Grade 10 Agriculture Crop Production – Growing Selected Crop Notes

Specific learning outcomes (SLOs)

1. Identify crops commonly established through a nursery.
2. Grow a selected crop by raising it from a nursery bed (practical steps included).
3. Explain and justify management practices used for that selected crop.

Crops commonly established through a nursery (Kenyan context)

Common smallholder and commercial crops in Kenya that use nurseries:

• Tomato — widely grown in many regions (greenhouse and open field).
• Cabbage and other brassicas (kale/Chinese cabbage) — give uniform seedlings.
• Onion (seedlings transplanted after 6–8 weeks).
• Vegetable seedlings: pepper, eggplant, sweet pepper.
• Tree seedlings: tea, coffee (seedling/grafting nurseries), avocado, fruit trees.

Materials and site for a nursery bed

• Site: well-drained, near water, partly shaded (avoid direct hot sun).
• Nursery bed size: common width 1 m (reach both sides easily), any convenient length; height 15–20 cm above ground helps drainage.
• Soil/media: topsoil mixed with compost and sand (good drainage). Seed trays or polythene bags can be used.
• Seeds, watering can, shade cloth or grass mat for shading, labels, basic tools (hoe, rake).
• Record book to note date of sowing, seed source, germination % and observations.

Step-by-step: Raising a crop from nursery bed (example: tomato)

1. Seed selection: Use certified seed where possible (KEPHIS-approved) or good-quality seed from trusted suppliers.
2. Bed preparation: Clear weeds, dig to 15–20 cm, level and firm. Mix compost into topsoil (1 part compost : 2 parts soil) for nutrients.
3. Sowing: Make shallow drills 1–2 cm deep. Sow seeds thinly or use trays. Cover lightly and press gently.
4. Watering: Water gently immediately after sowing and keep media moist (not waterlogged). Early morning watering is best.
5. Shading & ventilation: Protect young seedlings from scorching sun for first 7–14 days with 30–50% shade. Ensure air moves to reduce fungal disease.
6. Thinning: Once true leaves appear, thin to leave the strongest seedlings—this reduces competition.
7. Fertilisation: Apply weak liquid fertilizer or top-dress with compost when seedlings develop 2–3 true leaves. Avoid strong/high nitrogen at seedling stage.
8. Pest & disease management: Inspect daily. Remove cut seedlings, use safe control (hand-pick pests, use neem oil or recommended agro-inputs if needed). Keep nursery clean.
9. Hardening off: Gradually expose seedlings to sun and wind for 7–10 days before transplanting—reduce watering slightly to toughen plants.
10. Transplanting: Transplant at the right age: tomatoes 4–6 weeks, cabbage 3–5 weeks, onions 6–8 weeks (depends on variety). Transplant in the evening or on a cloudy day, water well after planting.

Simple daily/weekly nursery care schedule (quick guide)

• Daily: Check moisture, pests and diseases; water if surface is dry.
• Every 3–4 days: Light fertilizer (if using) and check shading.
• Weekly: Remove weeds around the bed, inspect root development if using trays.
• Before transplanting: Harden seedlings for 7–10 days.

Why these management practices are used (justification)

• Nursery gives uniform seedlings: Easier to manage and leads to even crop establishment, higher yields.
• Shading prevents sun scorch: Young seedlings have fragile leaves and can be killed by direct sun.
• Hardening off: Prepares seedlings for field stress (wind, sun, less frequent water) so they survive transplanting.
• Good media and drainage: Prevents damping-off disease and root rot caused by waterlogging.
• Thinning & spacing: Reduces competition for light, water and nutrients — stronger plants result.
• Record-keeping & seed choice: Helps the farmer track germination, learn what works in local conditions and choose reliable seed next season.

Suggested learning experiences and activities (for learners aged ~15)

1. Class practical: In small groups, each group prepares a nursery bed (or seed trays), sow seeds (tomato or cabbage), observe and keep a diary for 6 weeks. Record germination rate, growth and problems.
2. Field visit: Visit a local seedling nursery or smallholder farm. Observe how they grow, water and harden seedlings. Ask about common pests/diseases and local solutions.
3. Experiment: Compare two treatments — shaded vs unshaded nursery, or compost-mixed soil vs plain soil. Record differences and present findings.
4. Role play & extension: Simulate an extension visit where students advise a farmer on nursery problems (prepare short advice sheet).
5. Community project: Grow seedlings for school garden or local market. Use proceeds to buy supplies or support a school activity.
6. Assessment ideas: Watch students transplant seedlings correctly, check their nursery diary and ask short oral questions linking practice to justification (why harden off? why compost?).

Safety and good practice

• Wash hands after handling soil; use gloves if handling chemicals.
• Follow label directions for any pesticide or fertilizer; ask a teacher/extension officer if unsure.
• Use clean trays and tools to reduce disease spread.
• Store seeds in cool, dry place; label seed packets with date and variety name.

Mapping to the specific learning outcomes

• (a) Determine crops established through nursery — see list of crops; ask learners to add crops common in their county.
• (b) Grow a selected crop — class practical, diary and transplanting demonstrate this outcome.
• (c) Justify management practices — use the "why" bullets and have learners explain reasons during assessment.