Department Of Agriculture Sarawak Official Website

1. Local Name: Leng-keng

2. Recommended varieties:

Clone	Characteristic
Diamond longan	Free flowering.
Edaw longan	Required flowering induction.
Kahola longan	Required flowering induction.

3. Soil Requirement:

Adaptable to different soils and growth is best in fertile and deep soils.
It does not tolerate waterlogging and saline conditions.

4. Spacing: 8m x 8m (156 trees/ha)

5. Fertiliser application:

Year	Time of application	Type of fertiliser	Amount / Stand / Year (kg)	Rate/ Application (kg)
0	At Planting	Rock Phosphate Dolomite Organic manure	0.20 0.10 5.00	0.20 0.10 5.00
1	Every 3 months	Compound - 15:15:15	0.60	0.15
2	Every 3 months	Compound - 15:15:15	1.20	0.30
3	Every 3 months	12:12:17:2 + TE	2.00	0.50
4 and onwards	Every 4 months	12:12:17:2 + TE Organic manure	3.00 20.00	1.00 20.00

Pruning : General pruning to keep tree at about 3 m height with well spreadout canopy. Selective removal of some branches maybe necessary to facilitate good air circulation and light penetration.

6. Vegetatif Stage: 2 - 3 years .

7. Economic Life: 15 - 20 years.

8. Yield:

Yields : 50 - 80 kg fresh fruit in medium sized trees (16 - 20 meter square canopy).

9. Flowering induction: Use NACLO3 at a rate of 15g per meter square canopy.

10. Pests of Longan:

Pests/Disease

Symtom

Control

1. False coding moth,
Cryptophlebia sp. (Lepidoptera : Tortricidae)

Host plants : Citrus, maize

Life cycle :

Flattish, oval and whitish eggs are laid singly or in groups on the fruits.
After 3-6 days the larvae emerge. They are whitish pink in colour and grow to about 15 mm long.
After 8-12 days, a small brown moth emerges with a wingspan of about 16 mm.
The females live for about a week and lay 100 - 400 eggs.

Damage pattern:

If the fruits are immature,
the young larvae will bore
directly into the seeds, which is
completely eaten. The entrance hole which the young larvae have bored into the fruit, leaves a
yellow spot on the skin. The
flesh of the fruit where the larvae are feeding becomes
contaminated with their excrements. Infested fruits fall prematurely. Secondary infections due to fungus
can also occur.

1. Sanitation:

Fallen infested fruits should be collected twice a week. This could be composted or buried 50 - 100 cm deep in the ground.

2. Bagging:

Cover the fruit panicles with paper bags or fine net to exclude the pests.

2. Fruit borer,
Conopomorpha sp. (Lepidoptera : Gracillaridae)

Host plants : Rambutan, litchi

Life cycle :

Yellow scale-like eggs are laid on the fruits as well as on the leaves and shoots. The eggs hactch in 3 - 5 days and the larvae immediately penetrate the fruits, leaves or shoots. Mature larvae are 6 - 10 mm in length and brownish in colour, or green if they have fed on the leaves. After 8-12 days, they leave the feeding sites to pupate under mature leaves. The moth emerges after 5-7 days. During the off-season, when fruit is not available to the pest, it can survive by feeding on young leaves and shoots.

Damage pattern:

The larvae feed in the fruits
and damaged fruits may fall from the tree.
Damaged leaves and shoots are not serious as fruits are often preferred.

1. Sanitation:

Fallen infested fruits should be collected twice a week. This could be composted or buried 50-100 cm deep in the ground.

2. Bagging:

Cover the fruit panicles with paper bags or fine net to exclude the pests.

3. Pruning:

Prune branches to remove any remaining fruits that might harbour pupae of the pest.

4. Spraying:

No insecticide is recommended for these pests in Malaysia.

In Taiwan, China and Thailand, the following chemicals are used:

Permethrin
Cypermethrin
Deltamethrin
Fenthion

Chemicals are sprayed during early fruit set to prevent pest damage during fruit maturation.

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Source: Scheme Mechanics, 9MP (2006-2010) Fruit Industry Development Programme, June 2006

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