TARAR ( WILD YAM) A RARE MEDICINAL/CULNARY PLANT OF SHIVALIK BELT
Rakesh Verma, J&K Forest Services
INTRODUCTION: Dioscorea belophylla ,Synonym: Dioscorea glabra dy-oh-SKOR-ee-uh — named for Pedanios Dioscorides, 1st century Greek pharmacologist bel-oh-FIL-uh — spear or arrow-like leaves. The plant is native to India and Pakistan , although the genus Dioscorea , a pan-continental genus belonging to the family Dioscoreaceae, is found in Africa , Southeast Asia , Australia and tropical America (Jayasurya 1984; Wilkin 1998), with about 630 scientifically described taxa. (Prain and Burkill 1936) reported the occurrence of about 50 different Dioscorea in India , largely in the west, east and northeast regions. Many of the Dioscrorea species serve as a ‘life saving or famine food’ plant group to marginal farming and forest dwelling communities, during periods of food scarcity (Roy et al. 1988; Arora and Anjula Pandey 1996).
Dioscoria belophylla locally known as Tarar (Yam) is anticlockwise twining vine. Twining in thickets, over fences, over trees and shrubs in the woods, in hedges and over bushes, the thin, woolly, reddish-brown stem grows from 5-18 feet long. Wild yam is a perennial vine; the long, slender, knotted, contorted ,woody, tuberous rootstock is crooked and laterally branched and twining stems. Broadly ovate and cordate, the heart-shaped, leaves are from2-6 inches long and about three-fourths as wide, glabrous on top and finely fairy underneath on long stems. They are usually alternate, but the lower leaves sometimes grow in twos and fours. The tiny, greenish-yellow flowers, cinnamon scented, grow on branched stalks from the axils of the leaves, male and female on separate plants, blooms during June and July, the male flowers in drooping panicles, the female in drooping spicate racemes. The fruit is a three-winged (triangular) capsule containing winged seeds. The winged seed is used for the propagation of the plant. Tuber of the plant is used as vegetable also known as “Devil’s bones”.
DISTRIBUTION: The plant is commonly found in the foothills, ascending to 1400 mt. The tubers are prized for culinary purposes and sold in market under the name “Tarar”.
MEDICINAL PROPERTIES: The yams (Dioscorea species) are the most important tuber crops in West Africa. They are among the root and tuber crops which are widely distributed throughout the tropics with only a few members in the temperate regions of the world (Eka, 1998; FAO, 1985) Yams are consumed as staple food. Apart from food, yams are mainly used for medicinal purposes for the sapogenins, glycons of yam. Saponins are important mainly because of their steroid structure. They are precursors for the hemisynthesis of birth control pills (with progesterone and estrogen) as well as similar hormones and corticosteroids (Crabbe, 1979) Yams like higher plants have a complex phytochemical profile. The most predominant phytochemical characteristic of yam is the presence of dioscorine alkaloid and diosgenin saponin. Although dioscorine and diosgenin are traditionally considered as toxic, such toxicity is removed by washing, boiling and cooking (Eka, 1998) Some yam cultivars cannot be eaten raw because of itchiness, bitterness or toxicity of the raw tuber. The bitterness or acute toxicity in yams may be due to its alkaloid content while the saponins and sapogenins may constitute the pharmaceutical agent.( Poornima G.N. and Ravishankar Rai V. 2008)
The species was found to contain bioactive compounds comprising saponins (18.46 mg 100-1 g), alkaloids (0.68 mg 100-1 g), flavonoids (8.84 mg 100-1 g), tannins (4.2×102 mg 100-1 g) and phenols (2.8×103 mg 100-1 g). This yam contained vitamins such as ascorbic acid, riboflavin and thiamin. The importance of these chemical constituents is discussed with respect to the role of this Dioscorea . Yams have been well respected by the herbalist community for generations due to their potency in enhancing fertility in males. This may be due to the presence of steroidal sapogenins such as diosgenin which have been isolated from yams. Diosgenin from yams have been used as precursors for the synthesis of hormones and corticosteroids which improve fertility in males (Crabbe, 1979; Oliver-Bever, 1989). It should be noted that toxic saponins are removed by washing the tubers before consumption (Eka, 1998). Properties of saponins include formation of foams in aqueous solution, hemolytic activity and cholesterol binding properties and bitterness. Saponins natural tendency to ward off microbes makes them good candidates for treating fungal and yeast infections. These compounds served as natural antibiotics, which help the body to fight infections and microbial invasion (Sodipo et al., 2000). These compounds also appear to greatly enhance the effectiveness of certain vaccines. Plant saponins help humans to fight fungal infections, combat microbes and viruses, boost the effectiveness of certain vaccines and knock out some kinds of tumor cells, particularly lung and blood cancers (Barakat et al., 1993). They also lower blood cholesterol there by reducing heart disease. The most outstanding and exciting prospects for saponins are how they inhibit or kill cancer cells. They may also be able to do it without destroying normal cells on the process, as is the mode of some cancer fighting drugs. Cancer cells have a more cholesterol type compounds on their membranes than normal cells. Saponins therefore bind cholesterol and thus interfere with cells growth and division (Ryam and Shattuck, 1994).
Yams are an excellent source of potassium, with twice the amount as found in a medium sized banana. They are also a good source of vitamin C, B6, folate, iron and magnesium.
TRADITIONAL USE: In olden days the tubers of the plant were crushed with the help of stone and rubbed over the wet clothes, its leather removes the dirt of the clothes(P C Mehta et al 2005)
The tubers of D. belophylla & D. deltoids, its another species have been found in sufficient quantities in lower Shivaliks and intermediate zone not only in different parts of Jammu but also in adjoining states of Punjab , Himachal & Uttranchal. There are reports that sufficient quantity of this wild uncultivated tuber was available in the vegetable market/shops of towns and cities 30-40 years back but its supply/ availability now a days is on the decline with time and has affected the economy of some rural people especially those who are landless labourers. The reasons for its declining production in the forest are over exploitation by local collectors & lack of knowledge regarding the cultivation methods. Further over grazing, reduction in rainfall, vis-à-vis continuous prevalence of long dry spells especially in lower Shivalik hills also added to its declined production.
HARVESTING: Yam harvesting is labor-intensive and physically demanding exercise. For each 2-10 kilogram tuber harvested, it involves standing, bending, squatting, and sometimes sitting on the ground depending the size of mound, size of tuber or depth of tuber penetration. Care must be taken to avoid damage to the tuber, because damaged tubers do not store well and spoil rapidly. In forested areas, tubers grow in areas where other tree roots are present. Harvesting the tuber then involves the additional step of freeing them from other roots. This often causes tuber damage. Yam is a versatile vegetable. It can be barbecued; roasted; fried; grilled; boiled; baked; smoked and when grated it is processed into a dessert recipe.
During the winter months, its tubers, which are lying very deep in the soil are usually dug out the local villagers. These tuber after washing properly, are sold to local shopkeepers. It has also been noticed that local venders use to sell it directly at road side for Rs 50.00 to 100.00 per kg. This practice is prevalent in all over the Shivalik belt of Jammu, especially when one cross over the Tanda(Akhnoor) National Highway upto Sunderbani, persons with bags full of one kg tuber are directly seen selling the tubers at roadside and earning their livelihood. At some places it has also been noticed that the tubers after thorough washing are pickled. Due to its high demand, the species is over exploited. Very little care was shown towards the cultivation of the species. At some places attempts were made by individuals by pitcher planting as well as large sized (18″×24″) polybag planting. It has been noticed that an average plant can yield 2-3 kg tuber in pitcher planting method as well as poly bagged planting method. The need of the hour is to standrise the methods of its cultivation so that the posterity shall be able to taste the medicinally important vegetable.
CULTIVATION: The plant can be cultivated by seed, directly collected from the vine during winter months. Fresh seed can be sown in pitcher or polybags with 2:1:1 soil: FYM: sand ratio during March-April. It starts germination after few days. Proper stacking is required , with weeding & watering etc. an average plant can yield 2-3 kg tuber during winter, with sufficient quantity of seed. No special care is required for its cultivation.