Weeds – Uses and Control of Weeds and Economic Importance of Weeds (JSS 1)

AGRICULTURAL SCIENCE

PREVOCATIONAL STUDIES

THIRD TERM  

JSS 1

THEME: CONCEPT AND MEDIUM OF AGRICULTURAL PRODUCTION 

TOPIC – WEEDS 

LEARNING AREA

1. Meaning and Characteristics of Weed

2. Uses of Weeds

3. Methods of Weed Control

4. Effects of Weeds Control on Vegetation and soil.

PERFORMANCE OBJECTIVES 

By the end of the lesson, the students should have attained the following objectives (cognitive, affective and psychomotor) and should be able to –

1. list the characteristics of weeds.

2. indicate the uses of weeds.

3. briefly discuss methods of weed control.

4. state the effects of weed control methods on vegetation and soil.

ENTRY BEHAVIOUR

Weeds normally as grasses.

 

INSTRUCTIONAL MATERIALS

The teacher will teach the lesson with the aid of:

1. Charts and pictures of weeds.

2. Weeds specimen.

3. Weed album.

4. Herbicides.

METHOD OF TEACHING – Choose a suitable and appropriate methods for the lessons.

Note – Irrespective of choosing methods of teaching, always introduce an activities that will arouse pupil’s interest or lead them to the lessons. 

REFERENCE MATERIALS

1. Scheme of Work

2. 9 – Years Basic Education Curriculum

3. Course Book

4. All Relevant Material

5. Online Information

CONTENT OF THE LESSON  

MEANING OF WEEDS

Weeds are unwanted plants growing in the farm and other places. Any plant not planted on the farmland by the farmer and grow where they are not wanted is called a weed.

Weeds compete with the grown plant for food, water, air and space, such that the wanted plant may eventually die.

A good example of weeds is grass that is growing in a yam farm. Such a plant must be removed in time.

COMMON WEEDS

1. Elephant grass

2. Guinea grass

3. Spear grass

4. Giant star grass

5. bahama grass

6. Carpet grass

7. Pig weed.

CHARACTERISTICS OF WEEDS 

1. Easily Dispersed 

Plants cannot move but have many ways of getting around and grow easily. With the activities of man and animals make it easily spread or dispersed.

Seeds can be dispersed by wind, water, animals, and humans.

 

2. Long Dormancy 

Plants do not grow easily even under favorable environmental conditions for germination including, temperature, water, light, etc.

USES OF WEEDS TO THE FARMERS 

1. Weeds protect the soil from wind and water erosion.

2. Weeds retain the soil nutrients from plants use.

3. Weed keep and protect the microorganisms that increases soil nutrients for plants use.

4. Weeds are used cover yam from burning after planting.

5. Weeds are used for crops preservation and packaging.

6. Weeds are used for mat production.

7. Weeds are used for feeding livestock.

8. Weeds are used for herbal medicine.

9. Some of them are actually crops. For example, maize is a weed, if grown on yam farmland. The farmer may decide to keep it it is healthy and useful for yam.

 

ECONOMIC IMPORTANCE OF WEED

1. It reduces the crops production.

2. It reduces the quality of harvest.

3. It increases the cost of crops production.

4. It may poise the animals.

5. The cost of controlling weed is high.

6. It causes quicker wear and tear of farm implements.

 

EFFECTS OF WEED CONTROL METHODS ON VEGETATION AND SOIL 

1. Pollution of soil and ground water.

2. Contamination of livestock pasture.

3. Expose the soil to erosion – wind and water.

4. Destroy soil micro organisms.

5. It reduces the aquatic animals.

CONTROL METHODS ON VEGETATION AND SOIL

Biological Control 

This process involves using animals to feed on the weeds on a farm of tree crops that are fully grown, such as a citrus orchard, rubber plantation and palm plantation.

One disadvantage of this method is that the animals may also eat and destroy the wanted plants in the process.

 

Cultural Control 

Cultural control is the removal of weed by hands, cutlass or hoe.

It involves uprooting weeds with hands, cutlass or hoe.

This is also called manual control.

Chemical

A chemical is a man-made liquid or powder used for controlling or killing weeds.

It is also used for controlling or killing pets and diseases. This control is called weedicides.

PRESENTATION

To deliver the lesson, the teacher adopts the following steps:

1. To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the students some questions;

2. Guides the students to define and identify common weeds on the environment.

Student’s Activities – Define, identify and make a weed album.

3 Discusses problems created by weeds on farms.

Pupil’s Activities – State the problems created by weeds on farmers.

4. Demonstrates chemical control of weeds.

Student’s Activities – Practice weed control on the school farm.

5. Highlights the effects of weeds control methods on vegetation and soil.

Student’s Activities – State the effects of weed control on the environment.

6. Gives a board summary.

Student’s Activities – Copy the board summary.

CONCLUSION

To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.

LESSON EVALUATION 

Students to:

1. mention two characteristics of weeds.

2. state two uses of weeds.

3. state two weed control methods.

4. explain two effects of weed control on the environment.