Journal of Phytopathology and Pest Management 8(1): 46-63, 2021
pISSN: 2356-8577 eISSN: 2356-6507
Journal homepage: http://ppmj.net/
∗
Corresponding author:
Mohamed A. Abd-Elaziz,
E-mail: mohamedhassan.5419@azhar.edu.eg
46
Copyright © 2021
Biological control of some garlic diseases using
antagonistic fungi and bacteria
Mohamed A. Abd-Elaziz
*
, Mohamed M. El-Sheikh Aly, Abd-Elal A. Mohamed
Agricultural Botany Department, Faculty of Agriculture, Al-Azhar University, 71524 Assiut, Egypt
Abstract
Keywords: garlic, rhizobacteria, biofungicides, biofertilizers, Trichoderma.
Eight Trichoderma isolates which isolated from rhizospher of garlic plant and one isolte
T. asperellum was obtained on PDA medium, from the commercial product (Biocontrol
T34). Also eleven isolates of rhizobacteria namly; B. subtilis, two isolates (Bs1 and Bs2),
B.megaterium two isolates (Bm1and Bm2), P. fluorescens two isolates (Pf1 and Pf2), four
isolates A. chroococcum (Az1, Az2, Az3 and Az4) and Penibacillus polymyxa one isolate
were tested in vitro to study thir ability against S. ceprivorum , F. oxysporum f. sp. cepae
and P. terrestris which caused white rot, basal rot and pink rot of garlic plants,
respectively. The results showed that Trichoderma isolate number (T3) gave the highest
reduction on maycelial growth of three pathogenic fungi, which adentified as
Trichoderma harzianum, followed T. asperellum (T34), then isolate (T5) and isolate (T7).
which adentified as Trichoderma harzianum and Trichoderma hamatum, respectively.
Pseudomonas. fluorescens isolate (Pf1), followed by P. fluorescens (Pf2), B. subtilis (Bs2),
A. chroococcum (Az4) and B. subtilis (Bs1), then A. chroococcum (Az2), B. megaterium
(Bm2) and Penibacillus polymyxa gave highly antagonistic effect was clear against the
tested fungi respectively. A pot experiment was crried out under greenhouse conditions
to evaluate the efficacy of commercial biofungicides
biozeid , Bio-Arc, Plant Guard, T34
biocontrol and Rhizo-N, and biofertilizers Nitrobien, phosphoren, Biogen, Potassiumag,
Ascobein and carialin were evaluated individually against garlic white rot, basal rot and
pink rot diseases. Data showed that treated soil with biofungicides and biofertilizers
reduced white rot, basal rot and pink rot diseases compared with the control. Treated
soil with Rhizo-N, T34 biocontrol, Phosphoren and Nitrobien gave the best reduction of
disease severity throughout two successive growing seasons.
Abd-Elaziz et al., 2021
47
1. Introduction
Garlic (
Allium sativum
L.) is one of the
most important bulb vegetable crops and
is next to onion (
Allium
cepa)
in
importance (Hamma et al., 2013). It is
commonly used as a spice or in the
medicinal purposes. In Egypt,
it has been
generally cultivated for both local
consumption and export. Garlic is
affected by several fungal diseases, with
the most important being white rot
(
Sclerotium
ceprivorum
), Fusarium basal
rot (
Fusarium oxysporum
f.sp. cepae),
pink root rot (
Pyrenocheta terrestris
),
rust (
Puccinia allii
) and leaf blight
(
Stemphylium
spp.) (Laura et al., 2017).
White rot of garlic and onion, caused by
the soilborne fungi
Sclerotium cepivorum
Berk, is a continuing concern for
worldwide garlic production. An
inoculum density with few soil sclerotia
in a litter of field soil can result in great
crop losses (Davis et al. 2007). White rot
pathogen survives in the soil in the
absence of
Allium
crops as a dormant
small, round and poppy-seed-sized black
sclerotia on plant debris for more than 20
years (Entwistle, 1990).
Sclerotium
cepivorum
is widely distributed in Egypt
causing white rot of onions and garlic
(Embaby, 2003). According to the
pathogen properties control of white rot
disease is difficult (Crowe et al., 1993).
Among these, basal rot caused by
Fusarium oxysporum
f. sp.
cepae
Snyder
and Hansen is an economically important
and widespread disease in onion, garlic
and a number of other Allium species,
such as chive and shallot and causes
significant yield losses in all the growing
areas of the world (Behrani
et al.
2015;
Coskuntuna and Ozer 2008). Pink root rot
is one of the most important diseases that
attack cultivated
Allium
spp. Pink root rot
disease caused by
Pyrenochaeta terrestris
has been reported as a serious disease to
garlic in Egypt (Shalaby et al., 2002).
Pink root pathogen is soil-borne fungus,
which remains viable in the soil for many
years (Rengwalska and Simon, 1986).
Roots infected by
P. terrestris
turn pink
initially and then become brittle and die.
Although
P. terrestris
can be present in
roots, it does not invade the basal plate or
stem of the bulb (Coleman and
Ellerbrock, 1997). Crop rotation,
solarization, fumigation and chemical
fungicides are the most common methods
for controlling soil-borne diseases (Porter
et al., 1989).
Despite the fact that the
utilization of fungicides gave satisfactory
control against plant diseases, they could
accumulate hazardous toxic compounds
which pose threat to human life and the
surrounding environment. Pathogens are
additionally found to develop resistance
against several fungicides (Deising et al.,
2008). The other suggested control
methods are including application of
biological control. Several fungal and
bacterial antagonists have proved to
control different plant pathogenic fungi
(Blaszczyk, 2014).
The best results to
control white rot of onion and garlic
recorded by using
Trichoderma
harzianum, T. Koningii, T. asperellum,
Talaromyces flavus
and
Bacillus subtilis
(Mahdizadehnaraghi
et al.,
2015;
Shalaby
et al.
2013).
El-Meneisy Afaf
(2019) found that
Bacillus subtilis,
Bacillus amyloliquefacienes
and
Bacillus
velezensis
were the most effective
isolates to reduce
S. cepivorum
growth
in
vitro
and significant reduction of disease
index in pots experiment. Biological
control of Fusarium basal rot by
inoculation of antagonistic fungi and
bacteria such as
Trichoderma
and
Pseudomonas
has been considered as an
alternative approach to chemical control
(Coskuntuna and Ozer, 2008; Rajendran,
1996).
Pseudomonas fluorescens and T.
viride
exhibited the highest disease
reduction, i.e. 69.5 and 61.8%, followed
by 53.8, and 53.7% induced by
B. subtilis
Abd-Elaziz et al., 2021
48
and T. harzianum,
respectively of basal
rot infection of onion (El-Mougy Nehal
and Mokhtar, 2019). Four isolates of
Bacillus subtilis
exhibited the highest
antagonistic effect against
F. oxysporum
f. sp.
cepae
during
in vitro
testing up to
71% and caused a significant suppression
of garlic basal rot infection up to 58%
(Dragana et al., 2018). Microbial
antagonists as a bioagents are considered
a suitable ecologically way to substitute
chemical fungicides. This study aimed to
use an effective and safe method for
control white rot, basal rot and pink rot of
garlic as an alternative method instead of
using a harmful chemical fungicide.
Materials and methods
2.1 Isolation and identification of the
causal pathogens
Samples of garlic plants showing white
rot, basal rot and pink root rot symptoms
were collected from different farms in
Minia, Assiut, Sohag and Qena
governorates, Egypt.
Sclerotium
cepivorum
was isolated from sclerotia
formed on the surface of garlic bulbs
according to the methods of Clarkson et
al
.
(2002). The sclerotia were disinfected
in 70% ethyl alcohol for about two
minutes, dried well using sterilized filter
papers and transferred to Petri dishes
containing potato dextrose agar (PDA)
medium. The Petri dishes were kept at 20
ºC. After the germination and fungal
growth, hyphal tip technique was used to
purifying cultures (Brown, 1924).
Fusarium oxysporum
f.sp
. cepae
was
isolated from rot symptomatic garlic
bulbs by the tissue segment method
(Rangaswami, 1958), basal plate tissues
of diseased samples were cut into small
pieces using a sterilized scalpel, surface
sterilized with a 0.5% solution of sodium
hypochlorite for two minutes and then
washed several times in sterilized
distilled water to remove any residual
effect of Na-hypochlorite. The pieces
were dried between two sterilized filter
paper, then transfered on the Petri dishes
containing sterilized potato dextrose agar
(PDA) medium amended with
streptomycin sulphate (200 mg/l)
(Sigma-Aldrich, USA) and incubated at
25±2
o
C, then examined daily for fungal
growth. The fungal colonies were
purified using single spore or hyphal tip
techniques suggested by Booth (1985)
and Rangaswami (1972).
The cultures
were identified according to their
morphological and microscopical
characters as described by Booth (1985),
Barnett and Hunter (1972) and Leslie and
Summerell (2006).
Pyrenochaeta
terrestris
were isolated from garlic bulbs
exhibiting symptoms of pink root rot
(Mishra
et al.,
2012; Netzer
et al
., 1985).
The roots were cut in to 2-3 mm pieces
and surface sterilized with a 70% ethyl
alcohol for 30 seconds, immediately
rinsed in sterile water and dried on sterile
filter paper. The host tissue was plated on
water agar (WA) medium and were
allowed to grow for 4-5 days at 25
o
C.
Pinkish red colonies developed 4-5 days
after the inoculation placed onto Potato
Dextrose Agar (PDA) medium and were
purified by using single spore technique.
The pathogen was identified as
Pyrenochaeta
terrestris
by using relevant
literature (Schwartz and Mohan, 2008;
Boerema
et al
., 2004). The
obtained
isolates of
S. cepivorum
,
F. oxysporum
f.sp
. cepa
and
P. terrestris
were
maintained on
PDA slants and kept in
refrigerator at 5°C
for further studies.
The isolates were
confirmed by
Abd-Elaziz et al., 2021
49
Mycological Research
Center (AUMRC),
Assiut University, Egypt.
2.2 Pathogenicity tests
Pathogenicity tests of the isolated fungi
were carried out under greenhouse
conditions at Faculty of Agriculture, Al-
Azhar University (Assiut Branch), Egypt.
The plastic pots (25 cm diameter) were
sterilized by immersing in 5% formalin
solution for 15 minutes, then left for
several days to get rid of the poisonous
effect of the formalin. Thirteen isolates of
F. oxysporum
f.sp
. cepae
, nine isolates of
S. cepivorum
and seven isolates of
P.
terrestris
were obtained from different
locations. The fungi used throughout this
experiment as well as
the source of
isolates are shown in Table (1). The
inoculum which used in the foregoing
studies consisted of uniform agar discs 5
mm. in diameter bearing 7 days
҆
old and
grown in 500 ml. glass bottles containing
the following substrate per bottle (25 g
coarse sand, 75 g barley and 100 ml tap
water to cover the mixture in bottles).
The bottles were autoclaved for 30
minutes. The bottles were inoculated with
the tested fungi, then incubated at
20±2
o
C for two weeks to obtain sufficient
growth of the fungi. The sterilized pots
were filled with sterilized clay loam soil
and infested with the fungal inoculum at
the rat 2% (w/w) soil, then watered and
lift for one week before sowing to ensure
even distribution and growth of each
particular fungus. Disinfested
garlic
cloves cultivar
sides 40. were planted in
the infested pots, each pot was planted
with 5 cloves (25
cm
in diameter). Four
pots were used for each isolate, (which
were considered as replicates). Pots
containing sterile soil mixed with barley
grains free of any fungus were sown
similarly with disinfested garlic cloves at
the same rate to be used as control
treatment. Pots were kept under
observation and irrigated as needed.
Results were recorded after 90 days of
planting for white rot and after 120 days
for basal rot and pink rot. The infected
plants of each replicate were removed
from the soil after the end of inoculation
period, washed thoroughly to remove soil
debris. The white rot rating scale was as
follows: 1 = healthy plants, 2= slightly
severe (leaves yellowing, root system
reduced), 3 = moderate severe
(yellowing, die back of leaves and badly
decayed root system), 4 = severe
(completely yellowing plant, leaves die
back, semi soft rot of cloves and roots)
and 5 = highly severe (completely dead
plants, extensive decayed roots and
bulbs). The basal rot rating scale was as
follows: 1 = without symptoms, 2 up to
10% rotted roots, 3 = 10-30% rotted
roots with up to 10% rotted basal plates,
4 =completely rotted roots and 10-30 %
rotted basal plates and
5
= completely
rotted roots and more than 30% rotted
basal plate. The pink root rot rating scale
was as follows: 1
= without symptoms, 2
= less than 10% pink roots, 3 = 10-50%
pink roots, 4 = more than 50% pink
roots, and 5
= completely rotted roots.
(DS%) was estimated as the following:
DS (%) = Σ [ (1A+2B+3C+4D +5E) /5T] ×100
Where, A, B, C, D and E are the number
of plants corresponding to the numerical
grade, 1, 2,3,4 and 5 respectively and 5T
is the total number of plants (T)
multiplied by the maximum disease
grade 5, where T=A+B+C+D +E. To
detect the different degrees of disease,
Abd-Elaziz et al., 2021
50
plants were classified into five categories
according to Chemeda
et al
. (2015),
Rengwalska and Simon (1986) and
Shatla
et al
. (1980).
2.3 Isolation of
Trichoderma
spp.
Soil samples were collected from
rhizosphere of healthy garlic plants, In
growing fields of Assiut Governorate.
One hundred gram from rhizosphere soil
were collected into each sterile plastic
bag
and kept in the refrigerator at Plant
Pathology Laboratory, Faculty of
Agriculture, Al-Azhar
University (Assiut
Branch), Egypt for further analysis.
Isolation of antagonistic
Trichoderma
spp. from rhizosphere soil was made
using serial dilution technique according
to Waksman
(1922), and Belete and
Ahmed (2015). Eight
Trichoderma
isolates were
identified according to
Kubicek and
Harman (2002) based on
their conidial
morphology, color and
texture, and
growth characteristics. The
obtained isolates were confirmed by
Mycological Research Center, Assiut
University, Egypt as follow: two isolates
Trichoderma harzianum
(T3 and T5),
three isolates
T. hamatum
(T2, T6 and
T7), two isolates
T. koningii
(T1and T8)
and one isolate
T. viride
(T4).
2.4
In vitro
experiments
2.4.1 Evaluation of antagonistic
activity of
Trichoderma
spp. against
pathogenic fungi
Eight different species of
Trichoderma
isolated from rhizosphere of healthy
garlic plants and one isolate of
T.
asperellum
was obtained on PDA
medium, from the commercial product
(Biocontrol T34) provided by Shoura
Agrochemicals Company were screened
against the pathogenic
fungi
in vitro
. The
antagonistic effects of
each
Trichoderma
sp. and
T. asperellum
against
F.
oxysporum
f. sp
. cepae,
S. cepivorum
and
P. terrestris
were
tested using dual
culture technique (El-Sheshtawi
et al.,
2009; Coskuntuna and
Ozer, 2008). The
tested isolates of
Trichoderma
spp. were
grown on
potato
dextrose agar (PDA)
medium at 25°C, for
6 days and used as
inocula. Discs from
each isolate of
Trichoderma
sp. (5 mm
in diameter)
were
transfered on PDA
medium in one
side of Petri plate and the
opposite side
was inoculated by
pathogenic fungi. Four
replicates were
used for each treatment.
Inoculated plates
with pathogenic fungi
only were used as
the
control. After 5
days incubation
period at 22±2°C, the
linear growth of the tested pathogen was
recorded when the
growth of the
pathogen covered the plate
surface in the
control treatment. The
percentage of
mycelial growth inhibition
was
calculated according to the following
formula:
Mycelial growth inhibition (%) = [A–B/A] x 100
Where: A = the length of the hyphal
growth in the control, B = the length of
hyphal growth of the tested fungus. The
antagonistic
Trichoderma
isolates which
gave a higher percentage of mycelia
growth inhibition were identified as
follow;
T. harzianum
(T3 and T5) and
one isolate
T. hamatum
(T7) by
Mycological Research Center, Assiut
University, Egypt.
Abd-Elaziz et al., 2021
51
2.4.2 Evaluation of antagonistic
activity of rhizobacteria against
pathogenic fungi
Eleven isolates of rhizobacteria namly;
B.
subtilis
two isolates
, B. megaterium
two
isolates,
Penibacillus polymyxa
one
isolate,
P. fluorescens
two isolates and
four isolates of
A. chroococcum
were
obtained from
MERCIN, Faculty of
Agriculture, Ain Shams
University,
Egypt. These isolates were tested against
the pathogenic fungi
F. oxysporum
f.sp.
cepae, S. cepivorum,
and
P. terrestris
under vitro conditions. The tested isolates
of bacteria were grown on Nutrient
Sucrose Agar medium (NSA) (Peptone 5
g, beef extract 3 g, yeast extract 2g,
sucrose 5 g, agar 20 g, and distilled water
1liter) and incubated at 28°C for one day
and used as inocula (Sallam Nashwa et
al., 2013). Petri plates (9 cm in diameter)
containing potato dextrose agar (PDA)
medium were inoculated in the middle by
discs (5 mm in diameter) of pathogenic
fungi, then inoculated with the tested
bacterium on two opposite side of the
tested pathogen. Four replicates were
used for each treatment. Inoculated plates
with the pathogenic fungi only were
served as the control. After 5 days of
incubation period at 22±2°C, the linear
growth of the tested pathogens was
recorded when the growth of the
pathogens covered the plate
surface in the
control treatment. The percentage of
mycelial growth inhibition were
calculated according to the following
formula:
Mycelial growth inhibition (%) = [A–B/A] x 100
where: A = the length of the hyphal
growth in the control, B = the length of
hyphal growth in the tested isolate.
2.5 Effect of commercial biofungicides
and biofertilizers on controlling garlic
white rot, basal rot and pink root rot
diseases under greenhouse conditions
Five commercial biofungicides and six
biofertilizers were tested against garlic
white rot, basal rot and pink root rot
under greenhouse conditions during 2019
and 2020 growing seasons. The
commercial biofungicides were Biozeid
(
Trichoderma album
), Plant Guard (
T.
harzianum
), T34 biocontrol (
T.
asperellum
), Bio-Arc (
Bacillus
megaterium
) and Rhizo-N (
B. subtilis
).
Each commercial biofungicide were
tested at the rat 3 g /kg soil. While,
commercial biofertilizers were Nitrobien
(A
zotobacter
sp. and
Azospirillum
sp.),
Biogen (
Azotobacter vinelauvii
and
A.chroococcum
),Potassiumag (
Bacillus
circulans
and
Bacillus megaterium
var
.
phosphaticum
), Phosphoren (As
phosphorus solubilizing bacteria),
Carialin (
Azospirillum
sp.) and Ascobein
(As citric acid + ascorbic acid 38% and
Organic plant growth stimulating
materials 62%). These bio-fertilizers
were obtained from bio-fertilization Unit,
Agricultural Research Center Ministry of
Agriculture, Giza, Egypt. Each tested
commercial biofertilizers were used at
the rat 4 g /kg soil, except Ascobien was
used as foliar spraying at rat 1.3 g /L.
Plastic pots (25cm in diameter) were
filled with sterilized clay soil and mixed
with the pathogenic fungi
, F. oxysporum
f.sp.
cepae, S. cepivorum
and
P.
terrestris
at the rate 2% (w/w) one week
before adding biofungicides,
biofertilizers and planting. Pots were
filled with sterilized soil and infested
with the pathogenic fungi only served as
a control. The commercial biofungicides
and biofertilisers were added and
Abd-Elaziz et al., 2021
52
distributed in the infested soil at the time
of planting. Four pots were used for each
treatment as replicates, each pot was
planted with 5 cloves. At the end of the
experiment, garlic plants were uprooted,
washed, rated for disease severity as
mentioned before.
2.6 Greenhouse experiments
The effects of commercial biofungicides
Biozeid , Bio-Arc, Plant Guard, T34
biocontrol and Rhizo-N, also
biofertilizers Nitrobien, phosphoren,
Biogen, Potassiumag, Carialin and
Ascobein were
evaluated individually
against garlic white rot, basal rot and
pink root rot diseases incited by
F.
oxysporum
f. sp
. cepae, S. cepivorum
and
P. terrestris
under greenhouse conditions.
This experiment was carried out during
2019 and 2020 growing seasons, under
greenhouse conditions of Agricultural
Botany Department, Faculty of
Agriculture, Al-Azhar University, Assiut,
Egypt. Plastic pots were filled with
sterilized clay soil and mixed with fungal
inocula as described before at rate 2 % of
clay soil (w/w), one week before
planting. Biofungicides and biofertilizers
were added to the infested soil at rat 3 g
/kg soil and 4 g /kg soil at the time of
planting. Each pot was sown with 5
disinfested cloves of garlic Sides 40 cv.
Four pots were used for each treatment as
replicates. The infested pots individually
with pathogenic fungi only were sown
with disinfested garlic cloves and served
as control. At the end of the experiment
plants were uprooted washed, rated for
Disease severity. Disease severity was
estimated as described before.
2.9 Statistical analysis
Analysis of variance of the data was
carried out on the mean values of the
tested treatments according to the
procedures described by Gomez and
Gomez (1984).
The least significant
difference (L.S.D) at 5% probability was
used for testing the significance of the
differences among the mean values of the
tested treatments for each character.
3. Results
and Discussion
3.1 Isolation and identification of
garlic white rot, basal rot and pink
root rot the causal fungi
Twenty-nine fungal isolates were
isolated from infected roots of garlic
plants collected from different localities
in Minia, Assiut, Sohag, and Qena
Governorates, Egypt. Fungal isolates
were identified by using the
morphological features of mycelia and
spores as described by Barnet and Hunter
(1977) and Booth (1985) and confirmed
by Mycological Research Center
(AUMRC), Assiut University, Egypt. As
shown in Table (1) that the isolated fungi
were identified as thirteen isolates of
Fusarium oxysporum
f.sp
. cepae
Snyder
and Hansen,
seven isolates of
Pyrenochaeta terrestris
(Hansen)
Gorenz, Walker and Larson and nine
isolates of
Sclerotium cepivorum
Berk.
Abd-Elaziz et al., 2021
53
Table 1: Source of 29 fungal isolates which isolated from four
Egyptian governorates during 2017 growing season.
The isolated fungi
Isolate code
Governorate
F. oxysporum f.sp. cepae
F1
Sohag
F2
Sohag
F3
Assiut
F4
Assiut
F5
Minia
F6
Qena
F7
Qena
F8
Sohag
F9
Sohag
F10
Minia
F11
Minia
F12
Assiut
F13
Sohag
P. terrestris
P1
Minia
P2
Sohag
P3
Minia
P4
Minia
P5
Sohag
P6
Qena
P7
Assiut
S. cepivorum
S1
Minia
S2
Minia
S3
Sohag
S4
Sohag
S5
Sohag
S6
Assiut
S7
Minia
S8
Assiut
S9
Sohag
3.2 Pathogenicity tests
Twenty-nine fungal isolates were tested
to study their pathogenic capbilities on
garlic plants
(Sides 40 cv.) under
greenhouse conditions
during 2018
growing season. Data in
Table (2)
exhibited that all tested fungal
isolates of
S. cepivorum, F. oxysporum
f. sp
. cepae
and
P. terrestris
were able to infect garlic
plants causing white rot, basal rot and
pink root rot. All the tested isolates of
S
.
cepivorum
caused white rot disease
compared with the control. In this
respect,
S
.
cepivorum
(isolate No. 5)
gave
the highest disease
severity, reached it
82.67 % followed by isolates No. 1, 2, 6
and 3 which reached 77.33, 70.67, 65.33
and 61.33 % respectively. While,
isolates No7 and 4 gave moderate disease
severity (57.33and 53.33 %). At the same
time, isolates No. 8 and 9 came in the
last 45.33 and 40.5 % disease severity.
Data also showed that, all the tested
isolates of
F. oxysporum
f.sp
. cepae
caused basal rot disease compared with
the control. In this case,
Fusarium
isolate
No. 7 exhibited the highest disease
severity (74.66 %) followed by isolate
No. 3 and 2 reached it 62.67 and 60.5 %,
respectively. As regard, isolates No. 6, 4,
8, 13 and 10 gave the moderate disease
severity (57.33, 50.66, 46.67, 48.0 and
40.0 %, relatively. On the other hand,
P.
terrestris
with all tested isolates caused
pink root rot disease compared with
Abd-Elaziz et al., 2021
54
uninfected plants. As shown in this table,
isolate No. 3 recorded the highest disease
incidence, followed by isolates No. 5, 6
and 4, relatively (73.30, 59.96, 46.63 and
44.40 %) relatively. As mean, isolates No
1 and No. 7 showed lower disease
severity (37.73 and 33.30 %, while
isolate No. 2 came in the last (28.83).
Such results are in agreement with those
obtained by Ellojita et al. (2016),
Chemeda et al. (2015) and Shalaby et al.
(2012),
who
found that
F. oxysporum
f.
sp
. cepae , P. terrestris
and
S
.
cepivorum
caused basal rot, pink rot and white rot
diseases of garlic under greenhouse
and
field conditions.
Table 2: Disease severity of garlic white rot, basal rot and pink root rot
diseases caused by 29 fungal isolates under greenhouse conditions during
2017 growing season.
Isolate code
Disease severity (%)
White rot
Basal rot
Pink root rot
Sc1
77.33
0
0
Sc2
70.67
0
0
Sc3
61.33
0
0
Sc4
53.33
0
0
Sc5
82.67
0
0
Sc6
65.33
0
0
Sc7
57.33
0
0
Sc8
45.33
0
0
Sc9
40
0
0
F1
0
33.33
0
F2
0
29.33
0
F3
0
62.67
0
F4
0
50.66
0
F5
0
38.67
0
F6
0
57.33
0
F7
0
74.66
0
F8
0
46.67
0
F9
0
22.66
0
F10
0
40
0
F11
0
28
0
F12
0
60
0
F13
0
48
0
P1
0
0
37.73
P2
0
0
28.83
P3
0
0
73.3
P4
0
0
44.4
P5
0
0
59.96
P6
0
0
46.63
P7
0
0
33.3
Control
0
0
0
L.S.D at 5%
3.29
4.37
9.99
3.3 Preliminary tests for antagonistic
capability of fungi and bacteria against
the growth of pathogenic fungi
in vitro
It was shown in Table (3) that the
antagonistic fungal isolates
(
Trichoderma
spp.) were able to inhibit
mycelial growth of the tested pathogenic
fungi (
S. cepivorum
(Sc5),
F. oxysporum
f.sp. cepae
(F7) and
P. terrestris
(P3)
Abd-Elaziz et al., 2021
55
compared with the control.
Trichoderma
harzianum
(T3) gave the greatest
reduction of mycelial growth of the
tested pathogens followed by isolate
T
.
asperellum
(T34), then isolate
T.
harzianum
(T5) and isolate
T. hamatum
(T7). The other tested antagonistic
showed moderate inhibition against the
tested pathogenic fungi. While, the least
reduction of mycelial growth was
obtained by
Trichoderma koningii
(T1)
followed by (T8). These results are in
agreement with those recorded by El-
Sheshtawi et al. (2009) and Malathi
(2015). Antagonistic potential of
different
Trichoderma
species arranges
of mechanisms have to be considered one
in Production of antibiotic, volatile and
nonvolatile chemicals. These substances
influence the permeability of cell
membranes and result in anefflux of the
cytoplasm (Howell, 1998). The
antifungal enzyme system of
Trichoderma
spp. plays an important role
for detection and destroying the
pathogenic cell wall. Also, the
mechanism depends on competition,
Competitiveness is based on rapid
growth and the production of various
asexual generated conidia and
chlamydospores (Shi
et al., 2012; Chet et
al., 1998; Chet, 1990).
The direct
influence of
Trichoderma
spp. against
pathogens through colining their hyphae
around the hyphae of the pathogens to
prevent their continued growth.
Bettucci
et al. (1996)
reported that the secondary
metabolites trichozianins obtained from
T. harzianum
inhibited mycelial growth
of
S. cepivorum.
Table 3: Effect of antagonistic Trichoderma mycelial growth inhibition of the tested fungi in vitro.
Antagonistic Trichoderma
Mycelial growth inhibition (%)
Mean
S. cepivorum
(Sc5)
F. oxysporum f.sp. cepae
(F7)
P. terrestris
(P3)
T. koningii (T1)
26.6
28.1
32.6
29.1
T. hamatum (T2)
31.1
34.4
35.5
33.6
T. harzianum (T3)
74.4
69.5
86.6
76.8
T. viride (T4)
22.2
31.8
39.9
31.3
T. harzianum (T5)
77.7
58.1
84.4
73.4
T. hamatum (T6)
20.33
17.7
25.5
21.17
T. hamatum (T 7)
67.7
50.7
75.6
64.66
T. koningii (T8)
13.3
23.3
18.8
18.46
T. asperellum (T34)
78.8
57.3
85.5
73.86
Control
0
0
0
-
LSD at 5%
1.92
3.03
2.03
-
The same experiment was carried out by
using antagonistic bacteria. It was clear
from data present in Table (4) that all the
tested antagonistic rhizobacteria (PGPR)
inhibited growth of the tested pathogenic
fungi. The highest reduction of the
mycelial growth was acheived by
P.
fluorescens
isolate (Pf1),
followed by
P.
fluorescens
(Pf2),
B. subtilis
(Bs2),
A.
chroococcum
(Az4)
and
B. subtilis
(Bs1), whenever the mycelial growth it
71.9, 67.9, 64.46, 62.16, and 61.6 %,
respectively. At the same time, Az2,
Az1,
B. megaterium
(Bm2) and
Penibacillus polymyxa
(Bp) showed
moderate reduction of mycelia growth of
the tested pathogenic fungi. While, the
lowest inhibition of mycelial growth of
Abd-Elaziz et al., 2021
56
the tested fungi was obtained with
B.
megaterium
(Bm1) and
A. chroococcum
(Az3), except in case of
F. oxysporum
f.sp.
cepae
non-antagonistic was
observed. These results are in line with
those obtained by Manoj et al. (2014),
Haggag-Karima et al. (2015) and El-
Meneisy-Afaf et al. (2019).
Table 4: Effect of certain antagonistic rhizobacteria on mycelial growth inhibition of the tested fungi in vitro.
Antagonistic rhizobacteria
Mycelial growth inhibition (%)
Mean
P. terrestris
(P3)
S. cepivorum
(Sc5)
F. oxysporum f.sp. cepae
(F7)
P. fluorescens (Pf 1)
64.7
80.3
70.7
71.9
P. fluorescens (Pf 2)
70.3
58.4
74.03
67.6
Penib. polymyxa (Bp)
61.1
20.3
42.5
41.3
B. megaterium (Bm1)
57.3
24.4
37.3
39.6
B. megaterium (Bm2)
60.7
26.9
42.5
43.36
B. subtilis (Bs1)
69.6
50.3
65.1
61.6
B. subtilis (Bs2)
74.7
51.4
67.3
64.46
A. chroococcum (Az1)
58.8
18.1
61.1
46
A. chroococcum (Az2)
60.5
20.7
68.8
50
A. chroococcum (Az3)
61.1
37.3
0
32.8
A. chroococcum (Az4)
61.4
54.4
70.7
62.16
Control
0
0
0
-
LSD at 5%
2.62
2.61
2.57
-
Bacterial bioagents showed antifungal
potential against the tested fungi, which
could be attribute to mechanism of
diffusible antagonistic substances and
volatile metabolites depending on the
bacterium and the pathogen combination.
The diffusible substances include
antibiotics (pyrrolnitrin) and siderophores
(enterobactin and aerobactin) and
volatilic metabolites include hydrogen
cyanide and acetoin (Rakh et al., 2011).
Results from bioassays suggest
that
production of antifungal substances by
these
bacteria may be responsible for the
inhibition of fungal
growth, where no
direct contact
between bacterial colonies
and mycelium of pathogenic
fungi, so
that the fungal growth inhibition was
caused by
diffusion of substances into the
agar medium. On the
other hand, most of
bacteria that used as a biocontrol
agent
like
Bacillus
spp. produce antibiotics
responsible
for their antifungal activities
(Bhattacharjee and Dey, 2014).
3.4 Greenhouse experiments
3.4.1 Effect of commercial bio-
fungicides on controlling garlic white
rot, basal rot and pink root rot
diseases under greenhouse conditions
The influence of soil treatment with
different biofungicides Rhizo-N, Bio-
Arc, Plant-guard, Biozeid and T-34
(Biocontrol) on incidence of white rot,
basal rot and pink root rot diseases of
Sides 40 garlic cv. was carried out under
greenhouse conditions during 2019 and
2020 growing seasons. The obtained data
in Table (5) illustrated that the treated
soil with biofungicides significantly
reduced the disease severity of white rot,
basal rot and pink root rot diseases
compared with the control. The effect of
biofungicides against
S. cepivorum
, data
revealed that all biofungicides exhibited
slight decrease in disease severity caused
with
S. cepivorum
. However, T34
biocontrol was the most effective ones in
Abd-Elaziz et al., 2021
57
controlling garlic white rot disease,
followed by Plant- guard, whereas the
disease severity reached 27.9 and 30%,
respectively. Whatever the other
treatment gave moderate effective
compared with the control. At the same
time, Rizo- N followed by T-34 and
Plant-guard were the most effective in
reducing basal rot caused with
F.
oxysporum
f.sp.
cepae
as compared with
Bio-Arc and Biozeid as well as the
control, whereas the disease severity was
15.3, 19.9 and 21.9 %, respectively.
Concerning the tested biofungicides
decreased the disease severity of pink
root rot disease compared with the check
treatment. In this respect, all the tested
biofungicides gave promising results in
controlling pink rot caused with
P.
terrestris
. In addition, the tested
biofungicides Rizo- N, followed by T-34
and Plant-guard gave the best results in
controlling
P. terrestris,
whereas the
disease severity was 11.9, 18.3 and
21.3%, respectively. While, Bio-Arc and
Biozeid gave last effect in controlling the
disease. The efficacy of certain
biofungicides was observed in case of
infested soil with
P. terrestris
and
F.
oxysporum
f.sp.
cepae
, however, Rhizo-
N and T34 were effective biofungicides
in controlling garlic pink root rot and
basal rot diseases, which showed clear
effect in decreasing disease severity.
Table 5: Effect of different biofungicides on controlling garlic white rot, basal rot and pink root rot diseases
under greenhouse conditions during 2019 and 2020 growing seasons.
Biofungicides
Disease severity (%)
S. cepivorum (Sc5)
F. oxysporum f.sp. cepae (F7)
P. terrestris (P3)
2019
2020
Mean
2019
2020
Mean
2019
2020
Mean
Bio-Arc
36
38.6
37.3
28
32
30
25.3
24
24.6
Plant-guard
28
32
30
21.3
22.6
21.9
20
22.6
21.3
T-34 Biocontrol
29.3
26.6
27.9
18.6
21.3
19.9
18.6
20
18.3
Biozeid
37.3
40
38.6
33.3
29.3
31.3
32
34.6
33.3
Rhizo-N
34.6
37.3
35.9
13.3
17.3
15.3
10.6
13.3
11.9
Control
81.3
85.3
83.3
73.3
74.6
73.9
70.6
73.3
71.9
LSD at 5%
3.75
4.44
5.56
3.75
5.30
3.36
These findings are in agreement with
those previously obtained by Salama et
al. (2008) and El-Naggar et al. (2018).
Biofungicides may be microorganism
such as bacteria, fungi or yeasts based on
product like secondary metabolite.
Biocontrol bacteria such as Rhizo-N and
Bio-Arc suppressed the different growth
by the producing secondary metabolites
like antibiotic, cell wall degrading
enzymes and hydrogen cyanide (Bakker
and Schippers, 1987). Multiple
mechanisms seem to be used by
Bacillus
spp. in the biocontrol such as: (i) activate
the defense mechanisms of plant (ii)
competition for iron through production
of siderophores (iii) competition to
establish an ecological site and
metabolize root exudates (iiii)
degradation of pathogenicity factors such
as toxins (Castillo et al., 2013).
Also,
many studies showed that
Trichoderma
spp. have antagonistic effect against a
wide range of the soil borne
pathogens.
The inhibitory effect of Plant Guard is
related to the antagonistic action exerted
by
T. harzianum
. No single mechanism
of how
T. harzianum
is able to inhibit the
growth of fungal plant pathogen is
known. The competition, antibiosis and
Abd-Elaziz et al., 2021
58
mycoparasitsm are all important
depending on which plant-pathogen
situation is considered (Chet, 1987).
Metabolites produced by
T. harzianum
may also play a role in mycoparasitism of
the hyphae or the sclerotia produced by
S.
cepivorum
. The mycoparasitism and
penetration may be followed by the
release of antibiotics that permeate the
perforated hyphae and prevent
resynthesis of the host cell wall (Lorito et
al., 1996). In addition,
T. asperellum
has
been recently shown to induce systemic
resistance in plants through a mechanism
that employs jasmonic acid and ethylene
signal-transduction pathways (Zlata,
2008).
3.4.2 Effect of commercial
biofertilizers on controlling garlic
white rot, basal rot and pink root rot
diseases under greenhouse conditions
The treated soil with different
biofertilizers Nitrobien, Phosphoren,
Biogen, Potassiumag and Carialin, as
well as treated plants with Ascobein as
foliar spraying were evaluated for their
effectiveness to control pink root rot,
basal rot and white rot diseases of
Sides40 garlic cv. under greenhouse
conditions during 2019 and 2020
growing seasons. It was clear from data
presented in Table (6) that Phosphoren
has significantly decreased pink root rot
disease incidence (18.6%), followed by
Nitrobien (19.9%) and Biogen (35.3%)
compared with the control (71.9%).
While, treated plants with Ascobien as
foliar spraying gave the highest
percentage of
pink root rot disease.
Nitrobien followed by Phosphoren were
the most effective in reducing basal rot
caused with
F. oxysporum
f.sp.
cepae
if
compared with other treatments and also
with the control. Whereas the disease
severity was 20.6 and 30 %, respectively.
In this respect Ascobien and Biogen gave
the lowest effect in controlling
basal rot
disease. Data also revealed that all
biofertilizers exhibited slight decrease of
disease severity caused with
S.
cepivorum
. However, Nitrobien was the
most effective ones in controlling garlic
white rot disease, followed by
Phosphoren, whereas the disease severity
reached 35.3 and 36.6%, respectively.
While, the other treatment gave the
lowest effect in controlling white rot
disease caused with
S. cepivorum.
Table 6: Effect of different biofertilizers on controlling garlic white rot, basal rot and pink root rot diseases
under greenhouse conditions during 2019 and 2020 growing seasons.
Biofertilizers
Disease severity (%)
P. terrestris (P3)
F. oxysporum f.sp. cepae (F7)
S. cepivorum (Sc5)
2019
2020
Mean
2019
2020
Mean
2019
2020
Mean
Nitrobien
18.6
21.3
19.9
18.6
22.6
20.6
34.6
36
35.3
Phosphoren
28
29.3
18.6
28
32
30
36
37.3
36.6
Biogen
33.3
37.3
35.3
38.6
42
40.3
45.3
48
46.6
Potassiumag
34.6
37.3
35.9
29.3
33.3
31.3
38.6
40
39.3
Sarialein
36
40
38
32
34.6
33.3
42.6
41.3
41.9
Ascobein
41.3
45.3
43.3
40
41.3
40.6
52
54.6
53.3
Control
70.6
73.3
71.9
73.3
74.6
73.9
81.3
85.3
83.3
LSD at 5%
4.32
4.58
-
5.51
4.58
-
3.74
3.05
-
Generally, Nitrobien followed by
Phosphoren gave the best results in
controlling pink root rot, basal rot and
white rot diseases in both seasons. These
Abd-Elaziz et al., 2021
59
results are in line with those recorded by
El-Naggar et al. (2018). Bio-fertilization
was recently recommended to be
effective mean controlling soil-borne
fungal diseases on the ornamental plants
as reported by Abo El-Ela (2003) who
mentioned that, the benefit of bio-
fertilization might due to its cumulative
effects such as supplying the plant with
nitrogen in addition to growth promoting
substances produced by microorganisms.
Dhir (2017) stated that,
Azotobacter
brasilensis
and
A.
chroococcum
were
very effective against the infestation with
R.solani
and
F. oxysporum
. This effect
was attributed to the decrease of
population density in the Rhizosphere.
Also, Brown (2012)
observed that
Azotobacter
besides the N-fixation was
able to produce growth substances and
fungal antibiotics, and the response of the
crops to the inoculation could be
attributed to the substances produced by
the organisms. Also, Chung and Wu
(2000) recorded the efficiency of
Bacillus
megaterium
var.
phosphaaticum
to
control root-rot caused by
R.solani
also,
Potassiumag containing
Bacillus
cerculanes
was suppressive compared
with the control. These findings could be
interpreted in light that
Bacillus
increase
the plant P uptake, water status inside the
plant tissues and hence increases the
plant amino acids and activate its rates
and enhance the action of succinic and
lactic acids which induce the root growth.
References
Abd-Alla MA, El-Mohamedy RSR, El-
Mougy Nehal S, 2007. Control of sour
rot disease of lime fruits using
saprophytic isolates of yeast. Egyptian
Journal of Phytopathology 35(2): 39–51.
Abdel-Kader MM, El-Mougy S. Nehal, Aly
MDE, Lashin SM, 2012. Different
approaches of bio-control agents for
controlling root rot incidence of some
vegetables under greenhouse conditions.
International Journal of Agriculture and
Forestry 2(1): 115–127.
Abo El-Ela A, 2003. Management of the
three destructive soil borne fungal
diseases of carnation under protected
and field cultivation. Egyptian Journal of
Botany 18(5):27–52.
Bakker AW, Schippers B, 1987. Microbial
cyanide production in the rhizosphere in
relation to potato yield reduction and
Pseudomonas sp. Plant growth
stimulation. Soil Biology biochemistry
19: 551.
Barnet HL, Hunter B, 1972. Illustrated
genera of imperfect fungi. Burgess
Publishing Company, USA.
Behrani GQ, Syed RN, Abro MA, Jiskani
MM, Khanzada MM, 2015.
Pathogenicity and chemical control of
basal rot of onion caused by Fusarium
oxysporum f. sp. cepae. Pakistan Journal
of Agriculture, Agricultural Engineering
and Veterinary 31: 60–70.
Belete E, Ayalew A, Ahmed S, 2015.
Evaluation of local isolates of
Trichoderma spp. against Black root rot
(Fusarium solani) on Faba bean. Journal
of Plant Pathology and Microbiology
6(6): 279.
Bettucci L, Correa A, Roquebert MF, 1996.
Trichozianins activity on mycelial
growth of Sclerotinia sclerotiorum under
laboratory conditions. Cryptogamie
Mycologie 17: 123–8.
Bhattacharjee R, Dey U, 2014. An overview
of fungal and bacterial biopesticides to
Abd-Elaziz et al., 2021
60
control plant pathogens/diseases. African
Journal of Microbiology Research 8(17):
1749–1762.
Blaszczyk L, Siwulski M, Sobieralski K,
Lisiecka L, Jedryczka M, 2014.
Trichoderma spp. application and
prospects for use in organic farming and
industry. Journal of Plant Protection
Research 54(4): 309–317.
Boerema GH, Gruyter de, Noordeloos J,
Hamers MEC, 2004. Phoma
Identification Manual. Differentiation of
specific and intra-specific taxa in culture.
CABI Publishing, Wallingford, UK.
Booth C, 1985. The genus Fusarium. 2
nd
Ed.,
Surrey Commonwealth Mycological
Institute, Kew, England, 237 pp.
Brown M, 2012. Population of Azotobater in
rhizosphere and effect of artificial
inoculation. Plant and Soil 17(3): 15.
Brown W, 1924. A method of isolating single
strains of fungi by cutting out a hyphal
tip. Annals of Botany 38(150): 402–404.
Castillo HF, Reyes CF, Morales GG, Herrera
RR, Aguilar C, 2013. Biological control
of root pathogens by plant-growth
promoting Bacillus spp. In: weed and
pest control-conventional and new
challenges. Intech Open, England.
Chemeda D, Melaku A, Alemu L, Tariku H,
2015. Integrated management of garlic
white rot (Sclerotium cepivorum Berk)
using some fungicides and antifungal
Trichoderma species. Journal of Plant
Pathology & Microbiology 6(1): 1–9.
Chet I, 1987. Trichoderma -application, mode
of action and potential as a biocontrol
agent of soil borne plant pathogenic
fungi. In: Innovative Approaches to
Plant Diseases Control, Wiley and Sons,
New York, USA.
Chet I, Benhamou N, Haran S, 1998.
Mycoparasitism and lytic enzymes. In:
Harman GE, Kubicek CP (Eds.)
Trichoderma and Gliocladium, vol 2.
Enzymes, biological control and com-
mercial applications. Taylor and Francis
London, United Kingdom, pp. 153–171.
Chet J, 1990. Mycoparasitism–recognition,
physiology and ecology. In: Baker RR,
Dunn, PE (Eds) New Directions in
Biological Control: Alternatives for.
Suppressing Agricultural Pests and
Diseases. Alan Liss, New York, pp.
725–733.
Chung IY, Wu WS, 2000. Effect of Bacillus
megaterium. Review of Plant Pathology
80(1): 637.
Clarkson JP, Payne T, Mead A, Whipps JM,
2002. Selection of fungal biological
control agents of Sclerotium cepivorum
for control of white rot by sclerotial
degradation in a UK soil. Plant
Pathology 51(6): 735–745.
Coleman PM, Ellerbrock LA, 1997.
Reachion of selected onion cultigens to
pink root under field conditions in New
York. Plant disease 81(2): 138–142.
Coskuntuna A, Ozer N, 2008. Biological
control of onion basal rot disease using
Trichoderma harzianum and induction
of antifungal compounds in onion set
following seed treatment. Crop
Protection 27: 330–336.
Crowe F, Darnell T, Thornton M, Davis M,
Mcgrath D, Koepsell P, Redondo E,
Laborde J, 1993. White rot control
studies show promise of better future.
Onion World 9: 22–25.
Davis R, Hao JJ, Romberg MK, Nunez JJ,
Abd-Elaziz et al., 2021
61
Smith RF, 2007. Efficacy of germination
stimulants of sclerotia of Sclerotium
cepivorum for management of white rot
of garlic. Plant Disease 91: 204–208.
Deising HB, Reimann S, Pascholati SF, 2008.
Mechanisms and significance of
fungicide resistance. Brazilian Journal of
Microbiology 39(2): 286–295.
Dhir B, 2017. Bio-fertilizers and Bio-
pesticides: Eco-friendly Biological
Agents. In Advances in Environmental
Biotechnology, Springer, Singapore, pp.
167–188.
Dragana B, Maja I, Jelena M, Dragana M,
Zorica N, Jelica G, Maja K, 2018.
Bacillus isolates as potential biocontrol
agents of Fusarium clove rot of garlic.
Zemdirbyste-Agriculture 105(4): 369–
376.
Ellojita R, Pradyumna T, Satyabrata N,
Sanghamitra N, Raj KJ, 2016.
Evaluation of Cultivated and Wild
Allium Accessions for Resistance to
Fusarium oxysporum f.sp. cepae.
Proceedings of the National Academy of
Sciences, India, Section B: Biological
Sciences 86(3): 643–649.
El-Meneisy Afaf ZA, Samah Abdelaziz M,
Rabaa Yaseen YK, 2019. Biological
control of onion white rot disease using
different Bacillus spp. American-
Eurasian Journal of Agricultural &
Environmental Sciences 19(1): 64–73.
El-Mougy Nehal S, Mokhtar Abdel-Kader M,
2019. Biocontrol measures against onion
basal rot incidence under natural field
conditions. Journal of Plant Pathology
101: 579–586.
El-Naggar MAA, Zaki MF, El-Shawadfy
MA, 2018. Management of onion root-
rot diseases caused by soil born fungi
under Middle Sinai conditions. Middle
East Journal of Applied Sciences 8(1):
91–99.
El-Sayed Embaby M, 2006. Using a
biofungicide (Coniothyrum minitans
Campbell.) in controlling some
soilborne plant pathogenic fungi in
Egypt. Research Journal of Agriculture
and Biological Sciences 2(6): 423–432.
El-Sheshtawi M, El-Gazzar T, Saad ASM,
2009. Comparative study between
chemical and Non- chemical control
against sclrotium cepivorum, the casual
white rot of onion under Egyptian
conditions. Mansoura University Journal
of Agricultural Sciences 34(3): 2169–
2182.
Embaby El-Sayed M, 2003. Using some new
trends in controlling some storage and
soil pathogenic microorganisms affect
onion crops productivity. Ph.D. Thesis,
Faculty of Agriculture Moshtohor,
Zagazig University (Benha branch),
Egypt.
Entwistle AR 1990. Allium white rot and its
control. Soil Use and Management 6:
201–209.
Haggag Karima HE, Elshahawy IE, Abd-El-
Khair H, 2015. Antagonistic Activity of
Bacillus and Pseudomonas Isolates
Alone or in Combination with
fungicides against some soil borne plant
pathogen under laboratory and
greenhouse conditions. Middle-East
Journal of Scientific Research 23(10):
2354–2365.
Hamma IL, Ibrahim U, Mohammed AB,
2013. Growth, yield and economic
performance of garlic (Allium sativum
L.) as influenced by farm yard manure
and spacing in Zaria, Nigeria. Journal of
Agricultural Economics and
Abd-Elaziz et al., 2021
62
Development 2(1): 1–5.
Howell CR, 1998. The role of antibiosis. In:
Harman, G.E. & Kubicek, C.P. (Eds.)
Trichoderma and Gliocladium. Vol 2.
Enzymes, biological control, and
commercial applications. Taylor &
Francis, London, England, pp. 173–184.
Kubicek CP, Harman GE, 2002. Trichoderma
and Gliocladium: Basic Biology,
Taxonomy and Genetics. Vol. I, CRC
Press, USA, pp. 278.
Laura GP, Dolores MRM, Daniel PL, 2017.
In vitro and field efficacy of three
fungicides against Fusarium bulb rot of
garlic. European Journal of Plant
Pathology 148: 321–328.
Leslie JF, Summerell BA, 2006. The
fusarium laboratory manual. Blackwell
Publishing Professional, Ames, Iowa,
USA, pp. 388.
Lorito M, Farkas V, Rebuffat S, Bodo B,
Kucibek CP, 1996. Cell wall synthesis is
a major target of mycoparasite
antagonism by Trichoderma harzianum.
Journal of Bacteriology 178: 6382–6385.
Mahdizadehnaraghi R, Heydari A,
Zamanizadeh HR, Rezaee S, Nikan J,
2015. Biological control of garlic
(Allium) white rot disease using
antagonistic fungi-based
bioformulations. Journal of Plant
Protection Research 55(2): 136–141.
Malathi S, 2015. Biological control of onion
basal rot caused byFusarium oxysporum
f. sp. cepae. Asian Journal of Biological
Sciences 10(1): 21–26.
Manoj KM, Ramji S, Ajay T, 2014. In vitro
evaluation of antagonistic activity of
Pseudomonas fluorescens against fungal
pathogen. Journal of Biopesticides 7(1):
43–46.
Martins N, Petropoulos S, Ferreira I, 2016.
Chemical composition and bioactive
compounds of garlic (Allium sativum L.)
as affected by pre- and post-harvest
conditions: a review. Food Chemistry
211: 41–50.
Mishra RK, Sharma P, Srivastava DK, Gupta
RP, 2012. First report of Phoma
terrestris causing pink root rot of onion
in India. International Journal of Plant
Research 25(2): 306–307.
Netzer D, Rabinowitch D, Weintal CH, 1985.
Greenhouse technique to evaluate onion
resistance to pink root. Euphytica 34:
385–391.
Poter IJ, Merriman PR, Keane PJ, 1989.
Integrated control of pink root of onions
by dazomet and soil solarization.
Australian Journal of Agricultural
Research 40: 861–869.
Rajendran K, Ranganathan K,1996.
Biological control of onion basal rot
(Fusarium oxysporum f.sp. cepae) by
combined application of fungal and
bacterial antagonists. Journal of
Biological Control 10: 97–102.
Rakh RR, Raut SL, Dalvi MS, Manwar VA,
2011. Biological control of Sclerotium
rolfsii, causing stem rot of Groundnut by
Pseudomonas cf. monteilii. Journal of
Microbiology 3: 26–34.
Rangaswami G, 1958. An agar blocks
technique for isolating soil micro-
organisms with special reference to
pythiaceous fungi. Science and Culture
24: 85.
Rangaswami G, 1972. Diseases of crop
plants in India. Prentice Hall of India
Pvt. Ltd., New Delhi, India, pp. 520.
Abd-Elaziz et al., 2021
63
Rengwalska MM, Simon PW, 1986.
Laboratory evaluation of pink root and
fusarium basal rot resistance in garlic.
Plant Disease 70: 670–672.
Salama OUF, Mohamed IA, Ahmed EI, 2008.
In vitro evaluation of the biocontrol
activity of some biofungicides on
Sclerotium cepivorum. International
Journal of Agriculture and Biology
10(3): 241–248.
Sallam Nashwa A, Riad Shaima N, Mohamed
SM, Ahmed S, 2013. Formulation of
Bacillus spp. And Pseudomonas
fluorescens for biocontrol of cantaloupe
root rot caused by Fusarium solani.
Journal of Plant Protection Research
53(3): 296–300.
Schwartz HF, Mohan SK, 2008.
Compendium of onion and garlic
diseases. 2
nd
edn. American
Phytopathological Society Press. St Paul,
MN, USA.
Shalaby IMS, El-Korashy M, Ismail AA,
2002. Pink root of garlic in Egypt:
Occurrence, Pathogenicity and its
relation with basal rot. Egyptian Journal
of Applied Science 17(10) 544–555.
Shalaby ME, Ghoniem KE, El-Diehi MA,
2013. Biological and fungicidal
antagonism of Sclerotium cepivorum for
controlling onion white rot disease.
Annals of Microbiology 63: 1579–1589.
Shalaby SIM, Morsy SMA, Abd El Baky
AA, 2012. Evaluation of some assays
techniques for determination of
susceptibllity of garlic cultivars to the
pink root disease. Mansoura Journal of
Plant Protection and Pathology 3(7):
657–666.
Shatla MNZ, El-Shanawy AMB, Hanafi AA,
1980. Studies on Sclerotium cepivorum
Berk Toxins. Menoufia Journal of
Agriculture Research 3: 1–16.
Shi M, Chen L, Wang XW, Zhang T, Zhao
PB, Song XY, 2012. Antimicrobial
peptaibols from Trichoderma
pseudokoningii induce programmed cell
death in plant fungal pathogens.
Microbiology 158: 166–175.
Waksman SA, 1922. A Method for Counting
the Number of Fungi in the Soil. Journal
of Bacteriology 7: 339–341.
Zlata DKS, Jelena TL, Stevan NM, Jelica
MGV, Mirjana AV, Svjetlana RA, 2008.
Fusarium rot of onion and possible use
of bioproduct. Proceedings of the Matica
Srpska for Natural Sciences, Novi Sad,
Serbia 114: 135—148.