Longan (Dimocarpus longan) is a popular tropical fruit in few country such as China, Thailand, Taiwan and Vietnam. Other country growing longan was Australia, Florida and Hawai. The world largest longan exporter was Thailand with 238,000 mt in 1998 and growing about 41,500 hectare of longan. Malaysia import about 6,640 mt fresh longan from Thailand valued at RM 10.4 million not included the dried longan in 2007. In Malaysia longan olny planted in Johor, Melaka, Selangor, Kedah, Perak, Negri Sembilan at small scale about 60 hectare. The Writer managed to provide some technology for longan farmers in Muar Johor.
Few cultivars planted in Malaysia was Edaw, Chompoo, Biew Khiew and Diamond. Longan tree able to reach 10-20 meters height with large canopy size. The leaves are compound leaf with 6-9 pair and shining in dark green colour. There is 3 type of longan flower that was Male Flower, Female Flower and Hermaprodite Flower. Only hemaprodite flower will form longan fruit. The fruit caunted about 80 pieces weight about 5-20 gram/piece.
Soil type selection important for longan plantation. Fertile soil, proper drainage system and pH between 5.5-6.0 suitable for longan. Land preparation by ploughing and construction of farm road, drainage and basic buildings if necessary. Lining must properly arrange from East-West so that enough sunlight evenly reach the tree at 14 m x 10 m distance giving about 166 tree/ha. Planting hole 60m x60cm x60cm prepared with 0.5 kg/point GML, 10 kg organic manure and 250 gm TSP. Support needed for initial stage of longan seedling.
For the first 4 years manuring program, use NPK 15:15:15 at 1 kg/tree (1st year) increase to 4 kg/tree (4th year) gradually at 4 application, Organic manure and GML. Use NPK 13:13:13, NPK 15:15:15 and NPK 12:12:17:2 at reproductive stage as recomended rate. Pruning is an important activity in longan from formation pruning, maintainace and pruning of fruit or flower. Longan need about 13 liter/ha of water on initial stage , 26.5 liter/ha (Vegetative stage) and 38.7 liter/ha (Reproductive stage) using drip irrigation system.
There were pests and diseases attack longan in Malaysia. Fruit borer (Canopomorpha sinensis) attack longan fruit and control by chemicals. Thrips (Thrips spp) and Mites (Panonychus spp) also controlled by selected chemicals. Fruit Fly (Bactocera spp) and Stink Bug/Kesing (Tessaratoma papillosa) attack able to reduce fruit quality and quantity. Other longan pests was Web worm (Crocidosema spp), bats, birds and Keluang. Few identified longan disease was Sooty mould , Antracnose and Wilt (due to Fusarium, Phytium, Phythopthora, Clitocybe).
Weed control by manual and chemicals.
Tretment or Induce with Calium Clorate (KCO2) for edaw cultivar shows positive result in the local study. About 8 gram/m KCO2 sprayed under the longan canopy using standard table formulated. The longan flower will appear after 2-5 weeks of KCO2 treatment. In Malaysia the induce acticity best time is on August for harvesting Activity on January/Febuary of the following years. Longan fruit fully ripen after 5-7 months from flowering stage. It considered ripe when the fruit colour turn yellowish brown with smooth skin. Aout 3.4 mt/ha longan collected from 4 years old tree in selected longan farm in Muar. The fruit categorised in 3 grade that was Grade A (14-18 gm/fruit - 62 fruit/kg), Grade B (11 -13 gm/fruit - 77 fruit/kg) and Grade C (below 12 gm/fruit - >80 fruit/kg).
Local study shows that for 1 ha of longan required RM 327,775 as cost of production for 10 years with estimated gross income about RM 549,500. At the selling price of RM 2.50/kg ex-farm, the farmers will earn net farm income about RM 221,724 for 10 years or an average of RM 1,828 monthly. The NPV for longan was calculated at RM 48,323 and the IRR valued at 22% with BC Ratio at 1.56. The payback period for longan was at 8 years.
Study shows that there was few issues in longan growing in Malaysia. The first issue was the Biennial Bearing problem which was the most serious problem where the fruit bearing was peak in alternate year. Other issue was an occurrence of small size fruit, attack of Keluang/ Bats, Virus Witches Broom Disease, Crack Branch and requirement for flowering inducing program for longan. The longan technology in Malaysia need more study for more practical later.
FROM THAILAND... BUY LONGAN....
LOCAL FARMERS....TRY GROW LONGAN....
SETTLE THE ISSUE .... BETTER TO PLAN....
NEED MORE STUDY ... IMPROVE PRODUCTION...
Study Longan at Gerisek Muar