PESTS OF CROPS

Subject:

Agricultural Science

 

Class:

SS 2

 

Term:

Second Term / 2nd Term

 

Week:

Week 8

 

Topic:

GENERAL PESTS OF CROPS

 

Previous Knowledge: The pupils have previous knowledge of

 

      GENERAL EFFECTS OF DISEASE ON CROP PRODUCTION 

 

that was taught in their previous lesson.

 

 

Behavioural  Objectives : At the end of the lesson, learners will be able to

 

 

• Say the meaning of pests of crop
• Mention types of crop pests
• Write out the economic importance of Pests of crops

 

Instructional Materials 

• Wall charts
• Online Resource
• Textbooks
• Laptop
• Crop samples
• Pictures that are related to the subject matter
• Flash cards
• www.edudelighttutors.com

 

Methods of Teaching 

• Role modelling
• Questions and Answers
• Explanation
• Discussion
• Recitation
• Imitation
• Story Telling
• Dramatization

 

WEEK EIGHT                              

 

_________

TOPIC: PESTS OF CROPS

CONTENT

• Meaning of crop pest
• Types of crop pest
• Classification of insect pest

 

MEANING OF CROP PEST

A crop pest can be defined as any organism capable of causing damage to the crop.

 

TYPES OF CROP PEST

Important crop pest are grouped in to the following classes;

1. Insects
2. Birds
3. Rodents
4. Monkeys
5. Man
6. Nematodes

 

CLASSIFICATION OF INSECT PEST

1. Biting and chewing insects: they possess strong mandible and maxillae (mouth parts) which enable them to bite and chew plant parts e.g termites, grasshoppers, leaf worm, mantids, locusts and beetles.
2. Piercing and sucking insects: they possess strong mouthparts called proboscis which enable them to pierce through plants and suck liquid materials from them. Examples are aphids, cotton strainers, mealy bugs, scale insects, capsids, mirids and white flies.
3. Burrowing insects: they and their larva stage are capable of burrowing the tissue of the plant parts or fruits or seeds. Examples are bean beetles, stem borers, maize weevils and rice weevils.

IMPORTANT PESTS OF MAJOR CROPS

Pest	Crops Attacked	Natures of Damages and Economic Importance	Prevention and Control Measures
Stem burrower	Cereals e.g. rice, maize, guinea corn.	Larvae bore holes into stems They eat up the tissues They weaken the plant	Uproot and burn infected plant Spray with insecticides e.g. Gammalin 20  Reduced growth and yield Early planting  Crop rotation
Army Worm	Cereals e.g. maize	Larvae invade and eat up leaves and stem Reduce photosynthesis Retarded growth Reduced yield	Hand picking Spray with insecticides. E.g. DDT
Pod burrower	Legumes e.g. cowpea, soyabeans	Larvae bore into the pod They eat up the seeds Reduced yield	Crop rotation Early harvesting   Spray with insecticides Introduce diseases.
Aphids	Legumes e.g. cowpea, soyabeans	Stunted growth Galls on leaves Vectors of disease e.g. rosette, mosaic disease of cowpea	Spray with insecticides to kill vector Uproot and burn infected plant
Leaf beetle	Legumes e.g. cowpea, soyabeans	They eat up the leaves Reduce photosynthesis Reduced yield	Spray with insecticides Use pest-resistant varieties.
Cocoa mirids (capsids)	Beverages e.g. Cocoa	They inject toxic saliva into plant Transmits fungal diseases Reduced yield Stunted growth	Spray with insecticides e.g. Gammalin 20 Regular Weeding
Yam beetles	Tubers e.g yam	Boreholes into yam tubers Reduced yield Reduction in quality and market value	Dust yam setts with Adrin dust before planting Crop rotation
Cassava Mealybugs	Tubers e.g cassava	Twisting of stem and reduced internodes Swelling of shoots Reduced yield	Early planting  Use pest-resistant varieties. Cutting treatment Spray with insecticides
Green Spidermite	Tubers e.g cassava	They feed on the leaves Reduce rate of photosynthesis Reduced yield	Use biological control Spray with insecticides
Variegated Grasshopper	Tubers e.g Cassava, yam	Adults and larvae eat up the leaves and stem Reduce the rate of photosynthesis Reduced growth Reduced yield	Hand picking Spray with insecticides e.g. Adrex 40
Cotton Stainer	Cotton	They pierce and suck sap from plants Produce toxic saliva Transmit diseases Reduce quality of boll  Leaf distortion	Hand picking Spray with insecticides
Cotton bollworm	Cotton	Larvae feeds on the seeds of cotton Crop rotation Destroy the lint and reduce its quality Premature fall of cotton boll	Spray with insecticides to kill insects Burn cotton plant debris after harvesting.
Thrips	Vegetables e.g. Onion, tomato	Browning of leaves Wilting of plant Reduced yield	Spray with insecticides
Leaf rollers	Vegetable	Rolling and twisting of leaves  Reduction in rate of photosynthesis Reduced yield	Spray with insecticides e.g. Vetox 85
Leaf beetle	Vegetables e.g. pepper, okra and tomato	They eat up leaves and stems Reduced photosynthesis  Reduction in yield and quality	Spray with appropriate insecticides e.g. Vetox 85
Bean beetle, grain weevils	Stored produce e.g. rice, cowpea and maize.	Boreholes into grains and eat them up Reduce the quality of stored produce Reduced farmer’s income Reduce the market value of grains Reduce viability of insfested grains	Early harvesting Proper storage of produce Proper cleaning and fumigation of store with phostoxin tablets or with lindane dust. Store grains over fire places Proper drying of seeds to reduce moisture content and kill the eggs and larva of pests.
Birds	Rice, maize, millets and sorghum	Feed on grains in the field Reduction in quality and yield Reduction in income of farmers	Use of bird scarer or scare crow Use of cage traps with baits Shooting with catapult Drumming or noise making on the farm Use of explosive mechanism at regular intervals Use of avicides Fencing /Screening farms in greenhouse
Rodents e.g. bush rabbit, rats and squirrel	Rice, yam, cassava and fruits	They feed on crops Destroy whole plant Reduction in yield Increase in cost of production	Trapping with braits. Use of rodenticides Use of string/wire traps Use of predators e.g. dogs and cats Clean weeding of farms Shooting and fencing  Use of pit traps
Monkeys	Cocoa mango, banana, and orange	They eat up the fruits  Reduce the quality of fruits Losses to the farmer	Use traps Shooting with gun where possible.

 

ECONOMIC IMPORTANCE OF INSECT PESTS IN CROP PRODUCTION

1. They destroy crops in the fields through their biting, chewing, boring, sucking and defoliation activities.
2. They cause reduction in viability of stored produce
3. Spot of injuries by insect pests predispose crops to pathogen attack
4. They increase the cost of production as they are being controlled
5. They render vegetables and fruits unattractive and unmarketable
6. Some are of vectors of disease
7. The profits of farmers are reduced
8. They reduce the quality of produce either in the store or in the field
9. They generally reduce the yield of crops
10. They can also cause total death of crop plants.

 

 

 

 

 

The topic is presented step by step

Step 1: The class teacher revises the old topic

Step 2: The class teacher introduces the new topic

Step 3: The class teacher allows the pupils to give their own contributions and gives room for pupils” participation

 

Class Teacher and Pupils Activities. Interaction or Participation 

This involves class teacher and pupils’ interaction, conversation, imitation or modeling through discussion, play method or just by recitation or asking and answering questions that are related to the topic that has just been taught.

 

 

 

EVALUATION 

SECTION A

1. _____ is responsible for damages in crops. A. weeds B. water C. air D. pests
2. The following are rodents except _____. ?A. rat B. grasscutter C.squirrel D.monkey
3. The following are bitting and chewing insect except ____. A. termites B. capsids C.locust  D. beetles
4. Stem burrowers will attack A. cereals B. legumes C. tubers D. spices
5. Cotton strainers and meleabugs are examples of _____ insects. A. biting B. chewing C. piercing D. burrowing

 

SECTION B

1. A. What are pests
2. List the five types of pests
3. A. List five effects of pests in crop production
4. List three control measures of plant disease
5. What are crop pests?
6. List the three classes of insect pests.

 

Conclusion : 

The class teacher concludes the lesson by giving the pupils some notes on the topic that has just been taught. He goes round to mark and he does the necessary corrections.