in Saline‒Alkaline Wetlands

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1317
Author(s):  
Subang An ◽  
Xingtu Liu ◽  
Bolong Wen ◽  
Xiaoyu Li ◽  
Peng Qi ◽  
...  
Keyword(s):  
Respiration Rate ◽  
Phragmites Australis ◽  
Photosynthetic Capacity ◽  
Dark Respiration ◽  
Utilization Efficiency ◽  
Dark Respiration Rate ◽  
Response Curves ◽  
Water Shortages ◽  
Abandoned Farmland ◽  
The Impact

Water shortages have an important impact on the photosynthetic capacity of Phragmites australis. However, this impact has not been adequately studied from the perspective of photosynthesis. An in-depth study of the photosynthetic process can help in better understanding the impact of water shortages on the photosynthetic capacity of P. australis, especially on the microscale. The aim of this study is to explore the photosynthetic adaptation strategies to environmental changes in saline‒alkaline wetlands. The light response curves and CO2 response curves of P. australis in five habitats (hygrophilous, xerophytic, psammophytic, abandoned farmland, paddy field drainage) in saline‒alkaline wetlands were measured at different stages of their life history, and we used a nonrectangular hyperbolic model to fit the data. It was concluded that P. australis utilized coping strategies that differed between the growing and breeding seasons. P. australis in abandoned farmland during the growing season had the highest apparent quantum efficiency (AQE) and photosynthetic utilization efficiency for weak light because of the dark environment. The dark respiration rate of P. australis in the drainage area of paddy fields was the lowest, and it had the highest values for photorespiration rate, maximum photosynthetic rate (Pmax), photosynthetic capacity (Pa), biomass, maximum carboxylation rate (Vcmax), and maximum electron transfer rate (Jmax). The light insensitivity of P. australis increased with the transition from growing to breeding season, and the dark respiration rate also showed a downward trend. Moreover, Vcmax and Jmax would decline when Pmax and Pa showed a declining trend, and vice versa. In other words, Vcmax and Jmax could explain changes in the photosynthetic capacity to some extent. These findings contribute to providing insights that Vcmax and Jmax can directly reflect the variation in photosynthetic capacity of P. australis under water shortages in saline‒alkaline wetlands and in other parts of world where there are problems with similarly harmful environmental conditions.

Gibberellic acid and the growth of crop plants

1958 ◽  
Vol 50 (1) ◽  
pp. 49-59 ◽  
Author(s):  
D. G. Morgan ◽  
G. C. Mees
Keyword(s):  
Growth Rate ◽  
Gibberellic Acid ◽  
Crude Protein ◽  
Dry Matter ◽  
Field Trials ◽  
Natural Growth ◽  
Nitrogenous Fertilizer ◽  
Sodium Calcium ◽  
Normal Green ◽  
Stimulation Of

1. Field trials with gibberellic acid on grass, wheat, potatoes, turnips, carrots, peas, runner beans, lettuce, celery, blackcurrants, kale and maize are described. The effects on plant growth and crop yield were determined.2. The experiments on grassland were carried out between July 1953 and June 1956, and included trials at four different centres. They all gave essentially similar results.3. 2 oz. per acre of gibberellic acid sprayed at 100 gal. per acre stimulated the growth of all components of the swards. The stimulation was most clearly seen in spring and autumn when the natural growth rate was slow. At these times gibberellic acid was able to produce a grazeable growth of grass more rapidly than nitrogenous fertilizers. The stimulation of growth was accompanied by yellowing of the grass, but recovery to a normal green colour was speeded up by applying a nitrogenous fertilizer at the same time as the gibberellic acid spray.4. The dry-matter yields at the first cut following a treatment with gibberellic acid were increased by 0·6–10·8 cwt. per acre. The crude protein yields were also increased by the treatment, but to a relatively smaller degree, and the protein content of the grass was reduced by between ½ and 2%. The contents of phosphorus, potassium, sodium, calcium, barium, magnesium, manganese, copper, aluminium and tin were not altered.

Effects of Planting Density on Water Use and Productivity of Pearl Millet (Pennisetum Typhoides) Grown on Stored Water. II. Water Use, Light Interception and Dry Matter Production

1984 ◽  
Vol 20 (3) ◽  
pp. 215-224 ◽  
Author(s):  
S. N. Azam-Ali ◽  
P. J. Gregory ◽  
J. L. Monteith
Keyword(s):  
Pearl Millet ◽  
Water Use ◽  
Dry Matter ◽  
Dry Weight ◽  
Planting Density ◽  
Area Index ◽  
Wide Spacing ◽  
Neutron Probe ◽  
Matter Production ◽  
Intercepted Radiation

SUMMARYPearl millet was grown on stored water at Niamey, Niger, using three row spacings. Water extraction based on neutron probe readings was compared with crop transpiration using a porometer and allied measurements. Between 23 and 52 days after sowing, plants at the narrow and medium spacings used about 77 and 100 mm of water, respectively, and those at the wide spacing used between 59 and 75 mm. Estimates of seasonal crop evaporation from leaf resistances and from the green leaf area index (GLAI) of the crops were 103, 130 and 123 mm for the narrow, medium and wide spacings, respectively. The water use per unit of dry weight produced was similar for both narrow and medium spacings but water was used more efficiently in the wide spacing. Dry weight increased in proportion to intercepted radiation with the same efficiency (1·3 g MJ−1) irrespective of spacing.

The respiration rate and loss of dry matter from stored bran

1945 ◽  
Vol 35 (3) ◽  
pp. 126-132 ◽  
Author(s):  
Douglas Snow ◽  
Norman C. Wright
Keyword(s):  
Moisture Content ◽  
Respiration Rate ◽  
Total Nitrogen ◽  
Dry Matter ◽  
Dry Weight ◽  
Air Stream ◽  
Continuous Absorption ◽  
High Respiration Rate ◽  
Micro Organisms ◽  
Absorption Apparatus

1. Experiments were made on the respiration of bran at different moisture levels using a continuous absorption apparatus in which the humidity of the air-stream was adjusted to be at equilibrium with the respiring bran. The rate of respiration was accelerated with increasing moisture content and was very rapid deterioration due to the high respiration rate and microbiological damage.2. Experiments were made on the storage of bran at known moisture contents in closed tins in the laboratory and also in sacks kept under farm conditions. The total nitrogen content of the bran stored in the tins appeared to increase during storage. From similar increases in total phosphorus, it is clear that the increase in total nitrogen was caused by a loss of dry matter from the stored feeding stuff, a fact which was further demonstrated by the loss in dry weight of the sacks of bran with attributed to two causes: (1) the respiration of the plant cells still active in the bran itself, and (2) the respiration of developing micro-organisms. It is evident from these experiments that fresh bran, free from insect infestation and stored at a moisture content of less than 13%, will have a very low respiration rate and will, therefore, not be liable to heating. Bran of 15–19% moisture content respires at a much faster rate and the time for which such material can be stored with freedom from heating or other types of deterioration will be limited.

The growth and performance of cotton in a desert environment: II. Dry matter production

1969 ◽  
Vol 73 (1) ◽  
pp. 75-86 ◽  
Author(s):  
A. B. Hearn
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Initial Period ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Area Index ◽  
Vegetative Phase ◽  
Matter Production ◽  
Sink Size ◽  
And Performance

SUMMARYVariety, water and spacing were treatments in two experiments with cotton in 1963 and 1964 in which fruiting points, flowers and bolls were counted and the dry weights and leaf areas of plants were measured at intervals during the season.Until leaf-area index, L, started to decrease, the equation described how dry weight, W, changed. The equation gave smoothed estimates of crop growth rate, C, which were consistent with estimates of photosynthesis made with de Wit's (1965) model. The relationship between G and L conformed to , derived from Beer's Law, rather than C = aL — bL2 derived from the linear regression of E on L. When L > 3 the crop appeared to use most of the available light, so that C approached a maximum. Treatments initially affected dry-matter production through the numbers and types of branches and nodes, which in turn affected the sinks available and thus the proportion of dry matter reinvested in new leaf. This initial period, when growth was simple to describe in conventional terms, was denned as the vegetative phase of growth.The start of the reproductive phase of growth overlapped the vegetative phase. The change from one to the other was completed when the rate of dry weight increase of the bolls, CB, equalled C. This indicated that the sink formed by the bolls had increased sufficiently in size to use all the assimilates available for growth. Sink size increased as the crop flowered and was estimated from the product of the number of bolls and the growth rate of a single boll.When CB equalled C, bolls were shed which prevented the size of the sink to increase beyond the ability of the plant to supply it with assimilates. This agrees with Mason's nutritional theory of boll shedding. Because of the crop's morphology and because age decreased the photosynthesis of the crop, the size of the sink inevitably increased out of phase with the supply of assimilates. The extent to which this was so determined when CB equalled C. It is postulated that environment, genotype and agronomic practice affect yield according to whether they increase or decrease the extent to which the sink size and the supply of assimilates are out of phase.

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