Agriculture

1. METHODS OF WEED
CONTROL
Lesson Objectives
At the end of the lesson I should be able to;
 Mention the two types of weed.
 State the methods of controlling weeds.
WEEK 3

2. Starter Activity
Classify the diagrams below as chemical or physical method of weed control
A
B
C

3. Types of weeds
1. Annual weeds:- These are
weeds that complete their life
cycle within one year.
2. Perennial weeds:- These are
weeds which grow for more
than one year.

5. Methods of weed control
1. Crop rotation system:- This is a
method of controlling the growing
and spreading of weeds. This
involves planting different crops on
the same piece of land on different
periods.
2. Use of chemicals:- Special chemical
substance used to control the growth
and spread of weeds is referred to as
HERBICIDES.
There are two types of herbicides
namely;
a. Pre-emergence herbicides:- This is
applied to the soil before the crops
germinate e.g. atrazine,
pendimanthali etc.

6. b. Post-emergence herbicides:- These
herbicides are applied directly to
grown weed plants e.g. paraquat,
glyphosate.
Some herbicides are selective i.e. they
only act on specific weeds while non-
selective can kill any type of weed or
even cultivated crops.

7. 3. Uses of tools:- It involves the use of
implements such as hoes, cutlass to
clear farm of weed.
4. The use of farm machineries:- This
involves the use of machineries such as
mower, cultivator, tractor to control
weed.
5. Use of natural enemies:- This involves
the use of another plant, animals and
insects to control weeds.

8. Class Activity
a. State three methods of controlling weed.
b. Define annual and perennial weed.

9. Assignment
Mention five common weeds with their botanical names.