Theory question 106
Crop HusbandryDiscuss the production of yam under the following headings:
(a) materials of propagation
(b) soil requirement
(c) land preparation
(d) planting and spacing
(e) cultural practices
(f) three major pests and their control.
Show the model answer
(a) Setts: whole seed yams or pieces of tuber (head, middle, tail), or minisetts (25 g)
(b) Deep, well-drained, fertile loamy soil rich in organic matter; pH about 5.5–6.5
(c) Clearing, stumping, burning/removing trash, making mounds or ridges
(d) Plant at the start of rains (or late in the dry season); setts planted about 10 cm deep in mounds/ridges; spacing about 1 m × 1 m
(e) Mulching the mounds, staking, weeding, fertilizer application, earthing up, pest and disease control
(f) Any three with control: yam beetle – insecticide dusting of setts, crop rotation; nematodes – crop rotation, hot-water treatment of setts, clean setts; mealybugs/scale insects – treat setts with insecticide; rodents (grasscutters) – trapping, fencing
Cover all six headings with figures (spacing, depth).