The slow technology for seed yam production is one of three obstacles which stand in the way of cost
reduction and expansion in yam production in West Africa; others are the high labor requirement and
problems of pests and diseases. Yam is traditionally propagated by tuber, the edible part, with a very
low multiplication rate; often one plant produces only one seed yam. The low multiplication rate is
made worse by the long growth cycle of the crop and the long dormancy period. The growth period
is from 5 to 9 months, depending on variety and tuber size; the dormancy period is between 2 and 3
months after senescence. The worst scenario, which is common in practice, is that one plant which
produces one seed yam takes one year to produce another single seed yam. At best, if one tuber
produces five seed yam through being cut into pieces, after one year it could generate five seed
yam, i.e., before discounting for losses due to pests and diseases. This low rate of multiplication
and the use of the tuber, the edible part, for propagation make seed yam extremely expensive
(Nweke forthcoming). In this Working Paper the traditional technology for seed yam production and
emerging new technologies are first reviewed to provide the background for the discussion of seed
yam production using the aeroponics system