Bread-making Wheat Research Articles

An initial study to assess the use of geological parent materials to predict the Se concentration in overlying soils and in five staple foodstuffs produced on them in Scotland

Evidence suggests that dietary-intakes of the essential element selenium have fallen in Scotland in recent years, due to changing sources of bread-making wheat. The Scottish environment is thought to be Se-poor due to the geology and climate. This initial study assessed whether geological parent-materials could be used to predict relatively high and low soil-Se areas in Scotland and whether differences in soil-Se were reflected in foodstuff-Se produced on them. Samples (n = 8 per farm) of wheat, calabrese (broccoli), potato, beef-steak, milk, cattle pasture (grass) and soil were collected from pairs of farms (one in each high/low predicted Se area (PSA)). Potatoes and soils were collected from a further 34 farms in high/low PSAs to assess a greater geographical zone. Total soil-Se ranged from 0.115 to 0.877 mg kg -1 but most samples (90%) could be classed as Se-deficient (< 0.6 mg kg −1), irrespective of PSA. Total soil-Se was significantly higher (p < 0.05) in the high than in the low PSAs as expected; however, the difference between the two was small (mean 0.48 and 0.37 mg kg −1, respectively). Water-soluble soil-Se (6.69 to 26.78 μg kg −1) concentrations were not significantly different between the two PSAs (p = 0.71). Soil loss-on-ignition (indicating organic matter content) correlated significantly with total and water-soluble soil-Se (p < 0.001) and exerted a greater control than parent-material on soil-Se. Significant differences between the PSAs for beef-Se (p < 0.001), wheat-Se (p < 0.001), calabrese-Se (p < 0.01) and beef-farm grass-Se (p < 0.05) indicated partial success of the parent-material soil-Se prediction. However, only wheat-Se (p < 0.001) and potato-Se (p < 0.001) correlated significantly with total soil-Se. The results suggest that soil-Se concentrations in the main agricultural areas of Scotland are generally low. Given the low Se concentrations also reported in the food commodities; further investigations may be warranted to fully characterise the Se-status of Scottish produce and dietary-Se intakes in Scotland.

The complex shear modulus of dough over a wide frequency range

It is shown from small strain shear rheometry and low intensity ultrasonic shear wave measurements that power law behaviour describes the frequency dependence of the complex shear modulus of dough made from a strong North American breadmaking wheat flour. This is the first characterization of the linear viscoelastic behaviour over such a wide frequency range (more than eight decades). Standard rheometry was used to determine shear moduli at low frequencies while an inclined incidence wave reflection technique was used to measure the complex shear modulus in the 10 5 Hz region. The ultrasonic data demonstrate that previous descriptions of the constitutive properties of this rheologically complex material do not incorporate a sufficiently broad range of relaxation times to comprehensively model the rheology of dough at all frequencies. Modeling the dough as a power-law gel material permitted its linear viscoelastic response to be described well over the full frequency range.

Influence of water and barley β-glucan addition on wheat dough viscoelasticity

The effects of the addition of two barley β-glucan isolates (0.2–1.0% of wheat flour), differing in molecular weight, and water (53–63% in a poor breadmaking wheat flour, cv. Dion, and 58–68% in a good breadmaking wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep-recovery parameters of the dough. The evaluation was done separately for each combination of β-glucan isolate (BG1 of ∼10 5 Da and BG2 of ∼2 × 10 5 Da) and flour type. Besides the contents of β-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough’s viscoelastic behavior. Compared to BG1, the higher molecular weight β-glucan (BG2) brought about major changes on all the rheological responses of the fortified doughs. The addition of appropriate levels of β-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar viscoelastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora).

Proteome Changes in Wheat Subjected to Different Nitrogen and Sulfur Fertilizations

Controlling the quality of wheat for breadmaking is a major concern for the milling and baking industry. Wheat flour quality depends on both the genetic background and environmental factors during growth and storage. Amount and timing of application of fertilizer are factors that affect wheat quality. This study investigated the effect of different levels of nitrogen and sulfur on the tris-soluble and glutenin protein fractions by 2D-electrophoresis. Multivariate analysis was performed to study changes in the proteome pattern. In the tris-soluble fraction 20 proteins were changed in abundance due to S fertilization, whereas 16 proteins were changed in the glutenin protein fraction. It was found that induced sulfur deficiency during growth resulted in the most pronounced effect on protein composition. Understanding which proteins are affected by varying levels of fertilizers may help tailor specific traits in various wheat varieties.

Determination of parameters used to prevent ignition of stored materials and to protect against explosions in food industries

There are always risks associated with silos when the stored material has been characterized as prone to self-ignition or explosion. Further research focused on the characterization of agricultural materials stored in silos is needed due to the lack of data found in the literature. The aim of this study was to determine the ignitability and explosive parameters of several agricultural products commonly stored in silos in order to assess the risk of ignition and dust explosion. Minimum Ignition Temperature, with dust forming a cloud and deposited in a layer, Lower Explosive Limit, Minimum Ignition Energy, Maximum Explosion Pressure and Maximum Explosion Pressure Rise were determined for seven agricultural materials: icing sugar, maize, wheat and barley grain dust, alfalfa, bread-making wheat and soybean dust. Following characterization, these were found to be prone to producing self-ignition when stored in silos under certain conditions.

Effect of barley β-glucan molecular size and level on wheat dough rheological properties

The effect of adding low (10 5 Da) or high (2.03 × 10 5 Da) molecular weight barley β-glucans in two wheat flours of different breadmaking quality were studied. Mechanical spectra and creep–recovery analysis data within (low stress) and out (high stress) of the linear viscoelastic region were obtained. The results revealed that the rheological behavior of β-glucan-enriched doughs depend on concentration and molecular weight of the polysaccharide as well as on the flour type used. Addition of β-glucan increased the G′ values of the good breadmaking quality flour doughs, whereas decreased the G′ of the poor quality wheat cultivar. Supplementation with β-glucans increased the resistance to deformation, flowability and elasticity of the doughs under low stress. Significant correlations between frequency sweep and creep–recovery parameters of optimally developed doughs from both flours were found. The addition of β-glucan in the dough recipe of the poor breadmaking wheat flour may result in similar rheological responses to those obtained from a non-fortified good breadmaking quality wheat flour.

Effect of nitrogen application at anthesis on Fusarium head blight and mycotoxin accumulation in breadmaking wheat in the western part of Japan

In the western part of Japan, two wheat cultivars, Nishinokaori and Minaminokaori, are currently cultivated for breadmaking. Breadmaking wheat requires a higher protein content compared to the Japanese noodle wheat (the major type of wheat in Japan). This high protein level in the grain is obtained by top-dressing with nitrogen (N) near anthesis. Because such N applications may increase levels of Fusarium head blight (FHB) and consequent mycotoxin [deoxynivalenol (DON) and nivalenol (NIV)] accumulation in the grain, the effect of N application (0, 4, and 8 g/m2) at anthesis on FHB and mycotoxin accumulation in Nishinokaori and Minaminokaori was tested in the greenhouse in 2004 and 2005 and in two fields in 2006. In the greenhouse, plants were spray inoculated at 3, 10, and 20 days after N treatment. In field experiments, colonized maize kernels, which generate ascospores during the testing season, served as inoculum. In all experiments for both cultivars, N application at anthesis significantly increased grain protein as expected, but had no significant effect on FHB and DON and NIV levels in grain. These results suggest that, at least in these cultivars, N can be applied close to anthesis without increasing the risk of FHB and mycotoxin (DON and NIV) accumulation.

Intercropping with pulses to concentrate nitrogen and sulphur in wheat

SUMMARYThe effects of intercropping wheat with faba bean (Denmark, Germany, Italy and UK) and wheat with pea (France), in additive and replacement designs on grain nitrogen and sulphur concentrations were studied in field experiments in the 2002/03, 2003/04 and 2004/05 growing seasons. Intercropping wheat with grain legumes regularly increased the nitrogen concentration of the cereal grain, irrespective of design or location. Sulphur concentration of the cereal was also increased by intercropping, but less regularly and to a lesser extent compared with effects on nitrogen concentration. Nitrogen concentration (g/kg) in wheat additively intercropped with faba bean was increased by 8% across all sites (weighted for inverse of variance), but sulphur concentration was only increased by 4%, so N:S ratio was also increased by 4%. Intercropping wheat with grain legumes increased sodium dodecyl sulphate (SDS)-sedimentation volume. The effect of intercropping on wheat nitrogen concentration was greatest when intercropping had the most deleterious effect on wheat yield and the least deleterious effect on pulse yield. Over all sites and seasons, and irrespective of whether the design was additive or replacement, increases in crude protein concentration in the wheat of 10 g/kg by intercropping with faba bean were associated with 25–30% yield reduction of the wheat, compared with sole-cropped wheat. It was concluded that the increase in protein concentration of wheat grain in intercrops could be of economic benefit when selling wheat for breadmaking, but only if the bean crop was also marketed effectively.

The effect of environment on endosperm cell-wall development in Triticum aestivum during grain filling: an infrared spectroscopic imaging study

One of the major factors contributing to the failure of new wheat varieties is seasonal variability in end-use quality. Consequently, it is important to produce varieties which are robust and stable over a range of environmental conditions. Recently developed sample preparation methods have allowed the application of FT-IR spectroscopic imaging methods to the analysis of wheat endosperm cell wall composition, allowing the spatial distribution of structural components to be determined without the limitations of conventional chemical analysis. The advantages of the methods, described in this paper, are that they determine the composition of endosperm cell walls in situ and with minimal modification during preparation. Two bread-making wheat cultivars, Spark and Rialto, were selected to determine the impact of environmental conditions on the cell-wall composition of the starchy endosperm of the developing and mature grain, focusing on the period of grain filling (starting at about 14 days after anthesis). Studies carried out over two successive seasons show that the structure of the arabinoxylans in the endosperm cell walls changes from a highly branched form to a less branched form. Furthermore, during development the rate of restructuring was faster when the plants were grown at higher temperature with restricted water availability from 14 days after anthesis with differences in the rate of restructuring occurring between the two cultivars.

Shear and extensional properties of bread doughs affected by their minor components

The importance of the soluble fraction in flour in determining the rheological properties of dough subjected to large deformations and its possible consequence for breadmaking performance was investigated by measuring shear and extensional viscosities of native wheat flour and reconstituted doughs using creep–recovery tests and lubricated squeezing flow tests. Standard French breadmaking wheat flour was fractionated into water-soluble and insoluble fractions. Flour defatting and puroindoline additions were also tested. The large strain properties of doughs made from these fractions were studied in shear and biaxial extension by creep–recovery and lubricated squeezing flow tests, respectively. Shear viscosity η exhibited a Newtonian plateau at low shear rate γ ˙ and a shear thinning behaviour at higher γ ˙ in the range 10 −6–1 s −1. Apparent viscosity versus shear rate data could be fitted by Cross model. The results elucidated the lubricating role of the soluble fraction, and were confirmed by the bi-extensional test, although obtained over a narrower strain rate range ( ε ˙ b = 10 − 3 − 1 s − 1 ), for strain values in the range (0.1–1). The specific volume of bread was found to be inversely related to bi-extensional viscosity, whereas crumb fineness could be related to the strain hardening index, in agreement with gas retention and bubble growth phenomena during proofing.

Comparison of Small and Large Deformation Rheological Properties of Wheat Dough and Gluten

ABSTRACTThe rheological properties of dough and gluten are important for end‐use quality of flour but there is a lack of knowledge of the relationships between fundamental and empirical tests and how they relate to flour composition and gluten quality. Dough and gluten from six breadmaking wheat qualities were subjected to a range of rheological tests. Fundamental (small‐deformation) rheological characterizations (dynamic oscillatory shear and creep recovery) were performed on gluten to avoid the nonlinear influence of the starch component, whereas large deformation tests were conducted on both dough and gluten. A number of variables from the various curves were considered and subjected to a principal component analysis (PCA) to get an overview of relationships between the various variables. The first component represented variability in protein quality, associated with elasticity and tenacity in large deformation (large positive loadings for resistance to extension and initial slope of dough and gluten extension curves recorded by the SMS/Kieffer dough and gluten extensibility rig, and the tenacity and strain hardening index of dough measured by the Dobraszczyk/Roberts dough inflation system), the elastic character of the hydrated gluten proteins (large positive loading for elastic modulus [G′], large negative loadings for tan δ and steady state compliance [Je0]), the presence of high molecular weight glutenin subunits (HMW‐GS) 5+10 vs. 2+12, and a size distribution of glutenin polymers shifted toward the high‐end range. The second principal component was associated with flour protein content. Certain rheological data were influenced by protein content in addition to protein quality (area under dough extension curves and dough inflation curves [W]). The approach made it possible to bridge the gap between fundamental rheological properties, empirical measurements of physical properties, protein composition, and size distribution. The interpretation of this study gave indications of the molecular basis for differences in breadmaking performance.

Milling and baking properties of field grown wheat expressing HMW subunit transgenes

Abstract Milling and baking tests were carried out on three transgenic wheat lines and their parental varieties grown in the field at two UK sites. The transgenic and control lines were essentially similar in their milling properties but the subunit 1Ax1 and 1Dx5 transgenes had different effects on breadmaking. The subunit 1Dx5 transgene resulted in a low loaf volume and poor crumb structure when expressed in lines with two or five endogenous HMW subunits, and this was accompanied by a greatly increased elastic modulus of the gel protein fraction. In contrast, the 1Ax1 transgene resulted in improved breadmaking quality and a more modest increase in the gel protein elastic modulus when expressed in the two subunit background. Blending of flour from a line expressing the 1Dx5 transgene with flour from a normal breadmaking wheat variety resulted in decreased breadmaking quality, even at a ratio of 1:9. The difference in the results obtained with the 1Ax1 and 1Dx5 transgenes may relate to the presence of an additional cysteine residue in the protein encoded by the latter, which promotes a more highly cross-linked glutenin network.

Legume Species and Management for Stockless Organic Farming

ABSTRACT In systems of organic farming without livestock, with no nutrients imported in feed and bedding, or manure to transfer nutrients within the farm, supplying adequate nutrients for crop growth, particularly nitrogen (N), is a major challenge. Two identical experiments compared four legume species (red clover (Trifolium pratense L.), white clover (Trifolium repens L.), lucerne (Medicago sativa L.) and sainfoin (Onobrychis viciifolia Scop.)) as N providers over a two-year conversion period for a stockiess organic rotation. After ploughing-in the legumes, two successive wheat crops were grown to measure N supply and yield response. The two experiments (1992 to 1995; 1993 to 1996) were on a silty clay loam soil in eastern England. Mean accumulated above-ground N over the two years, in cut and mulched foliage, was greatest in red clover (mean 502 kg ha-1) and least in sainfoin (201 kg ha-1), with lucerne (497 kg ha-1) and white clover (408 kg ha-1) lying in between. Differences in wheat grain yield were poorly related to these figures, and neither legume species nor management had a consistent effect on wheat grain yield. Grain N concentration was consistently greatest following white clover (by between 0.06 and 0.38%). It is suggested that this was because the pattern of mineralization of the white clover residues favoured later uptake by the wheat, which influenced grain N concentration more than yield. Low grain N content is a major constraint to the greater use of U.K.-grown organic wheat for breadmaking. Growing white clover rather than the preferred red clover or lucerne fertility-building crops in stockiess organic rotations could make a significant contribution to improving grain quality in winter wheat.

Functional Properties and Agronomic Performance of Transgenic Tritordeum Expressing High Molecular Weight Glutenin Subunit Genes 1Ax1 and 1Dx5

Two transgenic lines of tritordeum line HT28 have been evaluated under field conditions for agronomic performance and processing quality. One line (line 3) contained the gene encoding for the high molecular weight (HMW) glutenin subunit 1Dx5 and the second (line 8) two genes for HMW subunits 1Ax1 and 1Dx5. The two transgenic lines showed similar agronomic performance which was inferior to the untransformed control line. Phenotypic differences between the transgenic and the control lines were observed for heading date, yield, harvest index, 1000-seed weight, test weight, and grain protein content. Alveograph studies showed that the addition of subunit 1Dx5 (line 3), which accounted for 27% of the total HMW glutenin subunits (HMW-GS), clearly improved the dough quality of tritordeum, increasing the tenacity and the deformation energy. This line showed dough properties as good as those of a good breadmaking wheat variety. In contrast, the addition of HMW-GS 1Ax1 and 1Dx5 together had little effect on the tenacity, extensibility or deformation energy when compared with the control HT28 line, even though they represented 25% and 37% of the total HMW subunit protein respectively.

Bread‐Making Wheat and Soil Nitrate as Affected by Nitrogen Fertilization in Irrigated Mediterranean Conditions

Mediterranean areas are suitable for the production of high quality bread‐making wheat (Triticum aestivum L.) because of the high temperatures during grain filling. Wheat quality is also influenced by variety and can be enhanced through the use of N fertilizer. However, N fertilization can increase residual soil NO−3 after harvest. The purpose of this study was to evaluate the effect of supplemental topdressed N fertilizer on quality and production of high quality bread‐making wheat and on residual soil NO−3 under irrigated Mediterranean conditions. Field experiments were conducted at two sites during two growing seasons on Calcixeroclic Xerochrept soils of the Ebro Valley (Spain). Five N treatments (100, 200, and 300 kg N ha−1 applied at the end of tillering and 150 or 250 kg N ha−1 at the end of tillering plus 50 kg ha−1 foliar‐applied N at the end of the boot stage) were imposed on two cultivars. Topdressed N increased yields, when increasing from 100 kg N ha−1 to higher rates only, in soils with low residual NO−3 However, N fertilization increased grain protein contents for all locations and years and bread quality parameters but with a greater effect in soils with low soil NO−3 Residual soil NO−3 after harvest increased little with increasing N rates. Grain protein, yield, and quality varied depending mainly on the year and amount of precipitation during grain filling. A topdress N rate of 200 kg N ha−1 would be the most appropriate way to produce high quality bread‐making wheat and minimize the risk of NO−3 leaching.

EFFECT OF COMPOSITION OF GLUTHNIN SUBFRACTIONS ON RHEOLOGICAL PROPERTIES OF WHEAT

Gluten extracted from defatted flours of cv. Aubaine (extra-strong), Hereward (strong) and Riband (weak) was separated into five different fractions (R2 to R6) by sequential centrifugation and addition of sodium chloride. A seven-minute mixing time was used to carry out fractionation on the basis of depolymerization of glutenin macropolymers (GMP). Depolymerization of GMP occurred at much higher rates in dough of the weak cultivar compared to the strong and extra-strong cultivars. Polypeptide compositions of different ghttenin fractions were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis under reduced and non-reduced conditions, followed by densitometric scanning of stained patterns. The amount of HMW-glutenin subunits decreased and LMW-glutenin subunits increased correspondingly in each cultivar with the fractionation from R2 to R6. The rheological behavior of the fractions was analyzed by small deformation rheological tests (strain sweep and frequency tests). The high molecular weight fraction (R2) from extra-strong wheat had a higher vahte of G' and a lower tan δ value as compared to strong and weak bread-making wheats. The moduli of HMW glutenin fractions (R2 and R3) were frequency independent and promoted the network properties, whereas moduli of LMW glutenin fractions were frequency dependent and gave rise to a plasticizing effect. Therefore, it was concluded from the present studies that HMW-glutenin subunits are not the only factors governing good bread-making quality but their proportions in relation to low molecular weight glutenin subunits is equally important in sinking a balance between viscous and elastic properties essential for bread making performance.

Separation kinetics of karnal bunt (Tilletia indica) infected wheat (Triticum aestivum) grains in a fluidized bed / Cinética de separación de granos de trigo (Triticum aestivum) infectados con carbon parcial (Tilletia indica) en un lecho fluidificado

Infection of breadmaking wheat grains by karnal bunt ( Tilletia indica) is a common disease in north- western Mexican states, causing major economic losses. In this work, the feasibility of separating infected from wholesome wheat grains by using fluidized bed technologies was evaluated. The pro posed separation equipment was of the batch type and fluidization was attained via direct air injec tion into the grain bed. Minimum fluidization rates were determined and effects of infected grain composition in the bed were studied. The experimental results showed that the separation of infected grains was quite possible with small losses of wholesome wheat grains. A quantitative characteriza tion of the separation process was made by determining the separation kinetics from the available experimental data. Separation kinetics were shown to be useful for estimating the equipment operat ing time to attain an allowed level of grain infection, as established by the Mexican government for the commercialization of wheat.

SDS‐Protein Gel Test for Prediction of Bread Loaf Volume

ABSTRACTFlour dispersed in aqueous solutions of sodium dodecyl sulfate (SDS) forms a proteinaceous gel when centrifuged at high speed. The conventional methodology for SDS gel testing was modified to develop a small‐scale (&lt;1 g of flour or wheat meal) screening test for evaluation of the protein quality of wheat for breadmaking. The principal modification involved centrifugation with a swinging‐bucket rotor to facilitate direct measurement of gel height, which is the primary test parameter. The effects of suspension temperature and time, centrifugation speed, sample size, and sieving of ground wheat or flour on the efficacy of the test were examined. Gel height, wet weight, and protein content were assessed as test parameters. In the standard test procedure that was developed, 0.67 g of flour or ground whole wheat was dispersed in 13.5 mL of 1.5% SDS solution for 15 min at 20°C, followed by centrifugation at 80,000 × g for 30 min. The test was evaluated using seven Canadian commercial wheat flours with diverse breadmaking quality. For the samples, gel height was strongly related to loaf volume (R2 = 0.89 and 0.95 for flour and ground wheat, respectively). Sieving flour through a 75‐μm sieve slightly increased the predictive power of the test (R2 = 0.94). SDS gel height gave better discrimination of samples for prediction of loaf volume than did the traditional SDS sedimentation test. The performance of the sedimentation test improved when sieved ground wheat was used. The relationship between gel height or protein content and flour protein content was comparatively poor (R2 = 0.25). The SDS gel test appears to primarily measure the effects of flour protein quality.

Quality and Value of Organic Grain from Contrasting Breadmaking Wheat Varieties and Near Isogenic Lines Differing in Dwarfing Genes

ABSTRACT Comparisons of Maris Widgeon, an old taller breadmaking variety, were made with more modern varieties of wheat in eight successive field experiments between 1987/88 and 1994/95 at Harnhill Manor Farm, Cirencester, Gloucestershire, U.K. for grain yield, specific weight, protein concentration, SDS-sedimentation volume and Hagberg falling number. The effect of quality of the grain on financial value was investigated by applying a range of penalties for insufficient protein, Hagberg falling number and specific weight. Values for feed and breadmaking quality wheat were also varied. For all of the different pricing scenarios, grain from Maris Widgeon was of lower value than that from the most modern variety. The higher protein concentration of Maris Widgeon, in comparison with Hereward, was insufficient to compensate for lower yields and Hagberg falling numbers. Reduced height genes (Rht1 and Rht2) in isogenic lines of Maris Widgeon, studied in one field experiment, increased grain yield and Hagberg falling number but reduced protein content. Interactions of variety with other factors relevant to organic systems were also investigated namely undersowing (four seasons), defoliation by mowing or sheep grazing in Spring (three seasons), and sowing date (two seasons) but these factors had little impact on the relative grain performance of the varieties studied.

Responses of two wheat varieties to sulphur addition and diagnosis of sulphur deficiency

Sulphur deficiency has become increasingly widespread in wheat in the U.K. Growth, nutrient content and biochemical responses to S and N supply of a breadmaking wheat variety (Hereward) and a non-breadmaking variety (Riband) were investigated in a pot experiment. Shoot dry matter (DM) at stem extension (Zadok's GS 37) and at maturity was increased markedly by S. Grain production of the Riband variety was more susceptible to the imbalance of N to S than the Hereward variety. At GS 37, the concentrations of total S and sulphate-S of shoots, chlorophyll meter readings and the concentrations of glutathione of the uppermost fully expanded leaves were increased significantly by increasing S supply, whereas the concentrations of nitrate and amides were decreased by S. The greatest relative changes in response to S supply were those of the glutathione and asparagine concentrations. Riband also showed greater response to S than Hereward. Critical values of various diagnostic indices at GS 37 were derived from the relationships between DM yield and different indices. The two varieties showed similar diagnostic curves except that for the ratio of total N to total S (N:S) in shoots. Either total S or sulphate-S can be used alone as a good indicator of deficiency, and with values of 1500 and 190 mg kg-1 DM in shoots for the two indices respectively. There was also a well defined relationship between DM yield and the glutathione concentration, with a critical value of 240 nmol g-1 FW. There were no advantages of using % of total S as sulphate-S. Shoot N:S ratio was found to be less accurate in predicting S deficiency than total S or sulphate-S. For prognostic purposes, a much higher S status at GS 37 was required to ensure no losses of DM yield due to S deficiency at maturity.