Gce Model Questions Vol1 2021 Agricultural Science Question 7

Practice essay / theory question 7 from the 2021 Gce Model Questions Vol1 Agricultural Science examination. This question covers Crop Pests .

Gce Model Questions Vol1 2021 Agricultural Science Essay / Theory
Topic: Crop Pests
Question 7 GCE_MODEL_QUESTIONS_VOL1 • 2021 • AGRICULTURAL_SCIENCE • essay

A farmer cultivates maize on a 5‑hectare field. During a scouting visit he observes stem borer (Busseola fusca) larvae on the crop. The farmer wishes to decide whether to apply the recommended insecticide and, if so, how many larvae per hectare would justify treatment.

Question Parts

( a )
Define the term *economic threshold* (ET) and explain at least three agronomic or economic factors that influence its value for a pest species.
( b )
Given the following data, calculate the Economic Injury Level (EIL) in number of larvae per hectare and then the Economic Threshold (ET). - Average grain loss per stem borer larva = 0.15 kg - Market price of maize grain = ₦120 per kg - Cost of the recommended insecticide per hectare = ₦2 500 - The insecticide kills 90 % of the larvae present. Assume the EIL formula: \[\text{EIL} = \frac{C}{V \times D \times K}\] where C = cost of control per ha, V = market value per kg, D = damage per larva (kg), K = proportion of pest killed. State the EIL (rounded to the nearest whole larva) and then compute the ET as 20 % of the EIL.
( c )
If the farmer’s scouting count shows an average of 12 larvae per hectare, advise whether the insecticide should be applied now, justifying your answer with reference to the ET calculated in part (b).
( d )
List two non‑chemical control methods that could be incorporated into an Integrated Pest Management (IPM) programme for stem borer and briefly explain how each reduces pest pressure.

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About This Question

This is Gce Model Questions Vol1 2021 Agricultural Science Question 7. It is one of the essay questions from the 2021 Gce Model Questions Vol1 Agricultural Science examination.

The question covers Crop Pests .

View More Gce Model Questions Vol1 2021 Agricultural Science Questions More Gce Model Questions Vol1 Practice Questions Back to Questions

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