WE are all familiar with this vegetable, consumed by many Sarawakians for a long time. Some may feel somewhat uncertain about the chemical composition and nutritional value of these greens to their health.
The botanical name is ‘Sauropus androgynus’, while colloquially, it is called either ‘cangkok manis’, ‘cekur manis’, or ‘sayur manis’ – all Malay words.
It has various names in other Asian cultures: it is ‘pak waan’ in Thailand, ‘katuk’ in Indonesia, ‘rau ngót’ in Vietnam, ‘Chinese Malunggay’ in the Philippines, ‘madhura cheera’ in Kerala, India and ‘amame shiba’ in Japan.
The Chinese name, ‘mani chai’, is also quite common among Sarawakians.
The small-shrub plant belongs to the family Phyllanthaceae, growing across much of tropical Asia.
It is notable for high yields and palatability. Several cultivars show some degree of variations with regard to the shape of and the chlorophyll content in the leaves, and each has a slight different taste from the other.
The young sweet shoots are sold as ‘tropical asparagus’, delicious when stir-fried with egg or dried anchovies. The domestic price is about RM20 per kilogramme now.
Morphology of the plant
The morphology of the plant is overshadowed by the horizontal foliage on the side branches, and tops with the young shoot. The woody stem is roundish, attains from the single main stem the size of a chopstick and may reach a height of up to one metre.
The red flowers appear on the ventral side of the older branches, and bear small purplish fruits not visible from the top of the plant.
Normally only the leaves and the young shoots are consumed as vegetables. Studies suggested that excessive consumption of the juiced leaves or shoots for body-weight control in Taiwan could cause lung damage due to its high concentration of the alkaloid papaverine in fresh extract drink, as reported in 1995.
It is not recommended for people with asthma either. The consumption of ‘cangkok manis’ is reported as being associated with bronchiolitis obliterans.
However, the leaves are safe to eat even in large quantities provided that they are properly cooked – heat seems to be able to denature the toxin.
The plant has a good source of Vitamin K.
The freshly-plucked leaves have high levels of Pro-Vitamin A and carotenoids, as well as vitamins B and C, protein and minerals – iron and zinc, notably. A 100g serving can provide 100 per cent of the daily recommended value of Vitamin C.
To me, it is not a difficult job growing this vegetable in our tropical environment as we have plenty of sunshine and a humid condition. The plant is propagated by vegetative cuttings of the stem after the leaves have been plucked for the dinner pans. The cuttings should be taken from the older section of the stem, with trimmed branches less than two inches in length.
The internodes are important for sprouting new growth. The seeds are not suitable for propagation purposes.
The soil medium is very important for successful cultivation, especially with good organic content or rich in manure.
The soil must be drainable to avoid water-logging. Basal dressing with chicken dump is a good practice. Weeding is a much-needed operation for bed maintenance; otherwise, use black plastic sheet to cover much of interrow spacing to avoid weed overgrowth.
Keep the bed damp by watering. Soil amendment using mycorrhiza fungus to improve heavy soils or the use of other microbes to improve the soil, is necessary.
Repeat fertiliser application with NPK pellets or organic manure every month.
A good crop, ready for harvesting, should yield three months after cultivation; repeat harvesting every month as more shoots would be produced and more foliage would appear.
Pests and diseases
Some pests are becoming a major issue. Take mealybugs for instance; they have become dominant in many cases when the natural controllers, the ladybugs, are not available.
The case is similar in ‘cangkok manis’, where the sucking pests are also carriers of several diseases.
The virus-based diseases that cause the leaves to become very small and wrinkly are some examples. There is not much that we can control other than roguing (identifying and removing altogether plants with undesirable characteristics from the patch).
Final reminder – do not eat this vegetable uncooked, and do not over-consume it as well. Happy Gardening!