COMMON WEEDS FOUND IN FARMS

Subject:

Agricultural Science

Class:

SS 2

Term:

THIRD Term / 3RD Term

Week:

Week 1

Topic:

COMMON WEEDS FOUND IN FARMS

Previous Knowledge: The pupils have previous knowledge of

      GENERAL EFFECTS OF DISEASE ON CROP PRODUCTION 

that was taught in their previous lesson.

Behavioural  Objectives : At the end of the lesson, learners will be able to

• Say the meaning of Weeds
• Mention the effects of weeds on crops and the Economy
• Write out the various types of weeds and their botanical names
• Mention different methods of weed control

Instructional Materials 

• Wall charts
• Online Resource
• Textbooks
• Laptop
• Crop samples
• Pictures that are related to the subject matter
• Flash cards
• www.edudelighttutors.com

Methods of Teaching 

• Role modelling
• Questions and Answers
• Explanation
• Discussion
• Recitation
• Imitation
• Story Telling
• Dramatization

WEEK ONE 

TOPIC: COMMON WEEDS FOUND IN FARMS

CONTENT

• Meaning of Weeds
• Effects of weeds on crops and the Economy 
• Various types of weeds and their botanical names
• Methods of weed control

MEANING OF WEEDS

A weed is any plant that grows in a place where it is not (expected to grow) wanted

ECONOMIC IMPORTANCE OF WEEDS

1. They compete with crops for space
2. Weeds compete with crops for sunlight
3. Weeds compete with crop for nutrient
4. Weeds harbour crop pests and pathogens
5. Weeds compete with crop for soil moisture
6. It leads to loss in crop yields
7. Weeds compete with crop for soil oxygen
8. They reduce the quality of crops
9. They reduce the income of farmers
10. They cause reduction in the taste of some grasses
11. Some weeds are toxic to farm animals

BENEFITS OF WEEDS TO FARMERS

1. Weeds helps in checking soil erosion
2. Some weeds are useful as food for humans
3. Some weeds serve as food for animals
4. Certain weeds have medicinal values
5. They can be used as green manure
6. Some are used for making roots, mats and baskets
7. Weeds are used for mulching
8. Weeds are used for compost making

CHARACTERISTICS AND GROWTH HABIT OF WEEDS

1. Production of large quantity of seeds
2. Some weeds reduced by seeds
3. Some weeds reduced by vegetative propagation
4. Growth of large leaves within a short time
5. Weeds growth is favoured during rainy season
6. Most weeds are wind pollinated 
7. Production of large quantity of pollen grains

DISPERSAL OF WEED SEEDS AND FRUITS

Most seeds and fruits of weeds are generally dispersed by wind and animals. The mode of dispersal are; 

1. Dispersal of seeds by wind

Such weeds have feathery, winged or powdery seeds e.g. Tridax (pwd weed), goats weed, guinea grass, elephant grass and many other species of grasses.

2. Dispersal of seeds by Animal

Animal dispersed weeds usually have sticky, hooked, edible or colourful fruits or seeds. The sticky and hooked types of fruits and seeds adhere to the coats of grazing animals and are carried from one place to another. Examples of such animals are; rabbits, rats squirrels, antelope and man. Pig weed and commelina spp are example of such weed.

3. Dispersal of seeds by water

Water dispered weeds have water proof cuticles, air spaces within the fruit and a light weight

4. Dispersal of seeds by explosive mechanism

Few plants and all leguminouns weeds are dispersed by explosive mechanism eg water leaf, centro, pueraria, calapo and mucuna.

Presentation : 

The topic is presented step by step

Step 1: The class teacher revises the old topic

Step 2: The class teacher introduces the new topic

Step 3: The class teacher allows the pupils to give their own contributions and gives room for pupils” participation

Class Teacher and Pupils Activities. Interaction or Participation 

This involves class teacher and pupils’ interaction, conversation, imitation or modeling through discussion, play method or just by recitation or asking and answering questions that are related to the topic that has just been taught.

EVALUATION 

1. What are weeds?
2. List five beneficial effects of weeds

Conclusion : 

The class teacher concludes the lesson by giving the pupils some notes on the topic that has just been taught. He goes round to mark and he does the necessary corrections.