Waec Model Questions Vol1 2023 Agricultural Science Question 14
Practice objective / multiple choice question 14 from the 2023 Waec Model Questions Vol1 Agricultural Science examination.
In a 10‑ha wheat field the incidence of a fungal disease follows I(t) = I₀e^{kt}, where I₀ = 5% at planting (t = 0 days) and k = 0.03 day⁻¹. A fungicide reduces the current incidence instantly by 60% of its value and may be applied at most twice, on days 20 and 40 after planting. After the last application the disease continues to grow according to the same exponential law. Each 1% of final incidence reduces yield by 0.8 tonnes per ha. Assuming harvest occurs on day 60, decide whether to apply the fungicide on each of the two possible days (you may skip any application) so that the total yield loss (in tonnes) is minimised. What is the minimum total yield loss?
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About This Question
This is Waec Model Questions Vol1 2023 Agricultural Science Question 14. It is one of the objective questions from the 2023 Waec Model Questions Vol1 Agricultural Science examination.
Difficulty level: Medium .
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