Agricultural Science Primary 5 Second Term Lesson Notes

Week 4: Control of Weeds

Subject: Agricultural Science

Class: Primary 5
Term: Second Term
Week: 4
Age: 9–10 years
Topic: Control of Weeds

Sub-Topic: Methods and Importance of Weed Control

Duration: 40 Minutes

Behavioral Objectives

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

1. Outline methods of controlling weeds.
2. Identify the importance of weed control in the farm.
3. Demonstrate weed control in the school farm and within the school compound.

Keywords: Weed control, herbicides, mulching, manual control, importance

Set Induction

The teacher takes pupils to a section of the school farm or compound with weeds and asks them to observe and describe what they see.

Entry Behavior

Pupils have learned about weeds, their effects, and possible solutions in previous lessons.

Learning Resources and Materials

• Tools like hoes, cutlasses, and rakes
• Pictures or samples of herbicides
• Mulching materials such as leaves or straw

Building Background/Connection to Prior Knowledge

Pupils are familiar with the harmful effects of weeds on crops and the need for controlling them.

Embedded Core Skills

• Teamwork
• Problem-solving
• Hands-on practical skills

Content

Methods of Controlling Weeds

1. Manual Control
   • Removing weeds by hand or using tools like hoes and cutlasses.
   • Best for small farms and gardens.
2. Chemical Control
   • Using herbicides to kill weeds.
   • Requires care to avoid damaging crops or harming humans.
3. Cultural Practices
   • Mulching: Covering the soil with leaves, straw, or plastic to suppress weeds.
   • Crop Rotation: Changing the type of crops grown in a field to reduce weed growth.
4. Mechanical Control
   • Using machines like tractors or mowers to remove weeds.
   • Suitable for large-scale farms.
5. Biological Control
   • Using natural predators or organisms to control weed growth.
   • For example, introducing insects that eat specific weeds.

Importance of Weed Control

1. Improved Crop Yield
   • Ensures crops have enough nutrients, water, and sunlight.
2. Healthier Crops
   • Reduces the risk of pests and diseases.
3. Easier Farm Operations
   • Makes planting, watering, and harvesting easier.
4. Reduced Cost of Farming
   • Prevents weeds from spreading and becoming harder to remove later.
5. Better Environment
   • Keeps the farm or compound clean and attractive.

Practical Demonstration: Controlling Weeds on the School Farm

• Divide pupils into small groups and assign areas in the school farm or compound for weeding.
• Provide tools and guide pupils on safe and effective weeding methods.

Evaluation

Fill-in-the-blank Questions
Choose the correct option (a, b, c, or d).

1. Removing weeds by hand is an example of ____ control.
   a. mechanical
   b. manual
   c. biological
   d. chemical
   Answer: b
2. Herbicides are used in ____ weed control.
   a. manual
   b. mechanical
   c. chemical
   d. biological
   Answer: c
3. Covering the soil with leaves or straw to reduce weeds is called ____.
   a. mulching
   b. harvesting
   c. spraying
   d. planting
   Answer: a
4. Weed control improves ____ crop yield.
   a. poor
   b. reduced
   c. improved
   d. stunted
   Answer: c
5. A machine used for removing weeds on large farms is a ____.
   a. hoe
   b. tractor
   c. cutlass
   d. rake
   Answer: b

Class Activity Discussion (FAQs)

Q1: What is weed control?
A1: Weed control is the process of removing or managing weeds to ensure they don’t harm crops.

Q2: Name two methods of controlling weeds.
A2: Manual control and chemical control.

Q3: Why is mulching important?
A3: Mulching helps suppress weed growth and retain soil moisture.

Q4: What are herbicides?
A4: Herbicides are chemicals used to kill weeds.

Q5: Why should we control weeds?
A5: To improve crop yield, reduce pests, and make farming easier.

Presentation Steps

1. Teacher’s Activities:
   • Explain the methods of weed control with examples.
   • Discuss the importance of weed control on farms.
   • Guide pupils in practical weeding activities.
2. Learners’ Activities:
   • List methods of controlling weeds.
   • Explain the importance of weed control.
   • Participate in the practical activity by weeding the school farm or compound.

Assessment

Short-answer Questions

1. What is weed control?
2. Mention three methods of controlling weeds.
3. Why is weed control important?
4. What is mulching?
5. Name one tool used in manual weed control.

Conclusion

The teacher summarizes the lesson by reviewing the methods and importance of weed control. Pupils are encouraged to practice weed control at home and in their communities.