N application increases pre-anthesis contribution of dry matter to grain yield in wheat grown on a duplex soil

1995 ◽  
Vol 46 (3) ◽  
pp. 507 ◽  
Author(s):  
JA Palta ◽  
IRP Fillery
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Flag Leaf ◽  
Early Growth ◽  
Tiller Number ◽  
Grain Number ◽  
N Application ◽  
N Supply ◽  
N Treatment ◽  
Days After Anthesis

The effect of fertilizer N on the growth, post-anthesis water deficits and remobilization of dry matter in spring wheat was measured on a duplex soil at East Beverley, Western Australia. Nitrogen was applied at 15, 30 and 60 kg N ha-1 with half being applied at seeding and the remainder at 35 days after sowing (DAS), immediately before the onset of tillering. The applied N generated differences in early growth (76-117 g m-2) and dry matter at anthesis (410-693 g m-2), mainly through the effect of N on tiller number (120-171 m-2) and tiller size. It also generated differences in the water deficit, particularly after flowering. During the first 21 days after anthesis, midday flag leaf water potential fell at rates of 0.04, 0.07 and 0.13 MPa day-1 at 15, 30 and 60 kg N ha-1 respectively. Grain yield at 60 kg N ha-1 was increased by 20% relative to that of 15 kg N ha-1. The increase in grain yield resulted from an increase in the number of ears and grain number per ear. The high N treatment probably induced the increase in the number of fertile tillers (tillers with an ear), but reduced the grain size by 16% relative to the low N treatment. Contribution of preanthesis dry matter to grain yield was 193 g m-2 for the wheat receiving 60 kg N ha-1, 71 g m-2 for wheat which received 30 kg N ha-1 and only 16 g m-2 for wheat which received 15 kg N ha-1. This indicates that at high N supply, grain growth was substantially supported by pre-anthesis stored assimilates.

scholarly journals Ear formation and grain yield of winter wheat as affected by time of nitrogen supply.

1983 ◽  
Vol 31 (3) ◽  
pp. 211-225 ◽  
Author(s):  
A. Darwinkel
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Grain Number ◽  
N Application ◽  
Leaf Emergence ◽  
N Dose ◽  
Ear Number ◽  
Fertile Spikelet

Winter wheat cv. Caribo (1979) or Arminda and Okapi (1980) was provided with an additional N dressing at different stages between tillering and ear emergence after a basal N dose applied at the onset of tillering. The effect of N on ear formation depended greatly on the growth stage at the time of N application. Max. effects on tiller formation and spikelet initiation were achieved when additional N was supplied at the beginning of tillering; on ear number when N was supplied at the onset of stem elongation; on the numbers of fertile spikelets, grains/fertile spikelet and grains/ear when N was applied during stem elongation until flag leaf emergence and on single grain wt. when N was applied at ear emergence. Variations in 1000-grain wt. were small, therefore grain yield/ear as well as yield/unit area was largely determined by grain number. Main shoots outyielded ear-bearing tillers because of a higher grain number. In ear-bearing tillers, grain yield largely depended on grain number, being highest in the older tillers. Grain formation of ear-bearing tillers was more strongly affected by the time of additional N application than that of main shoots. Top-dressings of N applied during stem elongation increased the grain number of ear-bearing tillers considerably, because both the number of fertile spikelets and the grain number/fertile spikelet were higher. In the young late-appeared tillers, the opt. time to apply additional N for grain set shifted to later stages of development. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Barley and Rigid Ryegrass (Lolium rigidum) Competition is Influenced by Crop Cultivar and Density

2009 ◽  
Vol 23 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Blakely H. Paynter ◽  
Andrea L. Hills
Keyword(s):  
Grain Yield ◽  
Morphological Traits ◽  
Dry Matter ◽  
Growth Habit ◽  
Early Growth ◽  
Tiller Number ◽  
Barley Plant ◽  
Seeding Rate ◽  
Rigid Ryegrass ◽  
The Impact

Western Australian growers are adopting no-tillage farming systems, which have a greater reliance on integrated weed management systems that include competitive cultivars, high seeding rates, strategic fertilizer placement, and narrow row spacing. At the same time, they are sowing more of their barley area to cultivars with a semidwarf habit. This study compared six two-row, spring malting barley cultivars with different morphological traits at two dates of planting and three crop densities, with nil-added and added rigid ryegrass at five sites. Four cultivars, ‘Buloke’, ‘Flagship’, ‘Hamelin’, and ‘Vlamingh’, had an erect early growth habit; the other two, ‘Baudin’ and ‘Gairdner’, had a prostrate, semidwarf early growth habit. Increasing the density of rigid ryegrass plants from 16 to 125 plants/m2decreased barley grain yield by reducing crop biomass production, tiller number, grain number, and harvest index. Average grain weight was also reduced at most sites. The impact of competition on grain yield varied across sites and cultivars, but did not interact with date of planting. Baudin, Flagship, and Hamelin were more competitive with rigid ryegrass than Buloke, Gairdner, and Vlamingh. Differences in competitiveness between cultivars did not appear to be strongly related to morphological traits that affect light interception such as canopy closure, plant height, and tiller number. Differences in cultivar competitiveness were cultivar-specific and not generic. Rigid ryegrass productivity (dry matter and tiller number) tended to be lower under the more competitive cultivars. Increasing barley plant density increased grain yield, and reduced both rigid ryegrass dry matter and tiller number. Barley density had a larger impact on rigid ryegrass productivity than crop cultivar. The impact of barley density on reducing rigid ryegrass tiller number was larger with the first planting date than the second, and higher in the added rigid ryegrass plots than the nil-added plots. This study highlights the importance of high barley seeding rate for the integrated management of rigid ryegrass.

Contribution of Stem Dry Matter to Grain Yield in Wheat Cultivars

1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Yield Potential ◽  
Percentage Reduction ◽  
Wheat Cultivars ◽  
Activity Increase ◽  
Structural Carbohydrate ◽  
Days After Anthesis

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.

Effect of in-season application methods of fertilizer nitrogen on grain yield and nitrogen use efficiency in maize

2004 ◽  
Vol 84 (2) ◽  
pp. 169-176 ◽  
Author(s):  
B. L. Ma ◽  
M. Li ◽  
L. M. Dwyer ◽  
G. Stewart
Keyword(s):  
Grain Yield ◽  
Nitrogen Use Efficiency ◽  
Dry Matter ◽  
Foliar Spray ◽  
Soil N ◽  
Nitrogen Use ◽  
N Application ◽  
Maize Hybrids ◽  
Use Efficiency ◽  
Application Methods

Little information is available comparing agronomic performance and nitrogen use efficiency (NUE) for N application methods such as foliar spray, soil application, and ear injection in maize (Zea mays L.). The objective of this study was to investigate the effects of various N application methods on total stover dry matter, grain yield, and NUE of maize hybrids using a 15N-labeling approach. A field experiment was conducted on a Dalhousie clay loam in Ottawa and a Guelph loam in Guelph for 2 yr (1999 and 2000). Three N application methods were tested on two maize hybrids, Pioneer 3893 and Pioneer 38P06 Bt. At planting, 60 kg N ha-1 as ammonium nitrate was applied to all treatments. In addition, 6.5 kg N ha-1 and 13.5 kg N ha-1 as 15N-labeled urea were applied to either foliage (Treatment I) or soil (Treatment II) at V6 and V12 stages, respectively. In Treatment III, 20 kg N ha-1 as 15N-labeled urea was injected into space between ear and husks at silking. The results showed that compared with soil N application neither foliar spray nor injection through ear affected grain yield or stover dry matter. The NUE values ranged from 12 to 76% for N fertilizer applied at V6 a nd V12 stages, or at silking for all treatments. There was no interaction of hybrid × N application methods on any variables measured with the only exception that for soil N application, grain NUE in Pioneer 38P06 Bt was significant higher than in Pioneer 3893. The difference in total N and NUE of grain and stover between soil N application and foliar N spray was inconsistent. However, NUE was substantially higher for N injection through the ear than for foliar or soil application without differential responses between the two hybrids. Nitrogen injection through the ear at silking might have altered N redistribution within the plant and improved NUE. Hence, it can potentially enhance grain protein content. Foliar N spray is not advocated for maize production in Ontario. Key words: Maize, Zea mays, nitrogen application methods, nitrogen-15, yield, nitrogen use efficiency

Growth and the distribution of phosphorus in wheat developed under various phosphorus and temperature regimes

1986 ◽  
Vol 37 (5) ◽  
pp. 459 ◽  
Author(s):  
GD Batten ◽  
IF Wardlaw ◽  
MJ Aston
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Flag Leaf ◽  
Standard Condition ◽  
Growth Period ◽  
Phosphorus Concentration ◽  
Floral Initiation ◽  
Stages Of Development ◽  
P Deficiency ◽  
P Supply

Experiments were designed to examine the effect of the level and duration of application of phosphorus (P) on yield in wheat and the effect of growth conditions prior to anthesis on the utilisation of P taken up during the early stages of development. In the first experiment, wheat (Triticum aestivum cv. Kite) was grown in sand and supplied with a complete nutrient solution containing either 1 mM phosphate or 0.25 mM phosphate. The supply of P was maintained until grain maturity, or stopped at different stages of development (floral initiation, flag leaf emergence, anthesis). The increase in total plant dry matter over this period ranged from 8.8 to 17.6 g/plant, with the 1.0 mM P supply and from 4.1 to 9.5 g/plant with the 0.25 mM P supply. Supply of P beyond anthesis resulted in more tiller dry matter and increased the P content of the grain, but did not increase grain yield at either level. With 1 mM P to maturity, up to 21% P of the grain P could be attributed to retranslocation of P within the plant after anthesis. With 0.25 mM P to floral initiation, 58% of the grain P could be attributed to such retranslocation. In a second experiment plants (cv. Kite) were grown initially at 18/13�C with 0.25 mM P until floral initiation and thereafter with a P-free solution until maturity. Between floral initiation and anthesis plants were placed in six dayhight temperatures, extending (in 3�C steps) from 15/10�C to 30/25OC, and then returned to the standard condition of 18/13�C. Higher pre-anthesis temperatures reduced the pre-anthesis growth period and the plant height, but increased the leaf phosphorus concentration and uptake of phosphorus per plant in both the pre- and post-anthesis periods. Net CO2 exchange indicated that leaf senescence in P-deficient plants was closely associated with the export of nitrogen as well as the export of P. Grain P increased from 0.15% to 0.3% when the preanthesis temperature was increased from 15/10 to 30/25�C, although grain yield per main culm did not vary greatly. These findings highlight the importance of environmental conditions in determining the level of P deficiency in wheat, and show that grain yield is not limited by the amount of P in the grain.

Plant population and shading studies in barley

1971 ◽  
Vol 77 (3) ◽  
pp. 445-452 ◽  
Author(s):  
R. W. Willey ◽  
R. Holliday
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Unit Area ◽  
Grain Filling ◽  
Crop Growth ◽  
Plant Population ◽  
Grain Number ◽  
Ear Development ◽  
Development Period ◽  
Lower Production

SUMMARYTwo barley experiments are described in which a range of plant populations were shaded during different periods of development. Shading during the ear development period caused considerable reductions in grain yield, largely by reducing the number of grains per ear. Shading during the grain-filling period caused no reduction in grain yield. It is suggested that under conditions of these experiments there was probably a potential surplus of carbohydrate available for grain filling and that grain yield was largely determined by the storage capacity of the ears. The importance of the number of grains per ear as an indicator of individual ear capacity is emphasized.The effects of plant population on grain yield and its components are also examined. It is concluded that the number of grains per ear is the component having greatest influence on the decrease in grain yield at above-optimum populations and attention is again drawn to the possible importance of ear capacity. It is argued that on an area basis the number of grains per unit area may give a good indication of ear capacity. Examination of this parameter shows a close relationship with grain yield per unit area for both the shading and population treatments. It is particularly evident that a decrease in grain yield at high populations was associated with a comparable decrease in the number of grains per unit area. It is suggested that this decrease in grain number may be due to a lower production of total dry matter during ear development rather than an unfavourable partitioning of this dry matter between the ear and the rest of the plant. This lower production of total dry matter is attributed to the crop growth rates of the higher populations having reached their peak and then having declined before the end of the ear development period. This crop growth rate pattern, through its effect on grain number per unit area, is put forward as the basic reason why, in the final crop, grain yield per unit area decreases at above-optimum populations.

scholarly journals The impact of source or sink limitations on yield formation of winter wheat (Triticum aestivum L.) due to post-anthesis water and nitrogen deficiencies

2010 ◽  
Vol 56 (No. 5) ◽  
pp. 218-227 ◽  
Author(s):  
A. Madani ◽  
A. Shirani-Rad ◽  
A. Pazoki ◽  
G. Nourmohammadi ◽  
R. Zarghami ◽  
...  
Keyword(s):  
Grain Yield ◽  
Triticum Aestivum L ◽  
Grain Weight ◽  
Grain Number ◽  
Water Regimes ◽  
N Supply ◽  
Nitrogen Deficiencies ◽  
Rainfed Wheat ◽  
Source Sink ◽  
The Impact

The experiments were laid out to understand the mechanisms causing yield limitations imposed by post-anthesis water and nitrogen deficiencies in plants with modified source-sink ratios. Two soil-water regimes were allotted to the main plots. At anthesis, three levels of N were applied: none, 25% and 50% of total the N supply. Spike-halving caused reduction in grain yield at both water regimes and all N supply levels, showing that the reduction in grain number can not be compensated by a higher individual grain weight. Sink reduction by trimming 50% of the spikelets reduced grain number per ear by 38.5% and increased individual grain weight by 12.0%, which shows the plasticity in grain weight and grain set of wheat if sufficient assimilates are available. Additional nitrogen supply at anthesis had no significant effect on the total aboveground biomass, but increased grain yield through more allocation of dry matter to grains. Our findings suggest that for rainfed wheat with optimum N supply and supplemental irrigation, wheat growers should choose cultivars with a high grain number per ear and manage the crop to increase grain number per unit of land (sink capacity).

Studies of grain production in Sorghum vulgare. II. Sites responsible for grain dry matter production during the post-anthesis period

1971 ◽  
Vol 22 (1) ◽  
pp. 39 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Atmospheric Carbon Dioxide ◽  
Dry Matter ◽  
Unit Area ◽  
Flag Leaf ◽  
Grain Production ◽  
Sorghum Vulgare ◽  
The Third ◽  
Matter Production

The relative contributions of different photosynthetic sites to the filling of the grain in grain sorghum (Sorghum vulgare cv. Brolga) were estimated by measuring the 14C in the grain after exposing various leaves and the head to radioactive carbon dioxide. Methods for preventing photosynthesis were also used. Of the grain yield, 93% was due to assimilation by the head and upper four leaves. The head contribution of 18 % was due equally to direct assimilation of atmospheric carbon dioxide and to reassimilation of carbon dioxide released within the grain by respiration of material translocated from the leaves. The remaining 75 % was equally assimilated by the upper four leaves, the flag leaf being the most efficient contributor per unit area and the third uppermost leaf the least efficient. The percentage contributions to the grain by the flag leaf and fourth leaf, estimated from the decrease in grain yield when they were shaded, agreed closely with the estimates obtained by using 14CO2.

The Field Performance of Induced Uniculm Grain Sorghum (Sorghum bicolor) in South-east Queensland, Australia

1986 ◽  
Vol 22 (4) ◽  
pp. 393-403 ◽  
Author(s):  
S. Fukai ◽  
C. J. Liwa ◽  
C. W. L. Henderson ◽  
B. B. Maharjan ◽  
R. C. Hermus ◽  
...  
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Root Development ◽  
Dry Matter ◽  
Flag Leaf ◽  
Field Performance ◽  
Grain Sorghum ◽  
Wet Season ◽  
Stages Of Growth ◽  
Dry Conditions

SUMMARYReduction of leaf area in sorghum without tillers (uniculm sorghum) might result in conservation of water at early stages of growth and hence in stability of grain yield under dry conditions. In two experiments in south-east Queensland, Australia, tillers were removed by hand to examine the growth of uniculm sorghum. Tiller removal promoted root development at the flag leaf stage but significantly reduced shoot dry matter and lowered grain yield by about 20% in a wet season. The saving in soil water as a result of tiller removal was relatively small but statistically significant.

scholarly journals Nitrogen deficiency regulates premature senescence by modulating flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shamsu Ado Zakari ◽  
Syed Hassan Raza Zaidi ◽  
Mustapha Sunusi ◽  
Kabiru Dawaki Dauda
Keyword(s):  
Grain Yield ◽  
Leaf Senescence ◽  
Flag Leaf ◽  
Grain Filling ◽  
Sugar Concentration ◽  
Premature Senescence ◽  
N Supply ◽  
Ros Homeostasis ◽  
N Assimilation ◽  
N Deficiency

Abstract Background Leaf senescence occurs in an age-dependent manner, but the rate and timing of leaf senescence may be influenced by various biotic and abiotic factors. In the course of stress, the function, composition, and different components of photosynthetic apparatus occur to be synthesized homogeneously or degraded paradoxically due to different senescence-related processes. Nitrogen (N) deficiency is one of the critical environmental factors that induce leaf senescence, and its incidence may curtail leaf photosynthetic function and markedly alter the genetic information of plants that might result in low grain yield. However, the physiological and genetic mechanism underlying N deficiency regulates premature senescence, and flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling are not well understood. In this paper, Zhehui7954 an excellent indica restorer line (wildtype) and its corresponding mutant (psf) with the premature senescence of flag leaves were used to study the effect of different N supplies in the alteration of physiological and biochemical components of flag leaf organ and its functions during grain filling. Results The results showed that the psf mutant appeared to be more susceptible to the varying N supply levels than WT. For instance, the psf mutant showed considerably lower Pn, Chl a, Chl b, and Car contents than its WT. N deficiency (LN) decreased leaves photosynthetic activities, N metabolites, but significantly burst O2•−, H2O2, and relative conductivity (R1/R2) concentrations, which was consistent with the expression levels of senescence-associated genes. Sucrose, glucose, and C/N ratio concentrations increased with a decrease in N level, which was closely associated with N and non-structural carbohydrate translocation rates. Increases in POD activity were positively linked with the senescence-related enhancement of ROS generation under LN conditions, whereas, SOD, CAT, and APX activities showed opposite trends. High N (HN) supply significantly inhibits the transcripts of carbohydrate biosynthesis genes, while N assimilation gene transcripts gradually increased along with leaf senescence. The psf mutant had a relatively higher grain yield under HN treatment than LN, while WT had a higher grain yield under MN than HN and LN. Conclusions This work revealed that the C/N ratio and ROS undergo a gradual increase driven by interlinking positive feedback, providing a physiological framework connecting the participation of sugars and N assimilation in the regulation of leaf senescence. These results could be useful for achieving a higher yield of rice production by appropriate N supply and plant senescence regulation.

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