الفهرس 
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Abstract
SOJIlIARY AJID aB:LUSIOB
Fruit rots caused by various fungi are considered
one of the most serious troubles that reflecting
considerable deterioration in both quantity and quality
of pome fruits during storage and retail marketing.
So, the present work was planned to study the
physiological and pathological deterioration of stored
fruits in order to reduce losses and increase the storage
life of fruits using some fungicides such as
thiabendazole a systemic or Botran a contact fungicides
as well as pre storage treatments with compounds that
increase the resistance of fruits to fungal invasion
and fruit deterioration such as caC12 and Vapor Gard
(Poly-I-methene 8-9 diyl). Moreover, evaluation some
consumer packages was carried out in this respect.
The present work was udnertaken during the seasons
of 1985, 1986 and 1987 in order to identification the
deterioration aspects of pome fruits during storage and
retail marketing.
In the first season, results obtained could he
summarized as follows :
1. Isolation from naturally rotted fruits indicated
that Penicillium expansum, Botrytis cinerea, Alternaria
alternata and ASpergillus ~ were the more frequent
isolates responsible for causing apple (Anna, Bercker)
cultivars and pear (Le Conte, Bartlett) cultivars, fruit
rots. Other fungi such as Rhiwopus ~ Cladosporium
Pencillium ~ and stymphyllium sp., occurred
in less frequency, while Diploida natalensis, Fusarium
§.E.:...L Trichothecium roseum and Negrospora .§.E..:.. showed
the least frequent rate.
2. Pathogenicity tests revealed that the degree
of infection was affected by the cultivar and the kind
of fungus. Le conte pear fruits showed higher vlaues
of infection followed by either Anna apple or Bartlett
pear fruits, but Bercker apple showed the least values
of disease severity.
Gray mould caused by the fungus B. cinerea was
the most important causal of fruit rot followed in
decreasing order by P. expansum, Alt. alternata and
ASpergillus .§E.
Therefore, the work was facused up on the
physiology of B. cinerea and its metabolic activities
on the more susceptible cultivar (Le Conte pear fruits)
during cold storage.
3. Physiological studies indicate that the
incidence of Botrytis rot developed on a _w___id--,e_....--------.-ranger-· of
tempera.tur-e for’ either -r------ ..
frui t infection or disease
severity. The proper temperature ranged between 20 -
While at 5°C the rot didn’t exceed. the inoculated
• region of the fruit till 6 days of incubation •
Under high relative humdiity (90 100 %) the
highest infection with B. cinerea was obtained. No
~i-n-f--e-ction was bserved at 14.5 % R.H. ... - ~----”””
The effect of different stages of fruit maturity
on fruit rot development proved that there was a ..p..o.=s-i.-t-.i--v--e
c~~ 19t..iPIl between the c1e9r~~_.9£ fruit maturity an,.
the incidence of Botrytis rot, where maturs
seemed to ’be resi$ts.nt~ Moreover, in vitro, mycelial
biomass increased significantly as the maturity stage
of fruit extract advanced.
4. Biochemical studies indicated that in~fectio---n------.J
with B. cinerea led to a pronouncing ir:n: s_~--ill. _r~g.’p-ciM---’
~. J:~. f;?~~ content of of mature fruits, while
sugars content in inoculated riEe fruits tended to ,defter 10 days incubation
Total phenols in mature green and greenhish yellow
pear frai ts were. generally higher than those in fruits
l\’- i
- ,Ii -
of other stages of maturity, where ,n.-o-----c--l-~a.x:..-..d--i.f-f” e-r-e-R---e-s
were noted between inoculated and\ln-inocu But at yellow green stage, the phenolic contents of
inoculated fruits were relatively higher than those in
healthy ones.
5. Rnzymatic assays in B. cinerea culture filtrate
resulted in detecting Peroxidase and polyphenol oxidase
\>-~t a }( (’ ~ ’t> J
(P. P•0) enzymes and ~th-”e”’-._m--a-x--i_m._u-m---_a.c_ti .._v-~-i” ~ was obtained
at the end of incubation~iod. Peroxidase and P.P.o.
enzymes activity was higher in the extracts of fruits
inoculated at m~~ or gre~~w stage than
other stages of maturity. Also, the levels of enzymes
In addition, the activity of Peroxidase enzymes was lower
in ripe fruits than that of mature green ones.
Studies ’of Pectolytic and cellulolytic enzymes
activity showed that B. cinerea produced Pectin
methylestrase, polygalacturonase and cellulase enzymes
in its culture filtrate, and its jactivities were
increased by prolonging the incubation period, in vitro
as well as in ~., In extracts of inoculated pear
frui ts, and after 10 days incubation PMEand PG enzymes
activity were as much two times as those of healthy
fruits. Futhermore, ex: enzymes acti vi ty was increased
in both infected and heal thy fruits and the reduction
in viscosity was more pronounced in inoculated fruits
than in healthy ones.
Studies on rot control in vitro revealed that
systemic fungicides (TBZ or Benlate) almost checked the
growth at relatively lower concentrations (500 ppm.),
while contact ones (Botran or Rovral) showed the same
effect at higher concentrations (1000 or 2000 ppm), but
caC1
2
was less effective. ~ studies, indicated that
all pre inocualtion treatments at higher concentrations·
gave highly protective effect against Botrytis rot. TBZ
treatment showed the best values followed in decreasing
order by Botran, Benlate, CaC12 and Vapor Gard, while
Rovral treatment was less effective in this respect.
Post inoculated treatments showed that TBZat 1500
ppm was more effective in reducing Botrytis rot followed
by Benlate and Botran treatments respectively. While
Rovral,
CaCI
Z
and Vapor Gard treatments were less
effective’ in this respect.
Results showed that residues in peel extract
reflected higher reduction in mycelial weight than that
\
In .p.;e..e.-l-.- extract, Benlate at
reduction effect followed in
~ CaCI
Z
and Botran respectivley.
1500
of flesh extract.
ppm gave the highest
’\.-
decreasing order by TBZ,
(1500 ppm)
in f.l.e.-s-h-= \
of TBZ,
extract, the highest concentration
2- vJ ~
Benlate and -Botran as well However,
at 2 % were statistically similar in their
as~
residual
effect.
On the other hand, -R_ovr.al- or - .Va--p-o-r. Gard
.c>
_ \68 -
treatments showed lower effects in either peel or flesh
extract.
7. St..o.-r--a--g...e studies were carried out for two seasons
(1986, 1987) on physical and chemical changes associated
with inoculation. Le conte pear fruits with B. cinerea
and stored
t
decay
at Results
Ztotal
showed a marked increase
loss in weight, c~lour
total soluble
-=f
soluble pectin,
~
chlorophyll,
solids,
percentage,,.J(
carotenoid
(’
total nitrogen content
accumulation
in
development,
and total
on the other hand a.continuous decreases in
1:- 3 ., ~ .4’
Calc~um, titratable ac~d~ty and mo~sture contents as
y
well as fruit firmness was obtained by increasing the
(25 ± 2°C) , fruits
Af~t-e--r---r--emoval to roo~ temperaturewere subjected to a sharp
period of incubation.
deterioration.
8. All compounds applied as a post-inoculated
treatments (TBZ, Botran, CaC12 and Vapor - Gard)
significantly reduced the percentage of deca.y and total
loss in weight as compared with inocualted control. TBZ
at 1000 ppm induced the lowest losses percentage during
cold storage and extended the shelf-life of treated
frui ts up to 12 days. The colour development was slower
than that in inocualted control, while the total
ti tratable acidity, moisture and calcium content were
increased as compared with inocualted control. On
contrary, total soluble solids, total soluble pectin
and total nitrogen content decreased in treated fruits.
9. Botran treatment at 1000 ppm, significantly
reduced the Botrytis rot during both cold storage and
shelf-life, but it was less effective than other
treatments in extneidng the shelf-life of treated fruits.
Moreover, the effect of Botran on the physical and
chemical properties of stored pears was somewhat similar
to that of healthy fruits.
10. The use of calcium chloride deQreased
signfiicant1y the total loss in weight, total soluble
pectin and total nitrogen content, delayed chlorophyll
degradation, carotenoids accumulation and subsequently
colour development and reduced loss of fruit firmness.
Decay percentage of inoculated fruits, was also reduced
during either cold storage or shelf-life to rank the
first treatment in this respect.
11. vapor Gard (V.G.) at 2 or 1 % was effective
in delaying the physical and chemical changes of
inocua1ted fruits, which led to fruit ripening. But
when V.G. was used at -2 % (in the first season) as ~
confirmed by .i:E. vitro data, fruits were subjected to ---- internal browning. For this reason, V.G. at 2 % was
¢ ~ es;;:: replaced by the concentration of 1 % in the second I
season. Moreover, V.G. treatment reduced significantly
loss in fruit weight, moisture content, the degradation
of either chlorophyll or pectin content and also the
accumulation of either total nitrogen or carotenoids.
A signficiant decrease in loss of fruit firmness, colour
development and Botrytis rot were signficiantly obtained
during cold storage, where the shelf-life was extended
for 12 days.
with 2 kg. capacity, i.e. perforated polyethylene bags,
Open meshed plastic bags, carton-box (with wrapped
or un-wrapped fruits) and kept at SoC, reduced
signfiicantly thatotal loss in weight and Botrytis rot
of packed fruits, except those packed in open meshed
bags.
13. perforated bags led to higher moisture content,
pronounced decrease in decay percentage during cold
storage and extended the shelf-life for 6 days. Moreover,
a significant increase in fruit firmness, total
titratable, acidity and chlorophyll contents was
obtained. On the other hand, colour development, total
soluble solids, carotneoids content, total nitrogen and
soluble pectin were markedly decreased.
14. Wrapping inoculated Le Conte pear fruits in
tissue papers and packing in caroton box, led to a marked
reduction in Botrytis rot during cold storage and
extended the shelf-life up to 6 days.
wrapped fruits
behaved similarly as those packed in perforated bags,
where the development showed a slow rate.
15. Levels of rotting and deterioration in
inocualted fruits packed in open meshed plastic bags
were significantly equal to those in inocualted control
during cols storage and
after transference to room
temperature.
16. Inoculated fruits packed in c..a.r..to.-n----b-o-x-, showed
a significant reduction in Botrytis rot and loss in fruit
weight, and extended the shelf-life for packed fruits
for only 6 days with less than 50 % sound fruits.
Moreover, the physical and chemical changes in packed
fruits were more or less the same as that of healthy
fruits.
from the previous results it could be concluded
that :
1. Store mature greeen Le conte pear fruits at
50C. seems to be suitable for prolonging the storage
life.
_ liz -
2. Treatments with some chemicals could be
considered supplementary to refrigeration of Le Conte
pear fruits.
3. The application of CaCl2 at 2 % revealed a
satisfactory results in reducing Botrytis rot as well
as Vapor Gard at I %, where CaCl2 ranked the first in
this respect.
4. post-harvest treatment with the. systemic
fungicide II Thiabendazolell revealed higher reduction in
frui trot, where vitro studies showed the rpesent of
its residues in both peel and flesh extract in treated
fruits.
S. When fruits were wrapped and packed in carton
box or when fruits were packed in perforated bage, as
a consumer package with 2 kg. capacity and kept at SoC.,
led to less decay percentages.