WAEC Agricultural Science 2022 Theory — Question 6

Model answer

(a)(i) [See graph: quantity of fertilizer (bags) plotted on the x-axis against tomato yield (kg) on the y-axis, showing yield rising from 2kg at 0 bags to a peak of 11kg at 6 bags, then declining to 4kg at 12 bags.] (ii) As the quantity of fertilizer increases, tomato yield initially increases; then after a point (6 bags), additional fertilizer results in a lower yield. This shows the law of diminishing returns — both insufficient and excessive fertilizer use negatively affect yield. (iii) Since the optimum yield of tomato (11kg) is recorded when 6 bags of fertilizer are applied, the most appropriate quantity of fertilizer to apply on the tomato farm is 6 bags. (b) Effects of subsidy withdrawal on agricultural production: - Decrease in cost effectiveness (higher input costs) - Increase in risks absorbed by farmers - Decrease in agricultural productivity (c) Print media for disseminating information about a new maize variety: - Pamphlets - Posters - Newspapers - Booklets/Magazines/Journals (d)(i) Maize insect pests: Grasshopper, aphids, earworm, army worm (ii) Orange insect pests: Fruit borer, white louse, citrus psyllid, mealybug