15th July 2020




CLASS: Grade 3

DATE: 26th June, 2020

SUBJECT: Basic Science and Technology

TOPIC: Pest and Diseases of Crops and Plants

Reference: Stan Basic Science and Technology for primary 4. And the Encyclopaedia Britannica.

Brief explanation

There are some insects and animals that attack our food crops, these insects or animals are known as pests. They are capable of destroying our food and rendering it uneatable.

Notes for the Pupils

Definition of Pests

Pests are insects and animals that destroy plants and food by feeding on them.


A disease is an abnormality in the system of a living thing which prevents proper functionality. Some common disease of crops are: tomatoes rot, maize smut, rice blast, cassava mosaic etc.

Examples of pests

  1. Insects e.g. grasshoppers, caterpillars, locust, beetles, aphids, bug etc.
  2. Birds e.g. sparrows
  3. Rodent e.g. squirrel, rat, mice, grasscutter etc.
  4. Monkeys

Some crop plants and their pest

  Crop plant Pest
1. yam beetles
2. cassava grasshoppers
3. maize rodents, aphids, beetles
4. okra aphids
5. banana and plantain beetles, monkeys
6. rice birds, rodents
7. beans weevil, aphid


Control of pests and diseases

  1. Chemical control: this involves the use of chemicals to control pest e.g pesticide, fungicides, insecticide, herbicides etc.
  2. Physical methods: this involves making the environment hostile for the pests e.g. control of the temperature of the environment, setting of traps.
  3. Protective practice: this involves weeding, mulching, overhead shaves etc.
  4. Cultural practice: this involves the use of resistant varieties of plants, quick removal of infected plants, crop rotation, planting treated seeds.


  1. Explain the following:

(a) Pests

(b) Diseases

  1. List 3 plants and their common pests
  2. Write 3 ways of pest control.