Agriculture Reference
In-Depth Information
Erratic rainfall distribution due climate change effect has deterring ef-
fect on fruit quality especially at growth and development stages. Onset
of unusual rains during flowering of mango cause negative effects and the
incidence of several pests. The occurrence of anthracnose and powdery
mildew pathogens has been reported. The anthracnose pathogens has been
reported to infect fruits quiescently and become visible during postharvest
conditions resulting poor appearance of fruits. Sudden rains after a dry
spell result the fruit cracking in several fruits (litchi, pomegranate, apple,
etc.) affecting postharvest quality, storability, and acceptability. Changing
rainfall amounts and patterns may modify this temperature effect for each
organism. Pathogens, which require free moisture or high humidity to re-
produce and establish (e.g., black spot in apple, brown rot in stone fruit
and a range of leaf and soil-borne pathogens of fruit and vegetables), are
less prevalent in those regions where spring and summer rainfall is likely
to reduce and dry conditions prevail for longer periods between rainfall
events, and vice versa for those regions where rainfall increases. As the
number of extreme rainfall events increases, soil conditions will favor the
establishment and reproduction of soil borne pathogens such as Phytoph-
thora cinnamomi in avocado.
The main effect of water stress on fruit growth according to the quantity
of water shortage and the period when stress occurred was to alter the final
mango size. The effect of water shortage by the partial root zone drying
technique on other quality traits was not significant, as shown by the total
soluble solids-to-acidity ratio or firmness measurements. Changing water
availability by reducing irrigation (40% of the daily evapotranspiration)
enhanced the increase of pulp dry matter content with fruit development
(Diczbalis et al., 1995). Late water stress accentuated the decline in fruit
Ca concentration (Simmons et al., 1995) and strongly affected fructose
concentration on a fresh mass basis (Léchaudel et al., 2005). The increased
levels of fructose indicated that this soluble sugar may have contribute to
osmotic adjustment of mango, as has been demonstrated for other fruits
under water stress condition (Mills et al., 1997).
17.3.4 OZONE
Ozone in the troposphere is the result of a series of photochemical reactions
involving carbon monoxide (CO), methane (CH
4
) and other hydrocarbons
