Second Term Examination Lesson Note for Week Three
Class : Primary Five
Subject : Agricultural Science
Topic : Pests and diseases (Meaning)
Duration : 40 minutes
Period : Single Period
Reference Book :
- Agricultural Science for Primary School , Book 5
- Lagos State Unified Schemes of Work for Primary Schools , (Primary 4 – 6)
- Online Resources
Instructional Material : charts showing images of some pests and their categories.
Learning Objectives : By the end of the lesson learners will be able to :
i. Define Pests and diseases of crop plants
ii. State the categories of pests
iii. Identify the effects of diseases on crops .
Previous Knowledge : Learners are familiar with some pest of crops and diseases.
Content:
A pest is any organism that is capable of causing damage to our plants.
There are different categories of pests of crops, which causes a lot of damages to stored Agricultural produce like maize, sorghum, cowpea, etc.
The classes of pests are:
i. Insect pest ẹ.g. Weevil, moth, grasshopper, cotton strainer, butterfly etc.
ii. Rodents ẹ.g. Squirrel, rat, etc.
iii. Birds
iv. Monkeys
v. Human pests.
Insect Pests of crops can also be grouped based on their mouth parts into three classes.
These are :
a.) Biting and chewing pests : These are insect pest that have mandibles which is like teeth for biting and chewing. Examples are weevil, grasshopper, etc.
b.) Piercing and sucking pests : These are insect pest that have proboscis which is threadlike in nature. The insect inject this proboscis into the crop and sucks the liquid contents of the crop . Examples are butterfly, cotton strainer, moths, aphids, etc.
c.) Boring pests : These are insects that bore into crop. For example Stem borer.
Disease is the condition of alteration or deviation from normal physiological function of the plants. It can also be defined as the deviation from normal state of health id a plant.
Diseases in plants are causes by parasites or unfavorable environmental conditions. Organisms capable of causing a disease condition in plants are called Pathogens .
Effects of diseases in plants
Diseases have different signs and symptoms which helps a farmer to know the particular disease affecting a plant.
The following are various signs and symptoms of some plants.
1. Stunted growth of plants
2. Physical defects such as poor coloration and irregular stem growth.
3. Poor or low yield
4. Premature death of plants.
5. Abnormal maturity of fruits.
Diseases are caused when the three conditions are present. These conditions are:
i. Susceptibility of host.
ii. Favourability of environment and
iii. Infectivity of the pathogen.
Presentation Steps :
Step 1 : The teacher revises the previous lesson taught with the learners by asking questions orally.
Step 2 : He/ she introduces the new topic by asking the learners to define pests and then diseases.
Step 3 : The teacher then identifies the classifications of pests with several examples
Step 4 : He/ she then describe the different signs and symptoms observed in plants.
Step 5 : State the causes of diseases in crop plants.
Evaluation : The teacher gives the following questions as class work to know if the lesson is well understood by the learners.
1. What are pests?
____________________________________________________________________________________________
2. List any two categories of pests.
i. ____________________ ii. _____________________
3. Give one example of each of the insect pests.
i. Piercing and sucking pests : _______________
ii. Biting and chewing pests : ________________
iii. Boring pests : __________________
4. Define disease
____________________________________________________________________________________________
5. Mention any two symptoms of diseases in plants
i. _____________________________________________
ii. ____________________________________________
Conclusion : At the end of the lesson, learners were able to answer the questions while the teacher makes some corrections and explain again.
Assignment:
1. Mention two causes of diseases in plants.
______________________________________________
______________________________________________
2. ____________ are organisms that are capable of causing a disease condition in plants. (a) Pathogens (b) Patoges (c) Partogenes
3. Two examples of rodent pests are __________ and __________.
4. ___________ are organisms that is capable of causing damages to our crops.
5. Biting and chewing pest uses ______________ while the piercing and sucking pests uses ____________.
6. Pests and diseases can cause low yield in crop production . (a) True (b) False (c) Not sure