Post harvest diseases fruits and vegetables - Xavier University ...

FREEDOM PALESTINE FREEDOM PALESTINE FREEDOM PALESTINE
290 Postharvest Diseases of Fruits and Vegetables
For several decades black rot was controlled by disinfection of the cut
area of the fruit with sodium or^/io-phenylphenate, sodium salicylanilide
or benzoic acid within 2 h after cutting (Eckert and Ogawa, 1985).
Several studies indicated that better control of black rot could be
achieved by postharvest fungicide applications (Cho et al., 1977; Eckert,
1990; Hernandez Hernandez, 1990), which should be applied within 6 to
12 h after harvest. Thiabendazole and benomyl may also be added to a
wax formulation applied to harvested fruits to control internal browning
and water loss, although they are less effective when mixed with wax
than when applied in water (Cho et al., 1977).
Refrigeration at 7-8°C arrests fungal development, even in the
presence of deep wounds, open for fungal penetration (Hernandez
Hernandez, 1990). This temperature is suitable for ripe fruit during
storage or transportation, but it may cause mature green fruits to fail to
ripen normally and to develop good flavor, therefore higher storage
temperatures (10-13°C) are required for such fruits.
PERSIMMON
Several fungi are involved in postharvest decay of persimmon fruits.
The most important are species of Alternaria, Botrytis, Colletotrichum,
Phoma, Cladosporium, Penicillium, Mucor and Rhizopus.
Alternaria alternata (Fr.) Keissler
This pathogen causes black spot disease or Alternaria rot. Direct
penetration of developing fruits can occur during the entire growth period of
the fruit. The infection remains quiescent and regains activity only after
harvest, when the fruits ripen (Prusky et al., 1981). Symptoms generally
appear after 10 weeks of storage at -1°C and, at a later stage, the disease
may involve the entire fruit surface. In addition, fungal penetration
frequently occurs via small cracks formed on the fruit shoulder beneath the
calyx as the fruit approaches harvest maturity. In the high humidity
environment of the rainy season, preharvest disease symptoms appear
beneath the cal}^ of riper fruits in the orchard (Prusky et al., 1981; Perez et
al., 1995). When the season is dry, no decay is recorded at harvest.
Control Measures
Protective fungicide treatments in the orchard are ineffective in reducing
decay development beneath the calyx (Perez et al., 1995). A preharvest
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