The Influence of Temperature on the Contribution of Awns to Yield in Wheat

1987 ◽  
Vol 14 (3) ◽  
pp. 299 ◽  
Author(s):  
LB Olugbemi ◽  
MG Bush
Keyword(s):  
Grain Growth ◽  
Flag Leaf ◽  
Dry Weight ◽  
Effect Of Temperature ◽  
Near Isogenic Lines ◽  
Grain Development ◽  
Photosynthetic Rates ◽  
Influence Of Temperature On ◽  
The Mean ◽  
Effect On Yield

The effect of temperature during grain set and grain growth on the contribution of awns to yield in wheat was examined in the Canberra phytotron. For eight pairs of awned and awnless near-isogenic lines, the mean advantage of the awned lines in grain dry weight per ear was greatest when plants were held at 21/16°C during grain development, less at 27/22°C and least at 15/10°C where grain weight per ear was highest. One pair, G16 (awned) and G18 (awnless), examined more closely, showed the same response with the yield advantage of the awned line tending to decline from 21/16°C to 33/28°C. There were no significant differences between G16 and G18 in photosynthetic rates of the flag leaves, but the presence of awns increased photosynthetic rates of the ears by up to 1.2 mg CO2 h-1 per ear. During the linear grain growth phase. the relative net contributions per hour by awns and flag leaf, neither of which were much affected by temperature, were about 1 : 10 in all treatments. It appeared probable that under well-watered conditions awns had an effect on yield only when assimilate supply was limiting. Awns did not always increase yield significantly in supra-optimal temperatures.

Nitrogen, Phosphorus and Water Contents During Grain Development and Maturation in Wheat

1977 ◽  
Vol 4 (5) ◽  
pp. 799 ◽  
Author(s):  
I Sofield ◽  
IF Wardlaw ◽  
LT Evans ◽  
SY Zee
Keyword(s):  
Grain Growth ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Growth Period ◽  
Calcium Content ◽  
Dry Weight ◽  
Water Entry ◽  
Grain Development ◽  
Nitrogen And Phosphorus ◽  
Steady Rate

Plants of five cultivars of wheat were grown under controlled-environmental conditions in order to analyse the effect of cultivar and of temperature and illuminance after anthesis on the accumulation of nitrogen and phosphorus by grains in relation to dry matter. The water relations of the grain during maturation were also examined, using calcium content as an index of water entry. The nitrogen and phosphorus contents of grains increased linearly throughout the grain growth period. The percentage of nitrogen and phosphorus in grains fell sharply during the first few days after anthesis but rose progressively thereafter. The higher the temperature, and the lower the illuminance, the higher was the percentage of nitrogen in the grain of all cultivars. Such conditions also reduce final grain size, but their effects on nitrogen concentration in the grain were apparent early in grain development. No evidence was found of a flush of nitrogen or phosphorus into the grain late in its development. Water entry into the grain continued at a steady rate until maximum grain dry weight was reached, then ceased suddenly. No evidence was found of an increased rate of water loss by the grain at that stage, and the rapid fall in water content at the cessation of grain growth may have been due to blockage of the chalazal zone of entry into the grain by the deposition of lipids. Accumulation of dry matter, nitrogen and phosphorus and entry of water into the grain all ceased at the time of lipid deposition in the chalazal zone.

Influence of temperature on blood pH of the human adult and newborn

1964 ◽  
Vol 19 (5) ◽  
pp. 897-900 ◽  
Author(s):  
Karlis Adamsons ◽  
Salha S. Daniel ◽  
Gillian Gandy ◽  
L. Stanley James
Keyword(s):  
Cell Concentration ◽  
Effect Of Temperature ◽  
Red Cell ◽  
Acid Base ◽  
Blood Ph ◽  
Influence Of Temperature On ◽  
The Mean ◽  
Ph Range ◽  
Two Populations

The effect of temperature upon pH of blood from adult and newborn humans was investigated. Although the mean ΔpH/ΔT values for the two populations differed, 0.0144/ °C for adults versus 0.0128 for the newborn, this was not peculiar to the source since the temperature-induced pH changes were identical when comparison was made between samples of similar pH and CO2 content. It was shown that even over the physiologic pH range ΔpH/ΔT is not constant but is a function of pH and CO2. No significant changes in ΔpH/ΔT were observed with oxygenation of hemoglobin. The influence of red cell concentration was detectable only when hematocrit values fell below 20%. A graph and an equation for the determination of ΔpH/ΔT of blood with a given pH and CO2 content is presented. acid base Submitted on December 9, 1963

The effects of soil moisture stress on the growth of barley. II. Grain growth

1965 ◽  
Vol 16 (3) ◽  
pp. 265 ◽  
Author(s):  
D Aspinall
Keyword(s):  
Water Stress ◽  
Grain Growth ◽  
Indirect Evidence ◽  
Dry Weight ◽  
Moisture Stress ◽  
Grain Development ◽  
Grain Moisture ◽  
Severe Water Stress ◽  
Influence Of Water ◽  
Major Period

The influence of water stress on grain growth has been investigated under conditions of intermittent stress with pot-grown plants and under longer periods of stress with plants grown in lysimeters. Premature cessation of growth was induced by even a moderate water stress, but the rate of grain growth (in dry weight) in the early stages of development was reduced only by severe water stress. There was evidence for an actual loss of dry matter in the final stages of maturation where plants were subjected to severe water stress. Grain moisture content was relatively unaffected by water stress during the major period of grain development, although grain water content dropped with increasing water stress during ripening. Spikelet chlorophyll content was also reduced by water stress, particularly in the later stages of grain development. Indirect evidence indicated that translocation of assimilate from the leaves to the ear was reduced by a moderate water stress. Tne significance of these findings in elucidating the mechanism of action of water stress on grain growth is discussed.

scholarly journals TEMPERATURE DURING EARLY DEVELOPMENT AFFECTS PLANT MORPHOLOGY OF BEGONIA × HIEMALIS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1086f-1086
Author(s):  
M. G. Karlsson ◽  
J. W. Werner ◽  
H.C.H. McIntyre
Keyword(s):  
Early Development ◽  
Plant Morphology ◽  
Dry Weight ◽  
Day Length ◽  
Effect Of Temperature ◽  
Flower Number ◽  
Main Shoot ◽  
Long Day ◽  
The Mean ◽  
Short Days

The effect of temperature during the initial long day period on morphology and plant dry weight was determined for Begonia × hiemalis `Hilda'. Multistem cuttings were planted in 10 cm pots and grown at 13°, 16°, 19°, 22°, 25° or 28°C. The day length was 16 hours at an irradiance level of 280 ± 20 μmol·m-2s-1. After 21 days, the plants were moved to a greenhouse maintained at 20° ± 2°C and short days of 10 hours at 125 ± 20 μmol·m-2s-1. The plants were grown under short days for 14 days and then moved to a day length of 16 hours. At data collection 21 days later (56 days from planting), plant height averaged 185 mm for plants initially grown at 13°, 16°, 19° or 22°C while pants originally grown at 25° and 28°C were 40 and 78 mm shorter than plants started at lower temperatures. The mean number of shoots was 4 on plants exposed to 16°, 19°, 22° or 25°C during early development and decrease to 3 shoots for plants grown initially at 13° or 28°C. The average flower number on the main shoot was similar for plants first exposed to low and intermediate temperatures but decreased rapidly to 0 for plants with early exposure to 28°C. Plants in treatments with early temperatures of 19° or 22°C had the largest above ground dry weight at an average 460 mg.

scholarly journals Studies on endogenous hormonal changes during grain development in wheat genotypes

2017 ◽  
Author(s):  
Sridhar Gutam
Keyword(s):  
Growth Rate ◽  
Plant Height ◽  
Grain Growth ◽  
Photosynthetic Rate ◽  
Genotypic Differences ◽  
Endogenous Hormones ◽  
Total Chlorophyll ◽  
Grain Development ◽  
The Mean ◽  
Ear Number

Pot culture experiment was conducted in the Rabi seasons of 2001 and 2002 in order to study the genotypic differences in grain growth rates and endogenous hormonal contents in the developing grains. The hexaploid new plant types and extant variety and other tetraploids are taken up for the study. The data on yield and yield components show that the tetraploids had higher ear number per plant but lesser number of seeds per ear and lower seed weight per ear. The most important yield component 1000-grain yield was also possessed by hexaploids. The mean plant height was found to be higher in hexaploids over tetraploids in general, and among them DL- 1266-1 and DL-1266-2 (new plant types) recorded higher plant height. Similarly, the ear length was also higher in these new plant types. But, the tiller number/plant and ear number/plant were significantly higher in tetraploids. The new plant types (hexaploids) possessed maximum grain growth rate at 5–15 DAA. DL-1266-2 recorded highest grain growth rate 0.093 g/g/day. The photosynthetic rate values show that the hexaploids possessed higher rate than tetraploids. At 7 and 15 DAA, in general, photosynthetic rate was more when compared to 25 DAA and 35 DAA. The results showed that the endogenous hormonal contents in grains during grain development had changed in sequence. At 7 DAA, gibberellic acid (GA3) content was at maximum and at 15 DAA (rapid growth phase), indole-acetic acid (IAA) reached maximum and at 25 DAA (dough stage), ABA was at the maximum. At the 35 DAA, ABA reached all time high and GA3 the least, IAA being intermediate. Among the genotypes, hexaploids recorded higher concentrations of endogenous hormones. The total chlorophyll content in flag leaves of hexaploids was higher than tetraploids. The mean total chlorophyll had increased slightly at 20 DAA when compared to 10 DAA and it decreased at 30 DAA. It appears that the high yielding hexaploids (DL-1266-1 & Dl- 1266-2) by the virtue of possessing more 1000-grain weight and leaf area along with endogenous hormones might be responsible for higher yield as compared to tetraploids. It appears that better photosynthetic rate and better mobilization of photosynthates during grain filling stage contributes for higher yield in hexaploids.

scholarly journals Evaluation of some Herbicides' Efficacy in Weed Control Accompanying some Wheat Cultivars and Their Effect on Yield and Its Components

2019 ◽  
Vol 32 ◽  
pp. 140-155
Author(s):  
Sura A. Khudur ◽  
Taha Y.M. Al-Edany ◽  
Layla A. Bnayan
Keyword(s):  
Field Experiment ◽  
Grain Yield ◽  
Protein Content ◽  
Weed Control ◽  
Flag Leaf ◽  
Dry Weight ◽  
Growing Season ◽  
Wheat Cultivars ◽  
Biological Yield ◽  
Effect On Yield

A field experiment was conducted at Al-Qaim area 90 km north of Basrah Province, Iraq during the growing season of 2018-2019. The purpose of this study was to evaluate the efficacy of three different herbicides includes Pallas 4.5%OD (125ml.Donum-2), Spotlight75%DWG(5g.Donum-2) and Clodex100EC (150ml.Donum-2) to control the weeds growing with two cultivars of wheat (Ebaa-99 and Buhooth-22). The results showed that Ebaa-99 cultivar was superior in the average of plant height (77.99 cm), flag leaf area (29.15cm2), number of tillers (701.50 tillers.m-2), number of spikes (615.61 spikes.m-2), weight of 1000 grain (43.41g), grain yield (5203.34 Kg.ton-2), biological yield (15216.58 Kg/ha), harvest indicator (35.25%), dry weight of narrow-leaved (14.14 g.m-2) and broad-leaved weeds (43.64g.m-2). While Buhooth-22 cultivar revealed superiority in the number of grains per spike (28.66 grain.spike-2), length of the spike (7.76 cm) and protein content (10.47%). Spraying treatments by the formulation of the herbicides Spotlight and Clodex were significantly exceeded other treatments in all crop plant growing components.

Factors Limiting the Rate of Dry Matter Accumulation in the Grain of Wheat Grown at High Temperature

1980 ◽  
Vol 7 (4) ◽  
pp. 387 ◽  
Author(s):  
IF Wardlaw ◽  
I Sofield ◽  
PM Cartwright
Keyword(s):  
High Temperature ◽  
Temperature Increase ◽  
Dry Matter ◽  
Flag Leaf ◽  
Dry Weight ◽  
Dry Matter Accumulation ◽  
Grain Development ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Lower Temperature

Increasing temperatures from 21/16°C to 30/25°C, during the period of development from anthesis to maturity, substantially reduced grain dry weight in wheat. Although this was associated with a shorter duration of grain development, the failure to obtain any compensating increase in the rate of dry matter accumulation, as occurs in the lower temperature ranges, was also considered important. There was no evidence that night temperatures were more important than day temperatures. Analysis of the movement of 14C-labelled photosynthate from the flag leaf to the ear indicated a faster rate of import of photosynthate by the grain at the higher temperature. However carbon lost through respiration is a component of the ear demand for photosynthate and it appears that increase in movement of photosynthate was balanced by greater respiratory losses. This additional carbon lost through enhanced respiration at high temperature could, however, only account at the most for 25% of the reduction in grain dry weight that occurred with the temperature increase from 21/16°C to 30/25°C. Altering either the demand for photosynthate by grain removal, or the supply of photosynthate by a defoliation and shading treatment, did not prevent the reduction in grain dry weight due to high temperature and this is a further indication that the temperature effect occurred mainly within, or close to, the grain itself, and did not result from an effect on the availability of photosynthate.

The effect of temperature on high-resolution TEM image contrast

1995 ◽  
Vol 53 ◽  
pp. 640-641
Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz
Keyword(s):  
Form Factor ◽  
Inelastic Scattering ◽  
Accurate Method ◽  
Waller Factor ◽  
Effect Of Temperature ◽  
Specimen Thickness ◽  
Influence Of Temperature ◽  
Debye Waller Factor ◽  
Influence Of Temperature On ◽  
Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

Research on dynamic characteristics of gear system considering the influence of temperature on material performance

2021 ◽  
pp. 107754632110026
Author(s):  
Zhou Sun ◽  
Siyu Chen ◽  
Xuan Tao ◽  
Zehua Hu
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
Poisson’S Ratio ◽  
Gear System ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
Time Varying ◽  
Influence Of Temperature ◽  
Meshing Stiffness ◽  
Influence Of Temperature On

Under high-speed and heavy-load conditions, the influence of temperature on the gear system is extremely important. Basically, the current work on the effect of temperature mostly considers the flash temperature or the overall temperature field to cause expansion at the meshing point and then affects nonlinear factors such as time-varying meshing stiffness, which lead to the deterioration of the dynamic transmission. This work considers the effect of temperature on the material’s elastic modulus and Poisson’s ratio and relates the temperature to the time-varying meshing stiffness. The effects of temperature on the elastic modulus and Poisson’s ratio are expressed as functions and brought into the improved energy method stiffness calculation formula. Then, the dynamic characteristics of the gear system are analyzed. With the bifurcation diagram, phase, Poincaré, and fast Fourier transform plots of the gear system, the influence of temperature on the nonlinear dynamics of the gear system is discussed. The numerical analysis results show that as the temperature increases, the dynamic response of the system in the middle-speed region gradually changes from periodic motion to chaos.

scholarly journals Admixing Chaff with Straw Increased the Residues Collected without Compromising Machinery Efficiencies

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1766 ◽  
Author(s):  
Alessandro Suardi ◽  
Sergio Saia ◽  
Walter Stefanoni ◽  
Carina Gunnarsson ◽  
Martin Sundberg ◽  
...  
Keyword(s):  
Energy Production ◽  
Dry Weight ◽  
Global Scale ◽  
Unit Weight ◽  
Residual Biomass ◽  
Energy Needs ◽  
The Mean ◽  
Field Efficiency ◽  
The One ◽  
Staple Crop

The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.

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