Wednesday, 18 September 2013 00:01
For the past couple of years, the consumers of Sri Lanka, especially in the supermarkets, were presented with a peculiar type of fruit, red in colour, generally round in shape, slighter bigger than a mango, but with soft leaflets protruding from the fruit. The fruit is dragon fruit, a new commercial crop introduced to Sri Lanka less than 10 years ago. The current fruit season is almost over and the next season will be in June 2014.
The fruit when cut open shows a two to three mm thick skin, with juicy white flesh and tiny black seeds distributed across the flesh. Almost 90% of the weight can be consumed; and being low in calories it is ideal for weight watchers. The fruit, which is eaten raw, is mildly sweet with a nutty flavour; the seeds are eaten together with the flesh. Dragon fruit can also be consumed with yoghurt, ice cream, as a smoothie or to flavour other beverages.
Dragon fruits are rich in vitamin C, and it is claimed that eating helps strengthen the immune system and promotes faster healing of bruises and wounds; eating it on a regular basis will also help ward off chronic respiratory disorders such as asthma and cough.
The fruit is high in fibre and low in cholesterol, saturated fat and trans-fat, so regular consumption will help manage blood pressure and control cholesterol levels. The fruit is excellent for diabetics, is considered to be a health food and is popular with the elderly. The dragon fruit which contains a wide range of minerals is also highly recommended for pregnant mothers.
“Eat dragon fruit as a good natural source of anti-oxidants which help to prevent the dangers of free radicals which can cause cancer and other undesirable health detriments. The number, quantity, and variety of antioxidants in real foods like dragon fruit is completely unmatched by any food supplement or pills - even those claiming to have ‘antioxidant’ health benefits. Nothing compares to the rich array of nutrients and antioxidants in a real natural food like the dragon fruit.” (‘Health Benefits of Dragon Fruit,’ http://www.naturalfoodbenefits.com)
Of the local fruits, dragon fruit is the only fruit which cannot be artificially ripened with calcium carbide or other chemicals. They need to be ripened on the tree, thus any dragon fruit purchased by a consumer is assured to have preserved all the beneficial aspects of fruits as a healthy diet.
The white-fleshed dragon fruit – also referred to as Pitaya – is a cacti of the genus Hylocereus undatus, and is believed have originated in Mexico and South America. The fruit was introduced to Southeast Asia by the Dutch and became immensely popular with the Chinese, who are the world’s biggest consumers. Currently, dragon fruit is cultivated extensively in countries like Cambodia, Thailand, Malaysia, Vietnam and Philippines, and in smaller quantities in southern parts of USA and in Australia.
The name dragon fruit was coined by the Chinese, who claim that, thousands of years ago two huge dragons were fighting in the sky, throwing flames at each other. Hot droplets of flame then rained down upon the earth, which when cooled became dragon fruit.
Nutritional value, health benefits and calorie count
Dragon fruit is low in calories and can offer several health benefits when consumed in moderation and as part of a balanced diet. In addition to its nutritional value and health promoting effects, the dragon fruit is praised for its appetising crunchy texture and refreshing, sweet flavour which is like a cross between a kiwi and a pear. To preserve most of its flavour and nutrients, the dragon fruit is usually eaten raw as a healthy snack, or is pureed into smoothies. (www.healwithfood.org/nutrition-facts/dragon-fruit)
Nutritional value and health benefits
Dragon fruit is known for its laxative properties.
A 100-gram serving of white-fleshed Pitaya provides an estimated 21 milligrams of vitamin C, which corresponds to 34% of the daily value set for vitamin C. By way of comparison, this is less than half the amount of vitamin C found in an equal serving of oranges, but more than three times the amount of vitamin C found in carrots. Vitamin C is perhaps best known for its ability to strengthen the immune system, but it also offers many other health benefits. When you eat dragon fruit or other foods that contain vitamin C, you boost your body’s natural ability to get rid of heavy metals and other toxins, promote the healing of your body’s cells, and improve your ability to cope with stress. Vitamin C is also an important antioxidant that is vital for overall good health and beautiful skin.Due its nutritional profile, dragon fruit can be used as a natural remedy for constipation. Dragon fruit seeds, in particular, appear to have strong laxative properties and can therefore be highly effective at stimulating bowel movement. One of the nutrients that contributes to the laxative properties of the dragon fruit is fibre. A 100-gram portion of dragon fruit delivers three grams of fibre, which is equivalent to 12% of the daily reference value for dietary fibre. Furthermore, dragon fruit seeds contain polyunsaturated fatty acids which have been shown to exert laxative effects.
If you are looking for fruits that are delicious and filling, but will help keep your weight in check, dragon fruits are a perfect choice. A 100g serving of dragon fruit has only 60 calories: 18 calories from fat (all unsaturated), eight calories from protein and 34 calories from carbohydrates. Dragon fruits do not have complex carbohydrates, so they can be easily broken down by the body. (www.fitday.com)
The dragon fruit comes in white, red and yellow varieties, but the most common type in Sri Lanka is the white-fleshed variety and the discussion relates to same under local climatic conditions.
Dragon fruit is a cactus is best grown in dry tropical climates with a moderate amount of rain, and the plants could be obtained from seeds or from a branch cutting. As the growth continues, the plant needs a support to climb on, which can produce aerial roots down from the branches in addition to the basal roots. Once the plant matures in 12 to 18 months, it will begin to flower.
The flowers bloom after night-fall and wilts in the morning by around eight. They rely on nocturnal pollinators such as moths or early bees for fertilisation. Flowers are white in colour, fragrant, and are huge – almost eight inches across – with typical cactus flower shape.
After flower buds become visible to naked eye, they flower in around 16 days and produce fruits that mature around 30 days after flowering, thus indicating fast growth. The fruits are normally 200 to 600g in weight and after harvesting, will keep fresh in the open for over a week (shelf-life) and over three weeks in a refrigerator (5-10 degrees C).
Flowers appear in cycles around seven days to 10 days apart. In a plantation, not every cycle bring widespread flowers, but a few flowers showing the cycle. One particular feature in dragon fruit is that all flowers in the cycle open on the same day, which means that the fruits ripen at the same time and making the harvest convenient to market. It has also noted that the cycles coincide throughout the country, making the market being saturated on a particular day; a week later, there may be no fruits in the market at all.
A good healthy plantation will yield around eight to 12 flowering cycles a year. The flower buds appear first in early April and can continue till August. It would be worth noting that during this period the sun crosses over Sri Lanka to the north and the day becomes longer than the night. The heavy fruiting season ranges from early June to late August, with its peak in July, although few fruits could mature until early November.
Young dragon fruit plants are common throughout the country in almost all plant nurseries. However, if you wish to have good fruiting plants, buy only from a reputed plantation since, although all plant cuttings would give a new plant, a good yield could only be obtained from cuttings from mature plants. Plants can also be obtained from seeds, but fruiting from seed plants could take three to four years.
Dragon fruit plants require very high levels of sunlight and need to be away from shade. As the plants are a cactus, they cannot withstand flooding and need to be planted on a slightly raised bed. The plant is a climber and is best planted against a concrete post seven to eight feet high, with four plants to a post, erected at 9’x9’ centres. This would allow 400 posts to an acre or 1,600 young plants.
The post needs a mechanism to hold a motorcycle tyre (as commonly used) that supports overhanging branches. Flower buds appear on the hanging branches. It is claimed that a dragon fruit plant has a life of up to 20 years. As such, the branch support will need to withstand the lifetime of the plant, and timber posts will not last the 20 years.
The plants are grown in a mixture of sandy soil, compost and cow dung, are watered every four to five days and need regular fertilising, depending on the growth. First flowers could be expected within a year (during the May – August season), but proper yields could be expected from the second year, with yields increasing up to fourth year and continuing onwards.
Diseases and pests
The plants are generally free from diseases; however branches could rot due to excessive rainfall, making this plant unsuitable to regions receiving heavy rainfall. As for pests, young fruits are attacked by the beetles in the night. Ripened fruits are loved by birds (kondayas, parrots), squirrels, bats and ants which can become a major problem if they become used to consuming the fruit. Lower hanging fruits succumb to porcupines, who also chew on the base of the plants. When flowers are open, heavy rains could wash off the pollen, which could wipe off most of the crop. Heavy rains also could cause the ripened fruits to split.
Worms are never found inside dragon-fruit, possibly due to the flower being night-blooming, and the fast growth of the fruit does not allow fruit-flies to lay eggs.
Harvesting is carried out when the fruits are ripe by separating the fruit from the stem with a pruning knife. It is best to harvest the fruit during the early morning; if harvested later the fruits need to kept spread out in the shade to allow disposal of farm-heat. Immediate heaping and packing the fruits with the farm-heat could reduce the shelf-life of the fruit considerably. If mature fruits are left on the tree, they would remain ripe for nearly two weeks, at the mercy of birds and the possibility of the fruit becoming overripe and therefore splitting. Each additional day on the tree will also reduce the shelf-life of the fruit.
Market and income
So far the market for dragon fruit has been mostly the middle and upper middle class society. Even the tourist hotels do not serve the fruits, probably due to high prices. However, the resident expatriates are massive consumers. Market retail prices vary from over Rs. 750 a kg during the beginning of the season to around Rs. 500, then crashing to Rs. 250 during the peak season.
Wholesale price of fruits during the current year varied from Rs. 350 during the commencement of the season and to below Rs. 200 during the peak. Some producers were forced to give their produce to small-time sellers who sold their produce on the way side. This year’s glut was due to the large number of new plantations coming into the market, and future prospects can be a problem, as every producer’s fruits enter the market at the same time.
Therefore, future large scale plantations need to aim at the export market, and expecting an export price of one US Dollar per kilogram would give a fair profit.
Other countries which produce dragon fruit also produce juices, smoothies and dried snacks in packed form. This has not yet commenced in Sri Lanka and could be the answer to the glut and excess production.
Any possibility of exports would be confined only to the Middle East market and Maldives. The US and the Europe have introduced legislation requirements practically closing their markets to all Asian countries. Their markets are open only to Israel, Turkey and South Africa. Any export oriented projects are best to be located in the deep south region of the country, where the climate is suitable, land is available and exports are possible from Mattala Airport.