Agriculture Reference
In-Depth Information
during postharvest conditions. Rains during fruiting periods may blacken
fruits (in mango) or prevent desirable fruit coloration (in guava), making
the produce less appealing for the consumers. Increase in humidity can ini-
tiate un-seasonal flowering. Various quality traits such as fruit coloration,
spottiness, fruit texture and taste can be altered by change in tempera-
ture, humidity and rainfall. Sudden rains after a long dry spell result the
fruit cracking in several fruits (litchi, pomegranate, apple, etc.) affecting
postharvest quality, storability, and consumer acceptability. Due to deficit
in rainfall water stress occurs which alter the fruit size, according to the
quantity of water shortage and the period when stress occur. Reduced wa-
ter availability (40% of the daily evapotranspiration) has been reported to
increase pulp dry matter content with development of fruit (Diczbalis et
al., 1995). Late water stress accentuate decline in fruit calcium concen-
tration (Simmons et al., 1995) and strongly affect fructose concentration
(Léchaudel et al., 2005).
16.2.4 OZONE
In the troposphere, ozone is formed as a result of series of photochemical
reactions involving carbon monoxide (CO), methane (CH 4 ) and other hy-
drocarbons in the presence of nitrogen species (NO + NO 2 ) (Schlesinger,
1991). During the period of higher temperature and solar irradiation in
summer seasons, ozone is formed (Mauzerall and Wang, 2001). However,
its production also occurs naturally in other seasons, reaching the peak in
the spring (Singh et al., 1978). Ozone enters in the plant tissue through
stomata, causing direct cellular damage especially in the palisade cells
(Mauzerall and Wang, 2001). The occurrence of damage by ozone is as
a consequence of changes in membrane permeability and may or may
not result in visible injury, reduced growth and, ultimately, reduced yield
(Krupa and Manning, 1988).
Strawberry fruits stored for three days under cold storage (2°C) in a
ozone-enriched atmosphere (0.35 µl/l) showed 3 times increase in vita-
min C content than berries stored at the same temperature under normal
atmosphere as well as a 40% reduction in emissions of volatile esters in
ozonized fruits (Perez et al., 1999). In another study, quality of persim-
mon fruits (cv. Fuyu) harvested at two different harvest dates was evalu-
ated after ozone exposure. Fruits were exposed to 0.15 mol/mol (V/V) of
Search WWH ::




Custom Search