Explanation:
(a) Ways in which weeds are beneficial to the farmer
Weeds help in checking soil erosion
Some weeds are useful as food for humans
Some weeds serve as feed for livestock
Certain weeds have medicinal properties
Weeds can be ploughed into the soil to replenish soil nutrients
Some weeds are used for roofmg, making mats, baskets etc
Weeds can be cut and used as mulch
For compost making
Leguminous weeds harbour bacteria that help to fix atmospheric nitrogen into the soil
(b)Classification of insect-pests based on their mode of feeding and examples:
(i) Biting and chewing insects e.g locusts, grasshoppers, termites, mantids, the stick and leaf insects, beetles, leaf worms, army worms, budworms, crickets, larvae of lepidopetera
(ii) Piercing and sucking insects e.g capsids, cotton stainers, whiteflies, scale insects mealy bugs, green shield bugs, aphids, thrips, tsetsefly, ticks
(iii) Boring insects e.g beetles, weevils, stem borers, fruit borers
(c) Ways by which pasture can be made available to cattle
Prepared as hay for livestock
As silage
Cut and carry as fresh fodder/zero grazing
Animals can be taken out for grazing