Rural Industries Research & Development Corporation

The New Rural Industries
A handbook for Farmers and Investors

Lychee and longan

Introduction

The lychee (Litchi chinensis Sonn.) and longan (Dimocarpus longan Lour.) are members of the Sapindaceae family to which the popular rambutan (Nephelium lappaceum L.) also belongs. All produce delicious fruit on evergreen trees that will eventually grow to heights of more than 20m. Lychee and longan are subtropical, although some cultivars will crop at higher altitudes in the tropics. The largest producers of lychee and longan are China, Thailand and Taiwan. Lychees are also important in India and Vietnam. Further expansion is occurring in these countries to meet demand generated by the increasing regional affluence.

Although lychee and longan were introduced into Australia more than 60 years ago, major commercial plantings commenced only in the 1970s. Currently, there are about 450 growers of lychee with an annual production of 3000 t worth $15m. Production has steadily increased over the past eight years (see Figure 1 - not included in this html version). Longan production is considerably smaller with a value of about $2m, but is also rising, especially as new plantings in northern Queensland begin to bear fruit.

Both crops are difficult to grow and yield consistently. The major production problems with lychee are irregular flowering and poor fruit retention, while in longan, alternate bearing and small fruit size reduce grower returns. Trees take three to five years to come into production, and will not yield substantial crops until year six or eight. They require regular chemical control measures for pests, and suffer heavy losses to birds and fruit bats if not netted. The fruit ripen only on the tree and have a very short self life without refrigeration.

Successful lychee and longan production requires an experienced horticultural manager able to deal with irrigation, tree nutrition and a considerable pest load. Efficient packing and cool room facilities are needed as both crops deteriorate very quickly after harvest.

Australia has an advantage in the international market because it produces fruit during the northern hemisphere `off season' including the lucrative Christmas and Chinese New Year festivities. Demand for high quality product far exceeds Australia's ability to supply. There are also opportunities in the domestic market, although some promotion and retail/consumer education are required.

Markets and marketing issues

There are approximately 500,000 t of lychee and 300,000 t of longans produced in Asia. Total production of lychee in the southern hemisphere is around 50,000 t, while longan production is almost negligible.

In South East Asia, about 100,000 t of longan and 25,000 t of lychee are traded as fresh fruit during the northern season. Longans are the most important of Thailand's fruit exports, with trade in the lucrative fresh fruit dominating, but with fruit also sold for canning or drying. The total value of this commerce is at least $50m. Trade is important and expanding in China, Taiwan and Vietnam, and about 15,000 t of lychee is exported to Europe from Madagascar and South Africa.

In Thailand during the northern summer, early longans may fetch from $3 to $5/kg, but as supplies increase, the price drops to below $1/kg. Returns for lychee are generally at least double those for longan. Out-of-season fruit from Australia during the northern winter would not necessarily achieve the higher returns.

The bulk of Australia's lychee production is sold locally, either at the farm gate or through the central markets, with about 30% exported. Exports have risen sharply in the past few years with improvements in postharvest handling, and the development of co-operative marketing groups and quality assurance programs. These groups export about 60% of their production.

The main markets are Hong Kong, Singapore, French Polynesia, the United Arab Emirates and the United Kingdom. Average net returns to the growers are about $5.50/kg. This is after taking the costs of freight, commissions and agent's fees etc. At this stage the lucrative markets of Japan and the United States are not available because of quarantine restrictions associated with lychee being considered a host of fruit fly.

There have been trial consignments of longan fruit from northern Queensland to Hong Kong, but outturns have sometimes been disappointing. It can be concluded from these studies, that further research on storage temperatures, packaging, etc. is required if growers are to fully exploit this market. Average net returns to the growers were about $4.50/kg, after taking into account freight, commissions and the extra costs of plastic crates.

Production requirements

About 50% of lychee production is in northern Queensland (Cairns, Ingham and the Atherton Tablelands), 40% in central and southern Queensland (Rockhampton, Bundaberg, Gympie, Nambour and Caboolture) and only 10% in northern New South Wales. Longans are mainly found on the Atherton Tableland, with smaller plantings on the coast as far south as Byron Bay in northern New South Wales (see map).

The lychee season lasts from about early November in northern Queensland to about March in northern New South Wales. Longan generally matures about two months later.

Trees perform best on well-drained clay loam soils of medium to high fertility, with a minimum of 1 m of well-drained topsoil. Trees may die on heavy clay soils that become waterlogged. There can also be problems on very sandy soils during hot weather in northern Queensland. Slopes greater than 15% are best avoided as they will not allow safe use of machinery for pest control, tree management, and harvesting, and may erode.

Lychee requires a period of cool weather (15-20°C) for successful flower initiation, but may be killed by frosts. Hot dry weather after fruit set has also been implicated in fruit drop, browning and splitting. Fruit under these conditions do not develop full red colour. Trees are also susceptible to wind damage, and should be protected by wind breaks.

Irrigation is normally required to produce commercial crops, but care must be taken with water quality. Water with an electrical conductivity of more than
600-1000 microsiemens/centimetre or dissolved salts of more than 500 parts per million may reduce productivity in lychee. It is generally considered that about 2-4 ML of stored water is required for each hectare of trees.

One person should be able to handle about 5-7 ha of mature trees without the need for other staff except during harvesting and packing. Depending on the yield and spread of cultivars, up to 5-10 staff would be required for harvesting over summer. Basic equipment required would include: an under-tree sprinkler irrigation system, tractor, sprayer, slasher or mower, trailer, harvesting equipment, netting and a packing shed and cold room.

A local horticulturist should be consulted about the growing and marketing of these crops before orders are placed for nursery plants. There is also valuable information in the Proceedings of the Lychee Seminar published every three to four years and in the Australian Lychee Growers' Association newsletter Living Lychee.

Cultivars

There are over 40 cultivars of lychee and 20 for longan in Australia. However, the development of the industry has been hindered by lack of performance data for the major production regions. This has been accentuated by difficulties in identifying cultivars. Highest prices are paid for early and late fruit with strong skin colour, firm flesh, aromatic flavour, a high proportion of edible flesh and small seed.

Lychee cultivars currently being planted in northern Queensland on the Atherton Tablelands and coast include `Kwai May Pink' (`Bosworth Number Three'), `Fay Zee Siu' and `Souey Tung', the latter two being quite early. `Kwai Mai Pink' is also popular in central and southern Queensland and in northern New South Wales, along with `Salathiel', and the late cultivar `Wai Chee'.

The longan cultivars exploited are predominantly from Thailand and include `Chompoo', `Haew' and `Biew Kiew'. The Hawaiian selection `Kohala' is also being planted because of its earliness and large fruit, but it loses flavour under some circumstances. `Biew Kiew' is very late and may not mature before winter in northern New South Wales. Plants are available from commercial nurseries, but must be ordered at least 6 months in advance.

Agronomy

A well-managed orchard should have a long commercial life. Hence, close attention to orchard layout and land preparation will bring rewards for many years.

Decisions need to be made on row direction, spacings, placement of waterways and drains, mounding, wind protection and all weather access to the block. The local horticulturist should be able to help with the layout of the orchard and care of young trees. There are also details in the Queensland Department of Primary Industries `Lychee Information Kit'.

Plantings generally range from 100-300 trees/ha. Recommended spacings are 12 m ¥ 6 m for spreading cultivars such as `Fay Zee Siu' and `Souey Tung' (equivalent to 140 trees/ha), and 6 m ¥ 6 m for upright or low vigour cultivars such as `Kwai May Pink', `Salathiel' and `Wai Chee' (equivalent to 280 trees/ha). In other countries, higher density plantings have given greater returns, but these types of orchards are only experimental in Australia. There is little information available for longan, although the data for lychee could be used as a guide.

Tree rows are usually considered to best run north-south, but erosion and operator safety should be considered. Strong winds can seriously affect tree growth and production, so windbreaks need to be considered in most localities.

A soil analysis (including soil pH) before planting will indicate any potential nutrient deficiencies or imbalances which can be corrected. Discuss these results with your local horticulturist. Some soils may need an application of lime, phosphorus, nitrogen and some organic matter into the planting site. Many growers sow a manure or cover crop before planting trees and incorporate this organic matter into the soil to improve soil texture, fertility and orchard establishment.

Irrigation is generally considered essential for regular production in most of the commercial growing areas of eastern Australia, and is normally provided by under tree sprinklers. These systems can also be used to fertigate trees. In dry areas, the young plants will probably require watering at least weekly until they are well established.

Experiments have shown that drought has impacts on leaf growth, flowering, fruit development and quality in lychee, and longan would probably respond similarly. However, in deep, moisture-retentive soils, it can take several weeks before drought has any impact on production.

Fertiliser management in lychee is currently based on the results of leaf and soil analyses collected annually in winter. During the early life of the orchard, before the trees start to crop, it is recommended that the trees be fertilised about every three months. You will need to gradually increase the amount of fertiliser as the trees become larger.

Timing of fertiliser application generally has little impact on production. Most nutrients can be applied in two or three applications between flowering and harvest. The most likely nutrients to be low or deficient are nitrogen (N), potassium (K), magnesium (Mg), zinc (Zn), iron (Fe) and boron (B). In contrast, many orchards in Australia have excess amounts of phosphorus (P). There is little information available for longan, but following recommendations for lychee would be a good starting point. Information on the types of fertilisers to use can be obtained from your local produce agent.

Pest and disease control

Lychee and longan are subject to a wide range of pests which attack the tree, flowers and fruit. However, only a few of the regular pests affect production and need to be controlled. Your local entomologist will help you identify the major pests in your area. There are also consultants who can monitor pests in your orchard, advise on a spray program and help calibrate your sprayer.

Erinose mite (Aceria litchi) is a major pest of lychee and causes a brown, felt-like growth on the developing leaves, flowers and fruit. It can be very difficult to eradicate once established in an orchard. Recommended control is with three sprays of dimethoate or wettable sulfur at 2-3 week intervals to coincide with the elongation and expansion of new leaf flushes. New air-layers should be treated before they are planted.

Macadamia nutborer attacks both lychee and longan every season, and can devastate the crops. Larvae develop mainly in green fruit with significant seed development, but before there is a large amount of flesh. Sprays of azinphos-methyl need to be applied to coincide with the hatching of the oldest 10% of the eggs so that the newly emerged larvae will be killed before they enter the skin of the fruit. Effective control will probably require a minimum of 2-3 sprays.

Flower caterpillars (Lobesia spp., Isotenes miserana, Prosotas spp. and Phycita leucomiltra) are major but occasional pests of lychee, which can be readily controlled with endosulfan or carbaryl. Trees should be sprayed before the flowers open.

Both the fruitspotting bug (Amblypelta nitida) and the banana spotting bug (A. lutescens) are common in southern districts. The banana spotting bug is common in central and northern Queensland. These bugs cause the developing green fruit to drop. Generally, lychees are less susceptible once the fruit have started to colour, whereas longans can be attacked right up to harvest. Two sprays of endosulfan starting two weeks after fruit set will generally provide adequate control.

Adult fruit piercing moths (Othreis fullonia and Eudocima salaminia) cause much damage to lychee and longan by piercing the skin of ripening fruit and sucking out the juice. No chemical control is available for these large nocturnal moths, although nets with a mesh of 15 to 20 mm will exclude them. These nets will also exclude birds and flying foxes. A smaller mesh with a cross hair would also keep out some macadamia nutborer and elephant beetles. These cost $15,000-25,000/ha. Check with netting suppliers in your area.

Harvest, handling and postharvest treatments

For lychee, the season commences with cultivars `Fay Zee Siu' in northern Queensland in November and finishes with cultivar `Wai Chee' in northern New South Wales in March. For longan, fruit are available from late January (cultivar `Kohala') until early April (cultivar `Haew') in the same regions. At any one location, harvesting normally lasts about six weeks with a spread of cultivars.

Neither lychee nor longan will ripen off the tree, so they must be picked mature. For lychee, maturity is indicated by a minimum brix:acid ratio of 35:1, although ripe fruit generally have a much higher ratio. Maturity of lychee is judged by the shape, size, colour and flavour of the fruit, which varies greatly with cultivar. Normally, longan fruit can be judged by fruit size and flavour. Both crops become bland if picked over-mature.

Fruit should be harvested early in the morning before they warm up. Some growers pick early season fruit individually off the panicle (spot-picking), but generally the bulk of the crop is picked in clusters. There is strong demand for longans on branches and branchlets in some markets.

Once lychees are picked, they start to dry out and brown. Fruit should be kept in a high humidity and cooled to 5°C as quickly as possible. Hydrocoolers or cool rooms are frequently used for this purpose. Untreated longan fruit suffer chilling injury and lose flavour below 9°C, but do not brown as quickly as lychee.

After picking, fruit are destalked and sorted visually on mechanical conveyors to remove small, poorly coloured or damaged specimens.

Industry quality standards have been developed for lychees, but none is available for longan. For lychee, `Extra class' must be practically free of defects, and typically comprises no more than 10% of the crop. `First class' fruit can have moderate defects, with skin blemishes not exceeding 60 mm² in total on any one fruit. Other standards operate for other segments of the industry which have a commitment to quality assurance and are members of the United Lychee Marketing Association (ULMA).

To reduce water loss and browning, lychee fruit are marketed in bulk or in crispywrap bags in 9 L cartons which hold 5 kg of fruit packed in two 2.5 kg low density polybags. Fruit can also be packed in 250 g punnets, with a cling wrap film. Longans are generally marketed in bulk packages, including non-recyclable plastic crates. Both fruit should be free of surface moisture before being packed to reduce the potential for disease development.

Fruit are normally shipped by refrigerated transport. This system retains the red skin colour in lychee and greatly prolongs shelf life in both crops. However, once the retailers open the bulk packs, fruit begin to deteriorate under air conditioning in the stores.

In Thailand, longan fruit (on branchlets) are treated with sulfur dioxide, packed in 10 kg plastic crates, cooled to 2-5°C, and cool transported to Bangkok for sea or air freight to Hong Kong, Singapore and Indonesia where they have a shelf life of up to six weeks. In Australia, there is temporary board approval of this treatment, which substantially reduces the incidence of the postharvest rots and off-flavours that may develop in cool storage.

Fruit are sold at the farm gate, consigned to the wholesale markets in Brisbane, Sydney or Melbourne, or exported. You can handle marketing yourself or join one of the lychee marketing groups. If sending fruit to some of the southern markets quarantine restrictions must be adhered to. These restrictions vary from season to season.

Economics of production

At least $150,000 is needed to set up a viable 7 ha lychee farm. This will cover basics such as purchase of a tractor, sprayer, slasher, small farm shed, and irrigation system, and tree establishment. It does not include the cost of land. A further $150,000 would be required for netting, picking and packing (including a cold room) once the trees started to bear. It would cost about the same to set up an equivalent longan enterprise.

Yields vary widely with cultivar, season and location, from about 10 to 100 kg/tree at year ten. Average yields would be expected to be about 5 kg/tree at year five rising to about 50 kg/tree at year ten. Longans are slightly more productive, especially on the Atherton Tableland in northern Queensland.

Prices also vary greatly with cultivar, season and quality, from about $2 to $12/kg. Average prices are about $4-5/kg for lychee, and slightly higher for longan

Gross margins have been calculated for lychees on the Atherton Tableland in northern Queensland. With a yield of 55 kg/tree and a planting density of 140 trees/ha (7.7 t/ha), estimated gross margin (income minus vari-able costs) was about $21,570/ha. These figures assumed that 50% of fruit was sold as first class at $6/kg, 40% as second at $5/kg and 10% at the farm gate at $4/kg.

The gross margin is very sensi-tive to price. With 50 kg/tree, it is $20,060 at $5.40/kg and only $9,048 at $3.60/kg. Further details of the economics of growing lychees and longans can be obtained from the Queensland Department of Primary Industries at Mareeba.

Key contacts

Key References

Coombs, B. (1995). Horticulture Australia. Morescope Publishing, Hawthorne East, Victoria, Australia. 618 pp.

Greer, N. (1990). Growing lychee in south Queensland. Queensland Department of Primary Industries. 44 pp.

Greer, N. (1997). Lychee information kit (Agrilink).

Queensland Department of Primary Industries.

Queensland Department of Primary Industries (1995). Longan and lychee. Choices Seminar Series No. 10. New opportunities for the Atherton land. 37 pp.

Welch, T. and Ferguson, J. (1997). Proceedings of the Fourth National Lychee Seminar, Yeepoon. 164 pp.

Acknowledgments

We thank Neil Greer and Terry Campbell for useful comments on the manuscript. Many of the recommendations for growing lychees in Australia come from the Queensland Department of Primary Industries Agrilink Information Kit on Lychee.

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