Agriculture Reference
In-Depth Information
in the presence of nitrogen species (NO + NO
2
) (Schlesinger, 1991). It
forms during periods of high temperature and solar irradiation, normally
during summer seasons (Mauzerall and Wang, 2001). It is also formed,
naturally during other seasons, reaching the peak of natural production in
the spring (Singh et al., 1978). However, higher concentrations of atmo-
spheric ozone are found during summer due to increase in nitrogen species
and emission of volatile organic compounds (Mauzerall and Wang, 2001).
Ozone enters plant tissues through the stomates, causing direct cellular
damage, especially in the palisade cells (Mauzerall and Wang, 2001). The
damage is probably due to changes in membrane permeability and may or
may not result in visible injury, reduced growth and, ultimately, reduced
yield (Krupa and Manning, 1988).
Strawberries cv. Camarosa stored for three days under refrigerated stor-
age (2 °C) in a ozone-enriched atmosphere (0.35 mL/L) showed a 3-fold
increase in vitamin C content when compared to berries stored at the same
temperature under normal atmosphere as well as a 40% reduction in emis-
sions of volatile esters in ozonized fruits (Perez et al., 1999).
The quality of persimmon (
Diospyros kaki
L. F.) fruits (cv. Fuyu) har-
vested at two different harvest dates was evaluated after ozone exposure.
Fruits were exposed to 0.15 mmol/mol (vol/vol) of ozone for 30 days at
15 °C and 90% relative humidity (RH). Ozone exposure was capable to
maintain firmness of second harvested fruits, which were naturally softer
that first harvested fruits, over commercial limits even after 30 days at
15 °C plus shelf life. Ozone-treated fruit showed the highest values of
weight loss and maximum electrolyte leakage. However, ozone exposure
had no significant effect on color, ethanol, soluble solids, and pH (Salva-
dor et al., 2006).
17.5 CONCLUSIONS
Despite the significant uncertainty regarding the scale, type, and interac-
tions of climate change impacts, mitigation and adoption strategies are
needed if we are to avoid the most serious consequences of global warm-
ing. It is not known if horticulture is a net emitter or sequester of GHG.
Many factors will need to be understood to be able to determine this for
the large range of commodities, regions, and farming systems utilized by
growers. Temperature variation can directly affect crop photosynthesis,
