(a) State one method of propagating each of specimens I (CASSAVA), J (YAMSEED), K (COCOYAM), and L (GINGER) (b) State three advantages of staking specimen J...

Answer Details

(a) One method of propagating each specimen

• I (cassava): by stem cuttings.
• J (yam): by seed yams / yam setts (tubers).
• K (cocoyam): by corms/cormels (or setts).
• L (ginger): by rhizomes (rhizome splits).

(b) Three advantages of staking specimen J (yam)

1. It exposes the leaves to more sunlight for better photosynthesis and higher tuber yield.
2. It keeps the vines off the ground, reducing pest and disease attack and rotting.
3. It makes weeding and other farm operations easier and improves aeration.

(c) Two pests and two diseases of specimen I (cassava)

Pests: cassava mealybug and variegated grasshopper (also green spider mite, rodents).

Diseases: cassava mosaic disease and cassava bacterial blight.

(d) Toxic substance in cassava and one process of reducing it

The toxic substance is hydrocyanic acid (cyanide / prussic acid, from linamarin). It can be reduced by grating and fermenting, followed by pressing/dewatering and thorough drying or roasting (e.g. in garri processing); soaking in water and boiling also reduce it.

(e) Two uses of specimen L (ginger)

1. Used as a spice/flavouring in food and drinks.
2. Used in medicine (herbal remedy) and in making beverages, and for export/income.