Crop Production: Plant Science, Soil Fertility and Crop Protection
Plant science fundamentals
A candidate must master the growth cycle of the main Sahelian and Sudanese crops (millet, sorghum, maize, cowpea, groundnut, cotton, rice, sesame, niebe). Know the difference between C3 and C4 plants, the role of photoperiod, and the stages: germination, vegetative growth, flowering, fruiting, maturity. Understand root development, water uptake, and the function of nitrogen, phosphorus, potassium, calcium and micronutrients. Trap: questions confuse deficiency symptoms - nitrogen deficiency causes uniform yellowing of older leaves, phosphorus deficiency causes purplish stems and stunted roots, potassium deficiency causes scorched leaf margins.
Soil fertility
Burkina Faso soils are mostly ferruginous, sandy and low in organic matter. Understand cation exchange capacity, pH, organic matter cycling, and the role of manure, compost and mineral fertiliser (NPK, urea). Know recommended doses and the technique of microdosing (placing small quantities of fertiliser at sowing). Trap: candidates mix up the difference between soil texture (particle size) and structure (aggregation). Another trap: assuming lime is always needed - most Sahelian soils are already neutral to alkaline.
Crop protection
Identify major pests: stem borers, millet head miner, cowpea aphids, cotton bollworm, locusts, and diseases such as downy mildew, rust, and bacterial blight. Know integrated pest management: resistant varieties, crop rotation, biological control, and rational pesticide use with correct dosage, protective equipment, and pre-harvest intervals.
Worked rule of thumb
Microdosing rule: apply 2 to 4 g of NPK per planting hole (about one bottle cap for 3 holes), placed 5 cm from the seed. This raises yields 30 to 50 percent at low cost. Remember: fertiliser must never touch the seed directly, or germination is burned.