Lesson Notes By Weeks and Term v4 - JHS 3

Lesson Video

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Performance objectives

• Describe the maturation stages of different crops.
• Explain how soil and seed beds affect crop growth.
• Compare maturation of crops in a school garden to other farms.
• Record and discuss your observations.

Lesson summary

In crop production, maturation is the process by which a crop grows from planting to the stage where it is ready for harvest. Farmers in Ghana must know when a crop is mature so they can harvest at the right time to avoid losses from pests, rotting, shattering (grain falling), poor taste, low yield, or poor market value. Different crops (e.g., maize, tomato, okro, cassava) mature differently, and even the same crop can mature differently depending on soil type and seed bed conditions. This lesson helps learners observe and describe differences in maturation by comparing crops grown in different soils/seed beds and by comparing local crops with those grown elsewhere.

Lesson notes

2.1 Meaning of Maturation in Crops Maturation is the gradual development of a crop until it reaches the harvestable stage. Physiological maturity: the crop has completed growth; maximum dry matter is reached (e.g., maize kernels fully formed). Harvest maturity: the stage when the crop is best to harvest for its intended use (fresh eating, storage, processing). Sometimes harvest maturity is earlier than physiological maturity (e.g., green maize harvested for roasting). 2.2 Common Maturity Stages (General) Most crops pass through these stages (names may vary by crop): Germination/Emergence: seed sprouts and comes out of soil. Vegetative stage: leaves, stems, roots develop rapidly. Flowering stage: flowers appear; pollination occurs. Fruiting/Grain filling/Tuber bulking: fruits/grains/tubers enlarge and fill. Maturity/Harvest stage: crop shows signs that it is ready for harvest. 2.3 Maturity Indicators (What to Observe) Learners should observe visible and measurable signs. Examples: (A) Cereals (e.g., maize, rice) Husk/cob: husk dries; silk turns brown and dry. Grain: becomes hard; cannot be dented easily with fingernail. Leaves: lower leaves turn yellow/brown and dry. Days after planting (DAP): depends on variety (e.g., maize 90–120 days). Moisture: mature grains have lower moisture; sound becomes “hard” when tapped. (B) Vegetables (e.g., tomato, okro, pepper) Colour change: tomato turns from green → breaker (slight colour) → red. Size and firmness: okro becomes fibrous if left too long; best harvested tender. Ease of detachment: mature fruits detach easily without damage. Taste/texture: mature pepper has stronger aroma; over-mature can wrinkle. (C) Roots and tubers (e.g., cassava, yam, sweet potato) Leaf yellowing and shedding: cassava leaves may yellow; growth slows. Tuber size: tubers become bigger and starchier. DAP: cassava often 8–18 months depending on variety and purpose. Skin: sweet potato skin becomes firmer; less easily scratched. 2.4 Differences in Maturation: Why Crops Mature Differently Crops mature differently because of: Crop type and variety Early-maturing maize variety may mature in 90 days, late-maturing in 120–140 days. Soil fertility Fertile loamy soil with enough nutrients supports faster, healthier growth. Poor sandy soil may lead to stunted growth and delayed maturity. Soil water-holding capacity Clay/loam holds water better than sand. Drought stress can cause early flowering but poor grain filling (small grains). Seed bed type and quality Raised beds drain well and warm faster → good for some vegetables. Flat beds may retain water; can be good in dry areas but may waterlog in rainy times. Mounds/ridges help tuber crops expand and reduce rotting. Plant spacing and competition Overcrowding reduces light and nutrients → delayed or uneven maturity. Pests and diseases Leaf diseases reduce photosynthesis → poor fruiting and delayed maturity. Weather (temperature, rainfall, sunlight) High sunlight supports faster photosynthesis; excessive rain may cause disease and slow maturity. 2.5 Worked Example (Observation Record and Interpretation)

Scenario: Two tomato beds in the school garden. Bed A: Loamy soil + compost, raised bed Bed B: Sandy soil, flat bed, no compost

Observation after 8 weeks (56 days):

| Feature | Bed A (Loam + compost) | Bed B (Sandy) | |---|---|---| | Plant height | 65 cm | 45 cm | | Flowering | Many flowers | Few flowers | | Fruits | 10 fruits/plant | 4 fruits/plant | | Fruit colour stage | Some “breaker” (starting to turn) | Mostly green | | Leaves | Dark green | Pale green |

Evaluation guide

• Observe and record the maturity stages of different crops grown in
• different soils and seed beds.
• Discuss the differences in maturity stages among the different crops
• on the different soils and seed beds.