1
Journal of PhytoPathology and Disease Management
Print ISSN: 3009-6111 Online ISSN: 3009-6170
Volume 13, Issue 1, 2026, Article ID 20992838
Article
Impact of microbial biofertilizers on the growth, yield, fruit quality, and
biochemical characteristics of two sweet pepper (Capsicum annuum L.)
cultivars
Sara T. Ahmed 1 | Mohamed M. El-Sheikh Aly2 | Fouad A. El-Amary2
1Agricultural Botany Department, Faculty of Agriculture, Qena University, Qena, Egypt
2Agricultural Botany Department, Faculty of Agriculture, Al-Azhar University, Assiut, Egypt
DOI:
10.5281/zenodo.20992838
ARK:
ark:/24629/PPDJ.v13i1.271
Received:
16 February 2026
Accepted:
25 April 2026
Published online:
28 April 2026
Correspondence:
Mohamed M. El-Sheikh Aly
Agricultural Botany Department,
Faculty of Agriculture, Al-Azhar
University, Assiut, Egypt.
Email: drmohamedelsheikh4@gmail.com
This is an open-access article distributed
under the terms of the Creative Commons
Attribution-Non-Commercial-Share Alike 4.0
International License, which allows others to
remix, transform, and build upon the work
non-commercially, as long as the author is
credited and the new creations are licensed
under the identical terms.
Abstract:
Sweet pepper (Capsicum annuum L.) is a commercially essential vegetable crop globally,
valued for its nutritional content and economic returns. Due to the environmental
concerns associated with the excessive use of chemical fertilizers, there is a growing
necessity for sustainable agricultural alternatives. This study evaluated the effects of
three commercial biological formulations applied as foliar sprays: Bio-Arc (Bacillus
megaterium), Bio-Nagy (Trichoderma asperellum), and Bio-Zied (Trichoderma album).
The treatments were applied at concentrations of 1, 2, and 3 g L⁻¹ on two sweet pepper
cultivars ('Topy Star' and 'Madrid' hybrid) grown under field conditions across two
consecutive seasons (2023 and 2024). The application of these biofertilizers significantly
enhanced plant growth, fruit quality, and biochemical parameters compared to
untreated control. Specifically, Bio-Nagy at 3 g L⁻¹ produced the firmest fruits (8.19 and
8.10 kg cm⁻² in 'Topy Star' and 'Madrid', respectively) and the highest total sugar content
(35.34% and 37.44%). The 'Madrid' hybrid treated with Bio-Zied at 3 g L⁻¹ recorded the
highest total soluble solids (TSS) (8.07%) and vitamin C content (145.60 mg 100 g⁻¹ FW).
Furthermore, biochemical profiles, including chlorophyll and phenolic compounds,
exhibited substantial increases under all biological treatments. Vegetative parameters
such as fresh shoot weight and average fruit weight were also significantly improved,
with the 'Madrid' hybrid reaching an average fruit weight of 12.70 g under the Bio-Zied
(3 g L⁻¹) treatment. In conclusion, the foliar application of T. asperellum, T. album, and
B. megaterium meaningfully improves the physiological performance, yield, and
nutritional quality of sweet pepper. These findings strongly support the integration of
microbial biofertilizers as a viable, eco-friendly alternative to chemical fertilizers in
sustainable horticultural practices.
Keywords:
Sweet pepper, Capsicum annuum, biofertilizers, Trichoderma spp., Bacillus megaterium,
fruit quality, sustainable agriculture.
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
2 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
1. Introduction
Sweet pepper (Capsicum annuum L.), a member of the
Solanaceae family, is a globally prominent vegetable crop
highly valued for its economic importance and nutritional
benets, including high levels of ascorbic acid and
antioxidant compounds (Shahein et al., 2015). The increasing
global demand for this crop has traditionally been met
through the intensive application of chemical fertilizers.
However, the excessive use of these agrochemicals has raised
severe environmental and soil health concerns, necessitating
a shift toward sustainable agricultural practices (Jarecki et al.,
2025). Consequently, the integration of microbial
biofertilizers has emerged as a promising, eco-friendly
strategy to mitigate environmental damage while
maintaining or enhancing crop productivity (Prisa et al.,
2023). Biofertilizers, comprising live microorganisms such as
benecial fungi and bacteria, play a pivotal role in sustainable
agriculture by improving nutrient availability and root zone
dynamics. These microorganisms enhance plant nutrition
through mechanisms such as nitrogen xation, phosphorus
solubilization, and the synthesis of phytohormones, which
collectively improve soil structure and biological activity (Bai
et al., 2015; Timofeeva et al., 2023). Among the widely studied
fungal bio-agents, Trichoderma species are renowned for
their ability to stimulate plant development and confer stress
tolerance (Ahmad et al., 2015). Recent studies have
demonstrated that Trichoderma inoculation can signicantly
enhance morphological traits, pigment content, and the
accumulation of soluble sugars and proteins in various
vegetable crops (Lian et al., 2023; Zhang et al., 2024).
Furthermore, Trichoderma-based biofertilizers have been
reported to increase the activity of benecial enzymes, such
as peroxidase and invertase, thereby improving soil nutrient
supply and crop performance (Yan et al., 2020). Similarly,
plant growth-promoting bacteria (PGPB), particularly the
genus Bacillus, are extensively utilized in agricultural
ecosystems (Sansinenea, 2019). Bacillus species improve
physiological crop characteristics and yield through various
mechanisms of action, potentially reducing the required
dosage of chemical fertilizers by up to 50% without
compromising plant performance (Sales & Rigobelo, 2024).
Despite the proven individual benets of Trichoderma and
Bacillus species, comparative eld studies evaluating their
ecacy specically as foliar bio-stimulants across dierent
commercial sweet pepper cultivars remain limited.
Therefore, the present study aims to evaluate and compare
the eects of foliar applications of Trichoderma asperellum,
Trichoderma album, and Bacillus megaterium on the
vegetative growth, yield parameters, and biochemical proles
(including fruit quality, sugars, and antioxidant content) of
two sweet pepper cultivars ('Topy Star' cv. and 'Madrid'
hybrid) under eld conditions.
2. Materials and Methods
2.1 Plant material and experimental site
Field experiments were conducted at the Experimental Farm
of the Faculty of Agriculture, Al-Azhar University, Assiut,
Egypt, during two consecutive growing seasons (2023 and
2024). This study evaluated the eects of selected microbial
biostimulants on the vegetative growth, yield, fruit quality,
and biochemical composition of sweet pepper (Capsicum
annuum L.). Two commercial cultivars were used: 'Topy Star'
cv. and 'Madrid' hybrid. Seeds of both cultivars were supplied
by Kanza Group Company for Seeds, Fertilizers, and
Chemical Fungicides, Giza, Egypt. The soil texture was clay
loam, and the plants were irrigated regularly.
2.2 Experimental design and bio-treatments
The experiment was laid out in a Randomized Complete
Block Design (RCBD) with three replicates. Each replicate
plot consisted of six plants. A total of 10 experimental
treatments were evaluated, comprising an untreated control
(sprayed with tap water) and three commercial biofertilizers
applied at three dierent concentrations (1, 2, and 3 g L⁻¹).
The biofertilizers used were:
• Bio-Arc: containing Bacillus megaterium.
• Bio-Nagy: containing Trichoderma asperellum.
• Bio-Zied: containing Trichoderma album.
All treatments were applied as foliar sprays. The rst
application was performed 30 days after transplanting,
followed by two additional sprays at 15-day intervals.
2.3 Measurements and analysis
2.3.1 Vegetative growth and yield characteristics
Three plants from each plot were randomly sampled at 45, 60,
and 75 days after transplanting to determine vegetative
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
3 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
growth parameters.
• Plant height (cm): Measured from the soil surface to
the plant apex.
• Stem diameter (cm): Measured using a digital
vernier caliper.
• Plant fresh and dry weight (g): Roots, stems, and
leaves were cleaned and weighed using an analytical
balance to determine fresh weight. The plant
samples were then oven-dried at 80°C until a
constant weight was reached to record the dry
weight.
• Yield parameters: Total yield per plant (g) and total
number of fruits per plant were determined by
cumulating the weekly harvested fruits. Average fruit
weight (g) was calculated by dividing the total fruit
weight by the total number of fruits per plant.
2.3.2 Fruit quality and biochemical characteristics
Pepper fruits were harvested every 15 days during the
production season for the following analyses:
• Fruit rmness (kg cm⁻²): Measured at four equatorial
points using a handheld texture analyzer (Axis
FB200, Poland).
• Total soluble solids (TSS, %): Determined using a
digital refractometer (Milwaukee MA871, USA).
• Titratable acidity (TA, %): Determined by titrating
the fruit juice ltrate with 0.1 N NaOH using
phenolphthalein as an indicator, and expressed as
malic acid percentage (La et al., 2021).
• Vitamin C (Ascorbic acid): Quantied using the 2,6-
dichlorophenol indophenol dye titration method
following homogenization in 3% metaphosphoric
acid (AOAC, 1990).
• Chlorophyll content: Chlorophyll a and b were
extracted using acetone, and optical density was
measured at 663 and 645 nm using a
spectrophotometer (Arnon, 1949; Holden, 1965).
• Phenolic compounds: Total and free phenols were
determined calorimetrically using the Folin–
Ciocalteu reagent (Snell & Snell, 1953). Conjugated
phenols were calculated as the dierence between
total and free phenols.
• Sugars: Total and reducing sugars were quantied
using the picric acid reduction method, with
absorbance measured at 540 nm (Thomas and
Dutcher, 1924). Non-reducing sugars were calculated
as the dierence between total and reducing sugars.
2.4 Statistical analysis
All data obtained from the eld experiments were subjected
to analysis of variance (ANOVA) appropriate for a
Randomized Complete Block Design (RCBD). The statistical
analysis was performed using CoStat software, version 6.4.
Mean comparisons among treatments were performed using
Fisher’s Least Signicant Dierence (LSD) test at a
probability level of 𝑃 ≤ 0.05. Results were expressed as
means, and values sharing the same alphabetical letters
within each column are not signicantly dierent.
3. Results and Discussion
3.1 Fruit quality and ascorbic acid (Vitamin C) content
The data presented in Table (1) demonstrate that the foliar
application of microbial biostimulants signicantly (𝑃 ≤
0.05) enhanced fruit rmness, total soluble solids (TSS),
titratable acidity, and vitamin C content in both sweet pepper
cultivars compared to the untreated control. Regarding fruit
rmness, the 'Madrid' hybrid and 'Topy Star' cultivar
exhibited their maximum signicant values when treated
with Bio-Nagy (Trichoderma asperellum) at 3 g L⁻¹, recording
8.10 and 8.19 kg cm⁻², respectively, at 60 days post-
transplanting. This enhancement in structural integrity is
likely attributed to improved calcium uptake and the
strengthening of cell wall polysaccharides induced by
Trichoderma inoculation, which delays fruit softening
(Harman et al., 2021; Kumar et al., 2022). Similarly, TSS and
titratable acidity were positively modulated by the biological
treatments. The 'Madrid' hybrid achieved its highest TSS
peak (8.07%) with Bio-Zied (Trichoderma album) at 3 g L⁻¹
(75 days), while 'Topy Star' responded earlier, peaking at
6.75% with Bio-Nagy at 2 g L⁻¹ after 45 days. Ascorbic acid
(Vitamin C) levels also exhibited a robust increase under
microbial treatments. The Bio-Zied treatment (3 g L⁻¹)
yielded the highest vitamin C content in the 'Madrid' hybrid
(145.60 mg 100 g⁻¹ FW), whereas 'Topy Star' responded
optimally to Bio-Arc (Bacillus megaterium) at 3 g L⁻¹ (102.34
mg 100 g⁻¹ FW). These genotype-specic responses highlight
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
4 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
the dierential mechanisms of plant growth-promoting
rhizobacteria (PGPR) and fungi in stimulating antioxidant
defense pathways and carbohydrate partitioning, consistent
with the ndings of Su et al. (2024).
Table 1: Effect of foliar biofertilizers on fruit firmness, total soluble solids (TSS), titratable acidity, and vitamin C
of two sweet pepper cultivars ('Topy Star' cv. and 'Madrid' hybrid) at 45, 60, and 75 days post-transplanting.
Bio-treatments
Conc.
(g L⁻¹)
Topy Star cv.
Madrid hybrid
Periods
(days)
Firmness
(kg cm⁻²)
TSS
)%(
Titratable acidity
(%)
Vitamin C
(mg 100g⁻¹)
Firmness
(kg cm⁻²)
TSS
(%)
Titratable acidity
(%)
Vitamin C
(mg 100g⁻¹)
Bio-Arc
1
45
4.74
4.43
0.22
35.83
5.2
4.67
0.38
28.25
60
5.29
4.78
0.2
39.39
4.79
5.63
0.9
37.15
75
4.4
4.2
0.17
44.87
4.15
6.33
1.23
112.5
2
45
5.89
3.48
0.26
60.37
5.65
5.57
1.3
44.45
60
6.25
3.65
0.26
82.65
5.15
5.6
1.6
99.71
75
4.5
3.55
0.13
94.59
4.73
6
1.1
127.54
3
45
6.39
4.55
0.35
79.1
7.85
5.23
1.1
47.15
60
6.48
5.08
0.28
89.11
7.53
5.36
0.73
95.07
75
5.89
4.13
0.19
102.34
5.38
5.7
0.7
123.48
Bio-Nagy
1
45
4.78
5.05
0.28
48.1
4.53
4.7
0.97
72.27
60
5.3
4.9
0.23
63.6
5.7
5.3
1.67
84.25
75
4.36
4.18
0.17
72.64
5.36
5.87
2.03
90.44
2
45
4.94
6.75
0.3
52.52
6.24
6.57
1.1
74.97
60
6.18
4.48
0.25
67.15
6.7
6.83
0.8
78.84
75
4.41
4.43
0.2
74.58
5.44
7.2
0.8
85.03
3
45
5.68
4.05
0.33
68.44
8.1
4.63
1.57
73.81
60
8.19
4.7
0.31
72.96
7.76
4.7
1.4
77.29
75
5.44
3.55
0.28
76.51
6.25
4.9
1
78.26
Bio-Zied
1
45
4.28
5.95
0.22
41.97
3.64
5.4
1.4
61.84
60
4.61
4.63
0.17
47.78
4.95
6.77
2.13
67.25
75
4.14
4.15
0.16
51.98
3.56
7.57
2.6
87.35
2
45
4.64
5.6
0.24
53.27
3.73
5.13
0.93
86.19
60
4.61
4.3
0.19
68.77
5.79
6.8
1.63
92.36
75
4.18
4.1
0.12
80.06
4.65
7.63
2.07
102.3
3
45
5.23
5.05
0.29
79.1
4.23
4.57
0.93
123.67
60
5.3
4.1
0.24
81.03
6.88
6.87
1.37
129.47
75
4.73
3.45
0.16
84.26
4.75
8.07
1.97
145.6
Control
_
45
4.28
4.8
0.21
46.17
5.83
4.8
0.8
27.44
60
4.29
4.8
0.19
51.65
5.3
5.5
0.93
46.77
75
3.13
3.08
0.13
54.56
3.96
6.27
1.03
52.1
3.2 Sugar accumulation and phenolic proles
As shown in Table (2), carbohydrate and phenolic compound
proles were signicantly modied by the bio-treatments.
Bio-Nagy (T. asperellum) at 3 g L⁻¹ recorded the highest total
sugar accumulation in both the 'Madrid' hybrid (37.44%) and
the 'Topy Star' cultivar (35.34%) (Figure 1). Interestingly, the
treatments exerted distinct eects on sugar fractions. The
highest non-reducing sugar content in 'Madrid' was induced
by Bio-Arc at 2 g L⁻¹ (6.65%), whereas in 'Topy Star', it was
maximized by Bio-Zied at 2 g L⁻¹ (9.35%). This divergence
indicates that specic microbial strains dierentially regulate
sucrose accumulation and hydrolysis pathways (Backer et al.,
2018). Phenolic compounds, which are crucial for stress
tolerance and nutritional value, increased signicantly across
all treatments. In the 'Madrid' hybrid, total phenols peaked
with Bio-Arc at 3 g L⁻¹ (6.25 mg g⁻¹), while Bio-Nagy at 3 g L⁻¹
yielded the highest total phenols (5.25 mg g⁻¹) in 'Topy Star'.
The observed shift between active (free) and reserve
(conjugated) phenolic pools under dierent microbial
applications suggests the activation of induced systemic
resistance (ISR) pathways, an established plant response to
benecial Trichoderma colonization (Shoresh et al., 2010).
3.3 Photosynthetic pigments (Chlorophyll a and b)
Foliar bio-treatments signicantly (𝑃 ≤ 0.05) augmented
chlorophyll accumulation in both pepper genotypes
compared to the untreated control (Table 3). The 'Madrid'
hybrid treated with Bio-Nagy at 3 g L⁻¹ registered the
maximum values for chlorophyll a, b, and total chlorophyll
(2.89, 4.58, and 7.98 mg g⁻¹ FW, respectively). Conversely,
the 'Topy Star' cultivar demonstrated its highest total
chlorophyll content (15.02 mg g⁻¹ FW) under the Bio-Zied
treatment at 3 g L⁻¹. The substantial increase in
photosynthetic pigments can be mechanistically linked to
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
5 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
the microbial enhancement of root architecture, which
facilitates greater uptake of essential structural elements like
nitrogen and magnesium. Furthermore, Bacillus and
Trichoderma species are known to delay chlorophyll
degradation by minimizing oxidative stress within
chloroplasts (Harman et al., 2021).
Table 2: Effect of different bio-treatments on sugar content and phenolic compounds of sweet pepper ('Topy Star' cv. and 'Madrid'
hybrid) under field conditions.
Bio-treatments
Conc.
(g L⁻¹)
'Topy Star' cv.
'Madrid' hybrid
Total Sugar
(%)
Reducing
Sugar
Non-reducing
Sugar
Total Phenols
(mg g⁻¹)
Free
Phenols
Conjugated
Phenols
Total Sugar
(%)
Reducing
Sugar
Non-reducing
Sugar
Total Phenols
(mg g⁻¹)
Free
Phenols
Conjugated
Phenols
Bio-Arc
1
11.24
7.33
3.91
3.25
2.75
0.5
14.1
12.8
1.3
3.85
3.15
0.7
2
12.04
10.6
1.44
4.07
2.96
1.11
18.25
11.6
6.65
4.45
3.8
0.65
3
16.86
15.18
1.68
4.44
3.11
1.33
22.3
16.65
5.65
6.25
5.1
1.15
Bio-Nagy
1
16.67
15.18
1.49
3.63
2.44
1.19
18.47
16.6
1.87
4.63
2.98
1.65
2
23.3
21.68
1.62
4.1
2.67
1.43
24.2
22.33
1.87
4.88
3.09
1.79
3
35.34
28.19
7.15
5.25
2.77
2.48
37.44
34.18
3.26
4.98
3.76
1.22
Bio-Zied
1
19.27
10.4
8.87
4.47
2.44
2.03
23.22
21.4
1.82
5.67
4.15
1.52
2
24.09
14.74
9.35
4.68
3.7
0.98
27.1
24.74
2.36
5.74
4.55
1.19
3
26.07
17.34
8.73
5.22
3.77
1.45
29.95
26.1
3.85
6.08
5.45
0.63
Control
—
15.09
11.25
3.84
3.35
2.6
1.25
16.7
12.8
3.9
4.4
3.11
1.29
Figure 1: Comparative effect of different bio-treatments and concentrations on total sugar content (%)
of Madrid hybrid and Topy star cultivar of sweet pepper under field conditions.
Table 3: Evaluation of different bio-treatments on photosynthetic pigments (chlorophyll a, b,
and total) of sweet pepper ('Topy Star' cv. and 'Madrid' hybrid) at 60 and 75 days.
Bio-treatments
Conc.
(g L⁻¹)
'Topy Star' cv.
'Madrid' hybrid
Chl A
Chl B
Total (A+B)
Chl A
Chl B
Total (A+B)
Bio-Arc
1
3.00
6.13
9.37
4.41
3.36
7.94
2
3.76
6.76
10.79
6.44
3.61
10.24
3
4.46
6.94
11.69
6.95
3.84
11.00
Bio-Nagy
1
4.11
8.61
13.05
4.87
3.69
8.74
2
4.26
8.63
13.22
7.34
4.00
11.65
3
5.41
9.10
14.88
7.42
4.18
11.75
Bio-Zied
1
3.08
5.91
9.22
7.07
4.08
11.38
2
3.27
6.36
9.88
7.55
4.11
11.88
3
3.67
6.67
10.61
8.80
5.92
15.02
Control
—
7.58
11.05
19.09
4.16
2.53
6.83
3.4 Vegetative growth, root biomass, and yield characteristics
Data summarized in Tables (4 and 5) reveal that microbial
inoculants signicantly promoted plant vegetative vigor and
overall yield compared to the control. The tallest plants in the
'Madrid' hybrid were observed under the Bio-Arc (B.
megaterium) treatment at 3 g L⁻¹ (80.67 cm), whereas Bio-
Nagy (3 g L⁻¹) produced the tallest 'Topy Star' plants. Stem
diameter followed a similar positive trend across both
genotypes. Biomass accumulation (shoot and root fresh/dry
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
6 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
weights) and yield traits were markedly superior under the
bio-treatments. Notably, Bio-Zied (T. album) at 3 g L⁻¹
recorded the highest fresh shoot weight (26.22 g) and average
fruit weight (12.70 g) in the 'Madrid' hybrid. In 'Topy Star', the
same treatment maximized fresh shoot weight (80.06 g) and
average fruit weight (6.62 g). Meanwhile, root dry biomass
was optimally enhanced by Bio-Nagy (3 g L⁻¹) in both
genotypes.
Table 4: Effect of different bio-treatments on vegetative growth and yield characteristics of the sweet pepper Madrid hybrid
under field conditions.
Bio-
treatments
Conc.
(g L⁻¹)
Madrid hybrid
Plant Height (cm)
Stem Diameter (cm)
Fresh Shoot Weight (g)
Dry Shoot Weight (g)
Fresh Root Weight (g)
Dry Root Weight (g)
Average Fruit Weight (g)
Bio-Arc
1
67.33
0.97
14.33
8.92
9.77
6.17
8.56
2
69.50
1.08
17.33
10.15
9.97
7.48
9.51
3
80.67
1.45
20.17
10.64
10.91
7.32
10.25
Bio-Nagy
1
62.67
0.90
22.19
10.63
10.38
5.15
9.90
2
67.00
1.15
23.83
12.82
10.93
5.60
10.15
3
73.33
1.74
25.22
13.12
11.80
6.27
12.13
Bio-Zied
1
57.00
0.86
19.35
9.61
9.17
4.11
10.17
2
62.83
1.10
21.55
10.68
10.98
4.70
11.05
3
72.50
1.40
26.22
11.02
12.00
5.95
12.70
Control
—
51.67
0.93
19.15
7.35
10.83
3.18
8.07
LSD 5%
T
3.84
N.S
0.84
1.26
0.09
0.56
0.89
C
4.66
0.11
0.70
0.76
0.42
0.59
0.63
T × C
N.S
N.S
1.21
N.S
0.72
1.01
N.S
Table 5: Effect of different bio-treatments on vegetative growth and yield characteristics of the sweet pepper 'Topy Star' cultivar
under field conditions.
Bio-
treatments
Conc.
(g L⁻¹)
Topy Star cv.
Plant Height (cm)
Stem Diameter (cm)
Fresh Shoot Weight (g)
Dry Shoot Weight (g)
Fresh Root Weight (g)
Dry Root Weight (g)
Average Fruit Weight (g)
Bio-Arc
1
27.58
4.00
45.70
18.43
1.54
0.56
4.51
2
31.50
4.35
49.89
19.11
1.74
0.81
4.63
3
33.75
4.60
56.62
20.04
1.92
0.96
4.97
Bio-Nagy
1
31.33
4.77
58.38
24.52
2.63
1.42
4.47
2
34.70
4.90
60.85
25.51
2.75
1.62
5.00
3
37.33
5.27
73.01
25.76
2.86
1.69
5.23
Bio-Zied
1
28.75
4.63
66.06
20.67
2.28
0.67
4.65
2
30.92
4.73
70.08
20.75
2.14
0.88
5.70
3
33.17
5.35
80.06
27.74
2.41
1.04
6.62
Control
—
24.25
3.87
26.69
10.58
1.29
0.61
5.89
LSD 5%
T
N.S
0.16
7.26
1.59
0.395
0.06
N.S
C
1.49
0.17
3.19
1.40
0.166
0.065
0.619
T × C
N.S
0.30
5.53
2.42
0.287
0.112
N.S
These substantial increments in growth and yield parameters
can be biologically attributed to the capacity of the applied
bio-agents to synthesize phytohormones (such as auxins,
gibberellins, and cytokinins) and to improve nutrient
solubilization. Enhanced root growth, explicitly stimulated
by these metabolites, improves water and nutrient
acquisition eciency, which directly translates into
heightened photosynthetic activity, greater assimilate
translocation to developing fruits, and ultimately, a
signicantly higher yield (Erturk et al., 2010; Olanrewaju et
al., 2017).
4. Conclusion
The present study substantiates the ecacy of foliar-applied
microbial biostimulants as a sustainable, eco-friendly
alternative to conventional agrochemicals in sweet pepper
cultivation. Our ndings explicitly demonstrate that the
foliar application of Trichoderma asperellum (Bio-Nagy),
Trichoderma album (Bio-Zied), and Bacillus megaterium
(Bio-Arc) signicantly enhances vegetative vigor, overall
yield, and critical fruit quality parameters, including ascorbic
acid, total sugars, and phenolic compounds. Importantly, the
study highlights distinct genotype-specic responses; the
'Madrid' hybrid exhibited optimal biomass and yield traits
under the T. album treatment (3 g L⁻¹), whereas T. asperellum
(3 g L⁻¹) maximized structural rmness and carbohydrate
accumulation across both investigated cultivars. Integrating
these specic microbial formulations into standard
horticultural management practices oers a viable strategy to
improve crop physiological performance while substantially
mitigating the environmental footprint associated with
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
7 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
excessive chemical fertilization. Future research should focus
on unraveling the underlying molecular mechanisms driving
these specic genotype-microbe interactions and evaluating
the eld ecacy of these biostimulants under varying abiotic
stress conditions.
Declarations
Funding Information: The authors received no external
funding for this article.
Conicts of Interest: The authors declare that they have no
known competing financial interests or personal relationships
that could have inuenced the work reported in this paper.
Ethics Approval and Consent to Participate: Not applicable.
This research did not involve human participants or animal
subjects.
Consent for Publication: Not applicable.
Data Availability Statement: The data that support the
ndings of this study are available from the corresponding
author upon reasonable request.
Declaration of Generative AI and AI-assisted Technologies:
The authors conrm that they have not used any articial
intelligence (AI) tools or technologies for the generation of
text, images, or data in the preparation of this manuscript.
CRediT Authorship Contribution Statement: All authors,
Sara T. Ahmed, Mohamed M. El-Sheikh Aly, and Fouad A. El-
Amary, contributed equally to this work. They jointly
collaborated on the study’s conceptualization and
methodology. All three authors performed the investigation,
data curation, and formal analysis, co-wrote the original
draft, and participated in the critical review, editing, and nal
approval of the published version.
Acknowledgment: Not applicable.
References
Ahmad, P., Hashem, A., Abd-Allah, E. F., Alqarawi, A. A.,
John, R., Egamberdieva, D., & Gucel, S. (2015). Role of
Trichoderma harzianum in alleviation of NaCl stress in
Indian mustard (Brassica juncea L.) by modulating
antioxidative defense and osmolyte accumulation.
Frontiers in Plant Science, 6, 868.
AOAC. (1990). Ocial Methods of Analysis of the Association
of Ocial Analytical Chemists (15th ed.). Association of
Ocial Analytical Chemists, Washington, DC, USA. 🔗
Arnon, D. I. (1949). Copper enzymes in isolated chloroplasts:
Polyphenoloxidase in Beta vulgaris. Plant Physiology,
24(1), 1–15.
Backer, R., Rokem, J. S., Ilangumaran, G., Lamont, J.,
Praslickova, D., Ricci, E., Subramanian, S., & Smith, D. L.
(2018). Plant growth-promoting rhizobacteria: Context,
mechanisms of action, and roadmaps to
commercialization of biostimulants for sustainable
agriculture. Frontiers in Plant Science, 9, 1473.
Bai, Y., Müller, D. B., Srinivas, G., Garrido-Oter, R., Pottho,
E., Rott, M., Dombrowski, N., Münch, P. C., Spaepen, S.,
Remus-Emsermann, M., & Schulze-Lefert, P. (2015).
Functional overlap of the Arabidopsis leaf and root
microbiota. Nature, 528, 364–369.
Erturk, Y., Ercisli, S., Haznedar, A., & Cakmakci, R. (2010).
Eects of plant growth promoting rhizobacteria on
rooting and root growth of kiwifruit. Biological Research,
43(1), 91–98.
Harman, G. E., Doni, F., Khadka, R. B., & Upho, N. (2021).
Endophytic strains of Trichoderma increase plants’
photosynthetic capability. Journal of Applied Microbiology,
130(3), 529–546.
Holden, M. (1965). Chlorophylls. In T. W. Goodwin (Ed.),
Chemistry and Biochemistry of Plant Pigments (pp. 461–
488). Academic Press. 🔗
Jarecki, W., Balawejder, M., & Matłok, N. (2025). Sustainable
fertilization management: Consequences to horticultural
crops. Horticulturae, 11(9), 1049.
Kumar, A., Patel, J. S., Meena, V. S., & Srivastava, R. (2022).
Recent advances of PGPR based approaches for stress
tolerance in plants for sustainable agriculture. Biocatalysis
and Agricultural Biotechnology, 43, 102405.
La, D. D., Nguyen-Tri, P., Le, K. H., Nguyen, P. T. M., Nguyen,
M. D.-B., Vo, A. T. K., Nguyen, M. T. H., Chang, S. W.,
Article | Ahmed et al. | Impact of biofertilizers on sweet pepper cultivars
8 | Journal of PhytoPathology and Disease Management | Vol. 13, No. 1 | Article ID 20992838
Tran, L. D., Chung, W. J., & Nguyen, D. D. (2021). Eects
of antibacterial ZnO nanoparticles on the performance
of a chitosan/gum arabic edible coating for post-harvest
banana preservation. Progress in Organic Coatings, 151,
106057.
Lian, H., Li, R., Ma, G., Zhao, Z., Zhang, T., & Li, M. (2023).
The eect of Trichoderma harzianum agents on
physiological-biochemical characteristics of cucumber
and the control eect against Fusarium wilt. Scientic
Reports, 13, 17606.
Olanrewaju, O. S., Glick, B. R., & Babalola, O. O. (2017).
Mechanisms of action of plant growth promoting
bacteria. World Journal of Microbiology and
Biotechnology, 33, 197.
Prisa, D., Fresco, R., & Spagnuolo, D. (2023). Microbial
biofertilisers in plant production and resistance: A
review. Agriculture, 13(9), 1666.
Sales, L. R., & Rigobelo, E. C. (2024). The role of Bacillus sp.
in reducing chemical inputs for sustainable crop
production. Agronomy, 14(11), 2723.
Sansinenea, E. (2019). Bacillus spp.: As Plant Growth-
Promoting Bacteria. In: Singh, H., Keswani, C., Reddy,
M., Sansinenea, E., García-Estrada, C. (eds) Secondary
Metabolites of Plant Growth Promoting
Rhizomicroorganisms. Springer, Singapore.
Shahein, M., Hassan, H., & Abou-El-Hassan, S. (2015).
Response of sweet pepper plants to fertilize by dierent
organic fertilizers under protected agriculture. Journal of
Plant Production, 6(5), 809-822.
Shoresh, M., Harman, G. E., & Mastouri, F. (2010). Induced
systemic resistance and plant responses to fungal
biocontrol agents. Annual Review of Phytopathology, 48,
21–43.
Snell, F. D., & Snell, C. T. (1953). Colorimetric methods of
analysis, including some turbidimetric and nephelometric
methods (Vol. 3). D. Van Nostrand Company. 🔗
Su, F., Zhao, B., Dhondt-Cordelier, S., & Vaillant-Gaveau, N.
(2024). Plant-growth-promoting rhizobacteria modulate
carbohydrate metabolism in connection with host plant
defense mechanism. International Journal of Molecular
Sciences, 25(3), 1465.
Thomas, W., & Dutcher, R. A. (1924). The colorimetric
determination of carbohydrates in plants by the picric
acid reduction method I. The estimation of reducing
sugars and sucrose. Journal of the American Chemical
Society, 46(7), 1662–1669.
Timofeeva, A. M., Galyamova, M. R., & Sedykh, S. E. (2023).
Plant growth-promoting soil bacteria: Nitrogen xation,
phosphate solubilization, siderophore production, and
other biological activities. Plants, 12(24), 4074.
Yan, X., Shi, F., Xu, Z., Sun, J., Wang, W., & Chen, W. (2020).
Growth promotion of peppers (Capsicum annuum L.) by
Trichoderma guizhouense NJAU 4742 and its ecient
colonization ability and biocontrol activity.
Microorganisms, 8(9), 1296.
Zhang, T., Jian, Q., Yao, X., Guan, L., Li, L., Liu, F., Zhang, C.,
Li, D., Tang, H., & Lu, L. (2024). Plant growth-promoting
rhizobacteria (PGPR) improve the growth and quality of
several crops. Heliyon, 10(10), e31553.
