Download Occurrence and Control of Strawberry Powdery Mildew in Al

Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
Occurrence and Control of Strawberry Powdery Mildew in Al-Shoubak/ Jordan
Muwaffaq Ramadan Karajeh1, Ziad Barakat Al-Rawashdeh2, and Ezz Al-Dein Muhammed Al-Ramamneh3
ABSTRACT
Powdery mildew of strawberry caused by the fungus Sphaerotheca macularis f. sp. fragariae was found in AlShoubak area under glasshouse conditions. White superficial fungal growth was more abundant on the lower
than the upper leaf surface and no cleistothecia were noticed on any plant parts. Top leaves were more
susceptible than middle or bottom leaves. Strawberry cultivars Albion and Camarosa were artificially inoculated
with the fungus under growth room conditions. Disease incidence and severity were 46.7% and 50.8% in cv.
Albion and significantly different from that (1.6% and 5.2%, respectively) in cv. Camarosa. In vitro leaflet
bioassays and a runner-tip plantlet experiment were done to assess the influence of some fungicides and
resistance-inducing chemicals in controlling the disease. Canvil was significantly effective in controlling the
disease while sulfur, Triadimefon, Mycozim and Punch were only effective at the high application rates. Both
calcium chloride at 1 g/l and hydrogen peroxide at 10 mM were effective in controlling powdery mildew on
strawberry.
Keywords: Cultivars, fungicides, management, Sphaerotheca.
INTRODUCTION
or glass-house) conditions in irrigated agricultural areas
The total area of greenhouses was estimated about
including Jordan Valley, uplands (e.g. Al-Shoubak) and
40,700 hectares worldwide (Witter and Castilla, 1995).
desert plains with a total annual production of about 175
The greenhouse industry as a whole represents a
tons in 2008 according to Jordan exports and producers
minuscule part of the total agricultural production, but
association for fruit and vegetables (JEPA).
the gross return to the economy could be significant
Powdery mildew of strawberry caused by the fungus
(Takeda, 2000). Strawberry (Fragaria X ananassa
Sphaerotheca macularis (Wallr. Ex Fr.) Jacz. f. sp.
Duchesne) production has increasingly been transferred
fragariae Peries, is a major disease of this crop
from the fields into covered systems. In Jordan,
worldwide (Spencer, 1978; Maas, 1998). The fungus
strawberry is mainly planted under greenhouse (plastic
attacks above-ground plant parts causing serious damage
to
1
Associate Professor of Plant Pathology, Department of
Plant Protection & IPM, Faculty of Agriculture, Mu’tah
University, Karak 7, Jordan.
2
Assistant Professor of Plant Protection, Al-Shoubak
College, Al-Balqa' Applied University, Al-Shoubak 71911,
Jordan
3
Assistant Professor of Horticulture, Al-Shoubak College,
Al-Balqa' Applied University, Al-Shoubak 71911, Jordan
Received on 17/5/2011 and Accepted for Publication on
30/4/2012.
the
foliage
and
resulting
in
reduction
of
photosynthesis due to dense mycelial coverage of leaf
surface, which can lead to necrosis and eventual
defoliation (Maas, 1998). Powdery mildew causes
economic losses in the marketable fruit yield (Horn et
al., 1972; Spencer, 1978).
Development of powdery mildew depends on
optimum temperature (15–25 °C) and high relative
-380-
© 2012 DAR Publishers/University of Jordan. All Rights Reserved.
Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
humidity, higher than 75 %, but less than 98 %
spraying, etc. The day temperature was ranged between
(Amsalem et al., 2006). Mycelia develop, survive in
15-25°C, while the night temperature during cool nights
green tissue under all condition and sporulate under 5–
was
30 °C (Miller et al., 2003).
temperature was approximately 14°C and 16°C during
Prevention is the best method of powdery mildew
between
8-15°C.
The
mean
daily
outside
the 2008 and 2009 strawberry growing seasons,
control of strawberry through avoiding the use of
respectively.
susceptible cultivars and through following up good
Pathogen identification and inoculum preparation
cultural practices. However, susceptible strawberries
may require protection with foliar sprays with fungicides
The powdery mildew population of Sphaerotheca
to reduce infection and consequently fruit yield losses
macularis f. sp. fragariae used in the inoculations
(Okayama, 1995; Ashour, 2009). Use of induced
originated from strawberries cv. Albion previously
resistance in disease management has a promising
grown in the same glasshouse. The fungus was identified
approach against several bacterial, fungal, and viral plant
under a slide stereoscopic microscope based on the
diseases during the past decade as the application of
morphology of conidia. Conidia are smooth-walled and
certain environmentally safe chemicals (e.g. calcium
barrel-shaped, 25 to 38 µm long and 15 to 23 µm wide
chloride or hydrogen peroxide) may activate the
(Braun et al., 2002). The fungus was maintained on
endogenous defense mechanisms of plants, providing
young susceptible plants of the same cultivar.
long-lasting resistance. Resistance-inducing chemicals
Sporulating colonies of powdery mildew on leaves
were investigated as safe alternatives for controlling
were put into a plastic Petri dish containing distilled
powdery mildews on cucurbits and strawberry (Abo-
water. Conidia were detached by brushing. The
Taleb, 2000; Hilall, 2004; Palmer, 2007; Hukkanen et
concentration of the fungal inoculum was adjusted to 107
al., 2007; Abada et al., 2008; Ashour, 2009).
conidia/ ml using a haemocytometer slide (Rodriguez-
Therefore, this research was conducted to study the
Tudela et al., 2003). The pathogenicity of the fungus
occurrence and control of strawberry powdery mildew
was confirmed by spraying the conidial suspension at 10
under glasshouse conditions in Al-Shoubak area of
strawberry plants (cv. Albion) under controlled growth
Jordan.
chamber conditions (20 ± 2°C and 12 hour-day light).
MATERIALS AND METHODS
Early foliar infections of Sphaerotheca macularis f. sp.
Greenhouse facilities and plant material
fragariae were characterized by small white patches of
Visual observations of strawberry powdery mildew
superficial growths of the fungus on leaf blade and
were carried out inside a commercial glasshouse at Al-
petiole and small fruits of the susceptible plants of cv.
Shoubak area of Jordan, situated approximately 260 km
Albion, dense mycelial growth and numerous chains of
south of Amman. The greenhouse had several passages
conidia give these patches a powdery appearance.
2
between planting lines and 100 m long polystyrene
Artificial
inoculation
under
growth
room
conditions
shelves on each side of the greenhouse. Each shelf
contained 400 strawberry (cv. Albion) plants in peat
Ten plants of strawberry cv. Camarosa or cv. Albion
bags in a single row. The height of the shelves above the
transplanted into pots containing a pasteurized mixture
floor could be adjusted whenever necessary for picking,
of clay, peat and perlite (1:1:1 v/v/v) were individually
-381-
Occurrence and Control of…
Muwaffaq Ramadan Karajeh et al
sprayed with the conidial suspension at 107 conidia/ ml
bioassay, leaflets (5cm-in-diameter) were individually
concentration. All plants were allowed to grow under
picked from strawberry (cv. Albion) plants and dipped in
growth room conditions with a 12 hour photoperiod
100 ml of the tested chemical solutions of each fungicide
under fluorescent light (4000 lux /day) for four weeks.
(Table 1) at the highest and lowest application rates
Spreader powdery mildew-heavily diseased plants were
according to manufacturer's instructions or resistance
distributed among the artificially inoculated plants to
inducer (hydrogen peroxide at 10 and 100mM or calcium
increase the possibility of infection. Disease severity was
chloride at 1 and 10 g/l) or distilled water as a control for
categorized using 0-4 disease scale (0: no infection, 1:
10 seconds and then sprayed with the conidial suspension.
small patch (up to 10%), 2: 11-25%, 3: 26-50% and 4:
Each leaflet was placed into a test tube containing 10 ml
more than 50 % leaf area covered with mildew growth)
distilled water and incubated in a full-controlled growth
as described by Okayama et al. (1995). The overall
chamber at 20°C with a 12 hour photoperiod under
disease severity % was the sum of numerical ratings per
fluorescent light (3000 lux /day) for one week. All
a treatment divided on the total number of leaves
treatments and control were arranged in a completely
observed multiplied 100 over the maximum disease
randomized design (CRD). Each treatment was replicated
category value (4). Disease incidence was expressed as
three times. Disease severity was rated from 0 to 100%
the % of diseased leaflets per a plant.
according to mycelial coverage of infected leaves and was
In vitro leaf discs bioassay
recorded one week after treatment.
Two in vitro leaflet bioassays were done, in the first
Table 1. Detailed information of fungicides used in this study:
Fungicide
Flusilazole
Hexaconazole
Triadimefon
Carbendazim
Sulfur
Trade name
Punch
Canvil
Triadimefon
Mycozim
H-Sulfur
Formulation
40% EC
5% SC
20% EC
50% SC
80% WP
Company
Dupont
Vapco
Singma
Taicang city
Al-Lahab
Chemical group
Triazoles
Triazoles
Triazoles
Benzimidizoles
Minerals
While in the second bioassay, powdery mildew-
treatment compared with that of the control. If the % of
infected leaflets (5cm-in-diameter) were individually
disease control more than 50% the treatment is
picked from strawberry (cv. Albion) plants, dipped in
considered effective in controlling the powdery mildew.
100 ml of the tested chemical solutions or distilled water
Runner-tip plantlets experiment
as a control for 10 seconds, placed into a test tube
Runner-tip plantlets slightly infected with powdery
containing cotton plug moistened with distilled water
mildew (around 30% disease severity) were individually
and incubated as before. Treatments and control were
picked from strawberry (cv. Albion) plants, transplanted
replicated three times and arranged in CRD. Disease
into small plastic pots (250ml in volume) filled with
severity % was assessed and recorded as before. The
moistened perlite and sprayed with the tested chemical
percentage of disease control was also recorded as the %
solutions or distilled water as a control and incubated in
of relative reduction in the disease severity % of the
a plant growth chamber at 20°C with a 12 hour
-382-
Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
photoperiod under fluorescent light (3000 lux /day) and
were noticed on the patches on the leaves, fruits or other
80% relative humidity for one week. Disease severity %
plant parts under field, greenhouse or laboratory
was assessed as previously described while disease
conditions.
Regarding to leaf position on strawberry plant, there
incidence was expressed as the % of diseased leaflets per
were no significant differences in disease severity %
a plantlet.
Statistical analysis
between top, middle or bottom leaves during 2008 in
Data were analyzed statistically using general linear
strawberry growing season under glasshouse conditions
model (GLM) procedure (SPSS software version 11.5;
while top leaves were more susceptible for powdery
SPSS Inc., Chicago, USA). Least significance difference
mildew infection during 2009 strawberry growing
(LSD) test and t-test were used for mean separation at
season (Figure 1). The edges of heavily infected leaves
the 0.05 probability level (Steel et al., 1997).
curled
upward.
Disease
incidence
and
severity
RESULTS
percentages were 46.7% and 50.8%, respectively on cv.
More patches were found on the lower surface than
Albion and significantly different from that (1.6% and
5.2%, respectively) on cv. Camarosa (Table 2).
the upper leaf surface. Few patches of the mycelial
growth were noticed on cv. Camarosa. No cleistothecia
Table 2. Disease incidence and severity of powdery mildew on two strawberry cultivars under growth room conditions.
Cultivar
Disease incidence %
Disease severity %
Albion
46.71 a2
50.8 a
1.6 b
5.2 b
Camarosa
2
Average of 10 plants/ treatment
Means within columns followed by the same letters are not significantly different at 0.05 probability level using t-test.
A- Strawberry growing season 2008
100
Disease severity %
1
80
top
60
middle
40
bottom
20
0
8 Mr
16 Mr
4 Ap
22 Ap
10 Ma
Date of disease assessment
-383-
28 Ma
Occurrence and Control of…
Muwaffaq Ramadan Karajeh et al
B- Strawberry growing season 2009
Disease severity %
100
80
top
60
middle
40
bottom
20
0
8 Mr
16 Mr
4 Ap
26 Ap
9 Ma
28 Ma
Date of disease assessment
Figure 1. Powdery mildew disease development on strawberry with respect to leaf position (top, middle and
bottom) during 2008 (LSD0.05= 10.5) and 2009 (LSD0.05= 22.4) growing seasons inside glass-house in Al-Shoubak
area of Jordan.
Table 3 shows the results of the two in vitro leaflet
(50% Carbendazim) and sulfur gave good control at their
bioassays. Among the tested fungicides, Canvil (5%
high application rates (77 and 58%, respectively). At
hexaconazole) at both low and high application rates
their low concentrations, both hydrogen peroxide (10
gave significant reductions in disease severity %
mM) and calcium chloride (1 g/l) as resistance inducers
compared to that of the control (water) and lead to more
gave 61 and 68% control, respectively.
than 50% control (58 and 64%, respectively). Mycozim
Table 3. Effect of fungicides and resistance-inducing chemicals on powdery mildew disease severity on strawberry (cv.
Albion) leaflets in two in vitro leaflet bioassays:
Fungicide/ resistance inducer
Canvil
Triadimefon
Punch
Mycozim
Sulfur
Conc.
DS1 %1
DS2 %2
Mean
Control %3
Low, 4ml/ 20L
11.74 c5
38.8 b
25.4 h
58
High, 8ml/ 20L
18.3 c
25.0 bc
21.8 j
64
Low, 4ml/ 20L
52.5 a
44.3 ab
48.6 c
20
High, 10ml/ 20L
13.8 c
62.3 ab
38.2 e
37
Low, 1ml/ 20L
44.4 ab
44.1 ab
44.4 d
27
High, 1.5ml/ 20L
56.8 a
44.5 ab
50.8 b
17
Low, 10 ml/20L
8.3 c
56.5 ab
32.6 f
47
High, 20 ml/20L
20.0 bc
7.7 c
14.0 l
77
Low, 40g/ 20L
10.1 c
67.0 a
38.7 e
37
High, 50g/ 20L
10.0 c
40.6 b
25.5 h
58
-384-
Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
Conc.
DS1 %1
DS2 %2
Mean
Control %3
Low, 1 g/L
7.5 c
31.0 bc
19.4 k
68
High, 10 g/L
18.4 c
43.8 ab
31.3 g
49
Low, 10mM
10.5 c
36.5 b
23.7 i
61
High, 100mM
51.3 a
46.5 ab
49.1 c
20
-
56.7 a
65.0 ab
61.0 a
-
Fungicide/ resistance inducer
Calcium Chloride
Hydrogen peroxide
Water
1
DS1%: disease severity % in the first assay recorded 1 week after treatment.
DS2%: disease severity % in the second assay recorded 1 week after treatment.
3
Control % = Powdery mildew disease severity% in control- that in treatment divided on disease severity in the control (water)
multiplied by 100%.
4
Average of 3 replicates.
5
Means within columns followed by the same letters are not significantly different at 0.05 probability level using LSD test.
2
Results of the runner-tip plantlet experiment
sulfur at their low application rates. Hydrogen peroxide
indicated that the % of disease leaflets and disease
at both concentrations (10 and 100 mM) gave 56 and
severity % were significantly reduced for the treatments
66% control, respectively while calcium chloride gave
than that for the control (Table 4). All of the tested
the highest % of control (79%) at 1 g/l concentration
fungicides and resistance inducers gave more than 50%
(Table 4).
control except for Triadimefon, Punch, Mycozim and
Table 4. Effect of fungicides and resistance-inducing chemicals on powdery mildew disease development on
strawberry (cv. Albion) runner-tip plantlets:
Fungicide/ resistance inducer
Canvil 5%SC
Triadimefon
Punch 40EC
Mycozim
Sulfur
Calcium Chloride
Hydrogen peroxide
Conc.
LD %1
DS %2
Control %3
Low, 4ml/ 20L
33.34 c5
25.6 c-f
63
High, 8ml/ 20L
33.3 c
28.8 b-f
59
Low, 4ml/ 20L
33.3 c
36.6 bcd
48
High, 10ml/ 20L
33.3 c
18.6 ef
73
Low, 1ml/ 20L
33.3 c
37.0 bcd
47
High, 1.5ml/ 20L
33.3 c
18.0 ef
74
Low, 10 ml/ 20L
33.3 c
36.2 b-e
48
High, 20 ml/20L
33.3 c
19.0 ef
83
Low, 40g/ 20L
50 b
46.0 b
34
High, 50g/ 20L
50 b
14.5 f
79
Low, 1 g/L
33.3 c
15.0 f
79
High, 10 g/L
33.3 c
36.5 b-e
48
Low, 10mM
50 b
20.5 ef
71
-385-
Occurrence and Control of…
Muwaffaq Ramadan Karajeh et al
Conc.
LD %1
DS %2
Control %3
High, 100mM
33.3 c
30.5 b-f
56
-
66.7 a
69.8 a
-
Fungicide/ resistance inducer
Water
1
LD%: % of diseased leaflets per a plantlet.
DS%: disease severity %.
3
Control % = Powdery mildew disease severity% in control- that in treatment divided on disease severity in the control (water)
multiplied by 100%.
4
Average of 3 replicates.
5
Means within columns followed by the same letters are not significantly different at 0.05
probability level using LSD test.
2
DISCUSSION
time of ripening and liberation of ascospores is
Powdery mildew of strawberry was found in Al-
important to development of integrated control of
Shoubak area of Jordan under glasshouse conditions.
powdery mildew (Jarmolica and Bankina, 2009). In our
The fungus Sphaerotheca macularis f. sp. fragariae was
study, no cleistothecia were found. It seems that the
the causal agent of the disease and its pathogenicity was
fungus does not form cleistothecia under glasshouse and
confirmed by inoculation on the susceptible strawberry
laboratory
cv. Albion under laboratory conditions. To our
powdery mildew were detected in Latvia (Jarmolica and
knowledge, this is the first study done on strawberry
Bankina, 2009) and Norway (Gadoury et al., 2007)
powdery mildew caused by Sphaerotheca macularis f.
while no cleistotheica were detected in England (Peries,
sp. fragariae of in Jordan.
1962) and Spain (Santos et al., 2002). Presence or
conditions.
Cleistothecia
of
strawberry
Regarding to plant leaf position, top leaves were
absence of cleistothecia as a source of genetic
found more susceptible than middle or bottom leaves for
variability, may affect the efficiency of applied
powdery mildew infection. Lower leaf surface was more
fungicides through developing resistance. Benomyl
susceptible for powdery mildew infection than the upper
failed to control powdery mildew on strawberry plants in
leaf surface. At least in part, the more-common
Maine
appearance of the pathogen on the lower leaf surface
Sphaerotheca macularis f. sp. fragariae were discovered
reflects escape of the upper epidermis from infection due
while in other US states (North Carolina, Tennessee and
to leaf folding during a critical susceptible phase
Arkansas) where no cleistothecia were found, benomyl
(Gadoury et al., 2007). Leaf and plant phenology can
successfully controlled the disease (Howard and
also be an important factor affecting tolerance. Higher
Albregts, 1982).
and
Michigan
where
cleistothecia
of
disease incidence on younger (top) leaves was noticed.
Strawberry cv. Camarosa was more resistant to
This agrees with Okayama et al. (1995), who observed
powdery mildew infection than cv. Albion. In a previous
that the youngest leaflets were more susceptible than the
study (Mertely et al., 2004) to evaluate the effect of
intermediate or the oldest leaflets and stolon-derived
powdery mildew on cv. Camarosa inside tunnels,
daughter plants were more susceptible to infection than
powdery mildew symptoms on plant foliage were light
mature plants.
and apparently unrelated to marketable yield. Therefore,
the more resistant cv. Camarosa could be effectively
The main source of infection is cleistothecia, and
-386-
Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
conditions (Ashour, 2009).
used to control powdery mildew.
Among the tested chemical fungicides, Canvil gave a
Hydrogen peroxide at 10 mM was effective in
considerable control for powdery mildew. Other
controlling powdery mildew on strawberry. After a foliar
fungicides (Sulfur, Triadimefon, Mycozim and Punch
spray with a solution of hydrogen peroxide, leaves
(40% flusilazole) were more effective at the high
exhibited resistant against Podosphaera fusca (Fr.) U.
application rates. Fungicides should be applied at the
Braun & Shishkoff fungus, the causal agent of cucumber
first sign of disease to control powdery mildew on
powdery mildew. Hydrogen peroxide (at 15 mM
susceptible cultivars. This is especially important when
concentration) was able to greatly decrease the disease
using protectant contact fungicides such as sulfur. The
severity in two subsequent cucumber growing seasons
control
(Hafez et al., 2008).
of
powdery
mildew
with
fungicides
is
problematic since only a limited number of appropriate
Resistance to downy mildew caused by Sclerospora
systemic fungicides, is available and powdery mildew
graminicola on pearl millet was chemically induced by
fungi have a high tendency of developing fungicide-
treating seeds of highly susceptible cultivars with the
tolerant strains as observed with other crops (Chin et al.,
resistance activator benzothiadiazole (BTH), calcium
2001; McGrath, 2001).
chloride and hydrogen peroxide giving 78%, 66% and
Foliar application of nutrients can reduce severity of
59% protection, respectively (Geetha and Shetty, 2002).
fungal diseases by supplementing the nutrition of the
Spraying barley leaves with 25 mM of hydrogen
plant, increasing natural foliar defence mechanisms and
peroxide inhibited powdery mildew pathogen (Blumeria
in
graminis f. sp. hordei) and symptom development
some
cases
adversely
affecting
the
fungal
(Hafez and Kiraly, 2003).
development (Palmer, 2007). Calcium appears to have
primary role in plant defence through maintenance of
In a conclusion, the powdery mildew of strawberry
membranes and cell walls (Marschner, 1995) by
can be managed effectively by the use of resistant
enhancing the cell wall rigidity (Graham, 1983; Datnoff
cultivar e.g. Camarosa and protective or curative foliar
et al., 2001).
sprays with effective fungicides or resistance-inducing
Calcium chloride was effective at 1 g/l. This agrees
chemicals. Further studies are needed to compare the
with Palmer (2007) who found that calcium chloride
influence of resistance-inducing chemicals with that of
foliar sprays were beneficial in controlling powdery
fungicides on strawberry under greenhouse and field
mildew on strawberry. Spraying of calcium chloride
conditions of Jordan.
caused significant decrement in the disease severity with
ACKNOWLEDGEMENTS
significant increment in the fruit yield when compared
This work was financially funded in part by the
Academic Research Deanship, Mutah University, Jordan.
with check treatments under glasshouse and field
REFERENCES
Abada K. A., R. Mervat and S. H. Mostafa. 2008. Induced
Abo-Taleb M. A. 2000. Biochemical changes associated with
resistance against powdery mildew in cucumber. Journal of
application of some resistance inducing compounds for
Biological and Chemical Environmental Sciences. 3: 45-56.
controlling powdery mildew of cucumber. Egyptian Journal
-387-
Occurrence and Control of…
Muwaffaq Ramadan Karajeh et al
of Applied Science. 16: 387-404.
symptom expression of barley susceptible and resistant to
powdery mildew. Acta Phytopath. Entomol. Hung. 38:
Amsalem L., Freeman S., D. Rav-David, Y. Nitzani, A.
227–236.
Sztejnberg, I. Pertot, and Y. Elad. 2006. Effect of climatic
factors on powdery mildew caused by Sphaerotheca macularis
Hafez Y. M., Y. A. Bayoumi, Z. Pap, and K. Noémi. 2008.
f. sp. fragariae on strawberry. European Journal of Plant
Role of hydrogen peroxide and Pharmaplant-turbo against
Pathology. 114: 283-292.
cucumber powdery mildew fungus under organic and
inorganic
Anonymous. 2006. Annual Statistical Book. Ministry of Public
International
production.
Journal
of
Horticultural Science. 3: 39-44.
Statistics. Amman, Jordan.
Hilall, M.R. 2004. Induced acquired resistance to cantaloupe
Ashour A. A. 2009. Effect of application of some systemic
powdery mildew by some chemicals under greenhouse
fungicides and resistance inducing chemicals on management
conditions. Egyptian Journal of Applied Science. 19: 82-
of cantaloupe powdery mildew disease. Egyptian Journal
90.
Phytopatholology. 37: 1-8.
Horn N. L., K. R. Burnside and R. B. Carver. 1972. Powdery
Braun U., R. T. Cook, A. J. Inman, H. D. Shin. 2002. The
mildew of strawberry. Plant Disease Reporter. 56: 368.
Taxonomy of powdery mildew fungi. In: Belanger R. R., W.
Howard C. M. and E. E. Albregts. 1982. Cleistothecia of
R. Bushnell, A. J. Dike, and T. L. Carver (eds.), The Powdery
Sphaerotheca macularis on strawberry plants. Plant
Mildews: A Comprehensive Treatise. APS Press, St. Paul,
Disease. 66: 261-262.
Hukkanen A. T., H. I. Kokko, A. J. Buchala, G. J. Mcdougall,
Minnesota, USA, 13-55.
Chin K. M., D. Chavaillaz, M. Kaesbohrer, T. Staub and F. G.
D. Stewart, S. O. Renlampi and R. O. Karjalainen. 2007.
Felsenstein. 2001. Characterizing resistance risk of Erysiphe
Benzothiadiazole induces the accumulation of phenolics
graminis f. sp. tritici to strobilurins. Crop Protection. 20: 87-
and
improves
strawberries.
96.
resistance
Journal
of
to
powdery
Agricultural
mildew
and
in
Food
Chemistry. 55: 1862 -1870.
Datnoff L. E., G. H. Snyder, and G. H. Korndorfer. 2001. Silicon
Jarmolica S. and B. Bankina. 2009. Powdery mildew of
in Agriculture. Elsevier Science, The Netherlands, 403 pp.
strawberries in Latvia under field conditions. Scientific
Gadoury D. M., A. Stensvand, R. C. Seem, C. Heidenreich, M. L.
Works of the Lithuanian Institute of Horticulture and
Herrero, and M. Welser. 2007. Overwinter survival of
Lithuanian University of Agriculture. Sodininkystė Ir
cleistothecia, ascospore release, and infection of strawberry by
Daržininkyste. 28: 79-83.
Podosphaera
macularis
in
New
York
and
Norway.
Maas J. L. 1998. Compendium of strawberry diseases. 2nd ed.
Phytopathology: 97: S38.
American Phytopathological Society Press, St. Paul. Minn,
Geetha H. M. and H. S. Shetty. 2002. Induction of resistance in
USA, 128 pp.
Marschner H. 1995. Mineral nutrition of higher plants. Soil.
pearl millet against downy mildew disease caused by
334: 11-31.
Sclerospora graminicola using benzothiadiazole, calcium
McGrath M. T. 2001. Fungicide resistance in cucurbit powdery
chloride and hydrogen peroxide a comparative evaluation.
mildew: experiences and challenges. Plant Disease. 81:
Crop Protection. 21: 601–610.
236-245.
Graham R. D. 1983. Effects of nutrient stress on susceptibility of
Mertely J., T. Seijo, C. Torres, and N. A. Peres. 2004.
plants to disease with particular reference to the trace elements.
Evaluation of fungicides to control powdery mildew on
Advanced Botanical Research. 10: 221-276.
annual strawberry. F&N Tests. 60: 2003-04.
Hafez Y. M. and Z. Kiraly. 2003. Role of hydrogen peroxide in
-388-
Jordan Journal of Agricultural Sciences, Volume 8, No.3 2012
Miller T. C., W. D. Gubler, S. Geng and D. M. Rizzo. 2003.
inoculum preparation for testing antifungal susceptibilities
Effects of temperature and water vapor pressure on
of filamentous fungi. Journal of Clinical Microbiology.
conidial germination and lesion expansion of Sphaerotheca
41: 5236-5237.
macularis f. sp. fragariae. Plant Disease. 87: 484-492.
Santos B., C. Blanco, M. Porras, C. Barrau and F. Romero.
Okayama K., T. Nakano, S. Matsutani and T. Sugimura. 1995.
2002. First confirmation of Sphaerotheca macularis on
A simple and reliable method for evaluating the
strawberry plants in southwestern Spain. Plant Disease.
effectiveness of fungicides for control of powdery mildew
86: 1049.
(Sphaerotheca macularis) on strawberry. Annals of the
Spencer D. M. 1978. Powdery mildew of strawberries. In: D.
Phytopathological Society of Japan. 61: 536-540.
M. Spencer, Editor, The Powdery Mildews, Academic
Palmer S. 2007. Strawberry Powdery Mildew: Epidemiology
Press, New York (1978), pp. 355–358.
and the Effect of Host Nutrition on Disease. Ph. D. Thesis,
Steel R.D., J. H. Torrie, and D. A. Dickey. 1997. Principles
the University of Adelaide, Adelaide, Australia, 278 pp.
and Procedures of Statistics: A Biometrical Approach. 3rd
Peries O. S. 1962. Studies of strawberry powdery mildew
edition, McGraw-Hill Inc., New York, USA, 612 pp.
caused by Sphaerotheca macularis: 1. Biology of the
Takeda F. 2000. Out-of-season greenhouse strawberry
fungus. Annals of Applied Biology. 50: 211-224.
production in soilless substrate. Advances in Strawberry
Research. 18: 4-15.
Rodriguez-Tudela J. L., E. Chryssanthou, E. Petrikkou, J.
Mosquera, D.W. Denning and M. Cuenca-Estrella. 2003.
Witter S. H. and N. Castilla. 1995. Protected cultivation of
horticultural crops worldwide. Hort. Technology. 5:6-23.
Interlaboratory evaluation of hematocytometer method of
-389-
‫…‪Occurrence and Control of‬‬
‫‪Muwaffaq Ramadan Karajeh et al‬‬
‫ﺤﺩﻭﺙ ﻭﻤﻜﺎﻓﺤﺔ ﻤﺭﺽ ﺍﻟﺒﻴﺎﺽ ﺍﻟﺩﻗﻴﻘﻲ ﻋﻠﻰ ﺍﻟﻔﺭﺍﻭﻟﺔ ﻓﻲ ﺍﻟﺸﻭﺒﻙ‪/‬ﺍﻷﺭﺩﻥ‬
‫ﻤﻭﻓﻕ ﺭﻤﻀﺎﻥ ﻜﺭﺍﺠﺔ‪ ،1‬ﻭﺯﻴﺎﺩ ﺒﺭﻜﺎﺕ ﺍﻟﺭﻭﺍﺸﺩﺓ‪ 2‬ﻋﺯﺍﻟﺩﻴﻥ ﻤﺤﻤﺩ ﺍﻟﺭﻤﺎﻤﻠﺔ‬
‫‪2‬‬
‫ﻤﻠﺨـﺹ‬
‫ﺘﻡ ﺘﺴﺠﻴل ﺤﺩﻭﺙ ﻤﺭﺽ ﺍﻟﺒﻴﺎﺽ ﺍﻟﺩﻗﻴﻘﻲ ﻋﻠﻰ ﺍﻟﻔﺭﺍﻭﻟﺔ ﺍﻟﻤﺘﺴﺒﺏ ﻋﻥ ﺍﻟﻔﻁـﺭ ) ‪Sphaerotheca macularis f. sp.‬‬
‫‪ (fragariae‬ﻓﻲ ﻤﻨﻁﻘﺔ ﺍﻟﺸﻭﺒﻙ ﺘﺤﺕ ﻅﺭﻭﻑ ﺍﻟﺒﻴﺕ ﺍﻟﺯﺠﺎﺠﻲ؛ ﺤﻴﺙ ﻅﻬﺭ ﻨﻤﻭ ﺍﻟﻔﻁﺭ ﺍﻷﺒﻴﺽ ﺒﻜﺜﺎﻓﺔ ﻋﻠـﻰ ﺍﻷﺴـﻁﺢ‬
‫ﺍﻟﺴﻔﻠﻴﺔ ﻟﻸﻭﺭﺍﻕ‪ ،‬ﻭﻟﻡ ﺘﻅﻬﺭ ﺍﻷﺠﺴﺎﻡ ﺍﻟﺜﻤﺭﻴﺔ ﺍﻟﻤﻐﻠﻘﺔ ﺍﻟـ ‪ cleistothecia‬ﻋﻠﻰ ﺃﻱ ﺠﺯﺀ ﻨﺒﺎﺘﻲ ﻤﻁﻠﻘﺎﹰ‪ ،‬ﻭﻜﺎﻨﺕ ﺍﻷﻭﺭﺍﻕ‬
‫ﺍﻟﻌﻠﻭﻴﺔ ﺃﻜﺜﺭ ﻋﺭﻀ ﹰﺔ ﻟﻺﺼﺎﺒﺔ ﻤﻥ ﺍﻷﻭﺭﺍﻕ ﺍﻟﻭﺴﻁﻰ ﻭﺍﻟﺴﻔﻠﻴﺔ‪ .‬ﺘﻡ ﺇﺠﺭﺍﺀ ﻋﺩﻭﻯ ﺍﺼﻁﻨﺎﻋﻴﺔ ﻟﺼﻨﻔﻲ ﺍﻟﻔﺭﺍﻭﻟـﺔ ﺍﻟﺒﻴـﻭﻥ‬
‫ﻭﻜﻤﺎﺭﻭﺯﺍ ﺘﺤﺕ ﻅﺭﻭﻑ ﻏﺭﻓﺔ ﺍﻟﻨﻤﻭ؛ ﺤﻴﺙ ﻜﺎﻨﺕ ﺸﺩﺓ ﺍﻟﻤﺭﺽ ﻭﻨﺴﺒﺔ ﺤﺩﻭﺜﻪ ‪ %46.7‬ﻭ‪ %50.8‬ﻓﻲ ﺼـﻨﻑ ﺍﻟﺒﻴـﻭﻥ‪،‬‬
‫ﻭﻫﻲ ﺃﻋﻠﻰ ﻤﻌﻨﻭﻴﹰﺎ ﻤﻥ ﺍﻟﺼﻨﻑ ﻜﻤﺎﺭﻭﺯﺍ )‪ %1.6‬ﻭ‪ %5.2‬ﻋﻠﻰ ﺍﻟﺘﻭﺍﻟﻲ(‪ .‬ﺘﻡ ﺇﺠﺭﺍﺀ ﻓﺤﺹ ﻤﺨﺒﺭﻱ ﺒﺎﺴﺘﺨﺩﺍﻡ ﻭﺭﻴﻘـﺎﺕ‬
‫ﺍﻟﻔﺭﺍﻭﻟﺔ ﻟﺩﺭﺍﺴﺔ ﺘﺄﺜﻴﺭ ﺒﻌﺽ ﺍﻟﻤﺒﻴﺩﺍﺕ ﺍﻟﻔﻁﺭﻴﺔ ﻭﺍﻟﻜﻴﻤﺎﻭﻴﺎﺕ ﺍﻟﻤﺤﻔﺯﺓ ﻟﻠﻤﻘﺎﻭﻤﺔ ﻓﻲ ﻤﻜﺎﻓﺤﺔ ﺍﻟﻤﺭﺽ؛ ﺤﻴﺙ ﺘﻔﻭﻕ ﻤﻌﻨﻭﻴـﹰﺎ‬
‫ﻻ ﻋﻨﺩ ﻨـﺴﺒﺔ ﺍﻻﺴـﺘﺨﺩﺍﻡ‬
‫ﻤﺒﻴﺩ ﻜﺎﻨﻔل ﻓﻲ ﻤﻜﺎﻓﺤﺔ ﺍﻟﻤﺭﺽ ﺒﻴﻨﻤﺎ ﻜﺎﻥ ﻜل ﻤﻥ ﺍﻟﻜﺒﺭﻴﺕ ﻭﺘﺭﺍﻴﺩﻴﻤﻔﻭﻥ ﻭﻤﺎﻴﻜﻭﺯﻴﻡ ﻭﺒﻨﺵ ﻓﻌﺎ ﹰ‬
‫ﻻ‬
‫ل ﻤﻥ ﻜﻠﻭﺭﻴﺩ ﺍﻟﻜﺎﻟﺴﻴﻭﻡ )ﻋﻨﺩ ‪ 1‬ﻏﻡ‪ /‬ﻟﺘﺭ( ﻭﺒﻴﺭﻭﻜﺴﻴﺩ ﺍﻟﻬﻴﺩﺭﻭﺠﻴﻥ )ﻋﻨﺩ ‪ 10‬ﻤﻠﻴﻤﻭﻟﺭ( ﻓﻌﺎ ﹰ‬
‫ﺍﻟﻌﻠﻴﺎ ﻓﻘﻁ‪ ،‬ﻭﻜﺎﻥ ﺍﺴﺘﺨﺩﺍﻡ ﻜ ّ‬
‫ﻓﻲ ﻤﻜﺎﻓﺤﺔ ﺍﻟﺒﻴﺎﺽ ﺍﻟﺩﻗﻴﻘﻲ ﻋﻠﻰ ﺍﻟﻔﺭﺍﻭﻟﺔ‪.‬‬
‫ﺍﻟﻜﻠﻤﺎﺕ ﺍﻟﺩﺍﻟﺔ‪ :‬ﺃﺼﻨﺎﻑ‪ ،‬ﻤﺒﻴﺩﺍﺕ ﻓﻁﺭﻴﺔ‪ ،‬ﺇﺩﺍﺭﺓ‪.Sphaerotheca ،‬‬
‫____________________________________________‬
‫‪(1‬‬
‫ﺃﺴﺘﺎﺫ ﻤﺸﺎﺭﻙ ﻓﻲ ﺃﻤﺭﺍﺽ ﺍﻟﻨﺒﺎﺕ‪ ،‬ﻗﺴﻡ ﻭﻗﺎﻴﺔ ﺍﻟﻨﺒﺎﺕ ﻭﺍﻟﻤﻜﺎﻓﺤﺔ ﺍﻟﻤﺘﻜﺎﻤﻠﺔ‪-‬ﻜﻠﻴﺔ ﺍﻟﺯﺭﺍﻋﺔ‪ ،‬ﺠﺎﻤﻌﺔ ﻤﺅﺘﺔ‪ ،‬ﺍﻟﻜﺭﻙ ‪ ،7‬ﺍﻷﺭﺩﻥ‬
‫‪ (2‬ﺃﺴﺘﺎﺫ ﻤﺴﺎﻋﺩ ﻓﻲ ﻭﻗﺎﻴﺔ ﺍﻟﻨﺒﺎﺕ‪ ،‬ﻜﻠﻴﺔ ﺍﻟﺸﻭﺒﻙ‪ ،‬ﺠﺎﻤﻌﺔ ﺍﻟﺒﻠﻘﺎﺀ ﺍﻟﺘﻁﺒﻴﻘﻴﺔ‪ ،‬ﺍﻟﺸﻭﺒﻙ ‪ ،71911‬ﺍﻷﺭﺩﻥ‬
‫‪(3‬‬
‫ﺃﺴﺘﺎﺫ ﻤﺴﺎﻋﺩ ﻓﻲ ﺍﻟﺒﺴﺘﻨﺔ‪ ،‬ﻜﻠﻴﺔ ﺍﻟﺸﻭﺒﻙ‪ ،‬ﺠﺎﻤﻌﺔ ﺍﻟﺒﻠﻘﺎﺀ ﺍﻟﺘﻁﺒﻴﻘﻴﺔ‪ ،‬ﺍﻟﺸﻭﺒﻙ ‪ ،71911‬ﺍﻷﺭﺩﻥ‬
‫ﺘﺎﺭﻴﺦ ﺍﺴﺘﻼﻡ ﺍﻟﺒﺤﺙ ‪ 2011/5/17‬ﻭﺘﺎﺭﻴﺦ ﻗﺒﻭﻟﻪ ‪.2012/4/30‬‬
‫‪-390-‬‬