WAEC Agriculture 2019 Paper

Concept:Plant population per hectare is calculated by dividing the total area of one hectare by the area occupied by a single plant.Explanation:First, convert one hectare into square centimetres.$1$ hectare $= 10{,}000$ m$^2$.Since $1$ m $= 100$ cm, $1$ m$^2 = 100 \times 100 = 10{,}000$ cm$^2$.Therefore, area of one hectare $= 10{,}000 \times 10{,}000 = 100{,}000{,}000$ cm$^2$.Next, find the area occupied by one maize plant using the given spacing.Spacing area per plant $= 100 \text{ cm} \times 50 \text{ cm} = 5{,}000$ cm$^2$.Expected plant population per hectare is:$\frac{100{,}000{,}000}{5{,}000} = 20{,}000$ plants per hectare.Answer:B. $20{,}000$ plants per hectare.