Page 32 - Agriculture_Form_3

Agriculture for Secondary Schools

Weed management
Weeds, if not timely and properly attended, can negatively impact maize yield.
When maize plants are impaired by weeds in their early stage of growth, they
hardly grow. Weeds compete with maize for water, nutrients, sunlight, and space,
ultimately reducing crop productivity. Usually, during the first 4 to 6 weeks after
FOR ONLINE READING ONLY
planting, any impairment can lead to stunted growth, reduced vigour, and lower
yields. Even if weeds are removed later, the damage may already be irreversible.
So, it is important to start weeding very early after emergence. Weed control
in maize can be achieved through various cultural, mechanical, chemical, and
Integrated Weed Management (IWM) practices.

Activity 2.6

After about three weeks since sowing maize, revisit your maize plot on a school
farm and carry out the following tasks:

1. Divide the field into two sub-plots (A and B).

2. Weed the crops in sub-plot A. Do not weed the crop plants in sub-plot B.
3. Thereafter, keep on observing and recording all notable differences in the two
plots.

4. Summarise the activities done, observations and lessons learnt in your
portfolio;

5. Based on your observations, what advice would you give to a farmer who
does not weed their crop plants?

Pest and disease management
Pests and diseases attack maize at different stages of growth. They reduce the
amount and quality of the harvest. Identifying the type of pest or disease is the
first step. After identification, the proper management strategies should be used
to protect the crop and improve yield.

Common maize pests and their management
Maize is attacked by various insect pests that can greatly reduce yield and
grain quality. These pests affect maize at different growth stages, from seedling
emergence to maturity. Major pests of maize include stalk borers, fall armyworm,
maize weevil and earworm.

Student’s Book Form Three 23

17/09/2025 14:11
AGRICULTURE F3.indd 23 17/09/2025 14:11
AGRICULTURE F3.indd 23