Among all foreign fruits, Rambutan is particularly popular and favoured in this country. This fruit is somewhat similar to lychee, but it is larger, roundish, and slightly spiky. The ripe fruit is bright red, orange, or yellow, in attractive colours. The outer skin of the fruit is covered with numerous soft hair-like protrusions, resembling the flowers of the pomelo.
In the Malay language, rambutan means “hair.” For the same reason, many people are familiar with this fruit as “hairy” or “hairy lychee.” Rambutan like lychee is evergreen, medium to tall, with unique long branches. It bears fruit during the rainy season in July-August. The unripened fruit remains green in colour. When the fruit is ripe, it undergoes a transformation into a bright red/maroon colour, and it is advisable to harvest the ripe fruit within two to three weeks.
Origin and Distribution:
The rambutan fruit originates from Malaysia, and Indonesia. It is also cultivated in Thailand, Cambodia, the Philippines, Vietnam, Myanmar, Brunei, and Sri Lanka. These countries have similar tropical climates suitable for the growth of rambutan. The cultivation of this fruit has expanded to other countries, or regions that have comparable weather conditions. For example, India and Bangladesh, where the intensity of cold weather is minimal, have seen an increase in rambutan cultivation and production.
Climate:
Rambutan cultivation is suitable for tropical and subtropical regions. This fruit tree cannot tolerate freezing temperatures. If the temperature falls below 10 degrees Celsius for 5–7 days during winter, the tree is likely to die. Rambutan is being cultivated in various regions of Bangladesh, including the southern and hilly districts, as well as larger cities like Dhaka, Mymensingh, Khulna, and Jessore.
In the Rangamati district, some Rambutan trees have been producing fruits for 30–40 years. In Netrokona, a few farmers have been successfully cultivating and marketing Rambutan fruits for about 20 years, and are earning good profits. Additionally, in the Shibalaya district of Narshingdi several farmers are inspired by the success of Rambutan cultivation, and are engaging in this venture alongside jute cultivation.
Most of the countries that are major producers of rambutan have expertise in rambutan cultivation, including collecting fruit/seeds. They have contributed significantly to rambutan cultivation in Bangladesh.
Nutritional Value:
Rambutan is a fruit, rich in medicinal properties. It contains abundant iron, calcium, potassium, fibre, and calories. Additionally, it is rich in various vitamins, and minerals, making it a beneficial fat-free fruit.
Soil:
Rambutan can be grown in almost all types of soil. However, fertile loamy soil with good irrigation, and drainage facilities, is more suitable for rambutan cultivation. If the soil is hard clayey or compacted, digging a pit of 5–7 feet wide, and deep filling it with compost, and creating a well-prepared planting medium can make rambutan cultivation more successful. The ideal pH of the soil for rambutan cultivation is between 5.5 and 6.5.
Rambutan cultivation primarily involves planting seedlings derived from seeds. The seeds are extracted from ripe fruits, and used to create seedlings in a fresh state. Typically, the natural germination capacity of rambutan seeds does not last more than 5–7 days. Therefore, it is necessary to plant the seeds soon after collection. To plant the seeds a suitable potting media is prepared. The media is prepared by combining coarse sand (25 grated coconut husk (25 decomposed organic manure or compost (25 and vermiculite (25%). These are mixed to create a well-drained soil mix for planting the seeds. The seeds should be placed at a shallow depth, and lightly covered with soil mixture.
It is good to treat seeds with fungicides before sowing. The seed tray should be kept in partial shade. Measures should be taken to prevent excess water or rainfall from soaking the soil or reaching the top layer. Seedlings should be protected from pests, that may eat or damage germinating seeds, through the use of pesticides or other methods. The soil in the tray should not dry out, so occasional light sprinkling of water should be done to keep the soil slightly moist. Excess water should not be given. The seeds will germinate within 10–20 days of sowing and then the growth of the seedlings will begin.
Fruit Harvesting:
The rambutan tree starts blooming in March, and the green fruits start to appear in April. After 3–4 months of flowering, the fruits ripen in July-August. When the fruit is fully mature, it undergoes a sudden change in colour from green to red or maroon. The fruit collection should be done within 15–20 days of this stage. Rambutan fruits are harvested manually. It is advisable to harvest the fruit along with the pedicel (1/2–1/4 inch) attached. This practice helps in producing more fruits the following year by stimulating the growth of new shoots. Some trees may produce a second crop of flowers and fruits during the off-season.
A mature tree can yield 150-250 kg of fruits per year. Under normal conditions, these fruits cannot be stored for a long period. The marketing or consumption tasks should be completed within 7 days of harvesting the fruits. However, if stored at a temperature of 10–12 degrees Celsius, the shelf life can be extended by 8–10 days.
Currently, the market price of this fruit in Bangladesh is approximately 400-500 BDT per kilogram. Rambutan farmers in Narsingdi, and Netrokona, are earning around 50,000 to 1,00,000 BDT by selling the fruit from each tree, which can be between 8–10 years old. They sell the seeds of each fruit for 5-7 BDT.
This profitable fruit cultivation has attracted many people to engage in rambutan farming and the cultivation of this fruit is gaining popularity in the country.
Citation:
Mr. Enamul Haque, is the Director-General (Additional Charge) of the Department of Agricultural Extension and a member of the Special Pool (ACS) in the Ministry of Agriculture.
