Longan production in Asia - United Nations in Indonesia

productivity on a per plant basis is comparable to that of China but far inferior to that of
Thailand.
Productivity on a per hectare basis ranges from a high of 12,701 kg/ha/year (1995)
to a low of 4,506 kg/ha/year (1996) (Table 6). These figures are far superior to those in
China and comparable, if not much higher, than those in Thailand. Since the productivity
on a per plant basis is comparatively low, the higher production on a per hectare basis can
be explained by the higher tree density in Taiwan Province of China. Tree densities of 300
to 600 trees per hectare are found in Taiwan Province of China compared to the lower
figures of 195-300 in China and about 50 in Thailand. Alternate bearing phenomenon is
very clearly seen in the productivity figures in Taiwan Province of China. The ‘off’ years
(1994,1996 and 1998) alternate with the ‘on’ years (1995 and 1997).
Table 6. Productivity of longan as affected by years in Taiwan Province of China
Year 1994 1995 1996 1997 1998
Yield
(kg/ha/year) 9,284 12,701 4,506 11,058 4,637
Yield
(kg/plant/year) 26 36 14 32 14
Source: Yen (2000).
Crops in Florida from trees 6 m tall and broad, have varied from light (22.5-45 kg)
to medium (68-113) and heavy (135-225 kg). The variation is largely due to alternate
bearing.
Yields of 40-50 kg per tree have been obtained for six to eight years old trees in
Australia.
11.2 Picking of fruits
Longan takes about 5 months from blooming to harvest. The fruits are nonclimateric
and have to be harvested when ripe. Maturity is determined by fruit shape, skin
colour and taste. Immature fruits are tasteless. The mature longan fruit has a dark, smooth
skin, the inside of which is netted and tastes sweet. Longan trees should be picked twice at
an interval of 7 - 10 days. Most cultivars lose flavour if harvesting is delayed, when fruits
are mature. The whole panicle of fruits with one or two leaves is cut with a knife or
scissors. Removal of too much leaves and wood with the fruit panicles at harvest reduces
flowering in the next season. Panicles should not be dropped. They are sorted for size,
insect damage and skin blemishes and bunched in a bulk tray. In Thailand, longan fruits
with stalk intact (about 21 - 22 kg) are packed in 35 cm x 50 cm round woven bamboo
baskets lined with longan leaves. Stalked fruits are reputed to remain fresher than
separated fruits after harvest. Fruit for export, often detached from the panicles, may be
packed in corrugated boxes or plastic baskets. It is recommended that fruit should not be
picked during rainy weather as this increases the risk of breakdown after harvest.
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