Annona Species Monograph.pdf - Crops for the Future

Chapter 11. Harvest & Processing
occurs between March and June and from October to December, with both
seasons producing high quality fruits. Along the Atlantic coast, below 500 m,
harvesting occurs between August and October, and the fruits have a very
low quality because of the poor genetic resources and the high temperatures
of the region (Torres and Sánchez, 1992). In Hawaii, soursop production
occurs during most of the year, with two peaks from January to April and
from May to August (Nakasone and Paull, 1998). In Brazil, production
occurs year round, but in some regions, depending on the temperature and
precipitation, the production shows harvesting peaks.
All annonas are characterized as climacteric ripening fruits, so fruits are
harvested when they reach physiological maturity and are still firm, full
ripening occurs after the climacteric peak. Fruits harvested prematurely will
soften but have poor quality (Accorsi and Manica, 1994; Coronel, 1994;
Nakasone and Paull, 1998). The time of harvesting is determined by the fruit
skin colour, which changes with the proximity of physiological maturity. At
harvesting time, soursop fruit skin changes from dark green to slightly
yellowish-green, while the cherimoya and sugar apple fruits change from
greyish green to yellowish-green, but in all cases their pulp should be firm
(Nakasone and Paull, 1998).
A skin colour index to guide the harvest depends on the location of the
market. For local markets, fruits must be harvested when mature, with 20 to
40% yellowish-green skin, and they will ripen in 4 to 6 days; for export
markets, 10 to 20% yellowish-green skin is satisfactory, as this will provide
slightly more time before ripening without the loss of quality. When the
fruits are harvested with more than 75% yellowish-green skin, they will ripen
in 1 to 3 days, while fruits harvested at less than 5% do not ripen completely
at all (George et al., 1987).
Fruit maturation within a plant or orchard is not synchronized, so the harvest
season can last for 3 to 6 months. Hence, each tree must be inspected
regularly to collect the fruits at the appropriate harvest point. The most
suitable time of day to harvest is in the morning just after the evaporation of
the dew, when the fruits are dry and fungal rot contamination is less likely
(Accorsi and Manica, 1994).
Cherimoya fruits are generally harvested when the skin colour changes from
greyish green to yellow-green, although some cultivars will change to almost
brown (Accorsi and Manica, 1994). However, sometimes the change of skin
colour is not very pronounced. Consequently, colour change, pollination time
and fruit size are not reliable harvest indices. Therefore, the harvest index
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