Climate requirements

The average maximum temperature in the litchi-producing areas of South Africa should be at least 23 °C during October and 24 °C during November, with a relative humidity of 50 % and higher.  The average monthly minimum temperature in areas where litchis are produced should be above 6 °C. Areas where heavy frost occurs are not suitable for litchi production. It should, however, be cold and dry enough in winter to ensure good dormancy.  The minimum temperature in some Lowveld areas (Malelane and Komatipoort) does not drop low enough in winter to give the trees the proper dormancy period. Trees can be forced into dormancy by withholding water/irrigation during the 3 coldest months of the year. Producers must, however, ensure that especially young trees do not dry out.

 

Soil

Litchis grow very well, especially in sandy soil in the cooler subtropical areas.  However, the trees also grow and produce well in clay soil in warmer areas.  Litchis are well adapted to different soil types.

 

Water supply

Because of the varying root distribution in different soils (deep in sandy soils, shallow in clay soils) water is very important for the optimum development of the plant.  In sandy soils short irrigation cycles with small quantities of water are usually effective.  In clay soils water is available for longer periods, but it is important that the soil does not become too wet or too dry.

 

Poorly-drained soil or soil with impenetrable layers shallower than 1 m below the surface is not suitable for litchis.  Although gravelly or rocky soils drain well, these do not supply enough water to the trees because of poor waterholding capacity. Good irrigation practices, such as wetting the soil more frequently with small quantities of water will make these soils more suitable.

 

Cultivars

Litchis were originally imported from China, India, Taiwan and Florida, USA. Cultivars grown in South Africa are divided into the following groups:

 

- Mauritius group

This group is usually planted locally as well as abroad and produces satisfactory yields and fruit of good quality, e.g. H.L.H. Mauritius, Muzaffarpur, Late Large Red, Hazipur, Saharanpur and Rose-Scented.

 

 

- Chinese group

These trees produce very poor yields, but the fruit is of excellent quality and has a high percentage of chicken-tongue seeds. Cultivars include Haak Yip, Shang Shou Huai, Kontand, Glutinous Rice and Three Months Red.

 

 

- Madras group

These trees bear colourful red fruit, but fruit quality is poor. Cultivars include Kafri, Shorts Seedless, Johnstone’s Favourite, Emmerson, Durbhanga, Maries, Mooragusha, Madras 19, Hazipur/Saharanpur, Red McLean, Brewster and Bedana.

 

Tree quality

A good air-layer tree has a single erect stem. The first scaffold branches should branch horizontally at a height of about 200 mm. Any acute forks that branch lower than 200 mm should be avoided.  In grafted trees the graft-union height should be about 200 mm from the ground so that the first scaffold branches can branch at 300 mm. The graft union must be strongly attached and nurserymen must remove the grafting strip so that girdling cannot occur.

 

Aftercare of grafted trees

Trees can also be propagated by means of grafting.  Weekly aftercare is very important and suckers and wild shoots that develop on the rootstock below the graft wound must be removed.  After 5 to 6 weeks the buds start swelling and growing. A small cut can then be made through the plastic next to the bud. The bud grows through this cut, but the plastic strip must not be removed too soon. Once the first new growth has hardened off, the strip can be removed.  Grafted trees have a better root system than trees developed from air layers and therefore show rapid initial growth. Air layering is, however, preferred to grafting because of a better end product.

 

Planting

Litchi trees have a long life and become large.  Trees should be planted far apart to eliminate competition and to prevent branches of adjoining trees from growing into each other.  The entire outer area of the tree must be exposed to sunlight and air movement.

A 25-year-old tree can reach a crown diameter of 12 m. If trees are widely spaced and later become uncontrollably big an economic yield will not be possible. If the trees are to be spaced closely together, size must be controlled from the start by pruning.  A planting distance of 9 x 6 m is recommended for semi-intensive plantings.

 

Planting the trees

Litchi trees can be transplanted any time of the year, but the best time is during spring or at the beginning of the rainy season.  Planting holes should be square (in deep-ploughed soil 300 x 500 mm and in nonploughed soil 1 x 1 m).  Mix the topsoil with compost and put it back into the bottom of the hole.  When planting the tree, remove the container and loosen the soil around the roots without damaging the roots.  After planting, compress the soil slightly by standing on it.  Wet the soil around the tree immediately after planting.  Place a mulch around the newly-transplanted tree.  Irrigate young trees regularly after planting. They must never suffer from a water shortage or too wet conditions.

 

Fertilisation

Do not fertilise newly-transplanted trees too soon. Fertiliser should only be applied about 1 year after transplanting. The applications must be very light and broadcast evenly, but not against the stems of the trees. Irrigate after applying fertiliser.

 

Water requirements

Litchi trees need regular watering and therefore it is essential that enough water must be available from the flowering stage until after the February/March flush following the harvest.  Because the edible portion of the litchi fruit has a water content of 86 %, the availability of water remains important during the development period.  A water shortage will delay development of the fruit and adversely affect the size, mass and quality of the litchis.  Irrigation must continue after harvesting to ensure that a normal growth flush occurs during February/March, just before the beginning of the dormant period.  During dormancy (April to July) irrigation should be reduced, but the tree should not suffer drought.  Young trees that are not producing yet are irrigated throughout the year.  Producers normally stop irrigating the trees during the coldest months of the year (June and July) so that they can have a proper dormancy period. In areas where it is never very cold, irrigation should stop to force the trees into dormancy.

 

Protecting against pests

Covering the fruit with paperbags prevents damage from fruitflies and litchi moths, as well as sunburn and cracking.  The best time for covering the clusters will vary from one locality to the next.  Paperbags are at present the most suitable and also the cheapest covering material.  The fruit develops a very attractive red colour inside the paperbags.  Covering the fruit also extends the harvest period because fruit can be left on the tree for a longer period.  The paperbag at present used is open at both ends. It is made from reinforced brown paper that is very resistant to the elements.

 

The fruit must, however, be covered in the correct way and during the right time of the day (not early in the morning or immediately after rain), because of the risk of decay when covered while still wet. Spray against litchi moth and fruitflies just before covering.  Remove all the leaves on the cluster stem before covering.  Do not put more than 25 litchis in one bag.  The bags must be fixed to hang to an angle to allow water to flow out.  Both sides of the bag must be closed and, if necessary, a small opening must be left for rainwater to run out. The open ends can easily and quickly be stapled together.  The paperbags will even keep fruit bats and birds away.  Another advantage is that the fruit is handled less during harvesting and this limits damage caused by rough handling.  When removed carefully, the bag can be used for another season.

 

The tree can also be attacked by pests such as bark borers, litchi moth and fruitflies. Consult your nearest garden center about ways to control these insects.

 

Harvesting

Litchis do not develop further after picking. The fruit must therefore remain on the tree until quite ripe.  Litchis harvested too early have an unattractive colour and have a sour taste.