1. Lychee is indigenous to Southeast Asia and makes a significant contribution to the lives and economic health of many millions of people in the Region. The species originated in southern China and northern Viet Nam, but has now spread to most countries that experience a sub-tropical climate for part of the year. The crop is most important in China, India, Viet Nam, Thailand, Bangladesh and Nepal. There is also interest in Australia, the Philippines and Indonesia. Production in the Asia-Pacific Region accounts for more than 95 percent of world cultivation, at about 2 million tonnes. The crop is very popular throughout the Region with strong domestic markets and increasing affluence. About 58 percent of the worlds population live in this Region. There is also some trade within the Region with exports to Singapore, Hong Kong and Malaysia. Most of the fruits are sold fresh, with a third of the crop dried in China, and limited processing and canning. The bulk of the crop is produced by smallholders with less than 100 trees each. Orchards with more than 1,000 trees are rare, except in southern China where there are single plantings of more than 10,000 trees. The fruit has a high value, and can significantly add to the income of smallholders. A few trees may double the income of such families. Despite the long history of cultivation in the Region, many areas experience low productivity, with average yields generally below 5 tonnes per hectare. This can be due to the weather affecting flowering, poor cultivars or lack of tree care. In Israel and some other countries, yields of up to 15 tonnes per hectare have been achieved. This indicates that there is a large gap between actual and potential yields. Much work is required to raise productivity across different locations. Prospects for increasing production and marketing of this crop are high if some of the growing, post-harvest handling and marketing issues are resolved. Intra-regional cooperation would assist industry development and the importance of the crop to local economies. Training for extension and scientific staff is also a priority.
2. Lychee trees require temperatures around 15°C (or lower) to flower successfully. A period of dry weather at this time can also assist cropping. Once trees have set fruit, warm weather with good soil moisture is usually associated with heavy yields. Cropping is thus limited to areas with some cool weather before flowering. Production is very erratic in the true tropics where night-time temperatures seldom fall below 25°C. The majority of the industries are thus based in areas with night-time temperature falling below 15°C. However, there are examples of industries with cultivars that will flower at slightly higher temperatures (e.g. Central Thailand). These areas often supply early season fruit and return higher incomes than fruit from traditional sub-tropical areas, but can fail some years. The quality of some of these cultivars is often inferior compared with the traditional types. New cultivars that have better fruit quality need to be developed for these areas. More research is required to define the optimum temperatures for flowering in the major commercial cultivars. There are also some growing techniques that can assist cropping in the warmer areas, but they have not been evaluated across the different environments. The other constraints related to weather are poor fruit set during cool damp weather, and damage to trees and fruit after typhoons. The risk to orchards is greater with plantings close to the coast (e.g. China and Viet Nam).
3. Lychee has a long history of cultivation in the Region, with many cultivars available. However, there is a paucity of information on the yield of different cultivars in the various countries. It is generally considered that the performance of many cultivars is disappointing and makes lychee production unprofitable. There are also differences in production season and fruit quality which impact on marketing. Many industries are based on one or two cultivars. Choice of cultivar along with growing area has a major influence on orchard viability. Lack of suitable cultivars probably limits lychee production in many countries. This is because the existing cultivars are low yielding or not well regarded in the marketplace. Exchange of germplasm would increase the production of the crop in many countries. There is only limited plant selection and plant breeding in the crop. Some countries such as India, China, Nepal and Viet Nam have many seedling trees, which could form the basis of a new genepool for future cultivars and industry expansion. A breeding programme is required in the long-term to develop better cultivars, and is best implemented with a regional focus. In the interim, the current genepool should be more systematically evaluated. Standardization of cultivar names and descriptions would assist cooperation. Based on the above, it can be concluded that there is a need for a much stronger varietal improvement programme in all countries.
4. Propagation is well described, with most orchards based on air-layers. However, grafting or budding is popular in China and grafting popular in Viet Nam. It is reported that grafted trees are more drought and wind resistant; however, little experimental evidence is available. Grafting also uses less planting material than air-layering. However, there are some disadvantages with grafting. Grafting is not as easy as air-layering and requires the growing of seedling rootstocks. Grafted trees are also slower to be planted out. There is little information on the compatibility between different cultivars and the impact on production and fruit quality. Lack of irrigation can be responsible for the failure of newly established young plants. Many countries reported serious loss of young plants at this stage. Education of nursery workers and growers in tree care and the provision of irrigation would improve success rates. It is apparent that further work is required to standardize nursery techniques.
5. Lychees can be grown on a range of different soil types, including soils with a pH ranging from 5 to 8. In very acid or alkaline soils there can be problems with iron, zinc, boron and other nutrients. The soil must be freely draining, although the trees can tolerate a wet profile for part of the day. Tree health and production are probably best with sandy, sandy loam and clay loam soils. Heavy clay soils are best avoided. Lychee production is unlikely to be restricted by poor soils throughout most of the Region.
6. It was agreed that production is probably best with irrigation of the orchards, especially during the fruiting cycle. Rainfall varies from month to month across the different agro-ecological zones. Most of the lychee orchards are not irrigated and are therefore dependent on regular rainfall. Experiments in Australia and South Africa have shown that drought can affect growth and fruit production, but the impact for local farms in Southeast Asia is not known. Most growers cannot afford the cost of irrigation. In any case, irrigation water is not available in most areas. In the absence of irrigation it was suggested that mulching and some cover crops would probably assist water conservation,. It can be concluded that new orchards should be irrigated if possible.
7. Most growers apply fertilizers to their orchards. Tentative leaf and soil standards are available for lychee, but the tests are possibly too expensive for smallholders. Local government extension staff could provide this service on a provincial or district basis. Most growers use a mixture of organic and chemical fertilizers, although the source of the fertilizer is unlikely to have any impact on production. In contrast, the effect of time of fertilizer application on cropping has yet to be resolved. Crop nutrient removal data could be used as a basis for estimating fertilizer requirements. The role of nutrient recycling in the lychee orchards was highlighted, with the possibility of organic farming in some circumstances.
8. High-density orchards are becoming popular in the Region, and would be expected to increase the returns to growers, especially in the early years of a planting. There is evidence that these orchards can have double the returns of traditional low-density plantings. Considerable experience has been developed in some countries such as China. These closer plantings would be expected to increase the returns for both small and large landholders. High-density plantings require some method of canopy management to control tree size, with close attention to water and nutrient management. Experiments in China and Australia have shown that trees should be pruned in the first few weeks after harvest. This research needs to be repeated in the other growing areas. Extension staff also need training in the various aspects and benefits of canopy management. There are also various methods for controlling flower initiation such as droughting, girdling, pruning and chemical defoliation that need evaluation across the Region.
9. Many insects and other pests affect the lychee tree, leaves, flowers and fruit; however, their impact on grower returns varies throughout the Region. Most countries need to develop their own systems of integrated pest management, although there could be cooperation for the control of erinose mite and some other pests. Pest management along with other methods of tree care must be suited to the needs and abilities of the smallholders. Diseases were not considered to have a strong affect on production, apart from anthracnose in China and Australia.
10. Lychee fruits are highly perishable and have a short shelf-life. This seriously limits the marketing and expansion of the crop across the Region. Much research has been initiated to reduce fruit browning and rotting; however, no protocols have been established which can guarantee fruit quality for more than a week or two. This includes heating and cooling the fruit, various packages, and application of various fungicides and other chemicals. Many of the industries in the Region are based on the treatment of the fruit with sulphur; however, this chemical may be withdrawn soon. This makes the development of a new post-harvest treatment more urgent. Many countries do not have reliable access to on-farm cool-rooms, hydro-coolers, or refrigerated transport.
11. Most of the lychees produced in the Region are marketed locally. There are some exports to Hong Kong, Malaysia and Singapore, and to a lesser degree Europe and the Arab States. There are certain problems with Japan and the USA because of quarantine issues with fruit flies. Disinfestation protocols need to be established for the various markets. The market potential within the Region is strong because of the rising affluence within Asia and the Pacific. Good quality fruit from the Region is also highly regarded in Europe. However, there has been very little market intelligence collected. The preferred cultivars, packaging, etc. for the different markets are not known. The potential size and value of each market is also unknown. Lack of freight space is a limit for some countries like Australia. Quality standards have been developed in some countries.
12. There is a growing awareness for organically produced food. Organic farming is one of several approaches to sustainable and environmentally friendly agriculture. Lychee farmers could have a share of the world organic market, which is growing at a rate of 15-20 percent every year. Therefore, it is worth exploring the possibility of organic farming.
13. The consultation revealed that there was a need for improving the skills and technological knowledge of research and extension staff in many of the participating countries, along with orchard management skills of lychee growers. This could be achieved through professional development of scientific and extension staff, seminars, workshops, study tours, and on-farm training across the Region. The establishment of a lychee network throughout the Asia-Pacific Region would assist this training, and foster the exchange of new cultivars and technology. However, much stronger Government support is required to assist expansion in the various countries. The consultation recommended the establishment of a lychee network to foster cooperation and exchanges within the Region.
14. National workshops are a possible way of increasing the understanding of the crop in the different countries. These would follow a FAO Regional Workshop on Lychee. Various stakeholders such as research scientists, extension staff and growers would be included in these national workshops.
15. There is a low base of information on growing and marketing lychee in many countries throughout the Region. A regional network as indicated above would assist the exchange of information. It was also suggested that a lychee production manual be produced by FAO to cover various aspects of the crop in the Asia-Pacific. The manual would be directed at research, extension staff and farmers, and provide information about improving returns from lychee enterprises, especially smallholders.