Gce Model Questions Vol1 2021 Agricultural Science Question 9
Practice objective / multiple choice question 9 from the 2021 Gce Model Questions Vol1 Agricultural Science examination.
In a wheat field of 4 ha, a random sample of 200 plants shows 30 with leaf‑rust symptoms. Of the symptomatic plants, 18 have severe infection (>50 % leaf area) and 12 have mild infection (≈25 % leaf area). Using the disease severity index (DSI) formula \(\text{DSI}=\dfrac{\sum (\text{severity rating}\times\text{number of plants})}{100\times N}\times100\), where the severity rating is expressed as a percentage (25 for mild, 75 for severe) and \(N\) is the total number of plants examined, calculate the DSI and state whether it exceeds the action threshold of 20 %.
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About This Question
This is Gce Model Questions Vol1 2021 Agricultural Science Question 9. It is one of the objective questions from the 2021 Gce Model Questions Vol1 Agricultural Science examination.
Difficulty level: Medium .
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