Hybrid Maize Production — Rift Valley (120 Days)

Lime Application (if needed)

If soil pH < 5.5, apply agricultural lime at 2–3 t/ha. Incorporate by ploughing. Lime needs 3–4 weeks to react — apply before planting rains.

Plough Field

Deep plough to 25–30 cm using disc plough or ox plough. Timing: at onset of long rains (March) or short rains (October). Break and invert soil to bury crop residue.

Secondary Tillage

Disc harrow or hand-hoe to break clods and create fine tilth. Incorporate compost or DAP fertiliser during this operation.

Variety Selection

Select appropriate hybrid: H614D (90-day) for drier areas, WH505 for higher altitudes, or DK8031 for Trans-Nzoia. Calculate seed requirement: 25 kg/ha for 75 × 30 cm spacing.

Seed Treatment

Treat maize seed with Gaucho (imidacloprid) or Apron Star (metalaxyl + thiram + imidacloprid) to protect against soil pests and seedling diseases. Follow label instructions exactly.

Mark Planting Lines

Use a rope or marking stick to ensure straight rows at 75 cm spacing. Straight rows simplify weeding, fertilisation, and mechanical harvesting.

Planting Day

Plant 2 seeds per hole, 5 cm deep, 30 cm within row. Apply DAP at 50 kg/ha in planting furrow, 5 cm below seed (do not place DAP in direct contact with seed — fertiliser burn). Cover with soil.

Germination Check (Day 4–5)

Check germination — should be 80%+ by Day 5–7. Replant any gaps immediately using pre-soaked seeds for quicker germination.

Thinning

At 3-leaf stage (Day 10–12), thin to 1 plant per hole, leaving the stronger seedling. Target plant population: 44,000–53,000/ha.

First Weeding

Weed at 2–3 weeks after planting (critical period). Use hand hoe or jab planter inter-row cultivator. Remove all weeds before they compete with maize for nutrients.

Top-Dress CAN (First Application)

Apply CAN (26% N) at 100 kg/ha when maize is knee-high (4–6 leaves, about Day 25–30). Place in furrow 10 cm from stem and cover with soil. Irrigate if no rain forecast in 3 days.

Stalk Borer Scouting

Scout for spotted stalk borer (Chilo partellus) — look for entry holes in stem, deadheart in young plants, and frass in leaf whorls. Economic threshold: 10% infestation.

Stalk Borer Control

Apply Duduthrin (lambda-cyhalothrin) granules into leaf whorls at Day 20–25. Apply 3–5 granules per plant, or use Coragen (chlorantraniliprole) spray as alternative.