Crop Science and Crop Production
Domain 1: Crop Science and Crop Production
This domain tests how crops grow and how Malawi farmers manage them from land preparation to harvest. Expect questions on crop classification, growth stages, seed rates, spacing, fertilizer use, rotations and yield components.
Core rules and concepts
- Classification: cereals (maize, rice, sorghum), legumes (groundnuts, soya, beans), root and tuber crops (cassava, sweet potato), cash crops (tobacco, cotton, tea, sugarcane).
- Growth stages: germination, vegetative growth, flowering, grain or fruit filling, maturity. Management must match the stage: basal fertilizer at planting, top dressing during vegetative growth.
- Plant population: target plants per hectare = 10,000 m² ÷ (row spacing × within-row spacing in metres).
- Rotation: alternate cereals with legumes to break pest cycles and add nitrogen; avoid continuous sole cropping.
Worked example
A maize field uses 75 cm between rows and 25 cm between plants. Calculate the target population.
Area per plant = 0.75 m × 0.25 m = 0.1875 m². Plants per hectare = 10,000 ÷ 0.1875 = 53,333 plants/ha. If field germination is 90%, seed should be sown for 53,333 ÷ 0.90 ≈ 59,259 viable seeds/ha. The reasoning matters: spacing gives the target stand, but germination and field losses mean you sow more than the target.
Traps that cost marks
- Forgetting to convert centimetres to metres before dividing.
- Treating target population as seed rate; seed rate also depends on seed weight and germination.
- Mixing basal and top-dressing fertilizers.
- Assuming all plants survive to harvest.