Environmental Engineering Reference
In-Depth Information
Special attributes and uses
The tubers are very palatable and are important for food security. Some cultivars are
also used for certain festivals. They are fried, boiled as
ampesi
, or pounded into
fufu
.
Bitter yam (D. dumetorum)
Ecology
The crop is grown in home garden agroforestry, orchards, agroforest non-home
gardens, and annual cropping land-use systems.
Planting time and land preparation
These are the same as for the bush yam.
Planting materials
The main sources of planting materials are heirloom cultivars and materials
purchased from the market or obtained from other farmers. Like other yam
species, the head is the most important planting material, followed by cuttings
and small tuber setts. The size of planting materials varies from 200 to 500 g with
250 g as the modal size.
Land preparation and planting
Bitter yams are grown on mounds constructed over planting holes measuring 30
cm to over 50 cm in diameter and 20 cm to 30 cm deep. They are planted as the
first crop in a mixed crop system, but no special order is required. The setts are
planted 10 cm deep. After planting the mound is capped with dried leaves. The
yam setts may be planted directly or nursed and transplanted following the stan-
dard nursery procedures.
Staking
The crop is normally staked using live stakes supported by leaders. Staking is
done when the vine is between 60 and 100 cm long. But this may be done earli-
er or later. The distance from a live tree stake to the mound varies between 100
and 230 cm.
Harvesting and storage
The tubers are ready for harvest five to six months after planting and nine months
after planting. Harvested tubers are usually short, measuring between 10 and
30 cm in length. Tubers are stored by delaying harvesting. Once harvested, they
remain palatable for only one day.
Maintenance
The crop is maintained by yearly planting or by retention in the field.
