Neco 2023 Agricultural Science Question 8

A farmer grows tomatoes on 1 ha of land. The field shows symptoms of two diseases: - Early blight (caused by *Alternaria solani*) affecting the foliage. - Bacterial wilt (caused by *Ralstonia solanacearum*) causing wilting of stems. Data collected: - Potential yield without disease: 8 tonnes per hectare. - Market price: ₦35,000 per tonne. - Untreated disease reduces yield by 30%. - A survey of 20 randomly selected plants for early blight gave the following rating distribution (0 = no symptoms, 1 = 1–25% leaves affected, 2 = 26–50%, 3 = 51–75%, 4 = 76–100%): Rating 0: 2 plants, Rating 1: 6 plants, Rating 2: 8 plants, Rating 3: 3 plants, Rating 4: 1 plant. - The action threshold for early blight is a Disease Severity Index (DSI) of 25%. - Recommended fungicide concentration: 0.5% active ingredient, applied at 2 L per hectare. Answer the following: