Journal of Phytopathology and Pest Management 10(1): 1-13, 2023
pISSN: 2356-8577 eISSN: 2356-6507
Journal homepage: http://ppmj.net/
∗Corresponding author: Mohamed F. A. Ahmed,
E-mail: mohamed_faah@yahoo.com
1
Copyright © 2023
The influence of certain eco-friendly treatments on the barley
powdery mildew disease under the impact of climate change
Sherin Ph. Mikhael1, Mohamed F. A. Ahmed2*
1Department of Barley Disease, Plant Pathology Research Institute, Agriculture Research Center, Giza, Egypt
2Central Laboratory of Organic Agriculture (CLOA), Agricultural Research Center (ARC), Giza, Egypt
Abstract
Keywords: barley, powdery mildew, biological control, oil extracts, inducers, fungicide.
This investigation's goal is to assess the effectiveness of eco-friendly treatments, i.e.,
biocide Blight stop, three natural oil extracts: black seeds, thyme and eucalyptus
oils, as well as fungicide Opus 12.5% Sc in reducing powdery mildew infection on
susceptible Egyptian barley varieties. These treatments were carried out under
greenhouse and field experiments conducted at Giza Experimental Station,
Agricultural Research Centre (ARC), during the 2020/21 and 2021/22 growing
seasons. All eco-friendly treatments and fungicide reduced disease severity
percentage, area under the disease progress curve (AUDPC) and average
coefficient of infection (ACI) compared to the control treatment in the two seasons,
in addition to increasing yield, total chlorophyll and carotenoids compared to the
control treatment. Spraying fungicide Opus provided the most effective treatments,
followed by biocide-Blight stop. On the other hand, thyme oil was recorded as
having the least effectiveness in comparison to the control treatment during both
seasons.
Mikhael Sherin & Ahmed, 2023
2
1. Introduction
In Egypt, barley is the principal crop that is
farmed on a large scale in the North Coastal
Province as well as in the recently reclaimed
regions with saline soils and a lack of pure
water. One of the most major cereal crops
worldwide is barley (Hordeum vulgare L.). It
is used for both human and animal nutrition,
according to Malcolmson et al. (2005). The
most harmful barley disease, powdery mildew,
is caused by the biotrophic fungus Blumeria
graminis f. sp. hordei (Abdullaev et al., 2021;
Tratwal and Bocianowski, 2014). The
production loss caused by powdery mildew can
exceed 30% in moderately temperate and
humid climates, with an average loss of 5–10%
(Agostinetto et al., 2014). Treatments of barley
powdery mildew with fungicides are typically
used to control plant diseases (Hafez & El-
Baghdady, 2013). However, the emergence of
fungicide-resistant pathogenic strains and their
detrimental impacts on human health and the
environment often make the use of fungicides
ineffective in the long term (Bourras et al.,
2018). The general idea is to utilize the
techniques that are greatest and most
environmentally friendly during a certain stage
of the farmed plant's development (Newton et
al., 2010). The cultivation of modern cultivars
in many different kinds of combinations and
complicated hybridised groups in line with the
theory of evolutionary plant cultivation is one
of the relatively simple and inexpensive
approaches that increases the lengthy viability
of genetic resistance (Matyjaszczyk, 2015).
The severity of barley powdery mildew
(Blumeria graminis f.sp. hordei) was
dramatically reduced when barley leaves were
treated with 0.5% black seed oil (BSO),
rapeseed oil (R oil), and paraffin oil (P oil),
from 63.4% (comparison group) to 9.4%
(BSO), 16% (R oil), and 16.4% (P oil) in
comparison with control treatment (Ali &
Blunden, 2003). It is clear that the protective
action of oils against powdery mildew is
mostly caused by inhibition of conidia
germination and reduction of the growth of
pathogenic fungi, with very little activation of
host defence systems according to
thymoquinone, the primary ingredient in both
the fixed oil and the essential oil (Ali &
Blunden, 2003). Therefore, it is crucial to pay
greater focus to BSO and other oils that are
effective against the microorganisms that
cause powdery mildew as safe and adequate
alternative control measures for the production
of healthy and organic foods (Hafez et al.,
2014). The treatment of pepper plants with
Blight stop at the rate of 1 l:50 l water recorded
the highest percentage of decrease in disease
incidence and severity of pepper plants, and
also recorded the highest increase in vegetative
growth, yield, fruit quality such and total
chlorophyll during the two growing seasons
2019/20 and 2020/21 compared with control
treatment (Ahmed et al., 2021). It is possible to
utilize non-traditional biological substances
and Trichoderma asperilium 34, a biological
commercial product, as an alternative to
fungicides for managing the symptoms of the
barley's net blotch disease. Additionally, the
treatments were successful in that they
considerably boosted the yield characteristics
compared to the control (Hafez et al., 2019).
The goal of this study is to investigate the impact
of some environmentally friendly materials, such
as plant extract oils and biological control, in
order to decrease the use of chemical
fungicides for controlling barley powdery
mildew, produce barley grains with high
quality and quantity without any toxicity at the
food chain, and maintain sustainable
development over the long term.
2. Materials and methods
2.1 Barley genotypes
Barley genotypes, whose names and pedigrees
are listed in Table (1), were kindly provided by
the Barley Research Department of the Field
Crops Research Institute, Agricultural Research
Centre in Egypt. These genotypes were used in
both greenhouse and field studies.
Mikhael Sherin & Ahmed, 2023
3
Table 1: Name and pedigree of two barley genotypes employed in greenhouse and field
experiments during two seasons 2020/21 and 2021/2022.
Cultivar Name
Pedigree
Giza 2000
C .C 89/3/Alanda/Hamra//Alanda-01
Giza 123
Giza 117/FAO 86
2.2 Compounds used to treat powdery
mildew on barley plants
In this study, Blight-stop as a biocide, three
natural oil extracts: black seeds, thyme and
eucalyptus oils, as well as Opus as a chemical
pesticide were applied on barley plants to
study their effectiveness against barley mildew
disease caused by Blumeria graminis f.sp.
hordei throughout the trial seasons of
2020/2021 and 2021/2022, as indicated in
Table (2).
Table 2: Technical data sheet of compounds used to treat powdery mildew on barley plants during two successive
seasons, 2020/2021 and 2021/2022.
Trade name
Active ingredient
Source
Opus
12.5% Sc Epoxiconazole
BASF Egypt for Agricultural Solutions, New Cairo, Egypt
Blight Stop
Trichoderma harzianum 30×10
6
spore/ml
Biological Control Production Unit Central Laboratory of
Organic Agriculture, CLOA, ARC, Egypt
Eucalyptus oil
Monoterpens, Sesquieterpenes and Aromatic phenols
Harraz for Food Industry & Natural Products
Thyme oil
40.5% Thymol, 23.6% P-cymen, 3.2% Carvacrol, 5.4%
Inalool, 2.6% B-caryphllene and Terpinen
Harraz for Food Industry & Natural Products
Black seed oil
Thymoquinone (21.01%), o-Cymene (18.23%), and β-
Thujene (17.22%)
Harraz for Food Industry & Natural Products
2.3 Greenhouse experiments
2.3.1 Samples of diseases and barley
powdery mildew isolates
According to the procedures described by Xu
et al. (2014), diseased leaves of barley were
taken from the disease nurseries' spreading lines,
and a single colony of Blumeria graminis f.sp.
hordei (Bgh) isolate was produced and preserved
on seedlings of the barley variety in test tubes
with a diameter of 5 cm and sterile soil.
2.3.2 Spore processing
Conidia of each isolate from the
aforementioned seedlings were placed onto the
barley seedlings of Giza 123 and Giza 2000,
which were grown in pots with 400 mL of
sterilised soil, and then incubated in a growth
chamber at 20±2ºC with continuous lighting to
multiply the Bgh isolates. Five layers of
cheesecloth were placed on the surface of a
glass cylinder with a 10 cm diameter to
completely enclose the seedlings and avoid
cross-contamination. After 3-5 days of white
mycelia's emergence, leaf segments of 5 cm in
length from the inoculated leaves were cut off,
placed upside-down on 1% agar plates, and
cultivated at 18±2ºC under a 16/8 h (light/dark)
lighting regime. The conidia were collected onto
tissue paper in the laminar flow after 5-7 days of
incubation and put into 2.0 ml centrifuge tubes.
The pathogenicity assay was conducted using
fresh conidia (Wang et al., 2023).
2.3.3 Typing in virulence
In the climate-controlled greenhouse of the
Barley Diseases Research Department of the
Field Crops Research Institute, Agricultural
Research Centre, Egypt, barley grains of the
varieties Giza 123 and Giza 2000 were grown
in clay pots with a diameter of 30 cm for eight
days. The most prevalent races of Blumeria
Mikhael Sherin & Ahmed, 2023
4
graminis f.sp. hordei were artificially
inoculated into each pot at the 2-leaf stage by
carefully shaking the sporulation leaf segments
while the plants were grown in a greenhouse at
a temperature of 20°C (Nair & Ellingboe,
1962). Twenty-four hours after inoculation,
leaves were sprayed with the recommended
doses of the aforementioned Blight-stop as a
biocide, three natural oil extracts: black seeds,
thyme and eucalyptus oils, as well as Opus as
a chemical pesticide. Plants were strictly
sprayed with distilled water only as a control
treatment. Three replicates of each treatment
were used in the experiment, which was
conducted using a completely randomized
block design. In addition, cultural practices
and irrigation were applied. According to
Jensen et al. (1992), the infection types (ITs) of
each barley variety collected from different
Bgh isolates were graded on a scale of 0 to 4,
and responses for resistance/susceptibility
were determined as follows: 0-2 for resistant
(R) and 3-4 for susceptible (S). Incubation
period (IP) was calculated as the number of
days between the inoculation and the first sign
of the disease's initial symptoms or signs, such
as spots. (Holliday, 2001). Latent period was
calculated as the number of days between the
day of inoculation and the day when 50% of
the conidia emerged and damaged the leaf
epidermal (Andrres, 1982). According to the
equation which described by Ahmed et al.
(2021), the disease severity was determined by
randomly analysing the leaves from each
treatment., using a 0 – 4 scale, where 0=no
disease; 1= 1–10% leaf area affected; 2= 11–
25% leaf area affected, 3= 26– 50% leaf area
affected and 4≥50% leaf area affected. The
formula was used to determine the percentage
disease severity index.:
DSI = ∑ (n × v)
Z × N ×100
Where: DSI= Disease severity index, n =
Number of leaves in each category, v =
Numerical value of each category, Z=
Numerical value of highest category and N =
Total number of leaves in the sample. The
Reduction in disease severity % was
calculated according to the following formula:
Reduction in disease severity % = Control − Treatment
Control ×100
2.4 Filed experiments (adult stage)
In order to evaluate the effectiveness of Blight-
stop as a biocide, three natural oil extracts:
black seeds, thyme and eucalyptus oils, as well
as Opus as chemical pesticide treatments
against the natural infection with powdery
mildew on the susceptible Egyptian barley
varieties, field experiments were conducted at
Giza Experimental Station, Agricultural
Research Centre (ARC), Egypt during the
2020/2021 and 2021/2022 growing seasons.
Seeds Giza 123 and Giza 2000 were studied in
randomised complete block design with three
replicate plots, each plot was sown in 10.5 m2
(3 × 3.5 m long), with 20 cm between rows. In
accordance with the Ministry of Agriculture's
guidelines, all traditional cultural practises
were implemented at the appropriate time. All
foliar spray treatments mentioned above with
recommended doses were separately applied
twice, the first time at heading stage (70 days
after planting), at the start of the infection, and
the second time after 10 days. According to,
disease severity was recorded.
2.4.1 Disease assessment under field conditions
In each trial, ten plants at heading stage from
each treatment were assessed visually on a 0–
10 scale for the percentage of leaf area covered
by powdery mildew (Large, 2007). Disease
scores were converted for analysis by Hafez et
al. (2014), i.e., 0 = 0 %, 1 = 0–3%, 2 = 3–6%,
3 = 6–12%, 4 = 12–25%, 5 = 25–50%, 6 = 50–
Mikhael Sherin & Ahmed, 2023
5
75%, 7 = 75–88%, 8 = 88–94%, 9 = 94–97%,
and 10 = 97–100%. Disease severity index
(DSI) was calculated using the following
formula :
DSI = ∑ 𝑅𝑎𝑡𝑖𝑛𝑔𝑠 𝑜𝑓 𝑒𝑎𝑐ℎ 𝑝𝑙𝑎𝑛𝑡
10 × 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑙𝑎𝑛𝑡𝑠 𝑟𝑎𝑡𝑒𝑑 ×100
Pathan and Park (2006) estimated the
coefficient of infection (CI) by multiplying the
severity score by a constant value of infection
type. The average coefficient of infection
(ACI) was computed by taking the mean CI
values for two years (Stubbs et al., 1986). The
area under disease progress curve (AUDPC)
was calculated using a simple formula adopted
by (Pandey et al., 1989) as follow:
AUDPC = D [½ (Y1 + YK) + (Y2 + Y3 + ………. + YK-1)]
Whereas D= days between two consecutive
(time intervals), Y1 + YK = sum of the first and
last disease scores, Y2 + Y3 + ………. + YK-1 =
sum of all in between disease scores.
2.4.2 Yield components
All harvested plants at maturity stage during
the two growing seasons 2020/21 and 2021/22
at Giza station and plots were recorded in terms
of biological yield (kg/plot). Following
harvesting, the grain yield (kg/plot) was
calculated from the harvested plants' or plots'
collected grains. The mean weight of 1000-
grain samples collected at random was used to
calculate the 1000-grain weight (g). The increase
over control in yield component was estimated
according to the equation adopted by Ahmed
(2013) and Hafez et al. (2014) as follow:
Increase over control % = Treatment − Control
Control ×100
2.4.3 Estimating the amount of chlorophyll
and carotenoids
The technique of Litchenthaler (1987) and Yu
et al. (2014) was used to determine the total
chlorophyll and carotenoids (mg/g).
2.5 Statistical analysis
The statistical analysis software SAS was used
to analyse the data. All multiple analysis was
initially evaluated through an analysis of
variance (ANOVA) comparison of means, the
least significant differences (LSD) AT P = 0.05,
and Duncan's multiple range test (Duncan,
1995) was used to determine the results.
3. Results
3.1 Greenhouse studies
3.1.1 Effect of some eco-friendly treatments
and fungicide on disease severity
According to data in Table (3), spraying
different environmentally friendly treatments,
such as Blight-stop as a biocide, three natural
oil extracts: black seeds, thyme, and eucalyptus
oils, and Opus fungicide, significantly decreased
the percentages of disease severity in inoculated
barley seedling varieties Giza 123 and Giza 2000
with Blumeria graminis f.sp. hordei under
greenhouse conditions as compared to control
treatment. The disease severity of powdery
mildew on both the Giza 123 and Giza 2000
types is totally controlled by the foliar
application of opus fungicide, contrary to other
eco-friendly treatments. The biocide Blight
stop caused the superior efficacy in reduction
(87.36 and 88.24%) followed by black seeds
oil (85.06 and 82.35%) of disease severity of
powdery mildew on Giza 123 and Giza 2000
barley verities, respectively compared with other
oils rather than untreated plants. On the
opposite side thyme oil caused the least effect
one. Finally, Giza 123 barley variety is higher
sensitive for infection with powdery mildew than
Giza 2000 during greenhouse conditions.
Mikhael Sherin & Ahmed, 2023
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Table 3: Effect of some eco-friendly treatments and fungicide as foliar spray on disease severity
percentage of inoculated barley seedling varieties Giza 123 and Giza 2000 with Blumeria
graminis f.sp. hordei under greenhouse conditions.
Treatments
Concentrations
Barley cultivars
Giza 123
Giza 2000
Disease severity (%)
Reduction (%)
Disease severity (%)
Reduction (%)
Blight stop
1 l/100 l
11.00
87.36
10.00
88.24
Black seeds oil
20 ml/l
13.00
85.06
15.00
82.35
Eucalyptus oil
20 ml/l
18.00
79.31
20.00
76.47
Thyme oil
20 ml/l
28.00
67.82
30.00
64.71
Opus
0.75 cm3/l
00.00
100.00
00.00
100.00
Untreated
Only water
87.00
0.00
85.00
0.00
LSD at 5%
2.12
2.11
3.1.2 Effect of some eco-friendly treatments
and fungicide on incubation and latent
periods (day) of barley powdery mildew
Powdery mildew infection of two barley
varieties Giza 123 and Giza 2000, expressed as
incubation period (IP) and latent period (LP)
were affected differently after spraying
primary leaves of barley seeds with the tested
ecofriendly and Optus fungicide treatments
compared with untreated plants. Data in Table
(4) revealed that, the foliar spraying of barley
seedlings with Blight-stop compounds as a
biocide, three natural oil extracts (black seeds,
thyme, and eucalyptus oils), and the fungicide
Opus showed their efficacy in lengthening the
incubation period (IP) and the latent period
(LP), which increased their effectiveness in
decreasing the severity of infection with the
barley powdery mildew, Blumeria graminis
f.sp. hordei, as seen at the previous Table (3),
compared to the control treatment. In light of
this, the fungicide Opus demonstrated a
significant increase in the lengthening of the
incubation period (IP) of 76.68% and the latent
period (LP) of 40.00% for the barley powdery
mildew Blumeria graminis f.sp. hordei when
compared to other natural oil extracts. Thyme
oil extract, on the other hand, showed the least
significant increase one.
Table 4: Effect of different eco-friendly treatments and fungicide on incubation and latent periods (day)
of inoculated barley seedling varieties Giza 123 and Giza 2000 with Blumeria graminis f.sp. hordei under
greenhouse conditions.
Barley varieties
Treatments
Concentrations
Disease severity (%)
Incubation period (day)
Increase (%)
Latent periods (day)
Increase (%)
Giza 123
Blight stop
1 l/100 l
9.75
72.26
11.25
36.36
Black seeds oil
20 ml/l
8.44
49.12
10.42
26.30
Eucalyptus oil
20 ml/l
7.23
27.74
9.25
12.12
Thyme oil
20 ml/l
6.98
23.32
9.00
9.09
Opus
0.75 cm3/l
10.00
76.68
11.55
40.00
Control
Untreated
Only water
5.66
0.00
8.25
0.00
LSD at 5%
0.92
1.18
Giza 2000
Blight stop
1 l/100 l
9.65
84.87
10.83
35.21
Black seeds oil
20 ml/l
8.12
55.56
10.02
25.09
Eucalyptus oil
20 ml/l
7.10
36.02
9.12
13.86
Thyme oil
20 ml/l
6.21
18.97
8.22
2.62
Opus
0.75 cm3/l
10.00
91.57
11.55
44.19
Control
Untreated
Only water
5.22
0.00
8.01
0.00
LSD at 5%
0.91
1.01
3.2 Filed experiments
3.2.1 The effect of ecofriendly treatment on
barley powdery mildew during 2020/21 and
2021/22 growing seasons
This investigation evaluated the efficacy of
Blight-stop as a biocide, three natural oil
Mikhael Sherin & Ahmed, 2023
7
extracts: black seeds, thyme, and eucalyptus
oils, as well as Opus as a chemical pesticide
with recommended doses as mentioned above
at Table (2) on powdery mildew of Giza 2000
and Giza 123 barley varieties in vivo trials
during 2020/2021 and 2021/2022 growing
seasons. The efficiency of foliar spraying with
tested ecofriendly and fungicide treatments
were employed to evaluate the barley powdery
mildew infection, which was expressed as
average percentages of mildewed leaf area
(PM disease severity %), area under the
disease progress curve (AUDPC), and average
coefficient of infection (ACI). The results in
Tables (5.a and 5.b) indicated that all
environmentally friendly and fungicide
treatments are highly effective in reducing the
severity of the barley powdery mildew disease,
the ACI, and the AUDPC when compared to
control treatments on both barley variety, Giza
123 and Giza 2000, during two successive
seasons, 2020/2021 and 2021/2022.
Table 5a: Effect of spraying different eco-friendly treatments and fungicide on disease severity percentage,
average coefficient of infection (ACI) and area under disease progress curve (AUDPC) of Blumeria
graminis f.sp. hordei on barley varieties Giza 123 and Giza 2000 under field conditions during the 2020/2021
growing season.
Barley varieties
Treatments
Concentrations
Disease severity (%)
Reduction (%)
ACI
Reduction (%)
AUDPC
Reduction (%)
Giza 123
Blight stop
1 l/100 l
10.22
87.74
3.57
95.22
52.50
89.30
Black seeds oil
20 ml/l
15.60
81.28
4.17
94.41
86.60
82.36
Eucalyptus oil
20 ml/l
20.45
75.46
10.17
86.38
96.13
80.41
Thyme oil
20 ml/l
22.76
72.69
11.50
84.59
113.8
76.81
Opus
0.75 cm3/l
09.83
88.21
3.41
95.44
51.29
89.55
Control
Untreated
Only water
83.35
0.00
74.65
0.00
490.8
0.00
LSD at 5%
1.12
0.88
2.65
Giza 2000
Blight stop
1 l/100 l
10.12
87.83
3.52
95.20
52.20
89.14
Black seeds oil
20 ml/l
14.5
82.56
4.15
94.34
85.40
82.24
Eucalyptus oil
20 ml/l
20.22
75.68
10.16
86.15
95.70
80.09
Thyme oil
20 ml/l
21.85
73.72
11.45
84.39
112.80
76.54
Opus
0.75 cm3/l
9.33
88.78
3.40
95.36
51.10
89.37
Control
Untreated
Only water
83.15
0.00
73.35
0.00
480.75
0.00
LSD at 5%
0.98
0.86
2.64
Table 5b: Effect of spraying different eco-friendly treatments and fungicide on disease severity percentage,
average coefficient of infection (ACI) and area under disease progress curve (AUDPC) of Blumeria
graminis f.sp. hordei on barley varieties Giza 123 and Giza 2000 under field conditions during the 2021/2022
growing season.
Barley varieties
Treatments
Concentrations
Disease severity (%)
Reduction (%)
ACI
Reduction (%)
AUDPC
Reduction (%)
Giza 123
Blight stop
1 l/100 l
9.44
88.63
3.50
95.22
52.10
89.05
Black seeds oil
20 ml/l
14.45
82.60
4.14
94.35
85.35
82.06
Eucalyptus oil
20 ml/l
20.12
75.77
10.00
86.35
95.55
79.91
Thyme oil
20 ml/l
21.33
74.32
11.33
84.53
112.78
76.29
Opus
0.75 cm3/l
9.22
88.90
3.20
95.63
51.00
89.28
Control
Untreated
Only water
83.05
0.00
73.25
0.00
475.63
0.00
LSD at 5%
1.10
0.76
2.62
Giza 2000
Blight stop
1 l/100 l
9.35
88.71
3.45
95.28
51.89
89.09
Black seeds oil
20 ml/l
14.23
82.82
4.22
94.22
85.16
82.10
Eucalyptus oil
20 ml/l
20.1
75.74
9.70
86.72
95.33
79.96
Thyme oil
20 ml/l
21.22
74.39
11.18
84.70
112.47
76.35
Opus
0.75 cm3/l
9.10
89.02
3.12
95.73
51.28
89.22
Control
Untreated
Only water
82.85
0.00
73.05
0.00
475.63
0.00
LSD at 5%
0.96
0.74
2.61
On the barley cultivars Giza 123 and Brief
2000, during the two subsequent seasons of
2020/21 and 2021, the fungicide Opus superior
to control treatments in regard to effectiveness
in reducing the severity of powdery mildew
disease, the average infection coefficient
(ACI), and the area under the disease
progression curve (AUDPC). Blight stop was
Mikhael Sherin & Ahmed, 2023
8
the next most effective treatment. On the other
hand, the therapy that involved spraying barley
plants with an extract of thyme oil was the least
effective. The results show that throughout the
two research seasons, cultivar Giza 123 of
barley was more susceptible to powdery
mildew disease than cultivar Giza 2000.
3.2.2 The yield components
Data in Tables (6a and 6b) illustrated that, all
environmentally friendly treatments, namely
Blight-stop as a biocide, three natural oil
extracts: black seeds, thyme, and eucalyptus
oils, and the chemical pesticide Opus, when
sprayed at the recommended concentrations in
Table (2) on barley plants of Giza 123 and
Giza 2000, resulted in a decrease in the
severity of infection and the development of
powdery mildew disease, as well as an
increase in the weight of a thousand grains (g)
and an increase in grain yield/plot (kg) in
comparison to the control treatment during the
two growing seasons of 2020/2021 and
2021/2022. In addition to spraying the plants
with the fungicide Opus, the highest reading in
the weight of 1000 grains (g) and the increase
in grain yield/plot (kg) for the two barley
cultivars were recorded, followed by an
increase in the productivity of the biocide
Blight-stop compared to the control treatment
during the two study seasons.
Table 6a: Effect of spraying different eco-friendly treatments and fungicide on 1000 kernel weight (g) of barley
varieties Giza 123 and Giza 2000 under field conditions during growing two seasons 2021/2022 and 2021/2022.
Barley varieties
Treatments
Concentrations
Growing season 2020/2021
Growing season 2021/2022
1000 grain weight (g)
Increasing (%)
1000 grain weight (g)
Increasing (%)
Giza 123
Blight stop
1 l/100 l
55.15
23.38
55.30
23.30
Black seeds oil
20 ml/l
54.31
21.50
54.42
21.34
Eucalyptus oil
20 ml/l
53.14
18.88
53.51
19.31
Thyme oil
20 ml/l
51.66
15.57
51.85
15.61
Opus
0.75 cm3/l
56.05
25.39
56.10
25.08
Control
Untreated
Only water
44.70
0.00
44.85
0.00
LSD at 5%
0.42
0.52
Giza 2000
Blight stop
1 l/100 l
55.25
22.51
55.60
22.98
Black seeds oil
20 ml/l
54.52
20.89
54.77
21.15
Eucalyptus oil
20 ml/l
53.52
18.67
53.92
19.27
Thyme oil
20 ml/l
52.03
15.37
52.38
15.86
Opus
0.75 cm3/l
57.10
26.61
57.20
26.52
Control
Untreated
Only water
45.10
0.00
45.21
0.00
LSD at 5%
0.40
0.51
Table 6b: Effect of spraying different eco-friendly treatments and fungicide on green yield/plot (kg) of barley
varieties Giza 123 and Giza 2000 under field conditions during growing two seasons 2021/2022 and 2021/2022.
Barley varieties
Treatments
Concentrations
Growing season 2020/2021
Growing season 2021/2022
Grain yield/plot (kg)
Increasing (%)
Grain yield/plot (kg)
Increasing (%)
Giza 123
Blight stop
1 l/100 l
5.15
25.00
5.18
23.63
Black seeds oil
20 ml/l
4.92
19.42
4.96
18.38
Eucalyptus oil
20 ml/l
4.81
16.75
4.83
15.27
Thyme oil
20 ml/l
4.64
12.62
4.70
12.17
Opus
0.75 cm3/l
5.23
26.94
5.25
25.30
Control
Untreated
Only water
4.12
0.00
4.19
0.00
LSD at 5%
1.10
0.76
Giza 2000
Blight stop
1 l/100 l
5.16
22.86
5.18
22.75
Black seeds oil
20 ml/l
4.98
18.57
5.02
18.96
Eucalyptus oil
20 ml/l
4.84
15.24
4.87
15.40
Thyme oil
20 ml/l
4.77
13.57
4.80
13.74
Opus
0.75 cm3/l
5.24
24.76
5.26
24.64
Control
Untreated
Only water
4.20
0.00
4.22
0.00
LSD at 5%
0.96
0.74
Mikhael Sherin & Ahmed, 2023
9
On the contrary, the thyme oil extract treatment
was the least effective. Provided data in Table
(7), indicate that all ecofriendly treatments i.e.
Blight-stop as a biocide, three natural oil
extracts - black seeds, thyme, and eucalyptus
oils, and the fungal pesticide Opus, when
sprayed at the recommended concentrations in
Table (2) on barley plants of Giza 123 and Giza
2000, increased total chlorophyll and carotenoids
(mg/g) as estimated the photosynthetic pigments
compared with control plants during the growing
seasons 2020/21 and 2021/22. The fungicide
Opus provided the highest level of total
chlorophyll and carotenoids (mg/g) in the
majority of cases, followed by biocide-Blight
stop. In contrast, thyme oil was the smallest
effectiveness. The results showed that
throughout the two research seasons, cultivar
Giza 123 of barley was more susceptible to the
powdery mildew disease and recorded in total
chlorophyll and carotenoids (mg/g) less than
cultivar Giza 2000.
Table 7: Effect of spraying different eco-friendly treatments and fungicide on total chlorophyll and carotenoids
(mg/g) of barley varieties Giza 123 and Giza 2000 under field conditions during growing two seasons
2021/2022 and 2021/2022.
Barley varieties
Treatments
Concentrations
Growing season 2020/2021
Growing season 2021/2022
Total chlorophyll (mg/g)
Carotenoids (mg/g)
Total chlorophyll (mg/g)
Carotenoids (mg/g)
a
b
a
b
Giza 123
Blight stop
1 l/100 l
3.1
3.0
2.9
3.2
3.1
3.0
Black seeds oil
20 ml/l
2.6
2.5
2.4
2.7
2.6
2.5
Eucalyptus oil
20 ml/l
2.3
2.2
2.1
2.4
2.3
2.1
Thyme oil
20 ml/l
1.7
1.6
1.5
1.7
1.6
2.0
Opus
0.75 cm3/l
3.2
3.1
3.0
3.3
3.2
3.1
Control
Untreated
Only water
1.3
1.2
0.9
1.3
1.0
1.1
LSD at 5%
0.42
0.24
0.23
0.22
0.27
0.25
Giza 2000
Blight stop
1 l/100 l
3.3
3.2
3.0
3.4
3.3
3.1
Black seeds oil
20 ml/l
2.7
2.6
2.5
2.8
2.7
2.5
Eucalyptus oil
20 ml/l
2.4
2.3
2.2
2.5
2.4
2.3
Thyme oil
20 ml/l
1.8
1.7
1.6
1.9
1.8
1.7
Opus
0.75 cm3/l
3.4
3.3
3.1
3.6
3.5
3.3
Control
Untreated
Only water
1.3
1.2
1.0
1.4
1.3
1.2
LSD at 5%
0.40
0.32
0.30
0.28
0.33
0.31
4. Discussion
The main idea of this research is to utilize the
techniques that are the most efficient and
environmentally friendly during a certain stage
of the farmed plant's development. The
environmentally friendly materials as
alternative of non-chemical control methods,
such as plant extract oils and biological
control, to be able to decrease the use of
chemical fungicides for controlling barley
powdery mildew to produce barley grains with
high quality and quantity without any toxicity
at the food chain, increasing the fertility of soil,
keeping the environment cleaning and
maintain the sustainability development over
the long term (Matyjaszczyk, 2015; Newton et
al., 2010). Obtained data and came to the
conclusion the use of biocide, plant oils as
Chemical inducers could be utilized as an
efficient and safe way to manage powdery
mildew disease of barley plants. The principle
of sustainable agriculture, which bases plant
protection on economic viability,
environmental friendliness, and social
acceptance, is to grow barley in a range of
mixtures. In light of this, modern systems of
cultivated plant protection should include any
viable techniques for fungus management. In
this case using twice spraying of eco-friendly
treatments such as Blight stop, thyme, and
Eucalyptus oils for controlling barley powdery
mildew, in addition compared with traditional
systemic Opus fungicide on barley seedlings
Mikhael Sherin & Ahmed, 2023
10
of the varieties Giza 123 and Giza 2000 under
greenhouse condition. Blight Stop
(Trichoderma harzianum) when used as a
foliar spray (10 ml/l) was the greatest
effectiveness in disease control of barley
powdery mildew, followed by black seeds oil.
On the contrary thyme oil with concentration
(20 ml/l) was the least impact one compared to
other treatments. Trichoderma species have the
ability to directly affect target fungi through
mycoparasitism, antibiosis, and competition as
their primary strategies for suppressing plant
pathogenic fungus (Ahmed, 2018). Although,
all the tested compounds clearly minimized the
mildewed area with varying degree of disease
severity percentage, prolonged both incubation
and latent periods which are considered the
main components of partial resistance (Wilson,
1994). The essential oils are rich bioactive
material such as antimicrobial and these
compounds are responsible for the aroma and
flavor characteristics which consider the most
effective inhibitors of the microbial growth
and having a good activity when direct
contacted with pathogens (Ahmed, 2013). To
put it another way, the foliar spray of Opus
(Epoxiconazole) which is among the systemic
fungicides under greenhouse conditions shows
that the disease was completely checked
compared to others. Field application to
evaluate the effectiveness of Blight-stop as a
biocide, three natural oil extracts: black seeds,
thyme and eucalyptus oils, as well as Opus as
chemical pesticide treatments against the
natural infection with powdery mildew on the
susceptible Egyptian barley varieties, field
experiments were conducted at Giza
Experimental Station, Agricultural Research
Centre (ARC), Egypt during the 2020/2021
and 2021/2022 growing seasons. The analyzed
of obtained data during the two seasons proved
in general that the use of different ecofriendly
treatment and fungicide resulted in a
significant reduction in disease severity
percentage, area under disease progress curve
(AUDPC) and average coefficient of infection
(ACI) compared to the control treatment. The
highest reduction was recorded by opus
fungicide followed by Blight stop biocide,
whereas thyme oil was recorded the lowest
disease protection compared with other
treatments. Although the ecofriendly
treatments proved less efficient at controlling
powdery mildew disease than the fungicides
under this investigation, they are less
persistent, thus being environmentally safer
for human than fungicides. Consequently, it's
crucial to pay more attention to basil and other
oils that are effective against the
microorganisms that cause powdery mildew as
safe and adequate alternative control measures
for the production of healthy and organic
foods (Hafez et al., 2014). In the light of the
routine and wide application of these
fungicides leave chemical residues in soil,
water and grains (Singh et al., 1996) and
subsequently may affects animal and human
health (Kúc, 1995). Due to its large amount of
residues fungicide pollution has become a
global environmental problem and found to be
highly toxic to aquatic organisms (Haque &
Oine, 2019). Control of powdery mildew in
this work went along with a sufficient increase
in grain yield components of the treated barley
plants (Giza 123 and Giza 2000) where there
was a direct relationship between the disease
infection and yield (Narelle & Piotr, 2021).
Additionally, the treatments were successful in
that they considerably boosted the yield
characteristics compared to the control (Hafez
et al., 2019). Presented data in this study,
indicate that all ecofriendly treatments and the
fungal pesticide increased total chlorophyll
and carotenoids (mg/g) as estimated the
photosynthetic pigments compared with
control treatment during the growing seasons
2020/2021 and 2021/2022. The fungicide
Opus provided the highest level of total
Mikhael Sherin & Ahmed, 2023
11
chlorophyll and carotenoids (mg/g) in the
majority of cases, followed by biocide-Blight
stop. In contrast, thyme oil was the smallest
effectiveness. This increase could be the result
of promoting pigment development, which
would increase the effectiveness of the
photosynthetic machinery and reduce in
phosphorylation rate that usually occur after
infection with greater probability of disease
resistance (Keutgen & Roeb, 1996). Moreover,
the application of some natural treatments was
found to increase potassium content, This
might multiply the amount of chloroplasts in
each cell or stimulate the production of
carotenoids, which guard chlorophyll against
oxidation.
5. Conclusion
The major goal of this investigation to assess
the efficiency of eco-friendly treatments i.e.,
biocide Blight stop, three natural oil extracts:
black seeds, thyme and eucalyptus oils, as well
as fungicide Opus in decreasing powdery
mildew infection on the susceptible Egyptian
barley varieties to assess the efficiency of were
conducted in the field conditions at Giza
Experimental Station, Agricultural Research
Centre (ARC), Egypt during the 2020/2021
and 2021/2022 growing seasons. All eco-
friendly treatments and fungicide reduced
diseases severity %, area under disease
progress curve (AUDPC) and average
coefficient of infection (ACI) compared to the
control treatment in the two seasons, in
addition increase the yield, total chlorophyll
and carotenoids compared to the control
treatment.
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