'Haying-off', the negative grain yield response of dryland wheat to nitrogen fertiliser II.Carbohydrate and protein dynamics

1998 ◽  
Vol 49 (7) ◽  
pp. 1083 ◽  
Author(s):  
A. F. van Herwaarden ◽  
J. F. Angus ◽  
R. A. Richards ◽  
G. D. Farquhar
Keyword(s):  
Grain Yield ◽  
Leaf Tissue ◽  
Water Soluble ◽  
Yield Response ◽  
Soluble Carbohydrates ◽  
Leaf Biomass ◽  
Yield Reduction ◽  
Absolute Amount ◽  
Potential Contribution ◽  
N Status

Changes in carbohydrate and protein in stems, leaves, spikes, and grain between anthesis and maturity were measured in 3 dryland wheat crops whose responses to applied nitrogen (N) ranged from increases in grain yield through to decreases in grain yield. This decrease in grain yield, known as haying-off, was described in Paper I in this series. Measurements reported there showed that apparent retranslocation, defined as the decrease in weight of vegetative organs during grain filling, was generally greater for crops of high-N status than for those of low-N status. Retranslocation in this context is the process of moving compounds assimilated before anthesis to the grain. The largest source of assimilates available for retranslocation in all crops at anthesis was water-soluble carbohydrates (WSC) contained in the stems and spikes, and represented a potential contribution of 34-50% to yield for the most severely hayed-off crops. The absolute amount of WSC present in high-N crops was less than that in low-N crops, despite a greater biomass. The lack of this form of assimilate available for retranslocation was the greatest single contributor to the yield reduction of the crops of high-N status. The quantity of protein retranslocated increased with crop N status, but the amounts involved were smaller than the quantity of WSC. Virtually all of the WSC reserves were utilised in all crops, in contrast to the protein reserves which were poorly retranslocated in the hayed-off crops. Most of the WSC was contained in the stems and most of the protein in the leaves. The potential contribution of retranslocated WSC and protein from leaves was more difficult to estimate because of an apparent loss of 40-50% of leaf tissue after anthesis. The nature of the loss was estimated from the amounts of acid detergent fibre (ADF; fibre not solubilised by hot acid detergent) present at anthesis and maturity. Since ADF comprises cellulose and lignin which decompose slowly, the loss of 30-37% of ADF was applied as a correction factor in calculating potential retranslocation from leaves. There was no loss of stem ADF. Using the correction, the potential retranslocation of leaf protein and leaf WSC was equivalent to 6-15% of yield. The export of all WSC and protein failed to account for the total decrease in leaf biomass, even after correction of leaf losses. We identified hemicellulose as an additional and previously unsuspected source of carbohydrate for retranslocation. Unlike WSC, the amount of leaf and stem hemicellulose at anthesis increased with crop N status, and the increase in hemicellulose between anthesis and maturity was equal to 10-17% of yield.

scholarly journals Genetic variation of stem characters in wheat and their relation to physiological characters and yield under drought

2020 ◽  
Vol 80 (04) ◽  
Author(s):  
Pooja . ◽  
Sonia . ◽  
Renu Munjal ◽  
Suresh .
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Osmotic Potential ◽  
Soluble Sugars ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Yield Reduction ◽  
Stem Solidness ◽  
Stressful Environments

Stem characters such as stem solidness and stem carbohydrates (water soluble carbohydrates and non-structural carbohydrates estimated as fructan) play an important role in stabilizing grain yield in stressful environments. Ten wheat genotypes were screened for carbohydrate content (Water soluble sugars and fructan) in peduncle along with other stem parameters namely, stem solidness, grain growth rate and stem osmotic potential under irrigated and drought conditions. Data was analyzed for correlation among these parameters along with biomass and yield. The results of present study indicated that stress-tolerant genotype RIL-S1-38 and WH 1235 accumulated higher fructan content in stem and contributed in grain growth rate, reduced osmotic potential and further imparted drought tolerance. Clear differences in stem solidness and fructan content exhibited lesser grain yield reduction under drought condition.

'Haying-off', the negative grain yield response of dryland wheat to nitrogen fertiliser III. The influence of water deficit and heat shock

1998 ◽  
Vol 49 (7) ◽  
pp. 1095 ◽  
Author(s):  
A. F. van Herwaarden ◽  
R. A. Richards ◽  
G. D. Farquhar ◽  
J. F. Angus
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Water Soluble ◽  
Yield Response ◽  
Soluble Carbohydrates ◽  
Field Crops ◽  
N Status

Post-anthesis drought and heat shock have been implicated in previous studies as factors contributing to ‘haying-off’ in wheat, but their relative importance has not been investigated. To separate the effects, wheat plants were grown at 2 levels of nitrogen (N) and then exposed to different levels of post-anthesis water deficit in factorial combination with the presence or absence of heat shock. The growth, yield, leaf carbon exchange, water use, and the contents of protein and soluble carbohydrate were measured and compared with the field results reported in Papers I and II of this series. The experiment consisted of wheat plants (cv. Janz) grown in 1·2-m-long tubes outdoors through winter and spring in Canberra, with either nil or 240 kg N/ha applied. The tubes were supported in a refrigerated box to maintain temperatures representative of those of soil in the field, and arranged to form mini-canopies with a density of 29 plants/m2. After anthesis, half of the plants at both levels of N were watered according to their transpiration demand and the other half at 75% of demand to reduce gradually the store of soil water so that water deficit could be initiated at the same time as heat shock. Fifteen days after anthesis, different temperatures were imposed by moving half of the plants into an adjacent glasshouse where heat shock was imposed by raising the air temperature to maxima of ~35ºC for 3 days, to simulate the pattern of temperatures experienced in the field during a heat wave. During this time, the control plants experienced daily maxima of ~25ºC. Following the heat shock, all plants were placed outside and rewatered to enable the assessment of treatment effects on potential leaf function. Both water deficit and high temperature reduced assimilation. After these measurements were taken, well-watered control plants were irrigated according to transpiration demand and the plants with imposed water deficit were watered at 50% of this amount. Yields increased in response to N at both levels of water status and both levels of temperature. That is, there was no evidence of the haying-off reported in Papers I and II of this series. Two factors are proposed to account for the difference between the field crops and the plants grown in the mini-canopy here. Firstly, the pattern of soil-water use differed from the field studies reported in Paper I, with the high-N plants using more soil water than low-N plants during grain filling. Secondly, the level of water-soluble carbohydrates (WSC) in the tube-grown plants of high-N status was greater than that for plants of low-N status, which was opposite to the pattern for field-grown plants reported in Paper II. In addition, the concentrations of WSC in the tube-grown plants were higher than those in the field-grown plants, apparently because lower spike density allowed better penetration of light into the mini-canopies and led to greater assimilate storage than by the denser field crops. The results confirm the conclusion of Paper I that high temperature is not necessary for haying-off, although it is likely that it would worsen the haying-off caused by post-anthesis drought and low WSC reserves in the field. The absence of the haying-off response in this experiment was mostly because the supply of WSC from the sparse canopy was adequate to ofiset the reduction of assimilation due to water deficit and heat shock. A contributing factor to haying-off in the field may therefore be dense canopies resulting in low levels of WSC

scholarly journals Rate and Timing Effects of Growth Regulating Herbicides Applications on Grain Sorghum (Sorghum bicolor) Growth and Yield

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Thierry E. Besançon ◽  
Ranjit Riar ◽  
Ronnie W. Heiniger ◽  
Randy Weisz ◽  
Wesley J. Everman
Keyword(s):  
United States ◽  
Grain Yield ◽  
Environmental Conditions ◽  
Southeastern United States ◽  
Grain Sorghum ◽  
Research Data ◽  
Growth And Yield ◽  
Yield Response ◽  
Yield Reduction ◽  
Timing Effects

Dicamba and 2,4-D are among the most common and inexpensive herbicides used to control broadleaf weeds. However, different studies have pointed the risk of crop injury and grain sorghum yield reduction with postemergence applications of 2,4-D. No research data on grain sorghum response to 2,4-D or dicamba exists in the Southeastern United States. Consequently, a study was conducted to investigate crop growth and yield response to 2,4-D (100, 220, and 330 g acid equivalent ha−1) and dicamba (280 g acid equivalent ha−1) applied on 20 to 65 cm tall sorghum. Greater stunting resulted from 2,4-D applied at 330 g acid equivalent ha−1or below 45 cm tall sorghum whereas lodging prevailed with 2,4-D at 330 g acid equivalent ha−1and dicamba applied beyond 35 cm tall crop. Regardless of local environmental conditions, 2,4-D applied up to 35 cm tall did not negatively impact grain yield. There was a trend for yields to be somewhat lower when 2,4-D was applied on 45 or 55 cm tall sorghum whereas application on 65 cm tall sorghum systematically decreased yields. More caution should be taken with dicamba since yield reduction has been reported as early as applications made on 35 cm tall sorghum for a potentially dicamba sensitive cultivar.

scholarly journals Variation of Water-Soluble Carbohydrates and Grain Yield in Iranian Cold Barley Promising Lines Under Well-Watered and Water Stress Conditions

2014 ◽  
Vol 68 (1) ◽  
pp. 65-75
Author(s):  
Soleiman Mohammadi ◽  
Reza Kas Nazani ◽  
Ayda Hosseinzadeh Mahootchi ◽  
Keiwan Ftohi
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Water Deficit ◽  
Dry Matter ◽  
Water Soluble ◽  
Stress Conditions ◽  
Soluble Carbohydrates ◽  
Dry Matter Content ◽  
Water Stress Condition ◽  
Water Soluble Carbohydrates

ABSTRACT In order to evaluate promising lines in terms of grain yield and water-soluble carbohydrates remobiliza-tion, an experiment with fifteen promising lines and two checks was carried out under full irrigation and terminal water stress conditions at Miyandoab Agricultural Research and Natural Resources Station. Mobilized dry matter content and remobilization percentage from shoot to grain under water deficit (177mg)(11.2%) were greater than those under well watering condition. The lowest (110 mg) and the highest (260mg) mobilized dry matter to grain were obtained for C-79-18 and C-83-15lines, respectively. Water deficit reduced grain yield of barley genotypes by 200-1600 kg/ha, and mean grain yield reduction was 800 kg/ha. Line 14 with 5.880and 5.300t/ha grain yield in favorable and water stress conditions was superior to the other lines. Under water deficit condition, line 14 had greater grain yieldby20% and 38% than the Bahman and Makouee cultivars, respectively. The results showed that greater grain yield in tolerant lines under water deficit was due to remobilization of unstructured carbohydrates from shoot to grain. Thus, it seems that selection of lines with higher translocated dry matter and contribution of pre-anthesis assimilate in grain filling under water stress, the suitable way for achieving genotypes with high grain yield under water stress condition.

scholarly journals Foliar Potassium Fertilizer Additives Affect Soybean Response and Weed Control with Glyphosate

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kelly A. Nelson ◽  
Peter P. Motavalli ◽  
William E. Stevens ◽  
John A. Kendig ◽  
David Dunn ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Leaf Tissue ◽  
High Yield ◽  
Yield Response ◽  
Soil Test ◽  
Potassium Fertilizer ◽  
K Fertilizer ◽  
Soil Test K

Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S), 0-0-25-17, 3-18-18-0, and 5-0-20-13) and additive rates (2.2, 8.8, and 17.6 kg K ha−1) on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1in a low-yield year (2005) depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K(P=0.03), S(P=0.03), B(P=0.0001), and Cu(P=0.008)concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.

Predictability of wheat growth and yield in light-limited conditions

2007 ◽  
Vol 145 (1) ◽  
pp. 63-79 ◽  
Author(s):  
F. D. BEED ◽  
N. D. PAVELEY ◽  
R. SYLVESTER-BRADLEY
Keyword(s):  
Solar Radiation ◽  
Grain Yield ◽  
Incident Light ◽  
Dry Weight ◽  
Water Soluble ◽  
Growth And Yield ◽  
Soluble Carbohydrates ◽  
Total Solar Radiation ◽  
Shoot Dry Weight ◽  
Source And Sink

In seeking better predictions of grain yield under light-limited conditions, shading was applied to field-grown winter wheat cv. Slejpner during each of five consecutive phases (canopy expansion, ear expansion, pre-flowering, grain expansion and grain filling). Absolute measures were taken of solar radiation and its effects on growth in three seasons, at a site where water and nutrient supplies were not limiting. Replicate mobile shades automatically occluded 0·80 of incident light when mean total solar radiation exceeded 250 J/m2 per s. Mean effects over seasons of shading on incident total solar radiation were −296, −139, −78, −157 and −357 MJ/m2 for the five phases respectively, and corresponding effects on shoot dry weight were −236, −184, −58, −122 and −105 g/m2. Estimated efficiency of radiation use after flowering was 1·2 g/MJ unshaded, tending to increase with shading. Shading in all phases reduced grain dry matter yield: mean effects over seasons were −106, −64, −61, −93 and −281 g/m2 for the five consecutive shading periods. Shading from GS31–39 increased mean maximum area of the two top leaves from 2700 to 3100 mm2 per leaf but, with fewer stems, canopy size remained unaffected. This and the next shading, from GS39–55, reduced specific leaf weight from 42 g/m2 by 4 and 3 g/m2 respectively, but effects on shoot dry weight were largely due to stem and ear. By flowering, stem weights, and especially their reserves of water-soluble carbohydrates, had partially recovered. Effects on yield of shading from GS31–39 were explained by a reduction in grains/m2 of 3070 from 26109. Shading from GS39–55 reduced grains/m2 by 4211 due to fewer grains per ear, whilst mean weight per grain increased in compensation. Shading from GS55–61 decreased grains/ear by 2·5. Shading from GS61–71 decreased ear growth and reduced stem weight, and at harvest resulted in 4·3 less grains/ear. Effects of the final shading from GS71–87 were fully explained by a reduction in mean dry weight/grain of 10·3 mg. Except for shading from GS71–87, source- and sink-based explanations of grain yield both proved feasible, within the precision of the measurements. Constraints to accurate comparison of source- and sink-based approaches are identified, and the implications for yield forecasting are discussed.

scholarly journals Differences in grain growth, crop photosynthesis and distribution of assimilates between a semi-dwarf and a standard cultivar of winter wheat.

1978 ◽  
Vol 26 (3) ◽  
pp. 233-249
Author(s):  
J.H.J. Spiertz ◽  
H. van de Haar
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Grain Number ◽  
Photosynthetic Production ◽  
Grain Filling Period ◽  
N Harvest Index ◽  
Standard Cultivar

The crop performance of semi-dwarf wheat cv. (Maris Hobbit) was compared with a standard-ht. cv. (Lely) at various levels of N supply. The grain yields of Maris Hobbit were considerably higher due to a higher number of grains and a heavier grain wt. Owing to the higher grain yield and a lower stem wt. the harvest index of Maris Hobbit was higher than that of Lely (0.47 and 0.40, resp.). The content of water-soluble carbohydrates in the stems of both cv. appeared to be very high until 3 wk after anthesis, despite the occurrence of low light intensities. Lely used more assimilates for structural stem material than did Maris Hobbit. Quantity and date of N application greatly affected grain number, but affected grain wt. to a lesser extent. Thus within each cv. grain number/m2 was the main determinant of grain yield. Late N dressings promoted photosynthetic production, grain wt. and CP content of the grain. The low CP contents of the grain were attributed to the low temp. during the grain-filling period. The distribution of N within the plant was only slightly influenced by N dressings and cv. differences. N harvest index ranged from 0.74 to 0.79. Grain N was derived from the vegetative organs (63-94%) and from uptake after anthesis (6-37%). The importance of carbohydrate and N economy for grain yield are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Weeds in grain-lupins. 2. The response of narrow-leafed lupins to pre-emergence herbicides

1977 ◽  
Vol 17 (84) ◽  
pp. 118 ◽  
Author(s):  
JM Allen
Keyword(s):  
Grain Yield ◽  
Lupinus Angustifolius ◽  
Yield Response ◽  
Yield Reduction ◽  
Yield Increase ◽  
Significant Yield

Results are reported from 18 experiments in which pre-emergence herbicides were evaluated in narrow-leafed lupins, (Lupinus angustifolius). At all 11 sites south of Perth (latitudes 32�S to 35�S) there was a significant lupin grain yield response to herbicides (P<0.05). There was a significant yield increase at only one of the seven sites north of Perth (latitudes 28�S to 32�S). Significant yield increases were obtained on at least one occasion with alachlor 1.1, 2.2 kg a.i. ha-1; diuron 0.4, 0.8, 1.3 kg a.i. ha-1; linuron 1:1, 2.2 kg a.i. ha-1; simazine 1.1, 1.7, 2.4 kg a.i. ha-1 and trifluralin 0.5, 1.1 kg a.i. ha-1 (P<0.05). Diuron 0.8 kg a.i. ha-1; linuron 2.2 kg a.i. ha-1 and simazine 1.1, 1.7 kg a.i. ha-1 each resulted in a significant lupin yield reduction on one occasion (P<0.05).

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