Observation

This question was surprisingly challenging to the candidates. Not many candidates attempted the question and few who did, could not convincingly state ways in which economic factor, technical know-how and small farm holdings limit agricultural mechanization in West Africa. In question 2 (b), students could not explain the classes of insects and many entirely forgot boring insect pests as one of the classes of insect pest.

The expected answers include:

2. (a) Ways in which the following limits agricultural mechanization in West Africa

(i) Economic factor

- Farmers cannot afford to buy farm machines

- Cost of hiring the machines is high

- Cost of maintaining machines is high

- Operators of machines demand high wage which farmers cannot afford

(ii) Technical Know-how

- Most farmers do not know how to operate the machines

- They cannot read the manuals that accompany the machines

- They cannot handle repairs when the machines break down

- Experts to do the technical work are not readily available

- Very few schools exist for training machine operators

(ii) Small farm holdings

- Farmers have access to small areas of land for cultivation

- The land area is scattered

- Prevailing land tenure system does not encourage acquisition of large areas of land

- The small area of land is not economical to mechanize

(b) Classes of insect pests based on their feeding habits

(i) Biting and chewing insect pests

- They bite and feed on plant leaves and young/succulent stems e.g. Grasshopper, Cricket , Locust

- Their mouth parts have maxillae and mandibles

- They may be insect larvae/caterpillars or adults

(ii) Piercing and sucking insect pests

- They pierce and suck juice from the leaves, stems, flowers and fruits of crop plants

- Their mouthparts possess proboscis

- They remove juice from plants thereby rendering the plant weak

- They provide entry for pathogens of plants e.g. Cotton stainer, Aphids, Butterflies, Moths, Mirids, Mealybugs, white flies, Scale insects

(iii) Boring insect pests

- They bore into plant tissues and seeds

- They are mostly field to store insect pests e.g. Weevils, Stem borers, bean beetles