TRICHOSANTHES diocica is a vegetable known as ‘perwal’ in Urdu and Hindi and ‘patol’ in Bangladesh. The plant — a trailing vine– belongs to the family Cucurbitaceae. It is abundantly grown for its edible green fruit in Bangladesh and India, which also has the distinction of being its original home.
The plant has to be provided support to grow and bear fruits. The green immature fruit is small in size and has white or yellow spots. It is cooked in more than one way and is largely consumed in the neighbouring countries for the maintenance of health. It is one of the prized vegetables, especially in Bangladesh and India of the health-conscious people and people with poor health.
This wholesome vegetable is still alien to us, as no attempt has so far been made to introduce it in our climate despite its not being unfavourable.
Climate and soil: Perwal thrives best in tropical and sub-tropical climate. In the absence of rainfall, irrigation can also do well. Well-drained, fertile, sandy-loamy soils are as good as river beds. The plant is, however, not tolerant of water-logging.
Propagation: Perwal can be propagated from its seed. But seed-produced vines give poor germination, growth is retarded and flowering is delayed. Hence, the common practice followed across the border is to propagate by cuttings and root-suckers. Cuttings of 50-60cm long are made from one –year-old fruiting vines of both male and female flowering vines. The cuttings are first raised in a sandy medium in a nursery in October, when vines are mature the rooted cuttings are transplanted in fields in February – March. Cuttings are planted in long furrows about 30 cm deep.
Fruit types: The immature fruits are picked from March to June. The fruits are grouped into four classes: dark green with white stripes and 10-13 cm long; thick, dark green with pale green stripes 10-16 cm long; roundish with white stripes 5-8 cm long; tapering green and stripped 5-8 cm long.
Research efforts: Besides indigenous varieties, good improved varieties have been evolved at the Narendra Dev University of Agriculture and Technology, Faizabad, UP, India. Efforts are also under way to introduce perwal since 1994 at the Forty Valley State University, Georgia, USA, to satisfy the demand of ethnic minorities from India, for whom it is imported from India.
Chemical composition: The chemical composition of ‘perwal’ shows that it is a rich source of minerals and vitamins A and C. It contains magnesium 9 mg, sodium 83gm., potassium 1.1 mg, copper 17 mg and sulphur per 100g of edible food.
Medical benefits: Perwal lowers cholesterol and blood sugar. It is also useful in cardiac aliments and nervousness and purifies blood. Perwal soup is best for the convalescing patients.
Remarks: Perwal is a vegetable that has still not caught the attention of our researchers or the progressive growers even for its introductory trials. Pakistan Agricultural Research Council – which is the country’s biggest research organisation – may send a vegetable expert to study the cultural methods of the vegetable in Bangladesh and lay small exploratory trials in the potential areas of the country.
Karachiites, who are aware of its benefits, are buying this vegetable at a higher cost, as it is not grown locally. It has to be imported or brought by visitors from across the border or Bangladesh, which adds to its cost. By producing this vegetable in our country, the cost can be brought down to an affordable level and the poor populace may also be able to enjoy it.
The country will be a proud producer of ‘perwal’ to add a new vegetable to the list of not only vegetarians but also meat and mutton eaters. Perwal is a delicacy with medicinal benefits and no one would like to miss it in ones diet.