Methods of Weed Control 

Back to: Agricultural Science Primary 4

 

Welcome to class! 

In today’s class, we will be talking about methods of weed control. Enjoy the class!

Methods of weed control

In the previous lesson, we learnt about what weeds are and their importance to farmers and the environment. If weeds are allowed to grow unchecked, the bad effects can overrule their good sides. Hence the need to control their growth.

Weed control is the process of removing weeds from the farm. There are three main ways of doing this: cultural control, biological control, and chemical control.

1. Cultural control: This is the process of removing weeds manually, usually with the hand, cutlass, or hoe.

• Weeding by hand: This is the removal of tall weeds in the farm by the farmer using his hands.
• Weeding with a cutlass: This is the process of uprooting weeds using a cutlass
• Weeding with a hoe: This is the process of uprooting small weeds with a weeding hoe.

Activity

1. Look into your garden, observe, and see if you can identify any weed growing along with the planted crops.
2. Can you uproot the weeds?

2. 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.

 

3. Chemical control: In chemical control, chemicals, called weedicides or herbicides, are sprayed on the farm to kill the weeds. The chemical used must be one that will not destroy the plant we want to protect. The spraying must also be carefully done such that the person spraying does not breathe the chemical.

Effects of chemical control of weeds on the soil and the environment

1. Some chemicals used for weed control may affect some soil nutrients negatively by their reactions.
2. Some chemicals may affect the stems of some fruits and seeds of plants.
3. Chemicals can kill useful insects, such as the butterfly, bee and moth.
4. Chemical control may expose the soil to erosion.
5. Some chemicals may pollute the air we breathe in.
6. Some chemicals may pollute water bodies, such as streams, dams and lakes.

Evaluation

1. What are weeds?
2. Why do we need to control weeds?

Assignments

1. Write three effects of weed on crop plants that make their control important.
2. Mention three cultural methods getting rid of weeds from our farm or garden.
3. Explain the biological method of weed control.
4. State three effects of using the chemical method to control weeds.

 

We hope you enjoyed the class.

Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.

Ready to make school management and growth easy? Book your free onboarding session now

Get more class notes, videos, homework help, exam practice on Android [DOWNLOAD]

Get more class notes, videos, homework help, exam practice on iPhone [DOWNLOAD]