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

FREEDOM PALESTINE FREEDOM PALESTINE FREEDOM PALESTINE
26 Postharvest Diseases of Fruits and Vegetables
blue mold, respectively, and Geotrichum candidum, the causal agent of
sour rot: these are typical wound pathogens. P. digitatum is an example
of a specific fungus that attacks only citrus fruits. On the other hand,
P. italicum, which is also a significant citrus pathogen, can attack other
fruits and vegetables, whereas Penicillium expansum, a significant apple
and pear pathogen, does not naturally attack citrus fruits at all.
The typical apple and pear pathogens include, among others,
P. expansum, Botrytis cinerea, Gloeosporium spp., Alternaria alternata
and Stemphylium botryosum, whereas the main pathogens of stone
fruits, such as peaches, apricots, nectarines and plums, are Monilinia
fructicola and Rhizopus stolonifer. Furthermore, while Penicillium spp.
are responsible for major losses in harvested citrus or apple fruits, they
are of little or no importance in most other crops.
The harvested strawberry, too, has its own typical fungal pathogens.
Out of the many airborne fungi found on the strawberry surface in the
field or after harvest, two would normally develop during storage: the
gray mold fungus (S. cinerea) and the soft watery rot fungus (R.
stolonifer). In Great Britain, Mucor was found replacing Rhizopus as an
additional pathogen to Botrytis in stored strawberries (Dennis and
Mountford, 1975).
Of the entire range of fungi that can be isolated from the surface of
harvested tomatoes, A. alternata is the major storage decay agent; at
times over 80% of the overall decay in the stored fruit is caused by this
particular fungus (Barkai-Golan, 1973). The main causal agents of soft
watery rot in harvested tomatoes are R. stolonifer, G. candidum and
Erwinia spp.
In much the same way, a celery head transferred to storage carries an
abundance of air- and soil-borne fungi and bacteria. Here, too, the major
decays that develop in the stored celery are generated by a small number
of typical microorganisms: the fungi Sclerotinia sclerotiorum and
B, cinerea, and the bacterium Erwinia cartovora.
Each picked fruit and vegetable, therefore, has its own group of
characteristic pathogens to which it is susceptible and for which it serves
as a suitable host.
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