Propagation of Crops II (Lesson note)

DETAILED LESSON NOTE

Subject: Agricultural Science

Class: JSS 2 (Grade 8)

Topic: Propagation of Crops

Sub-topic: Asexual Propagation

Date: 22/09/2025

Time: 40 minutes

Average Age of Students: 11 – 13 years

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Instructional Objectives

By the end of the lesson, students should be able to:

1. Define asexual propagation (Lower domain – Knowledge/Recall).
2. Mention and explain at least three methods of asexual propagation (Middle domain – Comprehension).
3. Differentiate between sexual and asexual propagation, and analyze the advantages and disadvantages of asexual propagation (Higher domain – Application/Analysis).

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Instructional Materials

• Cassava stem (for cutting).
• Yam tuber (as an example of vegetative propagation).
• Charts showing methods of propagation.
• Citrus or mango branch for grafting demonstration.
• Hoe/knife/cutlass (for practical illustration).
• Chalkboard/Marker board.

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Previous Knowledge

Students already know that plants can grow from seeds and may have observed farmers planting yam or cassava without seeds.

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Lesson Development

Step I: Introduction (5 minutes)

• Teacher asks: “Have you seen a farmer plant cassava using stems before? Did it grow?”
• Students respond: “Yes, it grows.”
• Teacher: “Good. That method is called asexual propagation. Today, we will study asexual propagation of crops.”
• Teacher writes the topic on the board.

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Step II: Definition of Asexual Propagation (5 minutes)

• Teacher defines: Asexual propagation is the process of growing new plants without seeds, using plant parts such as stem, root, leaf, or bud.
• Teacher gives examples: cassava (stem cutting), yam (tuber), sugarcane (stem cutting).
• Students repeat the definition and mention crops they know that are planted this way.

Objective 1 achieved (Lower domain).

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Step III: Methods of Asexual Propagation (10 minutes)

• Teacher explains and demonstrates with materials:
1. Cutting: Planting a part of a stem or root to grow a new plant (e.g., cassava, sugarcane).
2. Layering: Bending a branch until it touches the soil where it grows roots, then cutting it off as a new plant (e.g., guava, bougainvillea).
3. Grafting: Attaching a bud/shoot of one plant onto the stem of another so they grow together (e.g., orange, mango).
4. Budding: Fixing a bud from one plant onto another plant (e.g., citrus plants).
• Teacher shows a chart and simple demonstration.
• Students identify plant examples from their environment.

Objective 2 achieved (Middle domain).

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Step IV: Comparison and Analysis (10 minutes)

• Teacher explains difference:
• Sexual Propagation – uses seeds, produces new varieties.
• Asexual Propagation – uses plant parts, produces identical plants.
• Teacher highlights:
• Advantages: faster growth, early maturity, identical plants, useful for crops with poor seeds.
• Disadvantages: no variation, plants may be less resistant to diseases.
• Students in groups of 3 discuss one advantage and one disadvantage, then present orally.

Objective 3 achieved (Higher domain).

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Step V: Board Summary (3 minutes)
The teacher writes on the board:

Asexual Propagation

• Meaning: Growing new plants from stems, roots, leaves, or buds instead of seeds.
• Methods: Cutting, Layering, Grafting, Budding.
• Advantages: Fast growth, early maturity, identical plants.
• Disadvantages: No variation, less disease resistance.

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Step VI: Evaluation (5 minutes)
Teacher asks students:

1. What is asexual propagation?
2. Mention two crops that can be propagated by cutting.
3. State two methods of asexual propagation.
4. Differentiate between sexual and asexual propagation.
5. Mention one advantage and one disadvantage of asexual propagation.

Students respond orally and in writing.

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Assignment

Draw and label diagrams of two methods of asexual propagation. Write short notes on each with examples.

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Reference Materials

• UBE Agricultural Science for JSS 2.
• Teacher’s prepared notes.
• Agricultural Science for Junior Secondary Schools (by Olaitan et al).

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