الفهرس 
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Abstract
Our study was designed to combat rot the fruits of cucurbits Surveying the natural disease incidence of the most cucumber and
squash fruit rots occurrence in many locations of seven
governorates (i.e. Beheira, Kafr El-Sheikh, Qalubiya, Ismailia,
Sharkiya, Dakahliya and Giza) was performed. All laboratories, greenhouse and field experiments were carried out during autumn
and spring of 2003 and 2004 seasons.
The obtained results could be summariezed as following:
1- Surveying of cucumber and squash fruit diseases under
greenhouse conditions indicated that, the fruit rot disease
severity (DS) was obviously higher in 2003 than 2004 seasons
with great variation between seasons and tested locations.
2- Isolation trials showed that 152 and 81 fungal isolates were
isolated from rotted fruits of cucumber and squash
respectively. These fungal isolates included Alternaria spp., B.
cinerea, F. solani, Mucor spp., Penicillium spp., Pythium spp.
and Sclerotinia sclerotiorum.
3- On cucumber fruits, the highest DS was incited by B. cinerea
isolated from Ismaelia and Beheira and F. solani isolated from
Beheira, Kafr El-Sheikh and Ismaelia whereas, B. cinerea
isolated from Sharkia, Ismaelia and F. solani isolated from
Ismaelia recorded the highest DS on the squash fruits.
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4- Disease severity on cucumber or squash fruits were increased
with increasing inocula concentrations of the tested fruit rot
pathogens from 1000 to 7000 spores/ml. The highest
significant increase of DS was recorded when inocula
concentration increased from 6000 to 7000 spores/ml (B.
cinerea on cucumber and squash fruits) and F. solani (on
cucumber fruits) mean while increasing inocula concentration
of F. solani from 5000 to 6000 spores/ml caused the highest
significant increase in DS comparing with any other rots.
5- Fruits of cucumber Heikal cultivar seemed to be the most
resistant against infection with B. cinerea and F. solani
followed by Delta Star, Shams, New Star, Fysal, Sinai I and
Samar cultivars.
6- Disease severity caused by B. cinerea on cucumber fruits was
significantly higher than DS caused by F. solani meanwhile,
DS caused by both pathogens was significantly equal on
squash fruits. Also, DS of both tested pathogens were
increased as plant age and fruit age increased and it was
significantly higher on the wounded than the unwounded
cucumber or squash fruits.
7- Disease severity was significantly higher on fruits stored for 8
than those stored for 4 days. It was noticed that DS developed
more slowly on cucumber fruits stored at lower temperature
regimes (2, 5 and 7°C) than those stored at room temperature
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139
(24°C). At 24°C, DS caused by B. cinerea developed more
quickly than that caused by F. solani.
8- Disease severity was significantly affected by CO2
concentrations and storage period. The lowest DS on cucumber
fruits inoculated with B. cinerea or F. solani was recorded
after 10 days of storage under conditions containing 10% CO2
concentration.
9- Exposing fruits to the UV-treatments at 280 and 320 nm
resulted in significant decreases in DS. Applying the UVexposure
under conditions of the present study could not be
satisfactory practice for suppressing DS on the cucumber
fruits.
10- All tested fungicides were effective in suppressing the
growth of the tested fruit rot pathogens in vitro. Ronilan
fungicide was the most effective one where it completely
inhibited the growth of B. cinerea followed by Sumisclex
fungicide. However, the fungicides Rovral, Sumisclex,
Ronilan, and Tecto were the most effective ones respectively
for inhibiting growth of F. solani. Inhibition of fungal growth
(both tested pathoges) increased as the concentration of the
tested fungicides increased.
11- Spraying cucumber or squash plants with any tested
fungicide significantly decreased the fruit rot DS caused by B.
cinerea or F. solani. The fungicides Copral and Teledor were
the highly effective in controlling DS caused by B. cinerea
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140
whereas, Copral, Ridomil and Teledor were the best effective
fungicides in controlling DS caused by F. solani on cucumber
fruits. Also, Copral and Teledor were the best fungicides in
decreasing DS caused by B. cinerea and F. solani on squah
fruits. Increasing the fungicdal concentration decreased
gradually the recorded DS on infected cucumber or squash
fruits.
12- Spraying cucumber and squash plants with some resistance
inducers significantly reduced the fruit rot DS on the harvested
cucumber and squash fruits. On cucumber fruits, the lowest DS
caused by B. cineria was recorded on fruits harvested from
plants previously sprayed with KH2PO4, CaCl2 and Na2SO4,
SA, OA Meanwhile, OA, KH2PO4 and SA were the best for
controlling cucumber fruit rot DS caused by F. solani. In case
of squash fruits, the lowest significant DS caused by B. cineria
was recorded by SA followed by KH2PO4, OA, LiSO4, and
Na2SO4 comparing with the untreated control. Also, the least
DS of F. solani infections on squash fruits was recorded with
OA followed by KH2PO4.
13- Spraying of cucumber and squash plants with some
resistance inducers (Bion, SA, OA, KH2PO4 and CaCl2)
induced changes in the electrophoresis of the soluble proteins
in plant leaves. The number of protein bands was higher in
leaves of treated plants than the untreated control. Comparing
to the untreated cucumber leaves (control), 27 new protein
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141
bands with MW ranged between 51 and 39 kDa were appeared
in leaves of treated cucumber plants. Similarly, 22 new bands
with MW ranged between 55 and 47 kDa were detected in
squash leaves. In general, the highest number of the new
protein bands was detected in cucumber or squash leaves
treated with Bion or salicylic acid (SA).
14- Spraying cucumber and squash plants with the most tested
resistance inducers and fungicides resulted in conspicuous
increases in the quantities of total and free phenols in fruits
which inoculated with B. cinerea and F. solani comparing to
fruits harvested from untreated plants (control treatment). In
case of cucumber fruits, all tested treatments reduced the
conjugated phenols while, Catechol, Bion and Ethephon (B.
cinerea), Teledor, Copral and Catechol (F. solani) recorded the
highest increases in quantities of total and free phenols in
treated and infected cucumber fruits comparing with the
untreated control. Similar trend was recorded concerning
squash fruits. Spraying squash plants with Catechol recorded
the highest quantity of free phenols while the highest quantity
of total phenols was recorded with Copral fungicide treatment
in case of B. cinerea infection. In case of F. solani infection,
the highest quantities of free phenols were recorded with
Ethephon and Teledor treatments.
15- Spraying cucumber and squash plants with the tested
resistance inducers and fungicides affected the total amino
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142
acids content of harvested fruits, which inoculated with B.
cinerea and/or F. solani. The highest increase in total amino
acids in cucumber fruits harvested from plants sprayed with
Teledor and Catechol and squash fruits harvested from plants
sprayed with Calcium chloride (F. solani). On the other hand,
spraying cucumber plants with Catechol, Teledor, Copral or
Ethephon recorded the highest amounts of total amino acids in
cucumber fruits inoculated with B. cinerea whereas, Teledor
and Catechol were the best effective treatments in increasing
total amino acids content in squash fruits inoculated with B.
cinerea.
16- Spraying cucumber and squash plants with plant extracts or
kombucha tea preparation significantly decreased DS of fruit
rots caused by B. cinerea or F. solani. On cucumber fruits,
marjoram extract was the most effective as it completely
suppressed DS caused by B. cinerea followed by kombucha
tea, ginger and garlic, henna and nigella. However, nigella,
henna, marjoram and ginger preparations were the most
effective where they decreased DS caused by F. solani,
followed by thyme, kombusha tea, garlic and carnation,
respectively comparing with the untreated control. As for
squash fruits, henna, garlic, carnation and ginger preparations
were the most effective for decreasing DS caused by B.
cinerea followed by nigella, kombusha tea and marjoram
whereas, the preparations of garlic, henna, ginger, nigella,
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carnation and thyme were the most effective against fruit rot
caused by F. solani.
17- Using any of the tested plant extracts or kombusha tea
greatly decreased the activity of PME enzyme in cucumber
fruits inoculated with B. cinerea or F. solani comparing to the
untreated control. In cucumber fruits inoculated with B.
cinerea, ginger extract was the most effective for reducing
PME activity followed by marjoram, nigella, garlic,
kombucha, carnation, henna and thyme, respectively whereas,
ginger extract still the most effective for decreasing PME
activity in fruits inoculated with F. solani, followed by nigella,
marjoram, kombucha, garlic, thyme, carnation and henna,
respectively. In squash fruits inoculated with B. cinerea,
kombucha tea and nigella were the most effective for reducing
PME activity followed by marjoram, ginger, garlic, carnation,
henna and thyme particularly comparing to the untreated
control. However, in fruits inoculated with F. solani, nigella
and thyme extracts were the most effective and completely
suppressed PME activity followed by garlic, kombucha,
ginger, marjoram, henna and carnation, respectively.
18- Spraying cucumber and squash plants with any of the tested
preparation (plant extracts or kombusha) decreased activity of
the polygalacturonase (PG) enzyme in their fruits inoculated
with B. cinerea or F. solani comparing to the inoculated fruits
harvested from the untreated plants. In general, garlic extract
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144
caused the highest reduction in activity of PG followed by
kombucha, marjoram, nigella, carnation, henna, thyme and
ginger extracts, respectively in fruits inoculated with B.
cinerea. However, thyme extract caused the highest decrease
in PG activity in inoculated fruits with F. solani followed by
nigella extract, kombucha, henna, marjoram, ginger, garlic and
carnation, respectively.
19- The activity of polyphenoloxidase (PPO) enzyme was
higher in cucumber and squash fruits harvested fron plants
previously sprayed with any of the tested plant extracts or
kombusha tea after inoculation with B. cinerea or F. solani
comparing to inoculated fruits harvested from control
treatment (untreated). In fruits of cucumber, the highest PPO
enzyme activity was recorded with pre-harvest treatment with
nigella extract (B. cinerea) and marjoram and nigella extracts
(F. solani). As for squash fruits, the highest activity of PPO
enzyme was recorded in fruits harvested from plants formerly
sprayed with with nigella extract and kombusha followed by
thyme, henna and carnation extracts respectively (B. cinerea)
and marjoram, henna and carnation extracts (F. solani).
20- As for the activity of peroxidase (PRO) enzyme in
cucumber fruits under stress of infection with the tested fruit
rot pathogens, the highest PRO activity was recorded in fruits
harvested from cucumber plants previously sprayed with henna
followed by ginger and kombusha tea respectively (B. cinerea)and henna, kombusha and marjoram extract, respectively (F.
solani). In squash fruits inoculated with B. cinerea, the activity
of PRO enzyme was higher in fruits harvested from plants that
were pre-sprayed with henna and kombusha tea, respectively.
In case of squash fruits inoculated with F. solani, the highest
PRO activity was recorded in fruits harvested from plants
treated with nigella extract followed by henna.