Thangjing – A potential aquatic cash crop in Manipur

Prof N Irabanta Singh *

Thangjing sold at Lamlong Keithel on September 11 2016 :: Pix - Shankar Khangembam

Introduction

Thangjing (popularly known as black diamond or fox nut or gorgon nut) is botanically known as Euryle ferox Salisb and belongs to the family Euryalaceae (Nymphaeceae). It a monotypic genus that is having only one species. It is considered as an aquatic cash crop in Manipur.

The hobby of the present writer is to buy vegetables daily from the markets of Imphal specially Khwairamband bazar. He buys any new vegetables items at any cost. Thangjing is one of them he buys starting from early June/July onwards. The vendors sales Thangjing at the rate of Rs. 30 per Thangjing fruit or Rs. 50 for 2 Thangjing fruits.

In this article the writer made an attempt to describe about the potential of Thangjing cultivation for socio-economic development in Manipur. Distribution The plant is considered as a native of South-East Asia and China but distributed to every part of the world. In general, its distribution is extremely limited to tropical and sub-tropical region of South-East and East Asia and known to exist in Japan, Korea, Russia, North America, Nepal, Bangladesh and some states of India.

In India, it grows abundantly in some districts of Bihar, West Bengal, Assam and Manipur.

Cultivation

Thangjing is known as a cash crop of Ox-bow lakes, depressed land, swamps, paddy fields, ponds, etc. The seedlings are raised naturally from the seeds. If the cultivation in deep water paddy field sites, 2/3 times loosening of soil are required followed by water filling then left for one month. Naturally raised Thangjing seedlings having 4-5 leaves after attaining kitchen dish size are ready for transplantation to the sites (ditches) already earmarked for the plantation.

The transplanted plants are inserted in straight line at a distance of 6' (six feet). Just before plantation, mud from the earmarked ditches are removed about 6″ (six inches). Unwanted plants in between the rows and adjacent rows are removed at the rate of six feet distance. New leaves appeared from the 20 days old transplanted Thangjing plants. Care is taken to remove unwanted plants appeared near the Thangjing plantation.

While the plants are still young insects like aphids eat up the leaves of the Thangjing which can be controlled with the help of organic insecticides. Sometimes due to strong wind currents Thangjing leaves might be overturned but one has to keep it okayed by replacing leaves in the original place. After 65/70 days of plantation, Thangjing fruits are ready for first harvest. Subsequent harvest could be made after every 10/12 days of harvest.

For plantation in the pond, if the pond is continuously used for Thangjing plantation year after year, scarcely any external application of fertilizer or manure is needed. Hence, an ecosystem is established in which decayed mineralized organic matter from previous crop support by the subsequent crop.

Morphological structure

Thangjing has thick fibrous root comprising of 4-6 clusters, each consisting of about 15 rootlets. It is a perennial and growing from a short, thick erect rhizome.

Leaves show heterophylous growth. Leaves are about four different types appearing in the chronological order of sinuate, hastate, sagittate and orbicular types. The first three sets of leaves are not prickly but the last set of leaves is prickly. The orbicular leaves by their perpetual growth attained larger heavy orbicular, corrugated structure with spines (Singh, 2003).

The number of day to initiate flowering ranges from 145-156 days, number of effective fruits per plant ranges from 8-15; fruit diameter ranges from 4-8 inches; number of seeds per fruit ranges from 20-200; seed yield per fruit ranges from 15-150g; diameter of seed ranges from 0.4-1.5 cm; weight of 100 seeds ranges from 40-130g; seed yield per plant ranges from 150-1600g (Mishra et al, 2003). Edible parts The seeds of Thangjing are most important edible part.

The fresh seeds are lumpy and surrounded by streaked bright red arils. The arils are taken raw along with iromba (chutney) or Thangjing metpa. After 3-4 days, the aril of fresh seeds get decomposed and they turned into black colour. Seeds are bold enough and having a hard outer covering. The diameter varies from 0.5 to 1.5 cm. The edible part of the seed is its periderm which is white and starchy in nature. In Manipur, the periderm portion is taken as raw or after boiling for iromba or after cooking with Nakuppi (Allium tuberosum) (Chinese chives).

Nutritional and medicinal importance

The edible parts of Thangjing seeds contains 12.8% moisture, 9.7% protein, 0.1% fat, 76.9% carbohydrates, 0.5% mineral matters and 1.45 iron, besides a good proportion of sugar, ascorbic acid and phenol (Nath and Chakraborty, 1985).

Medicinally, it is also very important to have remedy for several human ailments; culinary, digestive, renal and reproductive problems. The seeds are used for the treatment of stomachache, articular pain, seminal loss, diabetes, spleen and gonorrhoea diseases. The puffs are easily digestible and good for human health because of its low fat content (Jha and Barat, 2003).

Economics of Thangjing plantation

A farmer in Imphal East district, planted Thangjing in his .32acre paddy field. After 70 days of plantation he could harvest the Thangjing fruits. In one month, a maximum of 5 (five) Thangjing fruits are harvested by him from a single plant. The sales price of Thangjing fruit at the farmer’s field is Rs. 15 per fruit. As such, a sum of Rs. 75 (Rs. 15 x5 = 75) can be earned from a plant in a month. As there are 300 plants he earns a sum of Rs. 22,500/- (Rs. 75 x 300) per month.

The productivity period are three months. So, during 3 months (August to October) he earns Rs. 67,500 (Rs. 22,500 x 3) from his .32 acre paddy field [Source: M. Ibomcha Singh, Thangjing farmer, Kongba Uchekon Khunou, Imphal East District] .

Discussion

Thangjing is also known as Makhana in other states (Bihar, Orissa, West Bengal and Assam) of India. It is either eaten as raw puff or blended with vegetables, dal, etc. The seeds are edible after being processed and highly nutritious. It is considered as one of the superior food qualities, which is reflected in its high amino acid index (89% to 93%) and arginine + lysine/proline ratio (4.74 – 7.6) (Nath and Chakraborty, 1985).

Calorific value (3.62 kcal/gm) is also remarkable as compared to staple foods (Anonymous, The wealth of India, 1952). It has a prominent place in Indian dietary chart with medicinal values for respiratory, circulatory, digestive, renal and reproductive diseases (Mandal et al, 2010).

In regards to economic of Makhana in Bihar state 13,000 ha are utilized for its cultivation and 90,000 tons nuts are being harvested from those areas per year. One hundred kilogram of fruits can produce about 35 kg of seeds. It is also reported that about 36,000 tons processed seeds are marketed every year (Choudhury et al, 2003).

Whereas in Imphal East district, Manipur a sum of Rs. 67,500/- could be earned by a farmer from his 0.32 acre paddy field in 3 months (August to October) in the cultivation of Thangjing. As such, Thangjing cultivation can fetch more revenue to low income group in Manipur.

Conclusion

Thangjing is one of the prominent nutritious aquatic crops in Manipur for imminent climate change and to enhance water bodies productivity. Its cultivation can fetch more revenue to the poor income groups. But it requires sincere efforts including dissemination of traditional knowledge as well as awareness to cultivate Thangjing.