Agriculture Reference
In-Depth Information
the cut part of the peduncle pointing down for about 30 min until the sap
fl ow stops. In Australia, 'Kensington Pride' fruits are washed in the fi eld. The
use of shallow lug boxes minimizes bruising. At the packing house, fruits are
usually placed in a water bath or
hand-washed to remove the stem sap from
the surface, and the peduncle is cut according to specifi cations. Sap removal
is essential to prevent sap burn and should be done within 24 h (Lovey
et al.
,
1992). Fruit anthracnose can be controlled by dipping into hot water (52°C,
5 min). A combination of hot water and a fungicide or chlorine may also be
used. When the fungicide is added to the hot water, the temperature can be
reduced slightly (Akamine, 1976).
Grade standards are usually based upon size, colour and freedom from
injury and defects. Other requirements include full development, freedom from
stains and fi rmness. Since the fruit is easily bruised, fruits are packed in single-
or double-layer cartons with adequate protective material or use of trays.
The US box contains about 4.5 kg and the EU box 5 kg. In the local markets,
mangoes are frequently packed in bamboo baskets or in wooden crates.
At ambient temperatures, shelf-life of this climacteric fruit is short: 7-14
days to fully ripe. Precooling to 10-13°C is benefi cial during hot weather or
when shipping is delayed. Fully ripe fruit can be stored at 8-10°C. The length
of shelf-life varies markedly with cultivar, maturity at harvest, injury, calcium
(Ca) sprays and exposure to ethylene. A dip in 4-6% calcium chloride can
signifi cantly increase shelf-life of some cultivars, with the response varying
with season, fi eld management practices and soil type. Fruit of 'Keitt', 'Tommy
Atkins' and 'Muska' from successive harvests show an increasing rate of
ripening changes during the 21 days' storage period at 12°C, suggesting a
decrease in storage potential as the season progressed.
Mango is a climacteric fruit and ethylene can be used to reduce the time till
ripening commences. A treatment of 100 ppm for 24-48 h at 25°C and 90%
relative humidity (RH) is adequate. Acetylene generated from calcium carbide
and ethephon can also be used. Skin colour is also enhanced by ethylene
treatment by increasing degreening. The best ripening temperature range is
from 21 to 24°C. At high temperatures of 32°C, ripening can be retarded.
Controlled atmospheres have been tested on mangoes and indicate some
possibilities; storage in atmospheres of 5% oxygen (O
2
) and 5% carbon dioxide
(CO
2
) is possible for 20 days, while of -fl avours and skin discoloration occur at
1% O
2
or high CO
2
(15%). Cultivar dif erences in response have been reported
and the extension in shelf-life may not be commercially viable. Controlled
atmosphere for ripe fruit is inef ective. Containers with controlled atmospheres
are available for transport. Modifi ed atmosphere storage using plastic bags
or wraps and waxing shows some delay in ripening. Of -fl avours have been
reported with some wraps and waxes that delay ripening. Waxes are widely
and successfully used commercially on mango to reduce water loss.
Postharvest disorders include chilling injury, sap burn, internal
breakdown and bumpy tissue (Wainwright and Burbage, 1989). Chilling
