1. Journal of Agricultural Science and Technology B 5 (2015) 365-375
doi: 10.17265/2161-6264/2015.06.001
Effect of Copper, Zinc and Boron on Green Leaf
Retention and Grain Yield of Winter and Spring Cereals
Syed Shah, Sarah Hookway, Andrew Richards, Carl Flint, Sarah Wilkinson and John Mark Fletcher
Agrii Technology Centre (AgriiFocus), North Farm, Swindon, SN8 2JZ, UK
Abstract: Crop nutrition has a significant effect on disease incidence, resistance or tolerance of various crops. There is currently a
lack of reliable recent UK-based research about the effect of copper, zinc and boron on disease incidence, green leaf area (GLA),
green leaf retention (GLR) and grain yield of winter wheat, spring wheat and spring barley. Data analysis showed that these trace
elements had positive effects on GLR. These positive effects may have been due to the role of copper, zinc and boron in the
production of defence related compounds (phenolics and lignin), which may have reduced the disease incidence resulting in
prolonged GLR. Grain yield was significantly enhanced by the application of these trace elements on the crop grown on high pH
calcareous soil, which can be partly attributed to enhanced GLR. Also trace elements have a positive role in reproductive growth,
flowering and male fertility. On average, zinc was found to be the most consistent trace element in terms of enhancing GLR and
grain yield. Across all trials, it was noted that for every 10% increase in GLA from trace elements, grain yields increased by 4.2% in
2012-2013, by 4.4% in 2013-2014 in winter wheat and by 3.9% in spring wheat in 2014. These are remarkably consistent and indicate
that increasing GLA by 10% by early dough stage was associated with a yield improvement of about 4%. These trace elements also had
a positive effect on grain protein content (GPC). This research concluded that the trace elements had positive effects in enhancing
GLA and yield. It can be speculated that with the use of these trace elements, there may be more scope for using less robust or
reduced rates of fungicides to control foliar diseases, which may help to maximize farm profits.
Key words: Trace elements, copper, zinc, boron, cereals, GLR, grain yield.
1. Introduction
Crop resistance, tolerance and susceptibility to
disease are generally variety specific [1], but
environment and nutrition have a significant role in
disease incidence and grain yield [2]. Crop nutrition
affects the development of a disease by affecting plant
physiology [3]. Nutrients affect the growth rate of the
plant, and sufficient supply of nutrients can result in
higher growth rate enabling seedlings or plants to
escape or avoid infection [4]. Nitrogen (N) is the most
important nutrient for achieving higher yield [5]. It
has been reported that N affects the occurrence of
pests and diseases in several crops [6, 7]. At higher N
rate, disease can be a limiting factor [8] and the
severity of disease increases with N [9]. This is
because at higher N rate, the metabolism of the plant
Corresponding author: Syed Shah, Ph.D., research fields:
plant and soil science.
changes, which leads to lower content of defence
related compounds (phenolics and lignin) [10]. At low
N rate, an increased synthesis of these defence related
compounds has been reported [3]. However, it is
worth mentioning that the effect of N on disease
incidence is dependent on the type of pathogen and
genotype. For example, the severity of obligate
pathogens, such as Puccinia graminis and Erysiphe
graminis tends to increase [10], while the severity of
facultative pathogens, such as Alternaria and
Fusarium tends to decrease with N rate [3].
Phosphorous (P) is the second important nutrient
for achieving higher yield. Its role in controlling
seedling and fungal diseases has been reported, but P
was found to be more beneficial when its application
resulted in a rapid root development, allowing plants
to escape diseases [11]. Foliar application of P has
shown to have benefits against downy mildew in
oilseed rape. Similar to P, potassium (K) is also very
DDAVID PUBLISHING

2. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals366
important for achieving higher yields and has a very
important role to play in plant susceptibility or
resistance to different diseases. K may promote the
development of thicker outer walls in epidermal cells
and may improve resistance against diseases [12].
Obtaining the optimum balance between N, P and K can
improve disease resistance of plants [3]. Calcium (Ca),
magnesium (Mg) and sulphur (S) have also shown
positive effects on plant disease resistance [7, 13, 14].
In recent years, trace elements, such as manganese
(Mn), copper (Cu), zinc (Zn), boron (B) and silicon
(Si) have become of specific interest to various
researchers. There are several reasons for this, but the
primary reason is the role of these trace elements in
improving resistance against biotic and abiotic
stresses. These trace elements also have a vital role in
reproductive growth as well as the uptake and
utilization efficiency of N, P and K [15], which can
have a positive effect on grain quality, such as grain
protein content (GPC), 1000-grain weight and specific
weight [16].
Amongst trace elements, Mn has a very important
role in the development of disease resistance in plants
[17]. Mn application has been reported to have
positive effects in controlling many foliar diseases,
such as powdery mildew, downy mildew, tan spot and
take-all [11, 17, 18]. This is because Mn controls the
biosynthesis of lignin and suberin through the
activation of several enzymes [17]. Lignin and suberin
have a crucial role in resistance against most foliar
diseases in wheat [2, 11].
It has been reported that Cu has a very important
role in disease resistance [15, 19] and reproductive
growth [20]. Cu deficiency may play a role in
increased infection, because Cu is necessary for cell
wall lignification. When lignification is disrupted, cell
walls are more susceptible to penetration by fungi [21].
In addition to its effects on leaf disease susceptibility,
evidence exists that pollen sterility and male sterility
are enhanced when Cu is deficient in cereal crops [22].
Cu deficient plants produced smaller anthers, and the
pollen had a high incidence of male sterility, which
had negative effects on grain yield [23].
Zn is a structural component of several enzymes
and is required for enzyme activation. Its application
may reduce disease severity, which could be due to
the direct effects of Zn on the pathogen but not
through the plant’s metabolism [4]. The role of Zn in
protein and starch synthesis is well documented, and
their positive effects on GPC and the baking quality of
winter wheat flour have been observed [16]. Zn
deficiency has negative effects on carbohydrate
metabolism and pollen structure which results in
lower yield [24].
B plays important roles in cell wall synthesis and
structure, and possibly membrane stability [25]. It has
a significant role in disease resistance, which is
attributed to its role in cell wall structure, cell
membrane permeability, stability and its role in the
production of phenolics and lignin [26, 27]. It has
been observed that B deficiency causes abnormal
development of reproductive organs [28, 29] which
reduces crop yield [30].
This paper reports the results obtained from a range
of Agrii trials which were carried out at the Agrii
Technology Centre (AgriiFocus), Swindon, UK,
during three growing seasons (2011-2014). The main
objective of these trials was to investigate the effects
of foliar application of the trace elements (Cu, Zn and
B) on disease incidence and green leaf area (GLA). It
was hypothesised that the trace elements have the
potential to improve disease resistance, which may
enhance green leaf area retention (GLR) and
maximize grain yield in situations when the supply of
N, P, K, S, Mg and Mn is sufficient.
2. Materials and Methods
Five trials were carried out at the Agrii Technology
Centre, Swindon, UK, located at 51°30′ N and 1°39′
W. These trials investigated the effect of a range of
trace elements, in particular Cu, Zn and B on GLR,
grain yield and yield related components of winter

3. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals 367
wheat, spring wheat and spring barley during the
2011-2014 growing seasons on high pH calcareous
soil. The calcareous and high pH soil for the trials was
chosen, because these soils are likely to be deficient in
micronutrients or the availability is limited due to high
pH. The range of products used in these trials is listed
in Table 1. Prior to planting, 24 individual cores (0-10
cm depth) were collected at different points from the
fields which were used for these trials. All the cores
were mixed in a clean plastic container and a
sub-sample was sent to Lancrop Laboratories,
Wellington Road, Pocklington, York, UK, for broad
spectrum soil analysis. Selected chemical properties of
the field are listed in Table 2. Plots were drilled using
a 16 row Wintersteiger plot drill. Winter wheat plots
received 270:150:150:75:37.5 kg/ha of
N:P2O5:K2O:SO3:MgO, respectively, as a standard
maintenance fertilizer treatment. Spring wheat and
spring barley received 180 kg/ha of N, while
P2O5:K2O:SO3:MgO were the same as for winter
wheat. A robust herbicide, insecticide, fungicide
programme was employed to control all weeds, pests
and diseases during the growing seasons.
Trace element treatments were applied at T0
(tillering stage), T1 (1st node detected), T2 (flag leaf
just visible) and T3 (ear fully emerged) using a
standard plot sprayer with 110° flat fan nozzles. Plots
were monitored to assess the effects of treatments on
disease incidence and grain yield. Plots were assessed
two to three times to record the level of disease
(Septoria and Rhynchosporium where applicable), but
data in this paper were selected from the last
assessment at Zadoks growth stage (ZGS-73), the
early milk stage, at which the effects of treatments
were more noticeable. On each assessment date, 10
tillers were randomly selected, and the percentage area
of the top three leaves with visible infection was
recorded. Since it was difficult to separate symptoms
of disease and natural senescence, results are
expressed as GLA [31]. Grain yield of the plots was
determined by combine harvesting one strip 1.85 m
wide and 10 m long using a Sampo 2010 plot combine.
Table 1 List of the products and their active ingredient (L/ha) used in the trials at the Agrii Technology Centre (Swindon,
UK).
Product name Active ingredient (g/L) Maximum individual rate (L/ha) Manufacturer
Hu-man extra S (93):Mn (150):Mg (12) 2.0 Verdicrop, UK
Magnor N (50):Mg (100) 2.0 Verdicrop, UK
Zinic S (20):Zn (140) 2.0 Verdicrop, UK
Copper 435 Cu (250) 0.5 Headland, UK
Opte B B (150) 2.0 Agrii, UK
Nutri-phite PGA 26% phosphite 5.0 Verdesian, UK
4-yield extra Mn (105):S (75):Mg (8.6):Cu (21) 2.0 Verdicrop, UK
Table 2 Selected chemical properties of the fields used for the trials during 2011-2014.
Properties
Crop and growing season
2011-2012 2012-2013 2013-2014
Winter wheat Winter wheat Winter and spring wheat Spring barley
pH 6.9 7.7 8.0 7.5
P (ppm) 20.0* 13.0^ 17.0* 12.0^
K (ppm) 256.0* 203.0* 261.0* 153.0*
Mg (ppm) 75.0* 64.0* 69.0* 66.0*
Mn (ppm) 126.4* 62.0^ 63.5 ^ 128.0*
Cu (ppm) 3.8^ 3.8^ 3.8^ 4.1*
B (ppm) 3.4* 2.5* 4.7* 2.8*
Zn (ppm) 7.5* 4.1* 9.1* 4.3*
* means normal and ^ means slightly low.

4. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals368
Table 3 List of treatments, product rate (L/ha) and date of application for winter wheat trial carried out the Agrii
Technology Centre during 2011-2012.
Treatment Product, rate (L/ha), application stage and date
Untreated -
Best trace elements programme
(1) Nutri-phite PGA (0.5) + 4-yield extra (1.5) + Zinic (0.5) at T0 applied on April 2, 2012;
(2) Nutri-phite PGA (0.5) + 4-yield extra (1.5) + Zinic (0.5) at T1 applied on April 24, 2012;
(3) Nutri-phite PGA (0.5) + Magnor (1.5) + Copper 435 (0.25) + Zinic (0.5) + Boron 150 (0.3) at
T2 applied on May 17, 2012;
(4) Nutri-phite PGA (0.5) + Magnor (1.5) + Copper 435 (0.25) + Zinic (0.5) + Boron 150 (0.3) at
T3 applied on June 18, 2012.
Table 4 List of treatments, product rate (L/ha) and date of application for winter wheat trial carried out the Agrii
Technology Centre during 2012-2013.
Treatment Product, rate (L/ha), application stage and date
Control -
Zn Zinic (0.75) at T0 and T1 applied on April 24, 2013 and May 21, 2013, respectively;
Cu Copper 435 (0.35) at T1 and T2 applied on May 21 and June 3, 2013, respectively;
B Opte B (0.3) at T2 and T3 applied on June 3 and June 26, 2013, respectively;
Zn + Cu + B
Zinic (0.75) at T0 applied on April 24, 2013, followed by Zinic (0.75) + Copper 435 (0.35) at T1
applied on May 21, 2013 followed by Copper 435 (0.35) + Opte B (0.3) at T2 applied on June 3,
followed by Opte B (0.3) at T3 applied on June 26, 2013.
The grain yield was adjusted at 15% moisture content.
The 1,000-grain weight and grains/m2
were recorded
to aid the interpretation of the effects of treatments in
the discussion section of this paper. GPC was
recorded using the InfratecTM
1241 grain analyzer
(FOSS, Denmark). This instrument has an extended
wavelength range of 570-1,100 nm of near infra-red
(NIR), which scans and analyses 10 sub-samples of
the input sample and gives a recorded reading of GPC.
Data were analyzed by analysis of variance (ANOVA),
using Genstat (14th ed., 2011, VSN International).
Means were separated by least significant difference
(LSD) when F values were significant at P < 0.05.
2.1 Effect of Trace Elements on GLR and Grain Yield
of Winter Wheat Variety (KWS Santiago) during
2011-2012
This trial was drilled on September 14, 2011 in a
randomized complete block design with four
replicates to investigate the effect of wide a range of
trace elements (Table 3) on disease incidence and
grain yield of winter wheat (KWS Santiago). The
whole plot area received an over spray of Hu-man
extra (1.0/ha) at T0 and T1, and Magnor (1.5/ha) at T2
and T3, respectively to supply Mn and Mg. Plots were
combined on September 7, 2012 to determine grain
yield.
2.2 Effect of Cu, Zn and B on GLR and Grain Yield of
Winter Wheat (KWS Santiago) during 2012-2013 and
2013-2014
Two trials were carried out during the 2012-2013
and 2013-2014 growing seasons. These trials were
drilled on October 29, 2012 and October 30, 2013,
respectively, in a randomized complete block design
with four replicates to investigate the effect of the
treatments (Tables 4 and 5) on GLA and grain yield.
The whole plot area received an over-spray of Hu-man
extra (1.0/ha) at T0 and T1, and Magnor (1.5/ha) at T2
and T3, respectively to supply Mn and Mg. Grain
yield was determined by harvesting plots on
September 1, 2013 and August 23, 2014.
2.3 Effect of Cu, Zn and B on GLR and Grain Yield of
Spring Wheat (KWS Alderon) in 2014
This trial was drilled on March 27, 2014 in a
randomized complete block design with three replicates.
The trial was combined on August 24, 2014 to
determine the effect of Zn, Cu and B (Table 6) on grain
yield. The whole plot area received an over spray of

5. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals 369
Table 5 List of treatments, product rate (L/ha) and date of application for winter wheat (KWS Santiago) at the Agrii
Technology Centre during 2013-2014.
Treatment Product, rate (L/ha), application stage and date
Control -
Zn Zinic (0.75) at T0 and T1 applied on April 9, 2014 and April 26, 2014, respectively;
Cu Copper 435 (0.35) at T1 and T2 applied on April 26, and May 14, 2014, respectively;
B Opte B (0.3) at T2 and T3 applied on May 14, and May 30, 2014, respectively;
Zn + Cu + B
Zinic (0.75) at T0 applied on April 9, 2014, followed by Zinic (0.75) + Copper 435 (0.35) at T1
applied on April 26, 2014, followed by Copper 435 (0.35) + Opte B (0.3) at T2 applied on May
14, 2014, followed by Opte B (0.3) at T3 applied on May 30, 2014.
Table 6 List of treatments, product rate (L/ha) and date of application for spring wheat (KWS Alderon) at the Agrii
Technology Centre in 2014.
Treatment Product, rate (L/ha), application stage and date
Control -
Zn Zinic (0.75) at T0 and T1 applied on May 17, 2014 and May 30, 2014, respectively;
Cu Copper 435 (0.35) at T1 and T2 applied on May 30, and June 11, 2014, respectively;
B Opte B (0.3) at T2 and T3 applied on June 11 and June 30, 2014, respectively;
Zn + Cu + B
Zinic (0.75) at T0 applied on May 17, 2014, followed by Zinic (0.75) + Copper 435 (0.35)
applied on May 30, 2014, followed by Copper 435 (0.35) + Opte B (0.3) applied on June 11,
followed by Opte B (0.3) applied on June 30, 2014.
Table 7 List of treatments, product rate (L/ha) and date of application for spring barley (Rhyncostar) at the Agrii
Technology Centre in 2014.
Treatment Product, rate (L/ha), application stage and date
Control -
Zn Zinic (0.5) at T0, T1 and T2 applied on April 21, May 5 and May 28, 2014, respectively;
Cu Copper 435 (0.25) at T0, T1 and T2 applied on April 21, May 5 and May 28, 2014, respectively;
B Opte B (1.0) at T0, T1 and T2 applied on April 21, May 5 and May 28, 2014, respectively;
Zn + Cu + B
Zinic (0.5) + Copper 435 (0.25) + Opte B (1.0) at T0, T1 and T2 applied on April 21, May 5 and
May 28, 2014, respectively.
Hu-man extra (1.0/ha) at T0 and T1, and Magnor (1.5/ha)
at T2 and T3, respectively to supply Mn and Mg.
2.4 Effect of Cu, Zn and B on GLR and Grain Yield of
Spring Barley (Rhyncostar) in 2014
This trial investigated the effect of Cu, Zn and B
applied at different growth stages (Table 7) on GLR
and yield of spring barley Rhyncostar. The trial was
drilled on March 18, 2014 in a randomized complete
block design with four replicates and combined on
August 20, 2014 to determine grain yield.
3. Results
3.1 Effect of Trace Elements on GLR and Grain Yield
of Winter Wheat (KWS Santiago) during 2011-2012
Trace elements had a significant effect on GLA.
The untreated plots had lost most of the green area of
the top two leaves, while the treated plots remained
green for a longer period and had 40% green leaves on
the assessment date (July 22, 2012) (Fig. 1). The
untreated plots produced 1 ton/ha lower yield than the
treated plots (Fig. 2).
3.2 Effect of Cu, Zn and B on GLR and Grain Yield of
Winter Wheat (KWS Santiago) during 2012-2013 and
2013-2014
Combined analysis of the two year data showed that
the trace elements had a significant effect on GLA
compared with the control plots (averaged over two
years) (Table 8). However, there was a significant
interaction of year and trace element. Plots which
received Zn, Cu and B in a sequence at different
growth stages produced 0.5 ton/ha higher yield than the

6. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals370
Fig. 1 Effect of trace elements on GLA of KWS Santiago on July 22, 2012.
Fig. 2 Effect of trace elements on grain yield (ton/ha) of KWS Santiago during 2011-2012.
control plots in the trial carried out during the growing
season of 2012-2013. Similar results were obtained in
2013-2014, but the plots treated with Zn alone produced
higher yields than the individual application of Cu or B
(Table 8). Zn treated plot had the highest GPC (Fig. 3).
3.3 Effect of Cu, Zn and B on GLR and Grain Yield of
Spring Wheat (KWS Alderon) during 2014
GLA was significantly affected by trace elements
(P < 0.001), and the Zn treated plot had the highest
GLA followed by Cu, while the lowest was recorded
in the B treated plots (Table 9). Grain yield was also
significantly (P < 0.028) affected by the trace
elements, and the highest yield was recorded from
the Cu + Zn + B treated plots, while the lowest
yield was recorded from the B treated plots, which
was not significantly different than the control plots
(Table 9).
Untreated Best trace elements programme
Grainyield(ton/ha)

7. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals 371
Table 8 Effect of Cu, Zn and B on GLA (%) and grain yield (ton/ha) of KWS Santiago at the Agrii Technology Centre,
Swindon during 2012-2013 and 2013-2014.
Treatment
GLA (%) Grain yield (ton/ha)
2012-2013 2013-2014 Mean 2012-2013 2013-2014 Mean
Control 76.7 60.8 68.7 9.73 11.25 10.49
Zn 77.1 71.2 74.2 9.70 11.82 10.76
Cu 78.3 63.5 70.9 9.73 11.56 10.65
B 78.8 63.0 70.9 9.64 11.68 10.66
Zn + Cu + B 88.7 66.5 77.6 10.17 11.69 10.93
Mean 79.9 65.0 9.8 11.6
P-value Year (< 0.001), treatment (< 0.001), interaction (< 0.001) Year (< 0.001), treatment (< 0.001), interaction (< 0.001)
LSD (P < 0.05) Year (1.79), treatment (2.83), interaction (4.0) Year (0.099), treatment (0.157), interaction (0.222)
CV (%) 3.8 1.4
Fig. 3 Effect of Cu, Zn and B on GPC of KWS Santiago during 2013-2014.
Table 9 Effect of Cu, Zn and B on GLA (%) and grain yield (ton/ha) of spring wheat (KWS Alderon) at the Agrii
Technology Centre, Swindon during 2014.
Treatment GLA (%) Grain yield (ton/ha)
Control 72.9 8.94
Zn 80.5 9.21
Cu 76.2 9.07
B 68.0 8.65
Zn + Cu + B 77.0 9.24
P-value < 0.001 0.028
LSD (P < 0.05) 3.76 0.371
CV (%) 3.3 2.7
Table 10 Effect of Cu, Zn and B on grain yield of spring barley (Rhyncostar) in 2014.
Treatment Grain yield (ton/ha)
Untreated 8.23
Cu 8.72
Zn 8.72
B 8.29
P-value 0.092
LSD (P < 0.05) 0.49
CV (%) 3.6
Grainproteincontent(%)

8. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals372
3.4 Effect of Cu, Zn and B on GLR and Grain Yield of
Spring Barley (Rhyncostar) during 2014
Trace elements had a positive effect on GLA and
GLR, but these effects were not significant (P > 0.05)
(data not reported). Grain yield was also affected by
the trace elements but the effect was not significant (P
= 0.092) (Table 10).
4. Discussion
Foliar diseases reduce the GLA of crops, which
consequently has negative effects on photosynthetic
activity and yield [32]. The extent of yield losses is
dependent on the crop growth stage at the time of
infection, rate of disease development and genotypes
[33]. Fungicides are one of the most commonly used
methods for controlling Septoria (Mycosphaerella
graminicola) and leaf blotch (Rhynchosporium secalis)
in susceptible varieties of wheat and barley,
respectively [34, 35]. Amongst fungicides, triazole
based chemicals when applied with succinate
dehydrogenase based products can give a better
control of Septoria in wheat [36] and leaf blotch in
barley [35]. It has been reported that trace elements
have a crucial role in enhancing disease resistance of
various crops, including cereals [3].
In one of the trials reported in this paper, the effects
of the best trace elements programme (Mn, Cu, Zn, B
along with Mg and phosphite) were investigated on
winter wheat variety KWS Santiago. This variety was
chosen due to its susceptibility to Septoria and yellow
rust, which could help us to investigate the benefits of
using these trace elements in enhancing disease
resistance and yield. Although the whole trial area had
received a robust fungicide programme to control all
diseases, it was noticed the plots which had not
received any trace elements had lost their entire GLA
by July 22, 2012. The trace element treated plots
remained green for a longer period (16 d) and looked
brighter and healthier. This outcome can be attributed
to the combined positive effects of Mn, Mg, Cu, Zn
and B. This result is in agreement with Dordas [3],
Graham and Webb [4], and Brown et al. [26], who
have reported the benefits of trace elements in
controlling diseases and maintaining GLA. This is
because trace elements, such as Mn control the
biosynthesis of lignin and suberin. These two
defence-related compounds have a crucial role in the
resistance against foliar diseases [4]. Similarly, Cu, Zn
and B play an important role in lignification and the
production of suberin [2, 11], which may have been
one of the reasons for enhanced GLR in our study.
The effect of Mn in controlling foliar and root
diseases is well documented [3], but the effects of Cu,
Zn, B in controlling diseases, e.g., Septoria, and
enhancing GLR in the UK climatic conditions are
limited. Two years trials data reported in this paper
indicated that Cu, Zn and B had enhanced GLA and
GLR, but there was a significant interaction of year
and trace element. This significant interaction was
partly attributable to the differences in weather
conditions and disease incidence. In the growing
season of 2012-2013, disease pressure was low, and
although the individual application of Cu, Zn and B
had positive effects on GLR, it was not significant
when compared with the control plots. However,
applying these trace elements in a sequence at
different growth stages resulted in a significantly
higher GLA than the control plots. The trial carried
out in 2013-2014 during which disease pressure was
high, tended to confirm the benefits of these trace
elements, but Zn alone proved to be best treatment in
enhancing GLA and GLR by 5 d compared with the
control and other trace elements.
The benefits of using Cu, Zn and B in maintain
GLA were also noticed in spring wheat and spring
barley. The individual applications of Zn, Cu and B in
a sequence at different growth stages resulted in
higher GLA and GLR when compared with control
plots of spring wheat variety KWS Alderon. Also, in
the spring barley (Rhyncostar), the greening effects of
these trace elements were noticed, but these effects

9. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals 373
were statistically not significant (data not reported).
This outcome may have been due to the fact that this
barley variety has a good level of disease resistance
against Rhynchosporium and probably did not need
the application of these trace elements to enhance
disease resistance. Further trials are needed to confirm
this suggestion.
It has been reported that foliar diseases reduce GLA,
which consequently has a negative effect on
photosynthesis and grain yield [32]. Any strategy
which protects green leaf, in particular the flag and the
penultimate leaves, can have positive effects on grain
yield [37]. In this paper, the enhanced trace element
programme prolonged the GLR, which resulted in 11%
higher yield than the plots which did not receive any
trace elements. Data analysis of other trials showed
the benefits of using Cu, Zn and B and the application
of these three trace elements in a sequence at the key
growth stages produced 0.44 ton/ha and 0.3 ton/ha
higher yield for winter and spring wheat, respectively.
These yield enhancements were attributed to increased
grains/m2
and average grain weight. This outcome is
in agreement with the results of Refs. [16, 19, 20],
which reported the positive effects of Cu, Zn and B on
yield due to the crucial role of these trace elements in
flowering, reproductive growth and disease resistance.
However, such effects were not significant for spring
barley. This outcome can be attributed to differences
in the susceptibility of the varieties to different
diseases. The varieties KWS Santiago and KWS
Alderon are susceptible to Septoria. The application of
trace elements improved the diseases resistance,
indicated by better GLR, which had positive effects on
yield. The spring barley variety used in this trial was
moderately resistant to the main barley disease
(Rhynchosporium), and as a result, the benefits of
trace elements in terms of grain yield enhancement
were not observed. Across all trials, it was noted that
for every 10% increase in GLA, grain yields increased
by 4.2% in 2012-13, by 4.4% in 2013-14 and by 3.9%
in spring wheat in 2014. These are remarkably
consistent and indicate that increasing GLA by 10% by
early dough stage will be associated with a yield
improvement of about 4%. Further trials are needed to
confirm the benefits of these trace elements on
susceptible and moderately resistant varieties of wheat
and barley in controlling diseases and enhancing yield.
It has been reported that Cu, Zn and B can improve
uptake and utilization efficiency of N, P and K [15],
which can have positive effects on grain quality, such
as the GPC [16, 38]. In this study, Zn had a positive
effect on GPC of KWS Santiago, which is in
agreement with the results of Peck et al. [16] on bread
wheat. It is worth noting that Zn can alter grain
protein composition, such as gluten, which is a major
component of flour protein that determines the
processing quality [39]. In this study, grain protein
composition was not assessed, but further trials are
recommended to investigate the effect of Zn on GPC
and composition of milling wheat. This may help to
improve GPC and baking quality of milling wheat
currently grown in the UK.
5. Conclusions
The set of trials reported in this paper confirmed the
importance of trace element nutrition (Cu, Zn and B)
in enhancing disease resistance. These benefits, in
most cases, were translated into higher yields, which
could be partly attributed to higher grains/m2
and
average grain weight. The higher average grains/m2
and grain weight were due to the positive effects of
these trace elements on GLA and GLR. Prolonged
GLR may have allowed the crop to produce
carbohydrates for a longer period, which were
translocated to the ear during the grain filling period.
Also these trace elements have a positive role in
reproductive growth, flowering and male fertility,
which may have resulted in higher grains/m2
and
consequently high yield. The results indicated that,
although the availability of trace elements in the soil
was optimum, their foliar application had positive
effects on enhancing disease resistance and grain yield.

10. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals374
Averaged over all trials, Zn performed consistently
better than Cu and B in terms of its effect on grain
yield. It also had a positive effect on GPC, which
tends to recommend its use for enhancing the GPC of
milling wheat.
Acknowledgments
The authors wish to thank Robert Lawton and Hugh
Bland, the owners of North Farm and Manor farm,
respectively, for the trial sites and the agronomy team
of Oxford Agricultural Trials Ltd. for carrying out the
trial work.
References
[1] Agrios, N. G. 2005. Plant Pathology, 5th ed.. New York:
Elsevier-Academic Press.
[2] Krauss, A. 1999. “Balanced Nutrition and Biotic Stress.”
In Proceedings of IFA Agricultural Conference on
Managing Plant Nutrition.
[3] Dordas, C. 2008. “Role of Nutrition in Controlling Plant
Diseases in Sustainable Agriculture: A Review.”
Agronomy and Sustainable Development 28 (1): 33-46.
[4] Graham, D. R., and Webb, M. J. 1991. “Micronutrients
and Disease Resistance and Tolerance in Plant.” In
Micronutrients in Agriculture, 2nd ed., edited by
Mortvedt, J. J., Cox, F. R., Shuman, L. M., and Welch, R.
M. Madison, USA: Soil Science Society of America,
329-70.
[5] Bouwman, A. F., Boumans, L. J. M., and Batjes, N. H.
2002. “Estimation of Global NH3 Volatilization Loss
from Synthetic Fertilizers and Animal Manure Applied to
Arable Lands and Grasslands.” Global Biogeochemical
Cycles 16: 1024-37.
[6] Howard, D. D., Chambers, A. Y., and Logan, J. 1994.
“Nitrogen and Fungicides Effects on Yield Components
and Disease Severity in Wheat.” Journal of Production
Agriculture 7 (4): 448-54.
[7] Amtmann, A., Trouffard, S., and Armengaud, P. 2008.
“The Effect of Potassium Nutrition on Pest and Disease
Resistance in Plants.” Physiologia Plantarum 133 (4):
682-91.
[8] Jordan, V. W. L., and Stinchombe, G. R. 1986.
“Interactions between Fungicide, Plant Growth Regulator,
Nitrogen Fertilizer Applications, Foliar Diseases and
Yield of Winter Barley.” Annals of Applied Biology 108
(1): 151-65.
[9] Tripathi, S. C., Sayre, K. D., Kaul, J. N., and Narang, R.
S. 2003. “Growth and Morphology of Spring Wheat
(Triticum aestivum L.) Culms and Their Association with
Lodging: Effects of Genotype, N Levels and Ethephon.”
Field Crops Research 84 (3): 271-90.
[10] Robinson, P. W., and Hodges, C. F. 1981.
“Nitrogen-Induced Changes in the Sugars and Amino
Acids of Sequentially Senescing Leaves of Poa pratensis
and Pathogenesis by Drechslera sorokiniana.” Journal of
Phytopathology 101 (4): 348-61.
[11] Huber, D. M., and Graham, R. D. 1999. “The Role of
Nutrition in Crop Resistance and Tolerance to Disease.”
In Mineral Nutrition of Crops: Fundamental Mechanisms
and Implications, edited by Renegal, Z. New York: Food
Product Press, 205-26.
[12] Marschner, H. 1995. Mineral Nutrition of Higher Plants,
2nd ed.. London: Academic Press.
[13] Huber, D. M. 1980. “The Role of Mineral Nutrition in
Defense.” In How Plants Defend Themselves, edited by
Horsfall, J. G., and Cowling, E. B. New York: Academic
Press, 381-406.
[14] Walters, D. R., and Bingham, I. J. 2007. “Influence of
Nutrition on Disease Development Caused by Fungal
Pathogens: Implications for Plant Disease Control.”
Annals of Applied Biology 151 (3): 307-24.
[15] Kirby, E. A., and Romheld, V. 2004. Micronutrients in
Plant Physiology: Functions, Uptake and Mobility. York,
UK: The International Fertilizer Society.
[16] Peck, A. W., McDonald, G. K., and Graham, R. D. 2008.
“Zinc Nutrition Influences the Protein Composition of
Flour in Bread Wheat (Triticum aestivum L.).” Journal of
Cereal Sciences 47 (2): 266-74.
[17] Heckman, J. R., Clarke, B. B., and Murphy, J. A. 2003.
“Optimizing Manganese Fertilization for the Suppression
of Take-All Patch Disease on Creeping Bent-Grass.”
Crop Science 43 (4): 1395-8.
[18] Brennan, R. F. 1992. “The Role of Manganese and
Nitrogen Nutrition in the Susceptibility of Wheat Plants
to Take-All in Western Australia.” Fertilizer Research 31
(1): 35-41.
[19] Reuter, D. J., Robson, A. D., Loneragan, J. F., and
Tranthim-Fryer, D. J. 1981. “Copper Nutrition of
Subterranean Clover (Trifolium subterraneum L. cv.
Seaton Park): Part II, Effects of Copper Supply on the
Distribution of Copper and the Diagnosis of Copper
Deficiency by Plant Analysis.” Australian Journal of
Agricultural Research 32 (2): 267-82.
[20] Agarwala, S. C., Sharma, P. N., Chatterjee, C., and
Sharma, P. C. 1980. “Copper Deficiency Induced
Changes in Wheat Anther.” Proc. Indian National Acad.
Sci. B 46 (2): 172-6.
[21] Graham, D. R. 1983. “Effects of Nutrients Stress on
Susceptibility of Plants to Disease with Particular
Reference to the Trace Elements.” Advances in Botanical
Research 10: 221-76.

11. Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals 375
[22] Graham, R. D. 1975. “Male Sterility in Wheat Plants
Deficient in Copper.” Nature 254: 514-5.
[23] McMullen, M. P., and Stack, R. W. 1999. Fusarium Head
Blight (Scab.) of Small Grains. Fargo: NDSU Extension
Service, North Dakota State University.
[24] Fang, Y., Wang, L., Xin, Z. H., Zhao, L. Y., An, X. X.,
and Hu, Q. H. 2008. “Effect of Foliar Application of Zinc,
Selenium and Iron Fertilizers on Nutrients Concentration
and Yield of Rice Grain in China.” Journal of
Agricultural and Food Chemistry 56 (6): 2079-84.
[25] Iwai, H., Hokura, A., Oishi, M., Chida, H., Ishii, T., Sakai,
S., and Satoh, S. 2006. “The Gene Responsible for Borate
Cross-Linking of Pectin Rhamnogalacturonan-II Is
Required for Plant Reproductive Tissue Development and
Fertilization.” Proc. Nat. Acad. Sci. 103 (44): 16592-7.
[26] Brown, P. H., Bellaloui, N., Wimmer, M. A., Bassil, E. S.,
Ruiz, J., Hu, H., Pfeffer, H., Dannel, F., and Romheld, V.
2002. “Boron in Plant Biology.” Plant Biology 4 (2):
205-23.
[27] Blevins, D. G., and Lukaszewski, K. M. 1998. “Boron in
Plant Structure and Function.” Ann. Rev. Plant Physiol.
Mol. Biol. 49: 481-500.
[28] Dell, B., and Huang, L. B. 1997. “Physiological Response
of Plants to Low Boron.” Plant and Soil 193 (1): 103-20.
[29] Huang, L. B., Pant, J., Dell, B., and Bell, R. W. 2000.
“Effects of Boron Deficiency on Anther Development
and Floret Fertility in Wheat (Triticum aestivum L.
‘Wilgoyne’).” Annals of Botany 85 (4): 493-500.
[30] Nabi, G., Rafique, E., and Salim, M. 2006. “Boron
Nutrition of Four Sweet Pepper Cultivars Grown in
Boron-Deficient Soil.” Journal of Plant Nutrition 29 (4):
717-25.
[31] Mercer, P. C., and Ruddock, A. 2005. “Disease
Management of Winter Wheat with Reduced Doses of
Fungicides in Northern Ireland.” Crop Protection 24 (3):
221-8.
[32] Robert, C., Bancal, M. O., Lannou, C., and Ney, B. 2006.
“Quantification of the Effects of Septoria tritici Blotch on
Wheat Leaf Gas Exchange with Respect to Lesion Age,
Leaf Number and Leaf Nitrogen Status.” Journal of
Experimental Botany 57 (1): 225-34.
[33] Scott, S. W., and Griffiths, E. 1980. “Effects of
Controlled Epidemics of Powdery Mildew on Grain Yield
of Spring Barley.” Annals of Applied Biology 94 (1): 19-31.
[34] Clark, W. S. 2006. “Septoria tritici and Azole
Performance: Fungicide Resistance—Are We Winning
the Battle but Losing the War?” Aspects of Applied
Biology 78: 127-32.
[35] Zhan, J., Fitt, B. D. L., Pinnschmidt, H. O., Oxley, S. J. P.,
and Newton, A. C. 2008. “Resistance, Epidemiology and
Sustainable Management of Rhynchosporium secalis
Populations on Barley.” Plant Pathology 57 (1): 1-14.
[36] Shah, S., Lee, S., Wilkinson, S., Flint, C., and Fletcher, J.
M. 2014. “Triazole vs. SDHI Based Fungicides: The
Incidence of Septoria Leaf Blotch (Mycosphaerella
graminicola) in Winter Wheat Varieties and Its Impact on
Grain Yield.” Aspects of Applied Biology 127: 77-87.
[37] Yang, J. P., Sieling, K., and Hanus, H. 2000. “Effects of
Fungicide on Grain Yield of Barley Grown in Different
Cropping Systems.” Journal of Agronomy and Crop
Science 185 (3): 153-62.
[38] Hemantaranjan, A., and Garg, O. K. 1988. “Iron and Zinc
Fertilization with Reference to the Grain Quality of
Triticum aestivum L..” Journal of Plant Nutrition 11:
1439-50.
[39] Shewry, R., and Tatham, A. S. 1997. “Disulphide Bonds
in Wheat Gluten Proteins.” Journal of Cereal Science 25
(3): 207-27.