CROP IMPROVEMENT

Subject:

Agricultural Science

Class:

SS 2

Term:

THIRD Term / 3RD Term

Week:

Week 3

Topic:

GENERAL CROP IMPROVEMENT

Previous Knowledge: The pupils have previous knowledge of

   GENERAL CONTROL OF WEEDS

that was taught in their previous lesson.

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

• Say the meaning of crop improvement
• Explain the objectives of crop improvement
• Write out the various methods of crop improvement
• Explain the processes of crop improvement

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 THREE

TOPIC: CROP IMPROVEMENT

CONTENT

• Meaning of crop improvement
• Aims of crop improvement
• Methods of crop improvement
• Processes of crop improvement

DEFINITION OF CROP IMPROVEMENT

Crop improvement is defined as the science that deals with the development of new crop varieties with superior quality and quantity.  

OBJECTIVES OF CROP IMPROVEMENT

1. To increase yield
2. To improve the quality of produce
3. To adapt to climatic conditions
4. To increase resistance to diseases
5. To increase resistance to pests
6. To meet the needs of growers
7. To produce crops with uniform agronomic characteristics
8. To breed crops with early maturity
9. To improve nutrient value of the produce
10. To meet the needs of consumers

DEFINITION OF SOME GENETIC TERMS

1. Genes: These are hereditary unit or basic unit of inheritance
2. Chromosomes: They are rod or thread like bodies found in the nucleus of a cell
3. Character or Trait: These are the inheritance attributes or features possessed by an organism e.g. seed colour 
4. Gamete: It is a mature sex cell
5. Zygote: is a single cell formed as a result of the union of a male gamate with a female gamate
6. Allelomorphs (allele): These are pairs of genes on the position of a chromosome that control a character
7. Phenotype: is the sum total of all observable features of an organism i.e. physical, physiological and behavioural traits e.g. height, weight and skin colour
8. Genotype: is the sum total of the genes inherited from parent.
9. Dominant character: This is a trait or character that is expressed in an offspring when two individuals with contrasting character or traits are crossed
10. Recessive character: This is the character or trait which does not produce the effect in the presence of dominant character.
11. Homozygous: An individual is said to be homozygous if it has two similar genes for the same character, i.e. the pair of gene controlling a given pair of contrasting characteristics are identical e.g TT for height T for Tall or tt for height t for short
12. Heterozygous: An individual is said to be heterozygous if the two members of a pair of genes controlling a pair of contrasting characters are different. e.g Tt for height T for Tall and t for short
13. Filial generation: The offspring of parents make up the filial generation. The first, second and third filial generations are represented by F1, F2 and F3 respectively.
14. Hybrid: These are offsprings from a cross between parents that are genetically different but of the same species.
15. Hybridization: This is the crossing of plants with contrasting characters. There are two major types of hybridization, this includes monohybridization and Dihybridization.
16. Dihybridization involves the crossing of plants with two pairs of contrasting characters.
17. Monohybridization involves the crossing of two pure traits.
18. Mutation: is a change in the genetic make-up of an organism resulting in a new characteristic that is inheritable.

MENDELIAN LAWS

1. The first law of Mendel is also called the law of segregation of genes states that; genes are responsible for the development of the individual and that they are independently transmitted from one generation to another without undergoing any alteration. This is clearly seen in monohybrid crossing.
2. The second law of Mendel which is also called the law of independent assortment of genes state that each character behaves as a separate unit and is inherited independently of any other character. This is clearly seen in the dihybrid crossing.

Presentation : 

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 

1. What is crop improvement?
2. State five aims of crop improvement
3. Discuss the four methods of weed control
4. Give three reasons why weeds are difficult to eradicate
5. Define; A. Gene B. Chromosome C. Trait
6. Explain; A. Mutation B. Hybridization C. Genotype

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.