LYCHEE is a tropical fruit tree and mostly found in China, India, Southeast Asia, and South Africa. Its fruit is high in Vitamin C and mineral potassium. It is an important fruit crop of China, India, Thailand, Vietnam, Nepal and Bangladesh. Lychee is a highly paying crop and accounts for 2½ times the income from any other fruit crop.

Three types of flowers appear in irregular sequence or, at times, simultaneously, in the lychee inflorescence: a) male; b) hermaphrodite, fruiting as female (about 30 per cent of the total); c) hermaphrodite fruiting as male. The latter tend to possess the most viable pollen. Many flowers have defective pollen which probably is the main cause of abortive seeds and also shedding of young fruits. The flowers require transfer of pollen by insects.

The plant requires warm, humid climate for vegetative growth. Dry hot air is injurious for the fruit. The soil which is rich in organic matter, moist with good drainage and free of artificial components is suitable for cultivation.

A lychee tree will provide some natural organic matter to its soil through leaf and occasional branch litter and any fruit drop that occurs. The lychee grows well under a variety of soil conditions but prefers a fairly deep loamy alluvial soil.

The planting time of the tree is late spring when frost risk is over and if irrigation is available planting can be done in late March and April. Regular irrigation is required for better establishment of the orchard.

There are only two common varieties Dera Dun and Bengal in South Asia. There are numerous lychee orchards in the sub-mountain region of Punjab. Panjore is a common variety with large heart-shaped orange to pink coloured fruit. Six varieties i.e., Rose Scented, Bhadvari, Seedless No.1, Seedless No. 2, Dehra Dun and Kalkattia are commonly grown.

Lychee propagation from seed is unsatisfactory because cultivars do not reproduce true from seed. Seedling trees often take 10 years or more to bear. The most common method of propagating lychee is air-layering, a technique for inducing a branch to form roots while it is still attached to the tree, after which it is removed and planted.

After two to four months, when several roots have formed and are visible through the plastic, the air-layered branch is cut off immediately below the plastic. The wrapping is then removed and the rooted air-layer planted in a suitable container. Removing about half of the leaves at the time of planting in the container will prevent excessive moisture loss.

Containers with newly transplanted air-layered plants should be placed in a shaded area for about two weeks with a lightweight plastic bag placed over the plant to retain humidity until the plant begins new growth. Later on, the plants can be gradually exposed to full sun to “harden.”

Transplanting the plant to field is best done during rainy season, but if this is not possible, the plants should be watered every two to three days until well established. The trunk and rooted area should not be buried more than 1-2 inches below the level of the soil in the container.

Removing about half of the leaves at the time of transplanting to the ground will prevent excessive moisture loss. Air layered trees usually take three to five years from planting to become established and begin bearing fruits.

Lychee trees typically begin to flower in the early winter months and continue to bloom throughout the months of January, February and March. Flowers appear as 12-30 inch clusters containing both male and female flowers on the terminal ends of the hardened off new growth. If there is sufficient chilling and dryness during the winter then there will generally be a larger portion of bloom instead of simply new growth.

Use organic fertilizers that contain compost extracts, seaweed or kelp. Avoid using artificial fertilizers (nitrogen, phosphorus, potassium) that may kill many essential organisms in the soil ecosystem of lychee tree.

The NPK fertilizers, if applied can burn the roots and cause soil particle aggregation, which negatively affects the water drainage and impedes micro environments where essential soil food web organisms thrive. Fertilizer by-products such as nitrates, sulfates and phosphates cause ground water contamination and regional environmental degradation and should not be used if there are alternatives.

Male flowers are the first to emerge and open. The fruit forms from the female flower that opens later than the male. When the flower is pollinated the ovary begins to swell. This becomes the actual lychee fruit. As the small lychee fruit develop many of the fruits will drop off the tree from wind and some simply from natural attrition. A variety of insect pests can damage the stem on the newly developing fruit leading to drop off.

The fruit begins to develop some coloration in late April and May. The commercial Mauritius varieties are the first to show ripening signs followed by the Brewster in Late May and early June. A slightly pink fruit is tart in taste. This is the stage when most growers pick and sell their crop.

Fruits mature in three to five months after flowering. Early cultivars are harvested in May and June and are removed by cutting or breaking the branch off just above the panicle. Fruits are harvested after their skins turn red.

Green fruits do not ripen satisfactorily after removing from the tree. After harvesting, the skin colour turns reddish brown in a few days if not refrigerated. Refrigeration at 32-40F (0-5C) and storage in plastic bags can prolong the colour and flavour for about two weeks.

Those to be refrigerated should be broken off the panicle, leaving a bit of stem attached. If the fruit is pulled from the stem, the skin may break, resulting in dehydration and possibly spoilage. Lychees are quickly frozen, dried, or canned. Harvesting in Hyderabad takes place on May 15, in Rohri on May 23, in Multan it ends by June and in the Northern Punjab in the first fortnight of July. The yield varies with the cultivar, age, weather, presence of pollinators, and cultural practices.

This is a highly perishable fruit and mainly sold at local or nearby markets in fresh form fetching good prices in big cities. The fruit remains fresh in baskets packed loosely. Lychee is neither exported nor imported, perhaps because the fruit still is sold on streets where adequate storage facilities not available.

In South-East Asia, lychee is very popular and large quantities are exported to Europe. Pakistan too, can take this advantage. The 2004 crop brought excellent prices of Rs50 per kg at the Karachi Sabzi Mandi Market against Rs100 for early lychee harvested in the last fortnight of May, due to its being early in South-Asia.

The production season is short, about one and half months from late May to early July. The large quantities produced in such a short time must be marketed immediately since the fruit turns brown and rots rapidly after harvest under ambient temperature. Short shelf-life limits the extension of lychee market in terms of time and space and causes heavy loss when the produced fruit cannot be marketed immediately.