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

FREEDOM PALESTINE FREEDOM PALESTINE FREEDOM PALESTINE
136 Postharvest Diseases of Fruits and Vegetables
combination of these conditions on decay control. Hypobaric pressure has
direct fungistatic effects on fungal spore germination and mycelium
growth of various storage fungi. Apelbaum and Barkai-Golan (1977)
showed that the degree of inhibition increased with the reduction in
pressure below 150 mm Hg. Reducing the pressure from 760 to 100 mm
Hg inhibited spore germination oi Penicillium digitatum, while inhibition
of spore germination of Botrytis cinerea and Alternaria alternata occurred
only at 50 mm Hg. Such a level had no effect on germination of
Geotrichum candidum spores. Reducing the pressure to 25 mm Hg totally
prevented spore germination of the first three fungi mentioned but had
almost no effect on the germination of Geotrichum spores (Fig. 24).
Colony growth and the consequent fungal sporulation of the four fungi
were markedly reduced at 50 mm Hg, while at 25 mm, Geotrichum was
the only fungus exhibiting some growth. Transfer of inhibited cultures
from hypobaric to atmospheric pressure resulted in renewed growth,
suggesting that there was no irreversible damage to the fungi.
150 100 50
Pressure(mm Hg)
Fig. 24. Hypobaric pressure effects on spore germination of Penicillium
digitatum (n), Botrytis cinerea (o), Alternaria alternata (A) and Geotrichum
candidum var. citri-curantii (•). (Reproduced from Apelbaum and Barkai-Golan,
1977 with permission of the American Phytopathological Society).
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