Common Name: Lesser Yam

General Information

Dioscorea esculenta is a perennial, climbing plant producing annual stems about 3 metres long from a tuberous rootstock. These stems scramble over the ground, or twine into the surrounding vegetation[].
A staple food, it is often cultivated in tropical areas, especially Asia and the Pacific, for its edible root[]. There is a history of cultivation of this species in China going back over 1,700 years[].

Known Hazards

Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[].

Botanical References

Range

E. Asia - India, Nepal, Bangladesh, Myanmar, Thailand, Vietnam, Malaysia, Indonesia, Philippines, New Guinea.

Habitat

Not known

Properties

Edibility Rating
Habit	Perennial Climber
Height	3.00 m
Cultivation Status	Cultivated

Cultivation Details

A plant of the drier to wet tropical lowlands, where it is found at elevations up to 900 metres. It grows best in areas where annual daytime temperatures are within the range 28 - 32°c, but can tolerate 17 - 45°c[]. It can be killed by temperatures of 9°c or lower[]. It prefers a mean annual rainfall in the range 800 - 2,000mm, but tolerates 600 - 8,000mm[]. Plants like a well-defined dry season of 2 - 5 months[]. This species will grow in drier climates than other yams, so long as the rainfall is evenly distributed through the year[].
Succeeds in full sun and also in light shade[]. For best yields, this species requires a deep, well-drained, sandy loam that is not liable to water-logging[]. This species will succeed in poor gravelly soils, especially if enriched with organic matter[]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 8.5[].
Daylengths of more than 12 hours are preferred during the early growing season since this encourages vegetative growth; daylengths of less than 12 hours towards the end of the growing season will encourage tuber formation and development[].
Crops take 7 - 10 months to mature, yields of 7 - 20 tonnes per hectare have been achieved[].
There are some named varieties[, ].
Two main forms of this plant are sometimes recognised:-
Var fasciculata (Roxb.)Prain. & Burk. Arose in cultivation and has no spines.
Var spinosa (Roxb.)Prain. & Burk. Is believed by many botanists to be the wild form. It has thorny roots protecting the crown of the rootstock[, ]. This is a variable characteristic, however[].
The plant rarely produces flowers[].
A dioecious species, both male and female plants need to be grown if seed is required.

Edible Uses

Root - cooked and used as a vegetable[]. Sweet and pleasant, with a flavour somewhat like sweet potato or chestnuts[]. The tubers are oval, up to 20cm long and 6 - 8cm in diameter. Each plant can produce 5 - 20 tubers. The flesh is yellow or white and the average tuber weight may be 250 - 1,000g, though larger ones can weight 3,000g[, ].

Medicinal

None known

Other Uses

None known

Propagation

Seed - not normally used to propagate this species.
Cuttings of tubers. Pieces of tuber, each weighing around 50 - 80g with dormant buds, are planted in situ 4 - 8cm deep with the stem pointing downwards[]. The cut tuber is often first left in the sun for several hours to promote wound healing and reduce the risk of fungal infection[].

Add a Comment:

If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.

Name:

Email(Private):

Message:

Captcha: what is greater, 5 or 9?