Lychee (Litchi) - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 233

(A) (B)

Figure 13.1. Fruit tree of lychee (A) and fruit and arils of lychee (B) grown in Guangdong Province, China. For
color detail, please see color plate section.

flower bud differentiation, flowering, fruit set, fruit qual-
ity, and flavor development are influenced significantly by
temperature and humidity (Dabral and Misra, 2007), but
the plant has adapted well to the subtropics, where summer
months are hot and wet and winter months are dry and cool.
However, hot summers free from hot wind and cool winters
free from frost are essential. It has been observed that flower
initiation in lychee requires comparatively low temperature.
Seasonal variation in temperature is favorable for proper
fruiting. Lychee fruit exhibits a sigmoidal growth pattern
(Huang, 1995). The seed and pericarp develop first, before
the arils (Huang and Xu, 1983). Fruit takes 80

Florida cultivars originate primarily from 'Chenzi,' 'Mauri-
tius,' and 'Sweet Cliff,' while most of the cultivars in Hawaii
consist of 'Dazao,' 'Groff,' 'Heye,' and 'Chenzi' cultivars.
In South Africa, the commercial cultivar is a synonym of
'Guiwei.'
As a nonclimacteric fruit, lychee requires harvesting after
attaining full maturity on the tree (Holcroft and Mitcham,
1996). Lychee fruit quality is determined by chemical pa-
rameters, color, fruit composition (vitamins and minerals)
and aroma volatiles (Badiyala, 1993). During fruit matu-
rity, titratable acidity (TA) declines and total soluble solids
(TSS) increase, which corroborate the appearance and color
on the fruit (Holcroft et al., 2005). Underhill et al. (2006)
recommended a minimum TSS/TA ratio of 30 − 40. For
'Muzaffarpur,' the highest TSS/TA ratio was found 78 days
after fruit set (Badiyala, 1993). However, general guide-
lines for harvesting are difficult to prescribe because of
the wide range of cultivars and production conditions. In
practice, maturity is usually based on fruit color and flavor.
Although skin color is the most commonly used harvest
index, the relationship between maturity and color varies
with cultivar, environment and cultural practices. Thus ac-
ceptable color levels for individual cultivars need to be
established.
Lychee fruits are harvested in bunches along with a por-
tion of the branch and a few leaves (Holcroft et al., 2005).
At the time of harvesting, care is taken to harvest selected
bunches that have attained the desirable maturity as de-
termined by color development and pulp taste. For distant
markets, fruits are harvested when TSS reaches 19 ◦ Brix

120 days
to develop from anthesis to mature stage. The pericarp is ini-
tially green and is capable of photosynthesis. Anthocyanins
are synthesized after chlorophyll degradation (Wang et al.,
2005). Bagging of 'Feizhixiao' lychee fruit on the tree ac-
celerates fruit maturation and improves skin color (Jiang
et al., 2006b).
About 68 cultivars of lychee are grown commercially in
the world (Li, 2008). Characteristics of individual lychee
cultivars are profoundly influenced by their growing envi-
ronment. Differentiations of the characteristics among the
large number of lychee cultivars are ascribed to the envi-
ronmental factors. About 26 cultivars of lychee are planted
and grown commercially in Guangdong, such as 'Sanyue-
hong,' 'Shuidong,' 'Fezixiao,' 'Heye,' 'Guiwei,' 'Nomici,'
and 'Huaizhi.' In Thailand, the major cultivars of lychee are
'Dazao,' 'Chacapat,' 'Heye,' and 'Huaizhi.' In Australia,
the most often planted cultivars are 'Dazao,' 'Bengal,'
'Hiye,' 'Huaizhi,' and 'Nomici.' In the United States,

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