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

FREEDOM PALESTINE FREEDOM PALESTINE FREEDOM PALESTINE
50 Postharvest Diseases of Fruits and Vegetables
enhanced appressorium formation and induced an early climacteric, but
did not trigger earlier lesion development: progress in lesion development
in ethylene-treated fruits was similar to that in untreated fruits (Fig. 11).
It was concluded that exposure of avocado fruits to exogenous ethylene did
induce multiple appressorium formation but did not activate disease
development. The activation of appressoria during avocado ripening may
rather be related to the decline in the antifungal diene in the peel, to
subfungitoxic concentrations (Prusky et al., 1982).
Ethylene application also stimulates Botrytis cinerea development in
strawberries (El-Kazzaz et al., 1983), and enhances J3. cinerea and
Alternaria alternata development in tomatoes (Barkai-Golan et al.,
1989a; Segall et al., 1974). For strawberries, which are non-climacteric
fruits and are, therefore, regarded as independent of ethylene for
ripening, it was found that storage life was extended by reducing the
ethylene level (Wills and Kim, 1995).
4 6
Days after harvest
Fig. 11. Effect of ethylene on decay development caused by Colletotrichum
gloeosporioides (A) and changes in fruit firmness (•) in overmature inoculated
avocado fruits (cv. Reed) as compared to decay (A) and firmness (o) in air
treated fruit. Fruit firmness was determined by a penetrometer and expressed
by N(=Newton, a parameter of fruit ripening). (Reproduced from Prusky et al.,
1996 with permission of the American Phytopathological Society).
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